Madelon van de Kerk, David P. Onorato, Jeffrey A. Hostetler, Benjamin M. Bolker, Madan K. Oli
<p>Abundant evidence supports the benefits accrued to the Florida panther (<i>Puma concolor coryi</i>) population via the genetic introgression project implemented in South Florida, USA, in 1995. Since then, genetic diversity has improved, the frequency of morphological and biomedical correlates of inbreeding depression have declined, and the population size has increased. Nevertheless, the panther population remains small and isolated and faces substantial challenges due to deterministic and stochastic forces. Our goals were 1) to comprehensively assess the demographics of the Florida panther population using long-term (1981–2015) field data and modeling to gauge the persistence of benefits accrued via genetic introgression and 2) to evaluate the effectiveness of various potential genetic management strategies. Translocation and introduction of female pumas (<i>Puma concolor stanleyana</i>) from Texas, USA, substantially improved genetic diversity. The average individual heterozygosity of canonical (non-introgressed) panthers was 0.386 ± 0.012 (SE); for admixed panthers, it was 0.615 ± 0.007. Survival rates were strongly age-dependent (kittens had the lowest survival rates), were positively affected by individual heterozygosity, and decreased with increasing population abundance. Overall annual kitten survival was 0.32 ± 0.09; sex did not have a clear effect on kitten survival. Annual survival of subadult and adult panthers differed by sex; regardless of age, females exhibited higher survival than males. Annual survival rates of subadult, prime adult, and old adult females were 0.97 ± 0.02, 0.86 ± 0.03, and 0.78 ± 0.09, respectively. Survival rates of subadult, prime adult, and old adult males were 0.66 ± 0.06, 0.77 ± 0.05, and 0.65 ± 0.10, respectively. For panthers of all ages, genetic ancestry strongly affected survival rate, where first filial generation (F1) admixed panthers of all ages exhibited the highest rates and canonical (mostly pre-introgression panthers and their post-introgression descendants) individuals exhibited the lowest rates. The most frequently observed causes of death of radio-collared panthers were intraspecific aggression and vehicle collision. Cause-specific mortality analyses revealed that mortality rates from vehicle collision, intraspecific aggression, other causes, and unknown causes were generally similar for males and females, although males were more likely to die from intraspecific aggression than females. The probability of reproduction and the annual number of kittens produced varied by age; evidence that ancestry or abundance influenced these parameters was weak. Predicted annual probabilities of reproduction were 0.35 ± 0.08, 0.50 ± 0.05, and 0.25 ± 0.06 for subadult, prime adult, and old adult females, respectively. The number of kittens predicted to be produced annually by subadult, prime adult, and old adult females were 2.80 ± 0.75, 2.67 ± 0.43, and 2.28 ± 0.83, respectively. The stochastic annual popul
{"title":"Dynamics, Persistence, and Genetic Management of the Endangered Florida Panther Population\u0000 Dinámicas, Persistencia y Manejo Genético de la Población en Peligro de Extinción de Pantera de Florida","authors":"Madelon van de Kerk, David P. Onorato, Jeffrey A. Hostetler, Benjamin M. Bolker, Madan K. Oli","doi":"10.1002/wmon.1041","DOIUrl":"https://doi.org/10.1002/wmon.1041","url":null,"abstract":"<p>Abundant evidence supports the benefits accrued to the Florida panther (<i>Puma concolor coryi</i>) population via the genetic introgression project implemented in South Florida, USA, in 1995. Since then, genetic diversity has improved, the frequency of morphological and biomedical correlates of inbreeding depression have declined, and the population size has increased. Nevertheless, the panther population remains small and isolated and faces substantial challenges due to deterministic and stochastic forces. Our goals were 1) to comprehensively assess the demographics of the Florida panther population using long-term (1981–2015) field data and modeling to gauge the persistence of benefits accrued via genetic introgression and 2) to evaluate the effectiveness of various potential genetic management strategies. Translocation and introduction of female pumas (<i>Puma concolor stanleyana</i>) from Texas, USA, substantially improved genetic diversity. The average individual heterozygosity of canonical (non-introgressed) panthers was 0.386 ± 0.012 (SE); for admixed panthers, it was 0.615 ± 0.007. Survival rates were strongly age-dependent (kittens had the lowest survival rates), were positively affected by individual heterozygosity, and decreased with increasing population abundance. Overall annual kitten survival was 0.32 ± 0.09; sex did not have a clear effect on kitten survival. Annual survival of subadult and adult panthers differed by sex; regardless of age, females exhibited higher survival than males. Annual survival rates of subadult, prime adult, and old adult females were 0.97 ± 0.02, 0.86 ± 0.03, and 0.78 ± 0.09, respectively. Survival rates of subadult, prime adult, and old adult males were 0.66 ± 0.06, 0.77 ± 0.05, and 0.65 ± 0.10, respectively. For panthers of all ages, genetic ancestry strongly affected survival rate, where first filial generation (F1) admixed panthers of all ages exhibited the highest rates and canonical (mostly pre-introgression panthers and their post-introgression descendants) individuals exhibited the lowest rates. The most frequently observed causes of death of radio-collared panthers were intraspecific aggression and vehicle collision. Cause-specific mortality analyses revealed that mortality rates from vehicle collision, intraspecific aggression, other causes, and unknown causes were generally similar for males and females, although males were more likely to die from intraspecific aggression than females. The probability of reproduction and the annual number of kittens produced varied by age; evidence that ancestry or abundance influenced these parameters was weak. Predicted annual probabilities of reproduction were 0.35 ± 0.08, 0.50 ± 0.05, and 0.25 ± 0.06 for subadult, prime adult, and old adult females, respectively. The number of kittens predicted to be produced annually by subadult, prime adult, and old adult females were 2.80 ± 0.75, 2.67 ± 0.43, and 2.28 ± 0.83, respectively. The stochastic annual popul","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"203 1","pages":"3-35"},"PeriodicalIF":4.4,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5775298","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}
Charles A. DeYoung, Timothy E. Fulbright, David G. Hewitt, David B. Wester, Don A. Draeger
<p>Density-dependent behavior underpins white-tailed deer (<i>Odocoileus virginianus</i>) theory and management application in North America, but strength or frequency of the phenomenon has varied across the geographic range of the species. The modifying effect of stochastic environments and poor-quality habitats on density-dependent behavior has been recognized for ungulate populations around the world, including white-tailed deer populations in South Texas, USA. Despite the importance of understanding mechanisms influencing density dependence, researchers have concentrated on demographic and morphological implications of deer density. Researchers have not focused on linking vegetation dynamics, nutrition, and deer dynamics. We conducted a series of designed experiments during 2004–2012 to determine how strongly white-tailed deer density, vegetation composition, and deer nutrition (natural and supplemented) are linked in a semi-arid environment where the coefficient of variation of annual precipitation exceeds 30%. We replicated our study on 2 sites with thornshrub vegetation in Dimmit County, Texas. During late 2003, we constructed 6 81-ha enclosures surrounded by 2.4-m-tall woven wire fence on each study site. The experimental design included 2 nutrition treatments and 3 deer densities in a factorial array, with study sites as blocks. Abundance targets for low, medium, and high deer densities in enclosures were 10 deer (equivalent to 13 deer/km<sup>2</sup>), 25 deer (31 deer/km<sup>2</sup>), and 40 deer (50 deer/km<sup>2</sup>), respectively. Each study site had 2 enclosures with each deer density. We provided deer in 1 enclosure at each density with a high-quality pelleted supplement <i>ad libitum</i>, which we termed enhanced nutrition; deer in the other enclosure at each density had access to natural nutrition from the vegetation. We conducted camera surveys of deer in each enclosure twice per year and added or removed deer as needed to approximate the target densities. We maintained >50% of deer ear-tagged for individual recognition. We maintained adult sex ratios of 1:1–1:1.5 (males:females) and a mix of young and older deer in enclosures. We used reconstruction, validated by comparison to known number of adult males, to make annual estimates of density for each enclosure in analysis of treatment effects. We explored the effect of deer density on diet composition, diet quality, and intake rate of tractable female deer released into low- and high-density enclosures with natural nutrition on both study sites (4 total enclosures) between June 2009 and May 2011, 5 years after we established density treatments in enclosures. We used the bite count technique and followed 2–3 tractable deer/enclosure during foraging bouts across 4 seasons. Proportion of shrubs, forbs, mast, cacti, and subshrubs in deer diets did not differ (<i>P</i> > 0.57) between deer density treatments. Percent grass in deer diets was higher (<i>P</i> = 0.05) at high de
{"title":"Linking White-Tailed Deer Density, Nutrition, and Vegetation in a Stochastic Environment\u0000 Relier la Densité de Cerf de Virginie, la Nutrition et la Végétation dans un Environnement Stochastique\u0000 Relación entre la Densidad de Venado Cola Blanca, la Nutrición y la Vegetación en Ambientes Variables","authors":"Charles A. DeYoung, Timothy E. Fulbright, David G. Hewitt, David B. Wester, Don A. Draeger","doi":"10.1002/wmon.1040","DOIUrl":"https://doi.org/10.1002/wmon.1040","url":null,"abstract":"<p>Density-dependent behavior underpins white-tailed deer (<i>Odocoileus virginianus</i>) theory and management application in North America, but strength or frequency of the phenomenon has varied across the geographic range of the species. The modifying effect of stochastic environments and poor-quality habitats on density-dependent behavior has been recognized for ungulate populations around the world, including white-tailed deer populations in South Texas, USA. Despite the importance of understanding mechanisms influencing density dependence, researchers have concentrated on demographic and morphological implications of deer density. Researchers have not focused on linking vegetation dynamics, nutrition, and deer dynamics. We conducted a series of designed experiments during 2004–2012 to determine how strongly white-tailed deer density, vegetation composition, and deer nutrition (natural and supplemented) are linked in a semi-arid environment where the coefficient of variation of annual precipitation exceeds 30%. We replicated our study on 2 sites with thornshrub vegetation in Dimmit County, Texas. During late 2003, we constructed 6 81-ha enclosures surrounded by 2.4-m-tall woven wire fence on each study site. The experimental design included 2 nutrition treatments and 3 deer densities in a factorial array, with study sites as blocks. Abundance targets for low, medium, and high deer densities in enclosures were 10 deer (equivalent to 13 deer/km<sup>2</sup>), 25 deer (31 deer/km<sup>2</sup>), and 40 deer (50 deer/km<sup>2</sup>), respectively. Each study site had 2 enclosures with each deer density. We provided deer in 1 enclosure at each density with a high-quality pelleted supplement <i>ad libitum</i>, which we termed enhanced nutrition; deer in the other enclosure at each density had access to natural nutrition from the vegetation. We conducted camera surveys of deer in each enclosure twice per year and added or removed deer as needed to approximate the target densities. We maintained >50% of deer ear-tagged for individual recognition. We maintained adult sex ratios of 1:1–1:1.5 (males:females) and a mix of young and older deer in enclosures. We used reconstruction, validated by comparison to known number of adult males, to make annual estimates of density for each enclosure in analysis of treatment effects. We explored the effect of deer density on diet composition, diet quality, and intake rate of tractable female deer released into low- and high-density enclosures with natural nutrition on both study sites (4 total enclosures) between June 2009 and May 2011, 5 years after we established density treatments in enclosures. We used the bite count technique and followed 2–3 tractable deer/enclosure during foraging bouts across 4 seasons. Proportion of shrubs, forbs, mast, cacti, and subshrubs in deer diets did not differ (<i>P</i> > 0.57) between deer density treatments. Percent grass in deer diets was higher (<i>P</i> = 0.05) at high de","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"202 1","pages":"1-63"},"PeriodicalIF":4.4,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5748034","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}
Bruce K. Johnson, Dewaine H. Jackson, Rachel C. Cook, Darren A. Clark, Priscilla K. Coe, John G. Cook, Spencer N. Rearden, Scott L. Findholt, James H. Noyes
<div> <section> <p>Understanding bottom-up, top-down, and abiotic factors along with interactions that may influence additive or compensatory effects of predation on ungulate population growth has become increasingly important as carnivore assemblages, land management policies, and climate variability change across western North America. Recruitment and population trends of elk (<i>Cervus canadensis</i>) have been downward in the last 4 decades across the northern Rocky Mountains and Pacific Northwest, USA. In Oregon, changes in vegetation composition and land use practices occurred, cougar (<i>Puma concolor</i>) populations recovered from near-extirpation, and black bear (<i>Ursus americanus</i>) populations increased. Our goal was to provide managers with insight into the influence of annual climatic variation, and bottom-up and top-down factors affecting recruitment of elk in Oregon. We conducted our research in southwestern (SW; Toketee and Steamboat) and northeastern (NE; Wenaha and Sled Springs) Oregon, which had similar predator assemblages but differed in patterns of juvenile recruitment, climate, cougar densities, and vegetative characteristics.</p> <p>We obtained monthly temperature and precipitation measures from Parameter-elevation Regressions on Independent Slopes Model (PRISM) and estimates of normalized difference vegetation index (NDVI) for each study area to assess effects of climate and vegetation growth on elk vital rates. To evaluate the nutritional status of elk in each study area, we captured, aged, and radio-collared adult female elk in SW (<i>n </i>= 69) in 2002–2005 and NE (<i>n </i>= 113) in 2001–2007. We repeatedly captured these elk in autumn (<i>n </i>= 232) and spring (<i>n </i>= 404) and measured ingesta-free body fat (IFBF), mass, and pregnancy and lactation status. We fitted pregnant elk with vaginal implant transmitters (VITs) in spring and captured their neonates in SW (<i>n </i>= 46) and NE (<i>n </i>= 100). We placed expandable radio-collars on these plus an additional 110 neonates in SW and 360 neonates in NE captured by hand or net-gunning <i>via</i> helicopter and estimated their age at capture, birth mass from mass at capture, and sex. We monitored their fates and documented causes of mortality until 1 year of age. We estimated density of cougars by population reconstruction of captured (<i>n </i>= 96) and unmarked cougars killed (<i>n </i>= 27) and of black bears from DNA analysis of hair collected from snares.</p> <p>We found evidence in lactating females of nutritional limitations on all 4 study areas where IFBF<sub>autumn</sub> was below 12%, a threshold above which there are few nutritional limitations (9.8% [SE = 0.64%, <i>n</i> = 17] at Toketee, 7.9% [SE = 0.78%, <i>n</i> = 17] at Steamboat, 7.3% [SE = 0.33%, <i>n</i> = 46] at Sled Springs, and 8.9% [SE = 0.51%, <i>n</i>
随着北美西部食肉动物种群、土地管理政策和气候变率的变化，了解自下而上、自上而下和非生物因素以及可能影响捕食对有蹄类种群增长的加性或补偿性效应的相互作用变得越来越重要。在美国北部落基山脉和西北太平洋地区，麋鹿(Cervus canada)的招募和种群趋势在过去40年中一直呈下降趋势。在俄勒冈州，植被组成和土地利用方式发生了变化，美洲狮(美洲狮)种群从近乎灭绝的状态中恢复过来，黑熊(美洲熊)种群增加。我们的目标是让管理者深入了解年度气候变化的影响，以及影响俄勒冈州麋鹿招募的自下而上和自上而下的因素。我们在西南(SW;托克提和汽船)和东北部(东北;俄勒冈州的韦纳哈和斯拉德斯普林斯，这两个地区有相似的捕食者组合，但在幼兽招募模式、气候、美洲狮密度和营养特征方面存在差异。利用独立坡度模型(PRISM)的参数高程回归数据和归一化植被指数(NDVI)估算了每个研究区域的月温度和降水量，以评估气候和植被生长对麋鹿生命率的影响。为了评估每个研究区麋鹿的营养状况，我们于2002-2005年在西南地区(n = 69)和2001-2007年在东北地区(n = 113)捕获成年雌性麋鹿，并对其进行老化和无线电项圈。我们在秋季(n = 232)和春季(n = 404)重复捕获了这些麋鹿，并测量了无摄食体脂(IFBF)、质量、妊娠和哺乳状态。我们在春季为怀孕的麋鹿配备阴道植入发射器(VITs)，并在西南地区(n = 46)和东北地区(n = 100)捕获了它们的幼崽。我们在这些婴儿身上放置了可扩展的无线电颈圈，另外还有另外110名西南地区的新生儿和360名东北地区的新生儿，通过手动或通过直升机进行网射捕获，并估计了捕获时的年龄、捕获时的出生质量和性别。我们监测他们的命运，并记录死亡原因，直到1岁。我们通过对捕获的(n = 96)和未标记的被杀的(n = 27)美洲狮的种群重建以及对从陷阱中收集的毛发进行DNA分析来估计美洲狮的密度。我们发现，在IFBFautumn低于12%的所有4个研究区域，哺乳期雌性都存在营养限制的证据，高于该阈值的营养限制很少(Toketee为9.8% [SE = 0.64%， n = 17]， Steamboat为7.9% [SE = 0.78%， n = 17]， Sled Springs为7.3% [SE = 0.33%， n = 46]， Wenaha为8.9% [SE = 0.51%， n = 23])。在春季，已知在前一秋季泌乳的雌性中，48% (SE = 3.3%， n = 56)有IFBFspring <2%，这表明严重的营养限制，而在前一秋季未泌乳的雌性中，这一水平为20% (SE = 1.7%， n = 91)。哺乳期雌性的IFBFspring水平较低可能是由于夏季和初秋营养不足的结转效应。我们发现东北地区夏季降水与IFBFautumn呈正相关，孕妇IFBFautumn与其翌年春季新生儿出生日期呈负相关(F1, 52 = 20.37, P < 0.001, r2 = 0.27)。Toketee (0.67, SE = 0.12, n = 15)、Wenaha (0.70, SE = 0.10, n = 23)和Sled Springs (0.87, SE = 0.05, n = 47)的哺乳期雌性平均妊娠率低于0.90，这是营养限制的阈值，但Steamboat (0.93, SE = 0.07, n = 14)没有。我们在东北冬季对麋鹿的股骨脂肪进行了采样，我们发现21只幼鹿中有3只(12%)濒临饥饿，它们全部被美洲狮杀死，12只成年麋鹿中有2只(17%)都死于非捕食事件。在西南地区和东北地区，6.5%和2%的VIT新生儿的出生质量分别为13公斤，在以前的研究中，这一质量与生存概率降低有关。sleedsprings地区VIT新生儿出生质量(= 18.3 kg, SD = 2.5, n = 59)高于Steamboat地区(= 16.3 kg, SD = 2.1, n = 21)或Toketee地区(= 16.1 kg, SD = 2.8, n = 24)，但低于Wenaha地区(= 17.1 kg, SD = 2.8, n = 36);F3, 132 = 7.63, P < 0.001)。VIT新生儿的中位和平均出生日期(5月29日)在地区之间没有差异(F1, 136 = 0.33, P = 0.56)，但NE在平均值附近的差异较大，表明分娩间隔较长。我们在研究区域和年份记录了293例幼崽死亡，其中262例死亡的直接原因是捕食，主要来自美洲狮(n = 203)，黑熊(n = 34)和其他或未知的捕食(n = 25)。我们还记录了未知死亡原因(n = 16)、人为死亡原因(n = 8)和疾病或饥饿死亡原因(n = 7)。我们记录了2例(1.4%)VIT新生儿被遗弃，4例(2.7%)VIT新生儿被捕食致死。 我们发现，亚成年雌狮和成年美洲狮的密度在不同区域之间存在4倍的差异(0.90-4.29/100 km2)，在不同年份的研究区域内存在2倍的差异，西南地区的美洲狮密度低于东北地区。在我们的研究区域，黑熊的密度从15-20/100平方公里不等。我们使用MARK计划中的已知命运模型估计了新生儿30天、16周和12个月的存活率。患有vit的女性所生新生儿的存活率与美洲狮密度、IFBFspring和女性质量有关，但与女性年龄、新生儿出生日期或出生质量无关。在春季，IFBF和质量较低的雌鱼所生的幼鱼存活率较高，这与我们的预测相反。在事后分析中，我们发现，与前一年不成功的雌性相比，成功抚养新生儿的雌性第二年更有可能成功，这可能解释了这一意想不到的发现。随着美洲狮密度的增加，已知营养状况的雌性所生的幼崽存活率下降。我们对所有捕获的新生儿按地区进行了单独的生存分析，以评估气候、自下而上(但不包括母体状况)和自上而下因素的影响。在东北地区，幼崽的存活率受年度气候变化的影响不大，但随着美洲狮密度的增加和出生日期的推迟而下降。与东北地区相比，西南地区4 - 5月降水较少，新生儿出生较晚，存活率较高，但受美洲狮密度的影响较小。在我们的4个研究区域中，前30天的生存率每年变化从0.61 (SE = 0.08)到1.00，前16周的生存率为0.41 (SE = 0.11)到0.90 (SE = 0.09)， 12个月(招募)的生存率为0.18 (SE = 0.06)到0.57 (SE = 0.11)，西南地区的生存率高于东北地区。幼鹿在30天(F1, 18 = 16.59, R2adj = 0.45, P < 0.001)、16周(F1, 18 = 21.07, R2adj = 0.51, P < 0.001)和12个月(F1, 11 = 18.94, R2adj = 0.60, P = 0.001)的存活率与美洲狮密度呈负相关。我们发现，随着美洲狮特异性死亡率的增加，幼崽存活率下降(= - 0.63,95% CI = - 0.84至- 0.42)，这表明美洲狮捕食是部分加性死亡率，因为估计的回归系数显著小于0但大于- 1。我们没有观察
{"title":"Roles of maternal condition and predation in survival of juvenile Elk in Oregon","authors":"Bruce K. Johnson, Dewaine H. Jackson, Rachel C. Cook, Darren A. Clark, Priscilla K. Coe, John G. Cook, Spencer N. Rearden, Scott L. Findholt, James H. Noyes","doi":"10.1002/wmon.1039","DOIUrl":"https://doi.org/10.1002/wmon.1039","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Understanding bottom-up, top-down, and abiotic factors along with interactions that may influence additive or compensatory effects of predation on ungulate population growth has become increasingly important as carnivore assemblages, land management policies, and climate variability change across western North America. Recruitment and population trends of elk (<i>Cervus canadensis</i>) have been downward in the last 4 decades across the northern Rocky Mountains and Pacific Northwest, USA. In Oregon, changes in vegetation composition and land use practices occurred, cougar (<i>Puma concolor</i>) populations recovered from near-extirpation, and black bear (<i>Ursus americanus</i>) populations increased. Our goal was to provide managers with insight into the influence of annual climatic variation, and bottom-up and top-down factors affecting recruitment of elk in Oregon. We conducted our research in southwestern (SW; Toketee and Steamboat) and northeastern (NE; Wenaha and Sled Springs) Oregon, which had similar predator assemblages but differed in patterns of juvenile recruitment, climate, cougar densities, and vegetative characteristics.</p>\u0000 \u0000 <p>We obtained monthly temperature and precipitation measures from Parameter-elevation Regressions on Independent Slopes Model (PRISM) and estimates of normalized difference vegetation index (NDVI) for each study area to assess effects of climate and vegetation growth on elk vital rates. To evaluate the nutritional status of elk in each study area, we captured, aged, and radio-collared adult female elk in SW (<i>n </i>= 69) in 2002–2005 and NE (<i>n </i>= 113) in 2001–2007. We repeatedly captured these elk in autumn (<i>n </i>= 232) and spring (<i>n </i>= 404) and measured ingesta-free body fat (IFBF), mass, and pregnancy and lactation status. We fitted pregnant elk with vaginal implant transmitters (VITs) in spring and captured their neonates in SW (<i>n </i>= 46) and NE (<i>n </i>= 100). We placed expandable radio-collars on these plus an additional 110 neonates in SW and 360 neonates in NE captured by hand or net-gunning <i>via</i> helicopter and estimated their age at capture, birth mass from mass at capture, and sex. We monitored their fates and documented causes of mortality until 1 year of age. We estimated density of cougars by population reconstruction of captured (<i>n </i>= 96) and unmarked cougars killed (<i>n </i>= 27) and of black bears from DNA analysis of hair collected from snares.</p>\u0000 \u0000 <p>We found evidence in lactating females of nutritional limitations on all 4 study areas where IFBF<sub>autumn</sub> was below 12%, a threshold above which there are few nutritional limitations (9.8% [SE = 0.64%, <i>n</i> = 17] at Toketee, 7.9% [SE = 0.78%, <i>n</i> = 17] at Steamboat, 7.3% [SE = 0.33%, <i>n</i> = 46] at Sled Springs, and 8.9% [SE = 0.51%, <i>n</i>","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"201 1","pages":"3-60"},"PeriodicalIF":4.4,"publicationDate":"2019-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6120076","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}
Daniel Gibson, Erik J. Blomberg, Michael T. Atamian, Shawn P. Espinosa, James S. Sedinger
<div> <section> <p>Energy development and its associated infrastructure, including power lines, may influence wildlife population dynamics through effects on survival, reproduction, and movements of individuals. These infrastructure impacts may be direct or indirect, the former occurring when development acts directly as an agent of mortality (e.g., collision) and the latter when impacts occur as a by-product of other processes that are altered by infrastructure presence. Functional or numerical responses by predators to power-line corridors are indirect impacts that may suppress demographic rates for certain species, and perceived predation risk may affect animal behaviors such as habitat selection. Greater sage-grouse (<i>Centrocercus urophasianus</i>) are a species of conservation concern across western North America that may be affected by power lines. Previous studies, however, have not provided evidence for causal mechanisms influencing demographic rates. Our primary objective was to assess the influence of power lines on multiple sage-grouse vital rates, greater sage-grouse habitat selection, and ultimately greater sage-grouse population dynamics. We used demographic and behavioral data for greater sage-grouse collected from 2003 to 2012 in central Nevada, USA, accounting for sources of underlying environmental heterogeneity. We also concurrently monitored populations of common ravens (<i>Corvus corax</i>), a primary predator of sage-grouse nests and young. We focused primarily on a single 345 kV transmission line that was constructed at the beginning of our study; however, we also determined if similar patterns were associated with other nearby, preexisting power lines. We found that numerous behaviors (e.g., nest-site selection, brood-site selection) and demographic rates (e.g., nest survival, recruitment, and population growth) were affected by power lines, and that these negative effects were predominantly explained by temporal variation in the relative abundance of common ravens. Specifically, in years of high common raven abundance, avoidance of the transmission line was extended farther from the line, re-nesting propensity was reduced, and nest survival was lower near the transmission line relative to areas more distant from the transmission line. Additionally, we found that before and immediately after construction of the transmission line, habitats near the footprint of the transmission line were generally more productive (e.g., greater reproductive success and population growth) than areas farther from the transmission line. However, multiple demographic rates (i.e., pre-fledging chick survival, annual male survival, <i>per capita</i> recruitment, and population growth) for groups of individuals that used habitats near the transmission line declined to a greater extent than for individuals using habitats more distant in the years following construction of the transmission line
{"title":"Effects of power lines on habitat use and demography of greater sage-grouse (Centrocercus urophasianus)","authors":"Daniel Gibson, Erik J. Blomberg, Michael T. Atamian, Shawn P. Espinosa, James S. Sedinger","doi":"10.1002/wmon.1034","DOIUrl":"https://doi.org/10.1002/wmon.1034","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Energy development and its associated infrastructure, including power lines, may influence wildlife population dynamics through effects on survival, reproduction, and movements of individuals. These infrastructure impacts may be direct or indirect, the former occurring when development acts directly as an agent of mortality (e.g., collision) and the latter when impacts occur as a by-product of other processes that are altered by infrastructure presence. Functional or numerical responses by predators to power-line corridors are indirect impacts that may suppress demographic rates for certain species, and perceived predation risk may affect animal behaviors such as habitat selection. Greater sage-grouse (<i>Centrocercus urophasianus</i>) are a species of conservation concern across western North America that may be affected by power lines. Previous studies, however, have not provided evidence for causal mechanisms influencing demographic rates. Our primary objective was to assess the influence of power lines on multiple sage-grouse vital rates, greater sage-grouse habitat selection, and ultimately greater sage-grouse population dynamics. We used demographic and behavioral data for greater sage-grouse collected from 2003 to 2012 in central Nevada, USA, accounting for sources of underlying environmental heterogeneity. We also concurrently monitored populations of common ravens (<i>Corvus corax</i>), a primary predator of sage-grouse nests and young. We focused primarily on a single 345 kV transmission line that was constructed at the beginning of our study; however, we also determined if similar patterns were associated with other nearby, preexisting power lines. We found that numerous behaviors (e.g., nest-site selection, brood-site selection) and demographic rates (e.g., nest survival, recruitment, and population growth) were affected by power lines, and that these negative effects were predominantly explained by temporal variation in the relative abundance of common ravens. Specifically, in years of high common raven abundance, avoidance of the transmission line was extended farther from the line, re-nesting propensity was reduced, and nest survival was lower near the transmission line relative to areas more distant from the transmission line. Additionally, we found that before and immediately after construction of the transmission line, habitats near the footprint of the transmission line were generally more productive (e.g., greater reproductive success and population growth) than areas farther from the transmission line. However, multiple demographic rates (i.e., pre-fledging chick survival, annual male survival, <i>per capita</i> recruitment, and population growth) for groups of individuals that used habitats near the transmission line declined to a greater extent than for individuals using habitats more distant in the years following construction of the transmission line","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"200 1","pages":"1-41"},"PeriodicalIF":4.4,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5770259","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}
Mary M. Rowland, Michael J. Wisdom, Ryan M. Nielson, John G. Cook, Rachel C. Cook, Bruce K. Johnson, Priscilla K. Coe, Jennifer M. Hafer, Bridgett J. Naylor, David J. Vales, Robert G. Anthony, Eric K. Cole, Chris D. Danilson, Ronald W. Davis, Frank Geyer, Scott Harris, Larry L. Irwin, Robert McCoy, Michael D. Pope, Kim Sager-Fradkin, Martin Vavra
<div> <section> <p>Studies of habitat selection and use by wildlife, especially large herbivores, are foundational for understanding their ecology and management, especially if predictors of use represent habitat requirements that can be related to demography or fitness. Many ungulate species serve societal needs as game animals or subsistence foods, and also can affect native vegetation and agricultural crops because of their large body size, diet choices, and widespread distributions. Understanding nutritional resources and habitat use of large herbivores like elk (<i>Cervus canadensis</i>) can benefit their management across different land ownerships and management regimes. Distributions of elk in much of the western United States have shifted from public to private lands, leading to reduced hunting and viewing opportunities on the former and increased crop damage and other undesired effects on the latter. These shifts may be caused by increasing human disturbance (e. g., roads and traffic) and declines of early-seral vegetation, which provides abundant forage for elk and other wildlife on public lands. Managers can benefit from tools that predict how nutritional resources, other environmental characteristics, elk productivity and performance, and elk distributions respond to management actions. We present a large-scale effort to develop regional elk nutrition and habitat-use models for summer ranges spanning 11 million ha in western Oregon and Washington, USA (hereafter Westside). We chose summer because nutritional limitations on elk condition (e. g., body fat levels) and reproduction in this season are evident across much of the western United States. Our overarching hypothesis was that elk habitat use during summer is driven by a suite of interacting covariates related to energy balance: acquisition (e g., nutritional resources, juxtaposition of cover and foraging areas), and loss (e g., proximity to open roads, topography). We predicted that female elk consistently select areas of higher summer nutrition, resulting in better animal performance in more nutritionally rich landscapes. We also predicted that factors of human disturbance, vegetation, and topography would affect elk use of landscapes and available nutrition during summer, and specifically predicted that elk would avoid open roads and areas far from cover-forage edges because of their preference for foraging sites with secure patches of cover nearby. Our work had 2 primary objectives: 1) to develop and evaluate a nutrition model that estimates regional nutritional conditions for elk on summer ranges, using predictors that reflect elk nutritional ecology; and 2) to develop a summer habitat-use model that integrates the nutrition model predictions with other covariates to estimate relative probability of use by elk, accounting for ecological processes that drive use. To meet our objectives, we used 25 previously
{"title":"Modeling Elk Nutrition and Habitat Use in Western Oregon and Washington","authors":"Mary M. Rowland, Michael J. Wisdom, Ryan M. Nielson, John G. Cook, Rachel C. Cook, Bruce K. Johnson, Priscilla K. Coe, Jennifer M. Hafer, Bridgett J. Naylor, David J. Vales, Robert G. Anthony, Eric K. Cole, Chris D. Danilson, Ronald W. Davis, Frank Geyer, Scott Harris, Larry L. Irwin, Robert McCoy, Michael D. Pope, Kim Sager-Fradkin, Martin Vavra","doi":"10.1002/wmon.1033","DOIUrl":"https://doi.org/10.1002/wmon.1033","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Studies of habitat selection and use by wildlife, especially large herbivores, are foundational for understanding their ecology and management, especially if predictors of use represent habitat requirements that can be related to demography or fitness. Many ungulate species serve societal needs as game animals or subsistence foods, and also can affect native vegetation and agricultural crops because of their large body size, diet choices, and widespread distributions. Understanding nutritional resources and habitat use of large herbivores like elk (<i>Cervus canadensis</i>) can benefit their management across different land ownerships and management regimes. Distributions of elk in much of the western United States have shifted from public to private lands, leading to reduced hunting and viewing opportunities on the former and increased crop damage and other undesired effects on the latter. These shifts may be caused by increasing human disturbance (e. g., roads and traffic) and declines of early-seral vegetation, which provides abundant forage for elk and other wildlife on public lands. Managers can benefit from tools that predict how nutritional resources, other environmental characteristics, elk productivity and performance, and elk distributions respond to management actions. We present a large-scale effort to develop regional elk nutrition and habitat-use models for summer ranges spanning 11 million ha in western Oregon and Washington, USA (hereafter Westside). We chose summer because nutritional limitations on elk condition (e. g., body fat levels) and reproduction in this season are evident across much of the western United States. Our overarching hypothesis was that elk habitat use during summer is driven by a suite of interacting covariates related to energy balance: acquisition (e g., nutritional resources, juxtaposition of cover and foraging areas), and loss (e g., proximity to open roads, topography). We predicted that female elk consistently select areas of higher summer nutrition, resulting in better animal performance in more nutritionally rich landscapes. We also predicted that factors of human disturbance, vegetation, and topography would affect elk use of landscapes and available nutrition during summer, and specifically predicted that elk would avoid open roads and areas far from cover-forage edges because of their preference for foraging sites with secure patches of cover nearby. Our work had 2 primary objectives: 1) to develop and evaluate a nutrition model that estimates regional nutritional conditions for elk on summer ranges, using predictors that reflect elk nutritional ecology; and 2) to develop a summer habitat-use model that integrates the nutrition model predictions with other covariates to estimate relative probability of use by elk, accounting for ecological processes that drive use. To meet our objectives, we used 25 previously ","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"199 1","pages":"1-69"},"PeriodicalIF":4.4,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6010862","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：