Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2004)157[1:EOMOOB]2.0.CO;2
PAUL R. KRAUSMAN, LISA K. HARRIS, CATHY L. BLASCH, KIANA K. G. KOENEN, JON FRANCINE
Abstract: Our objectives in this study were to determine whether military activities (e.g., overflight noise, noise from ordnance delivery, ground-based human activity) on the Barry M. Goldwater Range (BMGR) affect the behavior and hearing of Sonoran pronghorn (Antilocapra americana sonoriensis). We contrasted the behavior of pronghorn on BMGR with the closest population of pronghorn in the United States that was not subjected to routine military activity (i.e., on the Buenos Aires National Wildlife Refuge [BANWR], Arizona). Forty percent of the landscape used by the endangered Sonoran pronghorn in the United States is within the 5,739 km2 BMGR, a bombing and gunnery facility in southwestern Arizona. The range of Sonoran pronghorn covers about 88% of BMGR. The 179 Sonoran pronghorn that lived in the United States in December 1992 declined to 99 by December 2000. The Sonoran pronghorn has been listed as endangered for >30 years, but population limiting factors are unknown. Because Sonoran pronghorn use BMGR, land and wildlife managers raised concerns about the potential effects of military activities on the population. Possible indirect effects of military activities on Sonoran pronghorn, aside from direct mortality or injury, from ordnance delivery, chaff, flares, live ammunition, aircraft mishaps, interference from ground vehicles and personnel, include alteration of behavior or physiology.
We conducted the study on the North and South Tactical Ranges (NTAC and STAC), BMGR, from February 1998 to June 2000. Hearing exams were conducted in Camp Verde, Arizona, the University of Arizona, and on the East Tactical Range (ETAC), BMGR. Interactions between pronghorn and military activity were restricted to 4 observation points that provided viewing areas from which pronghorn and military activity could be observed from ≤ 10 km. We systematically located pronghorn with spotting scopes and telemetry. When located, we described their behavior and military activity using scan sampling. We tested hearing using auditory brainstem responses (ABR). We could not test the hearing of Sonoran pronghorn because of their endangered status, so we contrasted hearing of pronghorn near Camp Verde, Arizona, and desert mule deer (Odocoileus hemionus eremicus) that were and were not exposed to sound pressure levels from military activity. We recorded behavior observations of Sonoran pronghorn on 172 days (44,375 observation events [i.e., 1 observation/30 second]) over 373 hours. These data were compared with 93 days of behavioral data (24,297 observation events) over 202 hours for pronghorn not regularly influenced by military aircraft. Overall, we did not detect behavioral differences (i.e., time spent bedding, standing, foraging, traveling) between males and females. Pronghorn exposed to military activity, and those that were not, bedded the same amount of time. Pronghorn at BMGR foraged less and stood and traveled more than p
摘要/ Abstract摘要:本研究旨在研究巴里·m·戈德华特山脉(BMGR)的军事活动(如飞越噪声、武器发射噪声、地面人类活动)是否会影响索诺兰叉角羚(Antilocapra americana sonoriensis)的行为和听力。我们将BMGR上叉角羚的行为与美国最接近的叉角羚种群(即亚利桑那州布宜诺斯艾利斯国家野生动物保护区[BANWR])进行了对比。在美国，濒临灭绝的索诺兰叉角羚所使用的40%的景观都在5739平方公里的BMGR范围内，这是亚利桑那州西南部的一个轰炸和射击设施。索诺兰叉角羚的分布范围约占BMGR的88%。1992年12月生活在美国的179头索诺兰叉角羚到2000年12月减少到99头。索诺兰叉角羚被列为濒危物种已有30年了，但数量限制因素尚不清楚。由于索诺兰叉角羚使用BMGR，土地和野生动物管理人员对军事活动对种群的潜在影响表示担忧。军事活动对索诺兰叉角羚可能造成的间接影响，除了直接的死亡或伤害外，还包括弹药投放、箔条、照明弹、实弹、飞机事故、地面车辆和人员的干扰，包括行为或生理的改变。我们在1998年2月至2000年6月期间，对英国皇家陆军的南北战术靶场(NTAC和STAC)进行了研究。听力测试在亚利桑那州佛得角营地、亚利桑那大学和BMGR东部战术靶场(ETAC)进行。叉角羚与军事活动之间的相互作用仅限于4个观测点，这些观测点提供的观测区域可以从≤10公里处观察叉角羚和军事活动。我们用瞄准镜和遥测技术系统地定位了叉角羚。定位后，我们使用扫描采样描述了他们的行为和军事活动。我们使用听觉脑干反应(ABR)测试听力。由于Sonoran叉角羚处于濒危状态，我们无法测试它们的听力，因此我们将亚利桑那州Verde营地附近的叉角羚和沙漠骡鹿(Odocoileus hemionus eremicus)的听力进行了对比，这些叉角羚受到和没有受到军事活动声压水平的影响。我们记录了索诺兰叉角羚172天(44,375次观察事件[即1次观察/30秒])373小时的行为观察。这些数据与不受军用飞机影响的叉角羚在202小时内93天的行为数据(24,297次观察事件)进行了比较。总的来说，我们没有发现雄性和雌性之间的行为差异(即，花在床上、站立、觅食和旅行上的时间)。接触过军事活动的叉角羚和没有接触过军事活动的叉角羚睡在床上的时间是一样的。与没有接触过军事活动的叉角羚相比，BMGR中的叉角羚觅食更少，站立和行走更多。无论有没有人为活动，这些趋势都是一样的。只有7.3%的行为事件发生在可识别的刺激下。军事飞越发生363次(0.8%)，非军事飞越发生77次(0.2%)。叉角羚很少对军用飞机做出反应，但当地面刺激存在时，它经常移动10米。环境噪音水平高达123.1分贝(dB)。有军事活动日的平均声压级为65.3 dB，而无军事活动日的平均声压级为35.0 dB。由于我们获得了鹿和叉角羚的听力测试，我们能够开发一种有蹄类加权滤波器，用于处理A-10和F-16飞机飞越时产生的噪音。沙漠有蹄类动物听不到这些飞机产生的声压级(即低14-19分贝)。我们考察的军事活动对索诺兰叉角羚的影响微乎其微。叉角羚使用了全年与军队共享的范围，并且无论是否存在军事刺激，叉角羚的行为模式都是相似的。此外，暴露于军事活动的叉角羚的行为与未暴露于常规军事活动的叉角羚的行为相似。对于那些接触过和没有接触过军事活动的叉角羚，它们的听觉特征是相似的。美国索诺兰叉角羚的数量持续下降，濒临灭绝。显然，需要做更多的工作，但这里所衡量的军事活动并不是一个限制因素。
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Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2005)160[1:CEOHDO]2.0.CO;2
CHRIS J. JOHNSON, MARK S. BOYCE, RAY L. CASE, H. DEAN CLUFF, ROBERT J. GAU, ANNE GUNN, ROBERT MULDERS
Abstract: Recent discoveries of diamondiferous kimberlite deposits in the Canadian central Arctic led to unprecedented levels of mineral exploration and development. The cumulative effects of such activities are an issue of concern for government regulatory agencies, regional and international conservation organizations, wildlife managers, and indigenous peoples. We investigated the impacts of human activities and associated infrastructure on the distribution of Arctic wildlife in 190,000 km2 of the Taiga Shield and Southern Arctic ecozones 400 km northeast of Yellowknife, Northwest Territories, Canada.
We used covariates for vegetation, interspecific interactions, and human disturbance features to develop seasonal resource-selection models for barren-ground caribou (Rangifer tarandus groenlandicus), gray wolves (Canis lupus), grizzly bears (Ursus arctos), and wolverines (Gulo gulo). We used an information-theoretic approach to select 11 seasonal models for the 4 species. Nine models were good predictors of species occurrence and vegetation covariates were important components of all models. Mines and other major developments had the largest negative affect on species occurrence, followed by exploration activities, and outfitter camps. We did not, however, record strong avoidance responses by all species during all seasons to each disturbance type (i.e., major developments, mineral exploration sites, outfitter camps) and for some models carnivores selected for disturbance features (i.e., occurred closer to sites than comparison random locations). We used a geographic information system (GIS) to extrapolate each seasonal resource-selection model to the study area and quantified the reduction in habitat effectiveness as a function of modeled and hypothetical disturbance coefficients. Across all models, grizzly bears and wolves demonstrated the strongest negative response to disturbance and corresponding reduction in habitat effectiveness, followed by caribou and wolverines. The largest seasonal effect was recorded for caribou during the post-calving period, where model coefficients suggested a 37% reduction in the area of the highest quality habitats and an 84% increase in the area of the lowest quality habitats.
This is the first study to demonstrate the cumulative effects of multiple sources of human disturbance for caribou, wolves, bears, and wolverines found across the Canadian central Arctic. Resource selection models and corresponding maps of important habitats can be used to guide and evaluate future development proposals and can serve as a component of a regional environmental assessment. However, inferences from large-scale modeling efforts should be carefully evaluated when making detailed prescriptive recommendations. Study design, sample size, reliability of GIS data, and accuracy of model predictions are important considerations when evaluating the strength and scale of infe
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CHAD J. BISHOP, GARY C. WHITE, DAVID J. FREDDY, BRUCE E. WATKINS, THOMAS R. STEPHENSON
ABSTRACT
Concerns over declining mule deer (Odocoileus hemionus) populations during the 1990s prompted research efforts to identify and understand key limiting factors of deer. Similar to past deer declines, a top priority of state wildlife agencies was to evaluate the relative importance of habitat and predation. We therefore evaluated the effect of enhanced nutrition of deer during winter and spring on fecundity and survival rates using a life table response experiment involving free-ranging mule deer on the Uncompahgre Plateau in southwest Colorado, USA. The treatment represented an instantaneous increase in nutritional carrying capacity of a pinyon (Pinus edulis)—Utah juniper (Juniperus osteosperma) winter range and was intended to simulate optimum habitat quality. Prior studies on the Uncompahgre Plateau indicated predation and disease were the most common proximate causes of deer mortality. By manipulating nutrition and leaving natural predation unaltered, we determined whether habitat quality was ultimately a critical factor limiting the deer population. We measured annual survival and fecundity of adult females and survival of fawns, then estimated population rate of change as a function of enhanced nutrition. Pregnancy and fetal rates of adult females were high and did not vary in response to treatment. Fetal and neonatal survival rates increased in response to treatment, although the treatment effect on neonatal survival was marginal. Overwinter rates of fawn survival increased for treatment deer by 0.16–0.31 depending on year and fawn sex, and none of the 95% confidence intervals associated with the effects overlapped zero. Overwinter rates of fawn survival averaged 0.905 (SE = 0.026) for treatment deer and 0.684 (SE = 0.044) for control deer. Nutritional enhancement increased survival rates of fetuses to the yearling age class by 0.14–0.20 depending on year and fawn sex; 95% confidence intervals slightly overlapped zero. When averaging estimates across sexes and years, treatment caused fetal to yearling survival to increase by 0.177 (SE = 0.082, 95% CI: 0.016–0.337). Annual survival of adult females receiving treatment (Ś = 0.879, SE = 0.021) was higher than survival of control adult females (Ś = 0.833, SE = 0.025). Our estimate of the population rate of change (λ) was 1.165 (SE = 0.036) for treatment deer and 1.033 (SE = 0.038) for control deer. Increased production and survival of young (i.e., fetal, neonatal, and overwinter fawn survival) accounted for 64% of the overall increase in λ, whereas adult female survival accounted for 36% of the increase in λ. The effect of nutrition treatment on overwinter fawn survival alone accounted for 33% of the overall increase in λ.
We documented food limitation in the Uncompahgre deer population because survival of fawns and adult fe
20世纪90年代，人们对骡鹿(Odocoileus hemionus)种群数量下降的担忧促使研究努力确定和了解鹿的关键限制因素。与过去鹿群数量减少的情况类似，各州野生动物机构的首要任务是评估栖息地和捕食对象的相对重要性。因此，我们利用美国科罗拉多州西南部Uncompahgre高原上自由放养的骡鹿的生命表响应实验，评估了冬春季节增加鹿营养对繁殖力和存活率的影响。该处理能瞬间增加松(Pinus edulis) -犹他刺柏(Juniperus osteosperma)冬季范围的营养承载能力，旨在模拟最佳生境质量。先前对Uncompahgre高原的研究表明，捕食和疾病是鹿死亡的最常见的直接原因。通过控制营养和保持自然捕食不变，我们确定栖息地质量是否是最终限制鹿数量的关键因素。我们测量了成年雌性和小鹿的年存活率和繁殖力，然后估计了种群变化率作为营养增强的函数。成年女性的怀孕率和胎儿率很高，并且对治疗的反应没有变化。尽管治疗对新生儿存活率的影响很小，但胎儿和新生儿存活率在治疗后有所增加。根据年份和小鹿性别的不同，处理鹿的小鹿越冬存活率提高了0.16-0.31，与影响相关的95%置信区间均不重叠为零。处理鹿的小鹿越冬成活率平均为0.905 (SE = 0.026)，对照组为0.684 (SE = 0.044)。营养增强可使胎仔的成活率提高0.14 ~ 0.20，具体取决于年份和小鹿性别;95%置信区间略微重叠于零。当对不同性别和年龄的估计进行平均时，治疗导致胎龄存活率增加0.177 (SE = 0.082, 95% CI: 0.016-0.337)。治疗组雌成虫年生存率(Ś = 0.879, SE = 0.021)高于对照组(Ś = 0.833, SE = 0.025)。种群变化率λ分别为1.165 (SE = 0.036)和1.033 (SE = 0.038)。幼崽(即胎儿、新生儿和越冬小鹿)的产量和存活率的增加占λ总体增加的64%，而成年雌性存活率占λ增加的36%。单独营养处理对越冬小鹿存活率的影响占λ整体增加的33%。我们记录了Uncompahgre鹿种群的食物限制，因为小鹿和成年母鹿的存活率在营养增加的情况下显著增加。我们发现鹿的营养增加会降低土狼(Canis latrans)和美洲狮(Puma concolor)≥6月龄小鹿和成年母鹿的捕食率。我们的研究结果表明，观察到的土狼捕食本身对于评估土狼是否对鹿种群产生负面影响并不有用。我们的研究结果还表明，在某些情况下，美洲狮可能会在较差的条件下选择鹿，这表明美洲狮的捕食可能并不总是死亡率的一个附加来源。成年女性的疾病死亡率并没有随着营养的增加而下降。冬季栖息地质量是Uncompahgre高原骡鹿种群数量的限制因素。因此，我们建议对鹿的栖息地处理进行评估，以阻止演替，提高目前占主导地位的晚几代小松-杜松生境的生产力。RESUMEN Preocupaciones sominuciones poblacionales de venados bura (Odocoileus hemionus) durante los años noventa and incitado esfuerzos de investigación para identiidentider los factores claves limitantes de los venados。Semejante和disminuciones pasadas de los venados, la priorities of las autoridades estales era评估相对于hábitat和depredación的重要性。(1)在科罗拉多州，评估<s:1>技术发展的效果;评估<s:1>技术发展的效果;评估技术发展的效果;评估技术发展的效果;评估技术发展的效果;评估技术发展的效果;评估技术发展的效果。El tratamiento representó un aumento instantáneo en la capacidad nutrition en una área invernal dominado por piñon(松树)y enebro de Utah(松柏骨骨)，y fue pretendido类似la calidad óptima del hábitat。 在Uncompahgre高原的早期研究表明，捕食和疾病是鹿死亡的最常见原因。本研究的目的是评估鹿群的营养状况，并评估鹿群的营养状况。我们测量了成年雌性和鹿的繁殖力和年存活率，然后估计了种群变化作为营养增加的函数。成年女性的妊娠和胎儿率很高，对治疗的反应没有变化。治疗后胎儿和新生儿存活率增加，尽管治疗对新生儿存活率的影响很小。与对照组相比，治疗组的鹿冬季存活率显著提高。根据年龄和性别的不同，冬季存活率提高了0.16 - 0.31，与该效应相关的95%置信区间均不包括0。治疗鹿的平均冬季存活率为0.905 (EE=0.026)，对照鹿的平均冬季存活率为0.684 (EE=0.044)。根据年龄和性别的不同，增加营养治疗使一岁胎儿的存活率提高了0.14 - 0.20，尽管与该效应相关的95%置信区间仅包括0。通过平均估计的性别和年龄，治疗导致胎儿年龄存活率增加了0.177 (EE = 0.082, 95% ci: 0.016, 0.337)。鹿雌性接受救治存活率(Ś= 0.879,EE = 0.021)是高于生存鹿(Ś= 0.833控制,EE = 0.025)。我们估计的种群变化率λ对治疗鹿为1.165 (EE = 0.036)，对对照鹿为1.033 (EE = 0.038)。幼鹿的冬季存活率(即胎儿-新生儿-冬季鹿存活率)占总存活率的64%，而成年雌鹿的存活率占总存活率的36%。营养治疗对鹿冬季存活率的影响仅解释了λ总体增长的33%。我们记录了Uncompaghre鹿种群的食物限制，因为鹿和母鹿的存活率随着营养的增加而显著提高。我们发现强有力的证据表明，在6个月大的鹿和母鹿中，鹿营养的增加减少了土狼(Canis latrans)和美洲狮(Puma concolor)的捕食。我们的结果表明，仅观察到的土狼捕食对评估鹿的数量是否有负面影响是有用的。我们的研究结果表明，在某些情况下，美洲狮可能会选择条件较差的鹿，这表明美洲狮捕食并不总是死亡的额外来源。雌性鹿的疾病死亡率没有因营养增加而降低。冬季地区的栖息地质量是Uncompahgre高原bura鹿数量的限制因素。因此，我们建议对鹿的栖息地处理进行评估，这些处理旨在延迟演替的后期阶段，并提高目前在冬季占主导地位的杜松-松林栖息地的生产力。摘要20世纪90年代，对骡鹿(Odocoileus hemionus)数量下降的关注，使研究工作转向了识别和理解限制骡鹿数量的因素。在过去的衰退中，负责野生动物的国家机构的优先事项之一是评估栖息地和捕食的相对重要性。C即我们pourquoi avonsévalué升'impact (complément d 'alimentation hiver et au春天sur les taux survie fécondité等人
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Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2006)163[1:SATIDO]2.0.CO;2
ROBERT G. ANTHONY, ERIC D. FORSMAN, ALAN B. FRANKLIN, DAVID R. ANDERSON, KENNETH P. BURNHAM, GARY C. WHITE, CARL J. SCHWARZ, JAMES D. NICHOLS, JAMES E. HINES, GAIL S. OLSON, STEVEN H. ACKERS, LAWRENCE S. ANDREWS, BRIAN L. BISWELL, PETER C. CARLSON, LOWELL V. DILLER, KATIE M. DUGGER, KATHERINE E. FEHRING, TRACY L. FLEMING, RICHARD P. GERHARDT, SCOTT A. GREMEL, R. J. GUTIERREZ, PATTI J. HAPPE, DALE R. HERTER, J. MARK HIGLEY, ROBERT B. HORN, LARRY L. IRWIN, PETER J. LOSCHL, JANICE A. REID, STAN G. SOVERN
ABSTRACT
We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985–2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the subspecies and included federal, tribal, private, and mixed federal and private lands. The study areas also included all the major forest types that the subspecies inhabits. The analyses followed rigorous protocols that were developed a priori and were the result of extensive discussions and consensus among the authors. Our primary objectives were to estimate fecundity, apparent survival (ϕ), and annual rate of population change (λ) and to determine if there were any temporal trends in these population parameters. In addition to analyses of data from individual study areas, we conducted 2 meta-analyses on each demographic parameter. One meta-analysis was conducted on all 14 areas, and the other was restricted to the 8 areas that constituted the Effectiveness Monitoring Plan for northern spotted owls under the Northwest Forest Plan. The average number of years of reproductive data per study area was 14 (range = 5–19), and the average number of recapture occasions per study area was 13 (range = 4–18). Only 1 study area had <12 years of data. Our results were based on 32,054 captures and resightings of 11,432 banded individuals for estimation of survival and 10,902 instances in which we documented the number of young produced by territorial females.
The number of young fledged (NYF) per territorial female was analyzed by testing a suite of a priori models that included (1) effects of age, (2) linear or quadratic time trends, (3) presence of barred owls (Strix varia) in spotted owl territories, and (4) an even-odd year effect. The NYF varied among years on most study areas with a biennial cycle of high reproduction in even-numbered years and low reproduction in odd-numbered years. These cyclic fluctuations did not occur on all study areas, and the even-odd year effect waned during the last 5 years of the study. Fecundity was highest for adults (x̄ =0.372, SE = 0.029), lower for 2-year-olds (x̄ = 0.208, SE = 0.032), and very low for 1-year-olds (x̄ = 0.074, SE = 0.029). Fecundity was stable over time for 6 areas (Rainier, Olympic, Warm Springs, H. J. Andrews, Klamath, and Marin), declining for 6 areas (Wenatchee, Cle Elum, Oregon Coast Range, Southern Oregon Cascades, Northwest California, and Simpson), and slightly increasing for 2 areas (Tyee, Hoopa). We found little association between NYF and the proportion of northern spotted owl territories where barred owls were detected, although results were
摘要:本研究分析了1985-2003年来自华盛顿州、俄勒冈州和加利福尼亚州14个研究区域的北斑猫头鹰(Strix occidentalis caurina)的人口统计数据。我们分析的目的是对北斑猫头鹰在其大部分地理范围内的种群状况和趋势进行评估。这14个研究区域约占该亚种范围的12%，包括联邦、部落、私人以及联邦和私人混合土地。研究区域还包括亚种栖息的所有主要森林类型。分析遵循严格的协议，这些协议是先验的，是作者广泛讨论和共识的结果。我们的主要目标是估计繁殖力、表观存活率(φ)和年人口变化率(λ)，并确定这些人口参数是否存在任何时间趋势。除了对单个研究区域的数据进行分析外，我们还对每个人口统计参数进行了2次元分析。一项荟萃分析针对所有14个地区，另一项荟萃分析仅限于西北森林计划下构成北方斑猫头鹰有效性监测计划的8个地区。每个研究区的平均繁殖数据年数为14年(范围= 5 ~ 19)，每个研究区的平均捕获次数为13次(范围= 4 ~ 18)。只有一个研究区域有12年的数据。我们的研究结果是基于32,054次捕获和观察11,432只带状个体的生存估计，以及10,902个记录领地雌性幼崽数量的实例。通过测试一套先验模型(1)年龄的影响，(2)线性或二次时间趋势，(3)斑点猫头鹰领地中横斑猫头鹰(Strix varia)的存在，以及(4)偶数年效应)，分析了每个领地雌性羽化雏鸟(NYF)的数量。多数研究区NYF年际变化较大，呈双数年繁殖力高、奇数年繁殖力低的两年循环。并非所有研究区域都出现了这种周期性波动，在研究的最后5年里，双数年效应逐渐减弱。成人的繁殖力最高(x′=0.372,SE = 0.029)， 2岁儿童的繁殖力较低(x′= 0.208,SE = 0.032)， 1岁儿童的繁殖力极低(x′= 0.074,SE = 0.029)。6个地区(Rainier、Olympic、Warm Springs、H. J. Andrews、Klamath和Marin)的繁殖力随着时间的推移保持稳定，6个地区(Wenatchee、Cle Elum、Oregon Coast Range、Southern Oregon Cascades、Northwest California和Simpson)的繁殖力下降，2个地区(Tyee、Hoopa)的繁殖力略有增加。我们发现NYF与发现横斑猫头鹰的北方斑点猫头鹰领地比例之间几乎没有关联，尽管结果表明横斑猫头鹰对Wenatchee和Olympic研究区域有负面影响。对繁殖力的荟萃分析显示了大量的年度变化，没有增加或减少的趋势。华盛顿州东部混合针叶林地区的繁殖力最高(x′= 0.560,SE = 0.041)，俄勒冈海岸道格拉斯杉木(pseudosuga menziesii)地区的繁殖力最低(x′= 0.306,SE = 0.039)。我们使用Cormack-Jolly-Seber开放种群模型和Program MARK来估计1岁龄猫头鹰的表观存活率。我们发现除了1个地区(Marin)只有6年的数据外，性别之间的表观存活率没有差异。来自个别研究区域的表观存活率估计表明，不同年龄层之间存在差异，成年人的存活率通常高于1岁和2岁的儿童。成人的表观存活率为0.750 (SE = 0.026) ~ 0.886 (SE = 0.010)， 2岁儿童的表观存活率为0.626 (SE = 0.073) ~ 0.886 (SE = 0.010)， 1岁儿童的表观存活率为0.415 (SE = 0.111) ~ 0.860 (SE = 0.017)。这些估计与以前对亚种的研究得出的存活率相当。我们在5个研究区域(Wenatchee, Cle Elum, Rainier, Olympic和Northwest California)中发现了生存率负时间趋势的证据，而在其余区域中没有生存率趋势。有证据表明横斑猫头鹰对3个研究区域(Wenatchee, Cle Elum和Olympic)的表观存活率有负面影响。成年猫头鹰在8个监测区的存活率总体较高，为0.85 ~ 0.89 (SE = 0.010)，但在cleelum、Olympic和Northwestern California研究区呈下降趋势。表观存活率的meta分析表明，华盛顿州针叶树和道格拉斯-冷杉混交区的表观存活率在不同地区之间存在差异，且随时间变化呈下降趋势。表观存活率的荟萃分析也表明，第二年的繁殖力和存活率之间存在负相关，这表明繁殖成本对存活率有影响。 这种影响仅限于华盛顿的道格拉斯冷杉和混合针叶林地区以及俄勒冈州喀斯喀特山脉的道格拉斯冷杉地区。采用重参数化Jolly-Seber方法(λRJS)估算了研究区领地猫头鹰的年种群变动率。这个估计回答了一个问题，这些领地猫头鹰在地理上开放的种群中是否被取代了?在13个研究区域中，12个区域的λRJS点估计值为<1.0。分析提供了强有力的证据，表明在研究期间，韦纳奇、克莱埃勒姆、雷尼尔、奥林匹克、温泉、H. J.安德鲁斯、俄勒冈海岸山脉和辛普森研究区域的人口数量正在下降。13个研究区的平均λRJS为0.963 (SE = 0.009)，表明研究期间所有研究区的种群数量以每年3.7%的速度下降。西北森林计划8个监测区域的平均λRJS为0.976 (SE = 0.007)，而其他研究区域的平均λRJS为0.942 (SE = 0.016)，年均下降2.4- 5.8%。这表明，联邦土地上猫头鹰的人口比例高于其他地方;因此，西北森林计划似乎对北方斑点猫头鹰的人口统计有积极的影响。华盛顿的人口最穷，四个研究区域的存活率和人口都在下降。我们估计的λRJS通常低于之前的分析报告(λRJS = 0.997, SE = 0.003)，在许多相同的地区，在较早的日期。数量下降的可能原因包括但不限于木材采伐和火灾造成的栖息地丧失，与横斑猫头鹰的竞争以及天气模式。RESUMEN Analizamos datos demográficos de búhos moteados norteños (Strix occidentalis caurina) de catorce áreas de estudio en los estados de Washington, Oregón y California durante el periodo 1985-2003。e . propósito关于新情况análisis关于一般情况的报告evaluación关于发展趋势的报告búhos关于发展趋势的报告extensión geográfica。Las catorce áreas de estudio comprendían近似地描述了穷人的身份信息，例如extensión de esta subspecias comprendían tierras federales, tribales, privadas，或mezclas de tierras federales y privadas。这些条例áreas包括下列原则:关于人体的习惯和亚种。Los análisis seguian protocolos riguro
{"title":"Status and Trends in Demography of Northern Spotted Owls, 1985–2003","authors":"ROBERT G. ANTHONY, ERIC D. FORSMAN, ALAN B. FRANKLIN, DAVID R. ANDERSON, KENNETH P. BURNHAM, GARY C. WHITE, CARL J. SCHWARZ, JAMES D. NICHOLS, JAMES E. HINES, GAIL S. OLSON, STEVEN H. ACKERS, LAWRENCE S. ANDREWS, BRIAN L. BISWELL, PETER C. CARLSON, LOWELL V. DILLER, KATIE M. DUGGER, KATHERINE E. FEHRING, TRACY L. FLEMING, RICHARD P. GERHARDT, SCOTT A. GREMEL, R. J. GUTIERREZ, PATTI J. HAPPE, DALE R. HERTER, J. MARK HIGLEY, ROBERT B. HORN, LARRY L. IRWIN, PETER J. LOSCHL, JANICE A. REID, STAN G. SOVERN","doi":"10.2193/0084-0173(2006)163[1:SATIDO]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2006)163[1:SATIDO]2.0.CO;2","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>We analyzed demographic data from northern spotted owls (<i>Strix occidentalis caurina</i>) from 14 study areas in Washington, Oregon, and California for 1985–2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the subspecies and included federal, tribal, private, and mixed federal and private lands. The study areas also included all the major forest types that the subspecies inhabits. The analyses followed rigorous protocols that were developed a priori and were the result of extensive discussions and consensus among the authors. Our primary objectives were to estimate fecundity, apparent survival (ϕ), and annual rate of population change (λ) and to determine if there were any temporal trends in these population parameters. In addition to analyses of data from individual study areas, we conducted 2 meta-analyses on each demographic parameter. One meta-analysis was conducted on all 14 areas, and the other was restricted to the 8 areas that constituted the Effectiveness Monitoring Plan for northern spotted owls under the Northwest Forest Plan. The average number of years of reproductive data per study area was 14 (range = 5–19), and the average number of recapture occasions per study area was 13 (range = 4–18). Only 1 study area had <12 years of data. Our results were based on 32,054 captures and resightings of 11,432 banded individuals for estimation of survival and 10,902 instances in which we documented the number of young produced by territorial females.</p>\u0000 \u0000 <p>The number of young fledged (NYF) per territorial female was analyzed by testing a suite of a priori models that included (1) effects of age, (2) linear or quadratic time trends, (3) presence of barred owls (<i>Strix varia</i>) in spotted owl territories, and (4) an even-odd year effect. The NYF varied among years on most study areas with a biennial cycle of high reproduction in even-numbered years and low reproduction in odd-numbered years. These cyclic fluctuations did not occur on all study areas, and the even-odd year effect waned during the last 5 years of the study. Fecundity was highest for adults (<i>x̄</i> =0.372, SE = 0.029), lower for 2-year-olds (<i>x̄</i> = 0.208, SE = 0.032), and very low for 1-year-olds (<i>x̄</i> = 0.074, SE = 0.029). Fecundity was stable over time for 6 areas (Rainier, Olympic, Warm Springs, H. J. Andrews, Klamath, and Marin), declining for 6 areas (Wenatchee, Cle Elum, Oregon Coast Range, Southern Oregon Cascades, Northwest California, and Simpson), and slightly increasing for 2 areas (Tyee, Hoopa). We found little association between NYF and the proportion of northern spotted owl territories where barred owls were detected, although results were ","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2006)163[1:SATIDO]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6207316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PATRICK K. DEVERS, DEAN F. STAUFFER, GARY W. NORMAN, DAVE E. STEFFEN, DARROCH M. WHITAKER, JEFFREY D. SOLE, TOM J. ALLEN, STEVE L. BITTNER, DAVID A. BUEHLER, JOHN W. EDWARDS, DANIEL E. FIGERT, SCOTT T. FRIEDHOFF, WILLIAM W. GIULIANO, CRAIG A. HARPER, WILLIAM K. IGO, ROY L. KIRKPATRICK, MICHAEL H. SEAMSTER, HARRY A. SPIKER Jr., DAVID A. SWANSON, BRIAN C. TEFFT
ABSTRACT
The Appalachian Cooperative Grouse Research Project (ACGRP) was a multistate cooperative effort initiated in 1996 to investigate the apparent decline of ruffed grouse (Bonasa umbellus) and improve management throughout the central and southern Appalachian region (i.e., parts of Ohio, Pennsylvania, Rhode Island, Kentucky, West Virginia, Virginia, and North Carolina, USA). Researchers have offered several hypotheses to explain the low abundance of ruffed grouse in the region, including low availability of early-successional forests due to changes in land use, additive harvest mortality, low productivity and recruitment, and nutritional stress. As part of the ACGRP, we investigated ruffed grouse population ecology. Our objectives were to estimate reproductive rates, estimate survival and cause-specific mortality rates, examine if ruffed grouse harvest in the Appalachian region is compensatory, and estimate ruffed grouse finite population growth. We trapped >3,000 ruffed grouse in autumn (Sep-Nov) and spring (Feb-Mar) from 1996 to September 2002 on 12 study areas. We determined the age and gender of each bird and fitted them with necklace-style radiotransmitters and released them at the trap site. We tracked ruffed grouse ≥2 times per week using handheld radiotelemetry equipment and gathered data on reproduction, recruitment, survival, and mortality.
Ruffed grouse population dynamics in the Appalachian region differed from the central portion of the species' range (i.e., northern United States and Canada). Ruffed grouse in the Appalachian region had lower productivity and recruitment, but higher survival than reported for populations in the Great Lakes region and southern Canada. Population dynamics differed between oak (Quercus spp.)–hickory (Carya spp.) and mixed-mesophytic forest associations within the southern and central Appalachian region. Productivity and recruitment were lower in oak-hickory forests, but adult survival was higher than in mixed-mesophytic forests. Furthermore, ruffed grouse productivity and recruitment were more strongly related to hard mast (i.e., acorn) production in oak-hickory forests than in mixed-mesophytic forests. The leading cause of ruffed grouse mortality was avian predation (44% of known mortalities). Harvest mortality accounted for 12% of all known mortalities and appeared to be compensatory. Population models indicated ruffed grouse populations in the Appalachian region are declining (%LD = 0.78–0.95), but differences in model estimates highlighted the need for improved understanding of annual productivity and recruitment. We posit ruffed grouse in the Appalachian region exhibit a clinal population structure characterized by changes in life-history strategies. Changes in life history strategies are in response to gradual changes in forest structure, qu
阿巴拉契亚合作松鸡研究项目(ACGRP)是1996年发起的一项多州合作项目，旨在调查阿巴拉契亚中部和南部地区(即美国俄亥俄州、宾夕法尼亚州、罗德岛州、肯塔基州、西弗吉尼亚州、弗吉尼亚州和北卡罗来纳州的部分地区)皱松鸡(Bonasa umbellus)的明显下降，并改善管理。研究人员提出了几种假说来解释该地区松松鸡的低丰度，包括土地利用变化导致的早期演替森林可用性低、添加剂采伐死亡率低、生产力和招募低以及营养压力。作为ACGRP的一部分，我们调查了松鸡种群生态。我们的目标是估计繁殖率，估计存活率和原因特异性死亡率，检查阿巴拉契亚地区的松鸡收获是否具有补偿性，并估计松鸡的有限种群增长。1996年至2002年9月，在12个研究区分别于秋季(9 - 11月)和春季(2 - 3月)捕获松鸡3000只。我们确定了每只鸟的年龄和性别，给它们安装了项链式无线电发射器，并将它们释放到陷阱地点。我们每周使用手持式无线电遥测设备追踪松鸡≥2次，收集繁殖、招募、生存和死亡率的数据。阿巴拉契亚地区的松鸡种群动态与该物种分布范围的中心部分(即美国北部和加拿大)不同。阿巴拉契亚地区的松鸡产量和数量较低，但存活率高于大湖地区和加拿大南部的报告。在阿巴拉契亚南部和中部地区，栎(Quercus spp.) -山核桃(Carya spp.)和混合叶生林群落的种群动态存在差异。橡树-山核桃林的生产力和增收较低，但成虫存活率高于混合叶生植物林。此外，与混合叶生植物林相比，橡树-山核桃林的松鸡生产力和招募与硬杆(即橡子)产量的关系更强。松鸡死亡的主要原因是鸟类的捕食(占已知死亡率的44%)。收获死亡率占所有已知死亡率的12%，似乎是补偿性的。人口模型显示，阿巴拉契亚地区的松鸡数量正在下降(%LD = 0.78-0.95)，但模型估计的差异突出了对年生产力和招募的更好理解的必要性。我们假设在阿巴拉契亚地区皱松鸡表现出以生活史策略变化为特征的临床种群结构。生活史策略的变化是对森林结构、食物资源质量、降雪和积累模式以及捕食者群落的逐渐变化的响应。管理工作应侧重于在整个景观中创造一个林分年龄的马赛克，以分散栖息地资源，包括筑巢和产卵覆盖、成虫逃逸覆盖、栖息地点，以及最重要的食物资源。土地管理者可以通过林中砍伐、防护林采伐、群体选择和林分改善(包括各种疏林和规定的火灾)的组合来分散栖息地资源。管理人员应保持目前的松鸡收获率，同时提供高质量的狩猎机会。我们将高质量狩猎定义为低狩猎压力、低车辆流量和高冲洗率。管理人员可以通过封闭道路和生境管理相结合，提供高质量的狩猎机会。1996年1月1日建立investigación阿帕拉奇超级松鸡合作项目(ACGRP)建立多州合作项目，对declinación阿帕拉奇超级松鸡(Bonasa伞状松鸡)的证据进行调查，并对región阿帕拉奇中部和子经区域(俄亥俄州、宾夕法尼亚州、罗德岛州、肯塔基州、西维吉尼亚州、弗吉尼亚州、田纳西州、欧洲联盟)进行调查。ACGRP委员会，调查ecología超级ada和población超级松鸡。新目标:估计繁殖率，估计繁殖率causar-específicas死亡率，估计繁殖率causar-específicas死亡率，估计繁殖率causar-específicas死亡率，估计繁殖率causar-específicas死亡率，估计繁殖率región死亡率，估计繁殖率región死亡率región死亡率，估计繁殖率población死亡率población。Varias hipótesis se han ofrecido para explancia baja del grouse superado en la región，包括enddo la disponbilidad baja de los bosques jóvenes debido a los cambios en utilización del suvelo, mortalidad aditiva de la cosecha, bajo productividad by reclutamiento，和tensión alimenticia。 从1996年到2002年9月，我们在12个研究区域的秋季(9月至11月)和春季(2月至3月)捕获了超过3000只松鸡。我们确定了每只鸟的年龄和性别，用项圈式无线电发射器捕捉它们，然后把它们扔到陷阱现场。使用手持式无线电遥测设备每周跟踪超过≥2次的松鸡，收集繁殖、招募、存活和死亡率数据。阿巴拉契亚地区的松鸡种群动态与该物种的中部范围(即美国北部和加拿大)不同。与五大湖地区和加拿大南部的种群相比，阿巴拉契亚地区被击败的松鸡的生产力和招募水平较低，但存活率较高。在阿巴拉契亚南部和中部地区，橡树林(Quercus)、硬核桃林(Carya)和混合中生林的种群动态存在差异。橡树林和硬核桃林的生产力和补充水平较低，但成虫存活率高于混合中物理林。此外，在橡树和硬核桃林中，超过松鸡的生产力和补充与硬杆(即橡子)产量的关系比在混合中物理林中更强。松鸡死亡的主要原因是鸟类捕食(已知死亡人数的44%)。作物死亡率占所有已知死亡人数的12%，这似乎是一种补偿。人口模型表明在阿巴拉契亚地区grouse人民克服他们却(Λ= 0.78—0.95),但估计数差异模型表明,需要增强生产力和年度招募的理解。在阿巴拉契亚地区，由于食物资源质量、降雪和积累模式的逐渐变化，松鸡的种群结构呈现出斜向的变化。管理的努力应侧重于创建图年龄段支持伍兹通过点缀景观资源的生境包括甲板饲养口袋和年轻成人,信封的逃脱,衣架,更重要的是粮食资源网站。栖息地资源的干扰可以通过选择性切割、清除切割、规定的火灾和通过杀死单个树木创建低直径的亭子裂缝的组合来实现。收获管理的设计应保持目前的收获率，同时提供高质量的狩猎机会。我们将高质量的狩猎定义为狩猎压力低，车辆流量低，价格高。高质量的狩猎管理可以通过使用道路围栏和栖息地管理来实现。Écologie Grouse月人口Ruffed dans la Appalachienne地区 RÉSUMÉ 他projetde研究coopératif appalachien (multi-état ACGRP)était effort coopératif挤在他1996年pourétudier déclin表观ruffed grouse (Bonasa umbellus) et améliorent管理dans扩大地区appalachienne centrale méridionale (c -à-d。,国际de l ' 'Ohio PennsylvanieÎ的罗德,杜肯塔基州,他的Virginie银行Virginie, et du田纳西州,Etats-Unis)。作为acgrp的一部分，我们研究了松鸡种群生态学。我们的目标是:估计繁殖率，估计存活率和特定原因死亡率，检查在阿巴拉契亚地区收获的松鸡是否具有补偿性，并评估松鸡种群的最终增长。人们提出了几个假设
{"title":"Ruffed Grouse Population Ecology in the Appalachian Region","authors":"PATRICK K. DEVERS, DEAN F. STAUFFER, GARY W. NORMAN, DAVE E. STEFFEN, DARROCH M. WHITAKER, JEFFREY D. SOLE, TOM J. ALLEN, STEVE L. BITTNER, DAVID A. BUEHLER, JOHN W. EDWARDS, DANIEL E. FIGERT, SCOTT T. FRIEDHOFF, WILLIAM W. GIULIANO, CRAIG A. HARPER, WILLIAM K. IGO, ROY L. KIRKPATRICK, MICHAEL H. SEAMSTER, HARRY A. SPIKER Jr., DAVID A. SWANSON, BRIAN C. TEFFT","doi":"10.2193/0084-0173.168","DOIUrl":"https://doi.org/10.2193/0084-0173.168","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>The Appalachian Cooperative Grouse Research Project (ACGRP) was a multistate cooperative effort initiated in 1996 to investigate the apparent decline of ruffed grouse (<i>Bonasa umbellus</i>) and improve management throughout the central and southern Appalachian region (i.e., parts of Ohio, Pennsylvania, Rhode Island, Kentucky, West Virginia, Virginia, and North Carolina, USA). Researchers have offered several hypotheses to explain the low abundance of ruffed grouse in the region, including low availability of early-successional forests due to changes in land use, additive harvest mortality, low productivity and recruitment, and nutritional stress. As part of the ACGRP, we investigated ruffed grouse population ecology. Our objectives were to estimate reproductive rates, estimate survival and cause-specific mortality rates, examine if ruffed grouse harvest in the Appalachian region is compensatory, and estimate ruffed grouse finite population growth. We trapped >3,000 ruffed grouse in autumn (Sep-Nov) and spring (Feb-Mar) from 1996 to September 2002 on 12 study areas. We determined the age and gender of each bird and fitted them with necklace-style radiotransmitters and released them at the trap site. We tracked ruffed grouse ≥2 times per week using handheld radiotelemetry equipment and gathered data on reproduction, recruitment, survival, and mortality.</p>\u0000 \u0000 <p>Ruffed grouse population dynamics in the Appalachian region differed from the central portion of the species' range (i.e., northern United States and Canada). Ruffed grouse in the Appalachian region had lower productivity and recruitment, but higher survival than reported for populations in the Great Lakes region and southern Canada. Population dynamics differed between oak (<i>Quercus</i> spp.)–hickory (<i>Carya</i> spp.) and mixed-mesophytic forest associations within the southern and central Appalachian region. Productivity and recruitment were lower in oak-hickory forests, but adult survival was higher than in mixed-mesophytic forests. Furthermore, ruffed grouse productivity and recruitment were more strongly related to hard mast (i.e., acorn) production in oak-hickory forests than in mixed-mesophytic forests. The leading cause of ruffed grouse mortality was avian predation (44% of known mortalities). Harvest mortality accounted for 12% of all known mortalities and appeared to be compensatory. Population models indicated ruffed grouse populations in the Appalachian region are declining (%LD = 0.78–0.95), but differences in model estimates highlighted the need for improved understanding of annual productivity and recruitment. We posit ruffed grouse in the Appalachian region exhibit a clinal population structure characterized by changes in life-history strategies. Changes in life history strategies are in response to gradual changes in forest structure, qu","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173.168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6235263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2004)155[1:EOSNAP]2.0.CO;2
JOHN G. COOK, BRUCE K. JOHNSON, RACHEL C. COOK, ROBERT A. RIGGS, TIM DELCURTO, LARRY D. BRYANT, LARRY L. IRWIN
Abstract: Recent declines in numbers and juvenile recruitment in many elk (Cervus elaphus) herds in the western U.S. has sparked interest in factors that may cause these declines. Inadequate nutrition or delayed parturition, the latter of which may be caused by inadequate numbers of mature bulls (i.e., highly skewed sex ratios), may have separate or synergistic effects on population dynamics and productivity. We evaluated the implications of late parturition and summer-autumn nutrition on reproduction and survival of Rocky Mountain elk (C. e. nelsoni) using a captive herd of 57 cow elk.
We induced early (Sep) and late breeding (Oct) and 3 levels of summer-autumn nutrition on the cows. Food was offered ad libitum at 3 levels of digestible energy (DE): high = 2.9-3.0 kcal of DE/g of diets, medium = 2.6-3.0 kcal/g, and low = 2.3-3.0 kcal/g. Within these ranges, DE content was gradually reduced from late June through early November to mimic seasonal changes in the wild. During summer and autumn, we measured calf growth; body mass, nutritional condition, and breeding dynamics of cows; and growth and pregnancy of yearlings. We also measured carry-over (i.e., time-lag) responses including over-winter calf and cow survival and parturition date and birth mass, as functions of previous summer-autumn nutrition and previous parturition date. Between autumn 1995 and spring 1998, we conducted 2 years of parturition-date, summer-autumn nutrition experiments, 2 winters of calf survival experiments, and 1 winter of cow survival experiments.
Early birth provided calves with more time to grow before onset of winter. This “head-start” advantage was maintained through late autumn, but its magnitude was diluted in some instances due to faster growth of some late-born calves. Body mass, body fat, and timing and probability of conception by cows in autumn were little influenced by parturition date the previous spring.
Summer-autumn nutrition significantly affected calves and their mothers. Growth of calves in the low and medium nutrition groups ceased by mid-September and late October. By December, calves in the high nutrition group were 40% and 70% heavier than calves in the medium and low groups, respectively. Cows in the high nutrition group accumulated about 75% and 300% more fat than cows in the medium and low groups by mid-October. Eighty percent of cows in the low nutrition group failed to conceive, and those in the medium group bred 10–14 days later than cows in the high group. Summer-autumn nutrition of calves influenced their probability of becoming pregnant as yearlings. Probability of pregnancy approached 100% for those yearlings that had high summerautumn nutrition as calves and yearlings, despite near starvation their first winter of life.
Winter survival of calves was related to their size at the onset of winter. Smaller calves lost more body mass daily than did large calves, and thus they survived fewer da
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Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2006)162[1:PDOGSB]2.0.CO;2
PAUL L. FLINT, J. BARRY GRAND, THOMAS F. FONDELL, JULIE A. MORSE
ABSTRACT
Populations of greater scaup (Aythya marila) remained relatively stable during a period when populations of lesser scaup (A. affinis) have declined from historic levels. To assist in describing these differences in population trends, from 1991 through 2000, we studied the survival, nesting ecology, and productivity of greater scaup on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, to develop a model of population dynamics. We located nests, radio-marked females for renesting studies, estimated duckling survival, and leg-banded females to examine nest site fidelity and annual survival.
Greater scaup initiated egg laying later than other species, and most clutches (>80%) were initiated over 20 days each year. We located 1,056 nests; nest success ranged from 7 to 61 % among years. Following loss of their first clutch, 51 % of radio-tagged females attempted to renest. Duckling survival to 30 days of age was 37.5%. Our best model suggested that annual survival did not vary among years and averaged 81 %. Survival rate was positively related to structural body size. Only 8 of 214 banded individuals were reported as recovered (1 each in Maryland, Michigan, Minnesota, Washington, and Alaska and 3 in California).
Using a stochastic model, we estimated that, on average, breeding females produced 0.57 young females/nesting season. We combined this estimate of productivity with our annual estimates of adult survival and an assumed population growth rate of 1.0, then solved for an estimate of first-year survival (0.40). Under these conditions the predicted stable age distribution of breeding females (i.e., the nesting population) was 15.1% 1-year-old, 4.1% 2-year-old first-time breeders, and 80.8% 2-year-old and older, experienced breeders. We subjected this stochastic model to perturbation analyses to examine the relative effects of demographic parameters on k. The relative effects of productivity and adult survival on the population growth rate were 0.26 and 0.72, respectively. Thus, compared to productivity, proportionally equivalent changes in annual survival would have 2.8 times the effect on k. However, when we examined annual variation in predicted population size using standardized regression coefficients, productivity explained twice as much variation as annual survival. Thus, management actions focused on changes in survival or productivity have the ability to influence population size; however, substantially larger changes in productivity are required to influence population trends.
RESUMEN
Poblaciones de pato-boludo mayor (Aythya marila) se quedó relativamente fijo durante un período cuando poblaciones de pato-boludo menor (A. affinis
摘要:在小穗花楸(a . affinis)种群从历史水平下降的时期，大穗花楸(Aythya marila)种群保持相对稳定。为了帮助描述这些种群趋势的差异，从1991年到2000年，我们研究了阿拉斯加育空-库斯科维姆三角洲(Y-K三角洲)的生存、筑巢生态和生产力，建立了一个种群动态模型。我们定位了鸟巢，用无线电标记的母鸭进行了抵抗研究，估计了小鸭的存活率，用腿带的母鸭检查了鸟巢的保真度和年存活率。与其他种类相比，黄斑蝶的产卵开始时间较晚，并且大多数(80%)在每年20天以上开始产卵。我们找到了1056个鸟巢;这些年来，筑巢成功率从7%到61%不等。在失去了第一批卵后，51%的带有无线电标记的雌企鹅试图筑巢。雏鸭30日龄成活率为37.5%。我们的最佳模型表明，年生存率在年份之间没有变化，平均为81%。成活率与结构体大小呈正相关。据报道，214只被捆绑的个体中只有8只被恢复(马里兰州、密歇根州、明尼苏达州、华盛顿州和阿拉斯加州各1只，加利福尼亚州3只)。利用随机模型，我们估计，每个筑巢季节，繁殖雌性平均产生0.57只年轻雌性。我们将这一生产力估计值与我们每年对成人存活率的估计值和假设的人口增长率1.0结合起来，然后求解第一年存活率的估计值(0.40)。在此条件下，繁殖雌鸟(即筑巢种群)的稳定年龄分布为1岁15.1%，2岁首次繁殖者4.1%，2岁及以上经验繁殖者80.8%。我们对该随机模型进行了扰动分析，以检验人口统计学参数对k的相对影响。生产力和成虫存活率对种群增长率的相对影响分别为0.26和0.72。因此，与生产力相比，年存活率的比例相等变化对k的影响将是2.8倍。然而，当我们使用标准化回归系数检查预测种群规模的年变化时，生产力解释的变化是年存活率的两倍。因此，着重于生存或生产力变化的管理行动有能力影响人口规模;但是，要影响人口趋势，就需要在生产力方面有更大的变化。RESUMEN Poblaciones de pato-boludo市长(Aythya marila) se quedo relativamente fijo杜兰特联合国periodo cuando Poblaciones de pato-boludo menor(竹)disminuyo de historicos含量。Para participant en descriir estas差异和趋势población, 1991年至2000年，estudiamos la sobrevivencia, anidando la ecología，在育空-库斯库温三角洲(y - k三角洲)，阿拉斯加，Para desarrollar unmodelo de dinámica de población。Localizamos los nidos, hembras de radio-marked para - resting studios, sobrevivencia estimada de patito, hembras de pierna-rayó para examinar, fidelidad del sitio del nido by sobrevivencia annuale。Pato-boludo市长inició huevo-colocar luego que otra especie, y la mayoria de los embrague (>80%) fueron iniciados sobre 20 días cada año。Localizamos 1.056 nidos;<s:1>通讯通讯条例recorrió de 7 a 61 %中心años。La pancirdida siguente de su primer embrague, 51% de hembras de radio-tagged procuró al - est。30年的时间跨度días时间跨度37,5%。Nuestro major modelo sugirió que esa sobrevivencia annual no varió entre años y promedió 81%。短时间内的关系与实证研究tamaño结构模型研究。Sólo 8 / 214个人(1 /马里兰州、1 /密歇根州、1 /明尼苏达州、1 /华盛顿州、1 /阿拉斯加州、3 /加利福尼亚州)利用modelo estocástico, nosotros estimamos eso, en el promedio, criando hembras produjeron 0,57 temporada joven de hembras/anidando。Combinamos esta estimación de productividad con nuestrasestimacones annuales de sobrevivencia adult通过una tasa de recimiento asumida de población de 1 0 0, entonces results to para una estimación de primeo -sobrevivencia (0.40 de año)。研究结果表明:1岁儿童的预测结果为15.1%，2岁儿童的预测结果为4.1%，2岁儿童的预测结果为4.1%，2岁儿童的预测结果为8.8%，2岁儿童的预测结果为años, 2岁儿童的预测结果为más。Sujetamos este modelo estocástico a la inquieud分析para -考官的损失效应相对于parámetras demográficos en λ。 结果表明，生产力和成虫存活率对人口增长率的相对影响分别为0.26和0.72。因此，相对生产率，按比例等同的年存活率变化对λ的影响是2.8倍。然而，当我们使用预测的人口规模回归标准化系数来检验年变化时，生产力解释的生存变化是年变化的两倍。因此，以生存或生产力变化为重点的行政行动有能力影响人口规模，但需要更大的生产力变化来影响人口趋势。milouinan fuligule (Aythya mania)的种群在小fuligule (A. affinis)的历史种群水平下降的时期保持相对稳定。为了帮助阐明这两种趋势之间的差异，从1991年到2000年，我们研究了阿拉斯加育空和库斯科维姆三角洲的milouinan fuligule的生存、筑巢生态和生产力，以模拟种群动态。我们找到了巢穴，在雌性身上安装了无线电发射器，以研究替代孵化的幼崽，估计幼崽的存活率，并给雌性戴上戒指，以检查它们对产卵地点的忠诚和存活率。milouinan fuligule开始产卵的时间比其他物种晚，每年大多数孵化(> 80%)都在20天内开始。我们发现了1056个巢穴;根据年份的不同，筑巢成功率从7%到61%不等。在失去第一窝蛋后，51%的装有无线电发射器的雌性产下了另一窝蛋。30天前的存活率为37.5%。根据最佳模型，年平均存活率为81%，全年
{"title":"Population Dynamics of Greater Scaup Breeding on the Yukon-Kuskokwim Delta, Alaska","authors":"PAUL L. FLINT, J. BARRY GRAND, THOMAS F. FONDELL, JULIE A. MORSE","doi":"10.2193/0084-0173(2006)162[1:PDOGSB]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2006)162[1:PDOGSB]2.0.CO;2","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>Populations of greater scaup (<i>Aythya marila</i>) remained relatively stable during a period when populations of lesser scaup (<i>A. affinis</i>) have declined from historic levels. To assist in describing these differences in population trends, from 1991 through 2000, we studied the survival, nesting ecology, and productivity of greater scaup on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, to develop a model of population dynamics. We located nests, radio-marked females for renesting studies, estimated duckling survival, and leg-banded females to examine nest site fidelity and annual survival.</p>\u0000 \u0000 <p>Greater scaup initiated egg laying later than other species, and most clutches (>80%) were initiated over 20 days each year. We located 1,056 nests; nest success ranged from 7 to 61 % among years. Following loss of their first clutch, 51 % of radio-tagged females attempted to renest. Duckling survival to 30 days of age was 37.5%. Our best model suggested that annual survival did not vary among years and averaged 81 %. Survival rate was positively related to structural body size. Only 8 of 214 banded individuals were reported as recovered (1 each in Maryland, Michigan, Minnesota, Washington, and Alaska and 3 in California).</p>\u0000 \u0000 <p>Using a stochastic model, we estimated that, on average, breeding females produced 0.57 young females/nesting season. We combined this estimate of productivity with our annual estimates of adult survival and an assumed population growth rate of 1.0, then solved for an estimate of first-year survival (0.40). Under these conditions the predicted stable age distribution of breeding females (i.e., the nesting population) was 15.1% 1-year-old, 4.1% 2-year-old first-time breeders, and 80.8% 2-year-old and older, experienced breeders. We subjected this stochastic model to perturbation analyses to examine the relative effects of demographic parameters on k. The relative effects of productivity and adult survival on the population growth rate were 0.26 and 0.72, respectively. Thus, compared to productivity, proportionally equivalent changes in annual survival would have 2.8 times the effect on k. However, when we examined annual variation in predicted population size using standardized regression coefficients, productivity explained twice as much variation as annual survival. Thus, management actions focused on changes in survival or productivity have the ability to influence population size; however, substantially larger changes in productivity are required to influence population trends.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> RESUMEN</h3>\u0000 \u0000 <p>Poblaciones de pato-boludo mayor (<i>Aythya marila</i>) se quedó relativamente fijo durante un período cuando poblaciones de pato-boludo menor (<i>A. affinis</i","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2006)162[1:PDOGSB]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6218768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2006)167[1:HOBNAE]2.0.CO;2
KELLEY M. STEWART, R. TERRY BOWYER, ROGER W. RUESS, BRIAN L. DICK, JOHN G. KIE
ABSTRACT
Understanding herbivore optimization has implications for theories underpinning ecosystem processes, management of large herbivores, and the landscapes they inhabit. We designed an experiment to examine interactions related to density dependence of North American elk (Cervus elaphus) and resulting plant responses to herbivory in the Blue Mountains of Oregon, USA, from 1999 to 2001. We experimentally created high (20.1 elk/km2) and low (4.1 elk/km2) population densities of elk and built exclosures to examine effects of herbivory on productivity and species composition of plants. We hypothesized that if herbivore optimization occurred with increasing density of elk, there should be a concordant increase in plant production, followed by a decline in productivity as grazing intensity continued to increase (i.e., herbivore optimization). Net aboveground primary productivity (NAPP) increased from no herbivory to herbivory by elk at moderate density and then declined as herbivory by elk continued to increase in areas with high NAPP (mesic and logged forests) but not in areas with low NAPP (xeric forests and grasslands). Herbivore optimization occurred across all functional groups of plants, including graminoids, forbs, and shrubs for high-NAPP areas. Herbivore optimization may be difficult to detect in woody plants compared with graminoids because of their differing structure and growth forms. Although herbivore optimization previously has been reported in grasslands, our study documents this phenomenon in woody plant communities. We hypothesize that such subtle changes in NAPP from herbivory might be more common than previously thought; carefully designed experiments are required to detect those responses to herbivory by large herbivores. Apparent offtake of plants followed a similar pattern to NAPP and was greatest at intermediate levels of herbivory by elk, and then declined as NAPP approached zero. Quality of plants, as indexed by percent nitrogen (N), also exhibited a parabolic function with increasing density of elk. Nonetheless, we observed no changes in species composition or diversity of plants with our density manipulations of elk, probably because of the extensive history of grazing by native and domestic herbivores in the Blue Mountains, the resilience of the remaining plants to herbivory, and the short 3-year duration of our study. Likewise, we observed no increases in rates of nutrient cycling with changes in densities of elk, perhaps because areas where large amounts of elk urine and feces were concentrated (e.g., grazing lawns) did not occur in this ecosystem.
Herbivore optimization could have ramifications for population dynamics of ungulates. We argue that other processes, such as migration, predation, or harvest, might be necessary to maintain areas of increased NAPP be
了解草食动物优化对支持生态系统过程、大型草食动物管理及其栖息景观的理论具有重要意义。我们设计了一项实验，研究1999 - 2001年美国俄勒冈州蓝山地区北美麋鹿(Cervus elaphus)密度依赖性与植物对草食的反应之间的相互作用。实验设置高(20.1麋鹿/平方公里)和低(4.1麋鹿/平方公里)种群密度，并建立封地，考察草食对生产力和植物物种组成的影响。我们假设，如果草食动物优化是随着麋鹿密度的增加而发生的，那么植物产量会随着放牧强度的增加而增加，随后生产力会随着放牧强度的增加而下降(即草食动物优化)。在中等密度条件下，麋鹿的净地上初级生产力(NAPP)由无草食向草食逐渐增加，而后随着草食不断增加而下降，而在低密度条件下(干旱林和草地)则没有变化。草食优化发生在植物的所有功能类群中，包括高napp地区的禾本科植物、草本植物和灌木。木本植物与禾本科植物相比，由于其结构和生长形式的不同，草食优化可能难以检测。虽然草食动物优化之前已经在草原上报道过，但我们的研究记录了木本植物群落中的这种现象。我们假设，食草动物NAPP的这种细微变化可能比以前认为的更普遍;需要精心设计的实验来检测大型食草动物对食草的反应。植物的表观吸收遵循与NAPP相似的模式，并且在麋鹿食草的中间水平时最大，然后在NAPP接近零时下降。以氮含量为指标的植物质量也随麋鹿密度的增加呈抛物线函数关系。尽管如此，我们观察到麋鹿密度的变化并没有改变植物的物种组成和多样性，这可能是因为蓝山地区有大量的本地和家养食草动物放牧的历史，剩下的植物对食草的适应能力，以及我们研究的3年时间很短。同样，我们也没有观察到麋鹿密度的变化导致养分循环速率的增加，这可能是因为大量麋鹿尿液和粪便集中的区域(例如放牧草坪)并没有出现在这个生态系统中。草食优化可能对有蹄类动物种群动态产生影响。我们认为，其他过程，如迁徙、捕食或收获，可能是维持NAPP增加区域的必要条件，因为密度依赖性强的反馈和有蹄类动物对其食物供应的负面影响将使食草动物和它们的食物供应在我们记录的食草动物优化的低密度下无法平衡。我们还假设，在低至中等密度的草食动物种群中，NAPP的增加可能导致这些草食动物种群的快速增长，并有助于减少密度依赖性反馈，促进承载能力的超调。我们的数据不支持在西部牧场放养大量有蹄类动物以获得NAPP的峰值产量。如果目标是最大化NAPP和饲料质量，或者最大化有蹄类动物的身体状况和繁殖，我们建议在生态系统中保持低到中等的大型食草动物密度。RESUMEN El entender la optimización de la herbivoría tiene implicones en las teorías que sostienen los procesos de los ecosistemas, El manejo de los herbívoros grandes y los lugares que habitan。Diseñamos与植物间相互作用关系和密度依赖性的类比研究(美洲鹿)与植物间相互作用关系的类比研究(herbivoría en las montañas Azules de Oregón)，美国，1999年1月至2001年。试验结果表明，高原(20.1 alces/km2)和巴哈(4.1 alces/km2)土壤密度和土壤结构(áreas cercadas)对高原(herbivoría)土壤生产力的影响和高原(composición)对不同植物种类的影响。Nuestra称hipotesis秘鲁fue如果la optimizacion de herbivoria ocurria con el incremento en la densidad de los酒精度deberia haber联合国concordante incremento en la produccion de足底seguido为什么una disminucion en la produccion de acuerdo al incremento en la intensidad de forrajeo(比如,optimizacion de la herbivoria)。 我们将净地初级生产(NAPP)从非草食增加到中等觅食强度，然后在NAPP高(砍伐森林和mesica)的地区(生境)降低到中等觅食强度，但在NAPP低(干旱森林和牧场)的地区(生境)没有增加。放牧优化以前曾在牧场报道过;我们的研究记录了木本植物群落的这种现象。我们的假设是，食草动物的这些微妙的NAPP变化可能比之前认为的更常见，需要精心设计的实验来检测大型食草动物对食草动物产生的这种反应。植物表观采食量遵循类似的模式，在中间觅食强度水平较高，然后随着NAPP接近零而下降。以氮(N)百分比指数检测到的植物质量也随麋鹿密度的增加而呈抛物线函数。然而,观察变化在物种构成和多样性与我们的驼鹿,由于密度操纵源远流长的放牧食草动物的原生家庭和蓝山,抵抗herbivoría已在该地区的植物和短期研究(三岁)。同样,没有观测周期范围增加养分驼鹿由于密度的变化,也许是因为地区聚集了最多的粪便和尿液放牧地区驼鹿(例如)在该生态系统没有发生过。食草性的优化可能会对有蹄类动物的种群动态产生影响。我们认为，考虑到密集依赖的强烈反馈和大型食草动物对食物供应的负面影响，迁移、捕食或收获等其他过程可能需要维持牧场。我们还检验了我们的假设，即在低和中等人口密度下，NAPP的增加可以导致人口的快速增长，有助于减少密度依赖的反馈，并促进过度的承载能力。我们的数据不支持在西部牧区放置大量有蹄类动物以达到产量峰值。我们建议在生态系统中保持低或中等密度的大型食草动物，如果目标是最大限度地提高NAPP和饲料质量，或保持最大的生物质量和有蹄类动物的繁殖。北美麋鹿的草食优化:对理论和管理的影响摘要草食优化的理解对支持大型草食动物及其栖息地的生态系统过程和管理的理论有启示。1999年至2001年，我们在美国俄勒冈州蓝山进行了一项实验，研究了麋鹿(Cervus elaphus)的密度依赖性相互作用和植物对草食动物的反应。我们建立了高密度和低密度麋鹿种群，并建立了围栏，以研究草食对生产力和植物物种组成的影响。我们提出的假设是，如果草食优化是随着麋鹿种群密度的增加而实现的，那么植物生产力应该相应增加，然后随着放牧强度的持续增加而降低(即草食优化)。在没有草食动物的情况下，净穗初级产量(净穗初级产量)增加到中等放牧强度，然后在高穗生境(灌木或灌木)的放牧强度增加时下降。在低PPEN生境(干旱森林或草原)未观察到这种关系。在高PPEN生境中，对包括草、草本植物和灌木在内的功能植物群进行了草食优化。这种反应在木本植物(如灌木)中更难注意到，因为它们的结构和生长方式与草本植物相比。我们的数据表明，草食动物的优化并不局限于草地。 我们认为，由于食草性，PPEN的这些微妙变化比以前认为的更普遍;要发现大型食草动物对食草动物的这些反应，需要精心设计的实验。在分析外圈内和外圈外的生物量差异(“明显抵消”)时也观察到类似的反应;这在中间放牧水平最高，然后随着PPEN接近零而下降。以氮(N) %为指标的
{"title":"Herbivore Optimization by North American Elk: Consequences for Theory and Management","authors":"KELLEY M. STEWART, R. TERRY BOWYER, ROGER W. RUESS, BRIAN L. DICK, JOHN G. KIE","doi":"10.2193/0084-0173(2006)167[1:HOBNAE]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2006)167[1:HOBNAE]2.0.CO;2","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>Understanding herbivore optimization has implications for theories underpinning ecosystem processes, management of large herbivores, and the landscapes they inhabit. We designed an experiment to examine interactions related to density dependence of North American elk (<i>Cervus elaphus</i>) and resulting plant responses to herbivory in the Blue Mountains of Oregon, USA, from 1999 to 2001. We experimentally created high (20.1 elk/km<sup>2</sup>) and low (4.1 elk/km<sup>2</sup>) population densities of elk and built exclosures to examine effects of herbivory on productivity and species composition of plants. We hypothesized that if herbivore optimization occurred with increasing density of elk, there should be a concordant increase in plant production, followed by a decline in productivity as grazing intensity continued to increase (i.e., herbivore optimization). Net aboveground primary productivity (NAPP) increased from no herbivory to herbivory by elk at moderate density and then declined as herbivory by elk continued to increase in areas with high NAPP (mesic and logged forests) but not in areas with low NAPP (xeric forests and grasslands). Herbivore optimization occurred across all functional groups of plants, including graminoids, forbs, and shrubs for high-NAPP areas. Herbivore optimization may be difficult to detect in woody plants compared with graminoids because of their differing structure and growth forms. Although herbivore optimization previously has been reported in grasslands, our study documents this phenomenon in woody plant communities. We hypothesize that such subtle changes in NAPP from herbivory might be more common than previously thought; carefully designed experiments are required to detect those responses to herbivory by large herbivores. Apparent offtake of plants followed a similar pattern to NAPP and was greatest at intermediate levels of herbivory by elk, and then declined as NAPP approached zero. Quality of plants, as indexed by percent nitrogen (N), also exhibited a parabolic function with increasing density of elk. Nonetheless, we observed no changes in species composition or diversity of plants with our density manipulations of elk, probably because of the extensive history of grazing by native and domestic herbivores in the Blue Mountains, the resilience of the remaining plants to herbivory, and the short 3-year duration of our study. Likewise, we observed no increases in rates of nutrient cycling with changes in densities of elk, perhaps because areas where large amounts of elk urine and feces were concentrated (e.g., grazing lawns) did not occur in this ecosystem.</p>\u0000 \u0000 <p>Herbivore optimization could have ramifications for population dynamics of ungulates. We argue that other processes, such as migration, predation, or harvest, might be necessary to maintain areas of increased NAPP be","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2006)167[1:HOBNAE]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6207307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
LAYNE G. ADAMS, ROBERT O. STEPHENSON, BRUCE W. DALE, ROBERT T. AHGOOK, DOMINIC J. DEMMA
ABSTRACT Our understanding of wolf (Canis lupus) population dynamics in North America comes largely from studies of protected areas, at-risk populations, and wolf control programs, although most North American wolves experience moderate levels of regulated harvest. During 1986–1992, we investigated the population dynamics and harvests of wolves in the newly created Gates of the Arctic National Park and Preserve in northern Alaska, USA, where wolves were harvested by local residents. Our objectives were to determine wolf abundance, estimate important vital rates (i.e., productivity, survival, emigration), and characterize wolf harvests. We monitored 50 radiocollared wolves in 25 packs over 4 years (Apr 1987–Apr 1991) to assess patterns of dispersal, emigration, survival and mortality causes in the wolf population. We determined pack sizes, home ranges, and pups per pack in autumn (1 Oct) for instrumented wolf packs, and calculated wolf densities in autumn and spring (15 Apr) based on the number of wolves in instrumented packs and the aggregate area those packs inhabited. We also gathered information from local hunters and trappers on the timing, location, methods, and sex-age composition of wolf harvests during 6 winter harvest seasons (Aug 1987–Apr 1992).
Wolf densities averaged 6.6 wolves per 1,000 km2 and 4.5 wolves per 1,000 km2 in autumn and spring, respectively, and spring densities increased by 5% per year during our study. On average, pups constituted 50% of the resident wolf population each autumn. An estimated 12% of the population was harvested annually. Natural mortality, primarily intraspecific strife, equaled 11% per year. Young wolves emigrated from the study area at high annual rates (47% and 27% for yearlings and 2-yr-olds, respectively), and we estimated the emigration rate for the population at ≥19% annually. Yearlings and 2-year-olds were lost from the population at rates of 60% per year and 45% per year, respectively, primarily as a result of emigration; mortality was the principal cause of the 26% annual loss of wolves ≥3 years old.
On average, 47 wolves were harvested each winter from our study population, or twice the harvest we estimated from survival analyses of radiocollared wolves (23 wolves/yr). We suggest that the additional harvested wolves were transients, including local dispersers and migrants from outside the study area. Trapping harvest was well-distributed throughout the trapping season (Nov-Apr), whereas shooting harvest occurred mainly in February and March. Of 35 individuals who harvested wolves in the area, 6 accounted for 66% of the harvest.
We analyzed information from North American wolf populations and determined that annual rates of increase have an inverse, curvilinear relationship with human-caused mortality (r2 = 0.68, P < 0.001) such that population trends were not correlated with annual human take ≤29% (P
我们对北美狼(Canis lupus)种群动态的了解主要来自保护区、高危种群和狼控制计划的研究，尽管大多数北美狼经历了适度的管制收获。1986-1992年，我们在美国阿拉斯加州北部新建的北极之门国家公园和自然保护区调查了狼的种群动态和收获情况，当地居民在那里捕杀狼。我们的目标是确定狼的丰度，估计重要的生命率(即生产力、存活率、迁出率)，并描述狼的收成特征。在4年间(1987年4月- 1991年4月)，我们对25个狼群中的50只戴放射性项圈的狼进行了监测，以评估狼种群的扩散、迁移、生存和死亡原因。我们确定了秋季(10月1日)测量狼群的狼群规模、活动范围和每只狼的幼崽数量，并根据测量狼群的数量和狼群居住的总面积计算了秋季和春季(4月15日)的狼密度。在1987年8月至1992年4月的6个冬季收获季节，我们还从当地猎人和诱捕者那里收集了狼收获的时间、地点、方法和性别年龄组成的信息。狼密度在秋季和春季分别为6.6只/ 1000 km2和4.5只/ 1000 km2，春季密度以每年5%的速度增长。每年秋天，幼狼平均占到常住狼群的50%。据估计，每年有12%的犀牛被捕杀。自然死亡率，主要是种内冲突，相当于每年11%。幼狼的年迁移率很高(1岁狼和2岁狼的年迁移率分别为47%和27%)，我们估计种群的年迁移率≥19%。一岁和两岁的幼鼠分别以每年60%和45%的速度从种群中消失，主要是由于移民;死亡是3岁以上狼年损失率26%的主要原因。平均每年冬天从我们的研究种群中捕获47只狼，或者是我们从放射性项圈狼的生存分析中估计的两倍(23只狼/年)。我们认为额外的狼被捕获是短暂的，包括当地的分散者和来自研究区域以外的迁徙者。诱捕收获在整个捕集季节(11 - 4月)分布均匀，而射击收获主要发生在2月和3月。在该地区捕获狼的35个人中，有6个人占了捕获量的66%。我们分析了来自北美狼种群的信息，并确定年增长率与人类造成的死亡率呈负曲线关系(r2 = 0.68, P <0.001)，因此种群趋势与年人类摄入量≤29%无关(P = 0.614)。我们提供的证据表明，狼种群补偿人类开发≤29%，主要是通过调整扩散成分(即本地扩散、迁移和移民)，而生产力或自然死亡率的响应在抵消收成方面几乎没有作用。考虑到适度的人类活动对狼数量趋势的影响有限，以及在评估狼数量和因瞬变狼的存在而导致的收成方面的偏差，通过有管制的收成无意中减少狼数量的风险相当低。RESEMEN Nuestra称comprension秘鲁de la dinamica poblacional del lobo (Canis lupus) en Norteamerica就尤其de estudios protegidas领域,德poblaciones amenazadas y de下德控制de林狼aunque la mayoria de los林狼norteamericanos experimentan含量moderados de explotacion regulada。1986年至1992年期间，在阿拉斯加北部的国家公园和北极之门保护区进行了一项研究，研究了北极地区贫困居民的森林爆炸。Nuestros objtivos han sido determinar la abundance of lobos, estimar los parámetros vitales más importantes (productividad, supervivencia, emigración) y characterar la explotación de lobos。Hemos seguido 50 lobos radiomarcados en 25 manadas durante 4 años(1987年4月- 1991年4月)para conocer los patronones de dispersión, la emigración, la supervencia as causes de mortality idad de la población。Hemos determinado los tamaños de manada, las áreas de campeo y los cachorros/manada en otoño(10月1日)en las manadas con lobos marcados, y Hemos calculado la densidad de lobos en otoño y primavera(4月15日)consulanddo el número de lobos en las manadas controlada和la surfacie total占领了manadas。 我们还从当地猎人和诱捕者那里收集了关于6个冬季收获季节(1987年8月- 1992年4月)被杀狼的季节、地点、方法、性别组成和年龄的信息。秋季和春季的平均密度分别为6.6 / 1000平方公里和4.5 / 1000平方公里，春季密度每年增加5%。每年秋天，幼犬平均占常住人口的50%。我们估计每年有12%的人口被提取。自然死亡率，主要是种内斗争，达到每年11%。研究区域的幼狼年迁移率较高(1 - 2岁狼和2 - 3岁狼的年迁移率分别为47%和27%)，估计种群年迁移率≥19%。每年有60%和45%的1 - 2岁和2 - 3岁的狼从种群中消失，主要是由于迁移;死亡率是3岁以上狼每年损失26%的主要原因。在研究区域的开发项目中，平均每年冬天提取47只狼，这是我们通过分析放射性标记狼的存活率(23只/年)估计的数字的两倍。我们认为，剩下的被移走的狼是路人，包括当地的分散者和来自研究区域以外的移民。在整个捕集季节(11 - 4月)，捕集分布均匀，而火器捕集主要发生在2月和3月。在该地区捕获的35只狼中，有6只捕获了66%的捕获量。在分析了北美狼种群的信息后，我们确定年增长率与人为死亡率呈负曲线关系(r2 = 0.68, P <0.001)，因此当人类死亡率≤29%时，人口趋势与人类死亡率不相关(P = 0.614)。提供证据表明,当人是≤剥削率29%,狼的种群相称主要调整色散组件(即地方分散、移民和移民),而答案在自然生产力或死亡率供应量很少或没有的补偿作用。认为人类开采中度水平影响有限关于狼种群趋势和存在扭曲在种群估计和狼的存在引起的开采,旁观者缝地种群减少风险有序开发是相当低的。RÉSUMÉ诺compréhension loups (Canis人口动力的狼疮)d 'Amérique友provient grandement d 'aires清单,人口menacées ou的方案contrǒle好la plupart des loups du continent subissent des niveaux d 'exploitation modérés。从1986年到1992年，我们在阿拉斯加北部的新国家公园和北极之门保护区研究了狼的种群动态和捕猎情况，当地居民在那里捕猎狼。我们的目标是确定狼的数量，估计重要自然事件的速率(c- d)。生产力，
{"title":"Population Dynamics and Harvest Characteristics of Wolves in the Central Brooks Range, Alaska","authors":"LAYNE G. ADAMS, ROBERT O. STEPHENSON, BRUCE W. DALE, ROBERT T. AHGOOK, DOMINIC J. DEMMA","doi":"10.2193/2008-012","DOIUrl":"https://doi.org/10.2193/2008-012","url":null,"abstract":"<p><b>ABSTRACT </b> Our understanding of wolf (<i>Canis lupus</i>) population dynamics in North America comes largely from studies of protected areas, at-risk populations, and wolf control programs, although most North American wolves experience moderate levels of regulated harvest. During 1986–1992, we investigated the population dynamics and harvests of wolves in the newly created Gates of the Arctic National Park and Preserve in northern Alaska, USA, where wolves were harvested by local residents. Our objectives were to determine wolf abundance, estimate important vital rates (i.e., productivity, survival, emigration), and characterize wolf harvests. We monitored 50 radiocollared wolves in 25 packs over 4 years (Apr 1987–Apr 1991) to assess patterns of dispersal, emigration, survival and mortality causes in the wolf population. We determined pack sizes, home ranges, and pups per pack in autumn (1 Oct) for instrumented wolf packs, and calculated wolf densities in autumn and spring (15 Apr) based on the number of wolves in instrumented packs and the aggregate area those packs inhabited. We also gathered information from local hunters and trappers on the timing, location, methods, and sex-age composition of wolf harvests during 6 winter harvest seasons (Aug 1987–Apr 1992).</p><p>Wolf densities averaged 6.6 wolves per 1,000 km<sup>2</sup> and 4.5 wolves per 1,000 km<sup>2</sup> in autumn and spring, respectively, and spring densities increased by 5% per year during our study. On average, pups constituted 50% of the resident wolf population each autumn. An estimated 12% of the population was harvested annually. Natural mortality, primarily intraspecific strife, equaled 11% per year. Young wolves emigrated from the study area at high annual rates (47% and 27% for yearlings and 2-yr-olds, respectively), and we estimated the emigration rate for the population at ≥19% annually. Yearlings and 2-year-olds were lost from the population at rates of 60% per year and 45% per year, respectively, primarily as a result of emigration; mortality was the principal cause of the 26% annual loss of wolves ≥3 years old.</p><p>On average, 47 wolves were harvested each winter from our study population, or twice the harvest we estimated from survival analyses of radiocollared wolves (23 wolves/yr). We suggest that the additional harvested wolves were transients, including local dispersers and migrants from outside the study area. Trapping harvest was well-distributed throughout the trapping season (Nov-Apr), whereas shooting harvest occurred mainly in February and March. Of 35 individuals who harvested wolves in the area, 6 accounted for 66% of the harvest.</p><p>We analyzed information from North American wolf populations and determined that annual rates of increase have an inverse, curvilinear relationship with human-caused mortality (<i>r</i><sup>2</sup> = 0.68, <i>P</i> < 0.001) such that population trends were not correlated with annual human take ≤29% (<i>P</i> ","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/2008-012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6207314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-12-13DOI: 10.2193/0084-0173(2006)165[1:CSOWCI]2.0.CO;2
DAVID D. GUSTINE, KATHERINE L. PARKER, ROBERTA J. LAY, MICHAEL P. GILLINGHAM, DOUGLAS C. HEARD
ABSTRACT
The proximate role of predation in limiting caribou (Rangifer tarandus) populations is well documented, but the long-term effects of predation pressure on selection of calving areas and the subsequent impacts to calving success remain unclear. We examined the relationships among calf survival, predation risk, and vegetation characteristics among 3 calving areas and across spatial scales in the Besa-Prophet River drainage of northern British Columbia. Fifty woodland caribou (R. t. caribou) neonates were collared and monitored twice daily for the first month and once weekly during the next month of life in 2 summer field seasons (2002 and 2003). Predation risk was estimated using resource selection functions (RSFs) from Global Positioning System (GPS) locations of 15 grizzly bears (Ursus arctos) and 5 gray wolf (Canis lupus) packs. The Normalized Difference Vegetation Index (NDVI) derived from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) data were used to quantify large-scale characteristics of vegetation (indices of biomass and quality). We incorporated small- and large-scale characteristics (i.e., predation risk, vegetation, and movement of woodland caribou calves) of neonatal calving sites into logistic regression models to predict survival for the calving (25 May–14 Jun) and summer (15 Jun–31 Jul) seasons. Predation risk and vegetation characteristics were highly variable among calving areas and calving sites, and parturient woodland caribou responded to these characteristics at different scales. Minimizing gray wolf risk and selecting against areas of high vegetation biomass were important at large scales; areas with high biomass were likely associated with increased predation risk. Calving in areas high in vegetation quality was important across scales, as parturient woodland caribou took higher levels of predation risk to access areas of high vegetative change. Models using small-scale characteristics of calving sites to predict survival performed better in the calving season than in summer. Large-scale characteristics predicted survival of woodland caribou neonates better in summer than in the calving season, probably in part because of the unexpected role of wolverines (Gulo gulo) as the main predator of woodland caribou calves during calving. Gray wolves were the main cause of mortality during the summer. Movement away from calving sites corresponded to higher calf survival and appeared to be in response to increased access to forage during the peak demands of lactation and/or minimizing gray wolf risk in the summer. High variation in predation risk and vegetation attributes among calving areas and at calving sites within calving areas, with no differences in calf mortality related to that variation, illustrates the importance of behavioral plasticity as a life-history strategy fo
捕食在限制北美驯鹿种群中的近期作用已被充分记录，但捕食压力对产犊区选择的长期影响以及对产犊成功的后续影响尚不清楚。研究了不列颠哥伦比亚省北部贝萨-先知河流域3个产犊区和跨空间尺度的小牛存活率、捕食风险和植被特征之间的关系。在2002年和2003年的两个夏季野外季节，对50只林地北美驯鹿(r.t. caribou)幼崽进行了头一个月每天两次和下一个月每周一次的监测。利用全球定位系统(GPS)对15只灰熊(Ursus arctos)和5只灰狼(Canis lupus)群的定位信息，利用资源选择函数(rfs)估算了它们的捕食风险。利用Landsat Thematic Mapper (TM)和Enhanced Thematic Mapper (ETM)数据获得的归一化植被指数(NDVI)量化植被的大尺度特征(生物量指数和质量指数)。我们将小型和大型特征(即捕食风险、植被和林地驯鹿幼崽的运动)纳入到logistic回归模型中，以预测产犊季节(5月25日- 6月14日)和夏季(6月15日- 7月31日)的存活率。在不同的产犊地区和产犊地点，森林驯鹿的捕食风险和植被特征变化很大，并且在不同的尺度上对这些特征有不同的响应。在大尺度上，降低灰狼风险和选择高植被生物量区域是重要的;生物量高的地区可能与捕食风险增加有关。在植被质量高的地区产犊在各个尺度上都很重要，因为产仔的林地驯鹿冒着更高的被捕食风险进入植被变化高的地区。利用产犊地点的小规模特征来预测生存的模型在产犊季节比在夏季表现更好。大规模特征预测林地驯鹿幼崽在夏季比在产犊季节更容易存活，部分原因可能是狼獾在产犊期间作为林地驯鹿幼崽的主要捕食者而发挥了意想不到的作用。灰狼是夏季死亡的主要原因。远离产犊地的迁移与更高的小牛存活率相对应，似乎是为了在哺乳高峰期间增加获得饲料的机会和/或在夏季将灰狼的风险降到最低。在产仔区和产仔区内的产仔地点，捕食风险和植被属性的高度变化，与此变化相关的小牛死亡率没有差异，说明了行为可塑性作为林地驯鹿生活史策略的重要性。参考文献1 .关于depredación和limitación之间的因果关系的报告(Rangifertarandus) est<s:1> bibien documentado，关于影响因素的报告，关于presión和depredación之间的因果关系的报告，关于selección和áreas之间的因果关系的报告，关于后续的因果关系的报告，关于<s:2>和limitación之间的因果关系的报告，关于aún和混淆。Hemos examinado las relaciones entre la sobrevivencia de las crías, riesgo de depredación, y características de la vegetación en 3 áreas de crianza a a dises escalas espaciales en la cuenca del río del Besa-Prophet, en el norte de la Columbia Británica。2002年至2003年期间，墨西哥的农业生产活动(r.t. caribou)在墨西哥的农业生产活动(telemetría)在墨西哥的农业生产活动(día)在墨西哥的农业生产活动(2002年至2003年)。关于depredación的详细信息，关于selección回归性(RSFs)和posición全球系统(GPS)的信息，关于15只灰熊(熊)和5只灰熊(狼)的信息。El índice de vegetación de normalizadas (NDVI)衍生del Landsat专题映射器(TM)和Enhanced专题映射器(ETM)，并使用了para quantificar características a gran escala de la vegetación (índices de biomasa y calidad)。公司成立于características a pequeña y gran escala (o sea, riesgo de depredación, vegetación, y movimento de las crías de caribú de bosque)，成立于regresión logística，成立于1993年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年，成立于2002年。Las características de riesgo de depredación y vegetación fueron altamente变量enter áreas de crianza y情境de parto, y caribú de bosque parturiente respondió a estas características a escalas不同点。 减少灰狼的风险和选择高生物量区域在大尺度上是重要的;在本研究中，我们分析了不同物种的捕食风险。在整个范围内，在高植被质量的地区繁殖是很重要的，因为出生的森林驯鹿为了进入高植被变化的地区而接受了更大的捕食风险。结果表明，与夏季相比，夏季产仔地点的小尺度特征模型在繁殖季节表现更好。大型事先生存特点新生儿驯鹿木在夏天比在车站养育,可能部分是由于意想不到的角色(wolverines Gulo Gulo)的主要捕食者的幼崽驯鹿木期间养育。灰狼是夏季死亡的主要原因。在本研究中，我们观察到，在夏季，灰狼的数量增加了，而在冬季，灰狼的数量增加了，而在夏季，灰狼的数量增加了，而在冬季，灰狼的数量增加了。危险高变异性的掠夺和属性之间vegetacionales育种领域的遗址,在育种领域的出生,未分化在幼鼠死亡这种可变性,说明相关行为多样化的重要性和战略为驯鹿生活故事的森林。Survie des Nouveaux-Nés落下来des Bois dans unÉcosystè给我Plusieurs Prédate RÉSUMÉ 他答ô肥大南部prédation限制法des人口du落下来(Rangifer tarandus) est documenté好,但是他们的àlong-terme南prédation pression甄选des的空气d 'élevage et les影响subséquents pour Le succès du vêlage sont moins connus好。在不列颠哥伦比亚省北部贝萨河和先知河系统的3个不同空间尺度上，我们
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