<div> <section> <p>The piping plover (<i>Charadrius melodus</i>) was listed under the United States Endangered Species Act (ESA) because of habitat loss and excessive predation. The Missouri River provides important habitat for the Great Plains population of the species, some of which nest and forage on river sandbars deposited naturally during high river flows. The United States Army Corps of Engineers (USACE) operates a series of dams on the river that affect water level and the size, number, distribution, and vegetative cover of these sandbars. As a federal agency, USACE is required by the ESA to have a program to conserve the piping plover, and is prohibited from engaging in activities that jeopardize the plover's continued existence. Pursuant to these obligations, the USACE implemented a habitat creation program on the Gavins Point Reach (GVP) and Lewis and Clark Lake (LCL) on the Missouri River from 2004 to 2011. This habitat creation provided an opportunity to study the piping plover's demographic response to several habitat types, and in particular to habitat creation. The goal of this study was to assess the effects of management on plovers using the Missouri River. We studied the changes in engineered and natural habitats, and compared the effects of newly engineered habitat versus naturally created habitat on plover demography during 2005–2011. To this end, we estimated changes in nesting habitat (open or sparsely vegetated dry sand) and examined the factors affecting nest success, chick survival from hatching to fledging, survival, and movement (between and among engineered and natural sandbars) of hatch-year and adult birds, fidelity of plovers to the study area, and immigration of plovers into engineered habitat. We used demographic estimates to determine overall and habitat-specific reproductive output and overall population growth rate. Under the assumption that plovers are habitat limited on the Missouri River, we predicted that they would respond positively to the creation of engineered habitat, that their demographic rates would be higher at those sites than on older, natural sandbars, and that over time, the rates would resemble those on older, natural habitats. Engineered sandbars had proportionally more plover nesting habitat than natural sandbars, but the proportion of nesting habitat decreased through vegetation encroachment and erosion as the sandbars aged. Adult and hatch-year plovers immigrated to engineered sandbars, but immigration slowed as nesting density increased. Nesting density on engineered sandbars increased soon after sandbar construction, peaked 2–3 years later, and then declined to levels similar to those on older, natural sandbars. Birds that nested on engineered sandbars had higher nest success, and those nesting on LCL had higher chick survival than those that nested on GVP sandbars. Adult survival did not differ between engineered or natural habitat,
{"title":"Demographic responses of piping plovers to habitat creation on the Missouri river\u0000 Respuestas Demográficas del Frailecillo Silbador a la Creación de Hábitat en el Río Missouri\u0000 Réactions Démographiques des Pluvieurs Siffleurs à la Création d'Habitat sur la Rivière Missouri","authors":"Daniel H. Catlin, James D. Fraser, Joy H. Felio","doi":"10.1002/wmon.1016","DOIUrl":"https://doi.org/10.1002/wmon.1016","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The piping plover (<i>Charadrius melodus</i>) was listed under the United States Endangered Species Act (ESA) because of habitat loss and excessive predation. The Missouri River provides important habitat for the Great Plains population of the species, some of which nest and forage on river sandbars deposited naturally during high river flows. The United States Army Corps of Engineers (USACE) operates a series of dams on the river that affect water level and the size, number, distribution, and vegetative cover of these sandbars. As a federal agency, USACE is required by the ESA to have a program to conserve the piping plover, and is prohibited from engaging in activities that jeopardize the plover's continued existence. Pursuant to these obligations, the USACE implemented a habitat creation program on the Gavins Point Reach (GVP) and Lewis and Clark Lake (LCL) on the Missouri River from 2004 to 2011. This habitat creation provided an opportunity to study the piping plover's demographic response to several habitat types, and in particular to habitat creation. The goal of this study was to assess the effects of management on plovers using the Missouri River. We studied the changes in engineered and natural habitats, and compared the effects of newly engineered habitat versus naturally created habitat on plover demography during 2005–2011. To this end, we estimated changes in nesting habitat (open or sparsely vegetated dry sand) and examined the factors affecting nest success, chick survival from hatching to fledging, survival, and movement (between and among engineered and natural sandbars) of hatch-year and adult birds, fidelity of plovers to the study area, and immigration of plovers into engineered habitat. We used demographic estimates to determine overall and habitat-specific reproductive output and overall population growth rate. Under the assumption that plovers are habitat limited on the Missouri River, we predicted that they would respond positively to the creation of engineered habitat, that their demographic rates would be higher at those sites than on older, natural sandbars, and that over time, the rates would resemble those on older, natural habitats. Engineered sandbars had proportionally more plover nesting habitat than natural sandbars, but the proportion of nesting habitat decreased through vegetation encroachment and erosion as the sandbars aged. Adult and hatch-year plovers immigrated to engineered sandbars, but immigration slowed as nesting density increased. Nesting density on engineered sandbars increased soon after sandbar construction, peaked 2–3 years later, and then declined to levels similar to those on older, natural sandbars. Birds that nested on engineered sandbars had higher nest success, and those nesting on LCL had higher chick survival than those that nested on GVP sandbars. Adult survival did not differ between engineered or natural habitat,","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"192 1","pages":"1-42"},"PeriodicalIF":4.4,"publicationDate":"2015-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5909306","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}
Damon B. Lesmeister, Clayton K. Nielsen, Eric M. Schauber, Eric C. Hellgren
<div> <section> <p>Carnivore guilds play a vital role in ecological communities by cascading trophic effects, energy and nutrient transfer, and stabilizing or destabilizing food webs. Consequently, the structure of carnivore guilds can be critical to ecosystem patterns. Body size is a crucial influence on intraguild interactions, because it affects access to prey resources, effectiveness in scramble competition, and vulnerability to intraguild predation. Coyotes (<i>Canis latrans</i>), bobcats (<i>Lynx rufus</i>), gray foxes (<i>Urocyon cinereoargenteus</i>), raccoons (<i>Procyon lotor</i>), red foxes (<i>Vulpes vulpes</i>), and striped skunks (<i>Mephitis mephitis</i>) occur sympatrically throughout much of North America and overlap in resource use, indicating potential for interspecific interactions. Although much is known about the autecology of the individual species separately, little is known about factors that facilitate coexistence and how interactions within this guild influence distribution, habitat use, and temporal activity of the smaller carnivores. To assess how habitat autecology and interspecific interactions affect the structure of this widespread carnivore guild, we conducted a large-scale, non-invasive carnivore survey using an occupancy modeling framework. We deployed remote cameras during 3-week surveys to detect carnivores at 1,118 camera locations in 357 2.6-km<sup>2</sup> sections (3–4 cameras/section composing a cluster) in the 16 southernmost counties of Illinois (16,058 km<sup>2</sup>) during January–April, 2008–2010. We characterized microhabitat at each camera location and landscape-level habitat features for each camera cluster. In a multistage approach, we used information-theoretic methods to evaluate competing models for detection, species-specific habitat occupancy, multispecies co-occupancy, and multiseason (colonization and extinction) occupancy dynamics. We developed occupancy models for each species to represent hypothesized effects of anthropogenic features, prey availability, landscape complexity, and vegetative land cover. We quantified temporal activity patterns of each carnivore species based on their frequency of appearance in photographs. Further, we assessed whether smaller carnivores shifted their diel activity patterns in response to the presence of potential competitors. Of the 102,711 photographs of endothermic animals, we recorded photographs of bobcats (<i>n</i> = 412 photographs), coyotes (<i>n</i> = 1,397), gray foxes (<i>n</i> = 546), raccoons (<i>n</i> = 40,029), red foxes (<i>n</i> = 149), and striped skunks (<i>n</i> = 2,467). Bobcats were active primarily during crepuscular periods, and their activity was reduced with precipitation and higher temperatures. The probability of detecting bobcats decreased after a bobcat photograph was recorded, suggesting avoidance of remote cameras after the first encounter. Across southern Illinois, bob
{"title":"Spatial and temporal structure of a mesocarnivore guild in midwestern north America\u0000 Estructura Espacial y Temporal de un Gremio Mesocarnívoro en el medio oeste de América del Norte\u0000 Structure Spatio-Temporelle d'une Guilde de Mésocarnivores dans le Midwest Nord Américain","authors":"Damon B. Lesmeister, Clayton K. Nielsen, Eric M. Schauber, Eric C. Hellgren","doi":"10.1002/wmon.1015","DOIUrl":"https://doi.org/10.1002/wmon.1015","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Carnivore guilds play a vital role in ecological communities by cascading trophic effects, energy and nutrient transfer, and stabilizing or destabilizing food webs. Consequently, the structure of carnivore guilds can be critical to ecosystem patterns. Body size is a crucial influence on intraguild interactions, because it affects access to prey resources, effectiveness in scramble competition, and vulnerability to intraguild predation. Coyotes (<i>Canis latrans</i>), bobcats (<i>Lynx rufus</i>), gray foxes (<i>Urocyon cinereoargenteus</i>), raccoons (<i>Procyon lotor</i>), red foxes (<i>Vulpes vulpes</i>), and striped skunks (<i>Mephitis mephitis</i>) occur sympatrically throughout much of North America and overlap in resource use, indicating potential for interspecific interactions. Although much is known about the autecology of the individual species separately, little is known about factors that facilitate coexistence and how interactions within this guild influence distribution, habitat use, and temporal activity of the smaller carnivores. To assess how habitat autecology and interspecific interactions affect the structure of this widespread carnivore guild, we conducted a large-scale, non-invasive carnivore survey using an occupancy modeling framework. We deployed remote cameras during 3-week surveys to detect carnivores at 1,118 camera locations in 357 2.6-km<sup>2</sup> sections (3–4 cameras/section composing a cluster) in the 16 southernmost counties of Illinois (16,058 km<sup>2</sup>) during January–April, 2008–2010. We characterized microhabitat at each camera location and landscape-level habitat features for each camera cluster. In a multistage approach, we used information-theoretic methods to evaluate competing models for detection, species-specific habitat occupancy, multispecies co-occupancy, and multiseason (colonization and extinction) occupancy dynamics. We developed occupancy models for each species to represent hypothesized effects of anthropogenic features, prey availability, landscape complexity, and vegetative land cover. We quantified temporal activity patterns of each carnivore species based on their frequency of appearance in photographs. Further, we assessed whether smaller carnivores shifted their diel activity patterns in response to the presence of potential competitors. Of the 102,711 photographs of endothermic animals, we recorded photographs of bobcats (<i>n</i> = 412 photographs), coyotes (<i>n</i> = 1,397), gray foxes (<i>n</i> = 546), raccoons (<i>n</i> = 40,029), red foxes (<i>n</i> = 149), and striped skunks (<i>n</i> = 2,467). Bobcats were active primarily during crepuscular periods, and their activity was reduced with precipitation and higher temperatures. The probability of detecting bobcats decreased after a bobcat photograph was recorded, suggesting avoidance of remote cameras after the first encounter. Across southern Illinois, bob","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"191 1","pages":"1-61"},"PeriodicalIF":4.4,"publicationDate":"2015-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5842155","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}
Bradley C. Fedy, Kevin E. Doherty, Cameron L. Aldridge, Micheal O'Donnell, Jeffrey L. Beck, Bryan Bedrosian, David Gummer, Matthew J. Holloran, Gregory D. Johnson, Nicholas W. Kaczor, Christopher P. Kirol, Cheryl A. Mandich, David Marshall, Gwyn Mckee, Chad Olson, Aaron C. Pratt, Christopher C. Swanson, Brett L. Walker
<div> <section> <p>Animal habitat selection is an important and expansive area of research in ecology. In particular, the study of habitat selection is critical in habitat prioritization efforts for species of conservation concern. Landscape planning for species is happening at ever-increasing extents because of the appreciation for the role of landscape-scale patterns in species persistence coupled to improved datasets for species and habitats, and the expanding and intensifying footprint of human land uses on the landscape. We present a large-scale collaborative effort to develop habitat selection models across large landscapes and multiple seasons for prioritizing habitat for a species of conservation concern. Greater sage-grouse (<i>Centrocercus urophasianus</i>, hereafter sage-grouse) occur in western semi-arid landscapes in North America. Range-wide population declines of this species have been documented, and it is currently considered as “warranted but precluded” from listing under the United States Endangered Species Act. Wyoming is predicted to remain a stronghold for sage-grouse populations and contains approximately 37% of remaining birds. We compiled location data from 14 unique radiotelemetry studies (data collected 1994–2010) and habitat data from high-quality, biologically relevant, geographic information system (GIS) layers across Wyoming. We developed habitat selection models for greater sage-grouse across Wyoming for 3 distinct life stages: 1) nesting, 2) summer, and 3) winter. We developed patch and landscape models across 4 extents, producing statewide and regional (southwest, central, northeast) models for Wyoming. Habitat selection varied among regions and seasons, yet preferred habitat attributes generally matched the extensive literature on sage-grouse seasonal habitat requirements. Across seasons and regions, birds preferred areas with greater percentage sagebrush cover and avoided paved roads, agriculture, and forested areas. Birds consistently preferred areas with higher precipitation in the summer and avoided rugged terrain in the winter. Selection for sagebrush cover varied regionally with stronger selection in the Northeast region, likely because of limited availability, whereas avoidance of paved roads was fairly consistent across regions. We chose resource selection function (RSF) thresholds for each model set (seasonal × regional combination) that delineated important seasonal habitats for sage-grouse. Each model set showed good validation and discriminatory capabilities within study-site boundaries. We applied the nesting-season models to a novel area not included in model development. The percentage of independent nest locations that fell directly within identified important habitat was not overly impressive in the novel area (49%); however, including a 500-m buffer around important habitat captured 98% of independent nest locations within the novel area. We
{"title":"Habitat prioritization across large landscapes, multiple seasons, and novel areas: An example using greater sage-grouse in Wyoming\u0000 Priorización del Hábitat a través de Paisajes Extensos, Estaciones Múltiples, y Áreas Nuevas: Un Ejemplo Usando al Urogallo Mayor en Wyoming\u0000 Habitat Priorités au sein de Vastes Paysages, Plusieurs Saisons, et les Aires de Nouveaux: Un Exemple d'utilisation du Tétras des Armoises dans le Wyoming","authors":"Bradley C. Fedy, Kevin E. Doherty, Cameron L. Aldridge, Micheal O'Donnell, Jeffrey L. Beck, Bryan Bedrosian, David Gummer, Matthew J. Holloran, Gregory D. Johnson, Nicholas W. Kaczor, Christopher P. Kirol, Cheryl A. Mandich, David Marshall, Gwyn Mckee, Chad Olson, Aaron C. Pratt, Christopher C. Swanson, Brett L. Walker","doi":"10.1002/wmon.1014","DOIUrl":"https://doi.org/10.1002/wmon.1014","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Animal habitat selection is an important and expansive area of research in ecology. In particular, the study of habitat selection is critical in habitat prioritization efforts for species of conservation concern. Landscape planning for species is happening at ever-increasing extents because of the appreciation for the role of landscape-scale patterns in species persistence coupled to improved datasets for species and habitats, and the expanding and intensifying footprint of human land uses on the landscape. We present a large-scale collaborative effort to develop habitat selection models across large landscapes and multiple seasons for prioritizing habitat for a species of conservation concern. Greater sage-grouse (<i>Centrocercus urophasianus</i>, hereafter sage-grouse) occur in western semi-arid landscapes in North America. Range-wide population declines of this species have been documented, and it is currently considered as “warranted but precluded” from listing under the United States Endangered Species Act. Wyoming is predicted to remain a stronghold for sage-grouse populations and contains approximately 37% of remaining birds. We compiled location data from 14 unique radiotelemetry studies (data collected 1994–2010) and habitat data from high-quality, biologically relevant, geographic information system (GIS) layers across Wyoming. We developed habitat selection models for greater sage-grouse across Wyoming for 3 distinct life stages: 1) nesting, 2) summer, and 3) winter. We developed patch and landscape models across 4 extents, producing statewide and regional (southwest, central, northeast) models for Wyoming. Habitat selection varied among regions and seasons, yet preferred habitat attributes generally matched the extensive literature on sage-grouse seasonal habitat requirements. Across seasons and regions, birds preferred areas with greater percentage sagebrush cover and avoided paved roads, agriculture, and forested areas. Birds consistently preferred areas with higher precipitation in the summer and avoided rugged terrain in the winter. Selection for sagebrush cover varied regionally with stronger selection in the Northeast region, likely because of limited availability, whereas avoidance of paved roads was fairly consistent across regions. We chose resource selection function (RSF) thresholds for each model set (seasonal × regional combination) that delineated important seasonal habitats for sage-grouse. Each model set showed good validation and discriminatory capabilities within study-site boundaries. We applied the nesting-season models to a novel area not included in model development. The percentage of independent nest locations that fell directly within identified important habitat was not overly impressive in the novel area (49%); however, including a 500-m buffer around important habitat captured 98% of independent nest locations within the novel area. We","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"190 1","pages":"1-39"},"PeriodicalIF":4.4,"publicationDate":"2014-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5782536","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}
Gary L. Krapu, David A. Brandt, Paul J. Kinzel, Aaron T. Pearse
<div> <section> <p>We conducted a 10-year study (1998–2007) of the Mid-Continent Population (MCP) of sandhill cranes (<i>Grus canadensis</i>) to identify spring-migration corridors, locations of major stopovers, and migration chronology by crane breeding affiliation (western Alaska–Siberia [WA–S], northern Canada–Nunavut [NC–N], west-central Canada–Alaska [WC–A], and east-central Canada–Minnesota [EC–M]). In the Central Platte River Valley (CPRV) of Nebraska, we evaluated factors influencing staging chronology, food habits, fat storage, and habitat use of sandhill cranes. We compared our findings to results from the Platte River Ecology Study conducted during 1978–1980. We determined spring migration corridors used by the breeding affiliations (designated subpopulations for management purposes) by monitoring 169 cranes marked with platform transmitter terminals (PTTs). We also marked and monitored 456 cranes in the CPRV with very high frequency (VHF) transmitters to evaluate length and pattern of stay, habitat use, and movements. An estimated 42% and 58% of cranes staging in the CPRV were greater sandhill cranes (<i>G. c. tabida</i>) and lesser sandhill cranes (<i>G. c. canadensis</i>), and they stayed for an average of 20 and 25 days (2000–2007), respectively. Cranes from the WA–S, NC–N, WC–A, and EC–M affiliations spent an average of 72, 77, 52, and 53 days, respectively, in spring migration of which 28, 23, 24, and 18 days occurred in the CPRV. The majority of the WA–S subpopulation settled in the CPRV apparently because of inadequate habitat to support more birds upstream, although WA–S cranes accounted for >90% of birds staging in the North Platte River Valley. Crane staging duration in the CPRV was negatively correlated with arrival dates; 92% of cranes stayed >7 days. A program of annual mechanical removal of mature stands of woody growth and seedlings that began in the early 1980s primarily in the main channel of the Platte River has allowed distribution of crane roosts to remain relatively stable over the past 2 decades. Most cranes returned to nocturnal roost sites used in previous years. Corn residues dominated the diet of sandhill cranes in the CPRV, as in the 1970s, despite a marked decline in standing crop of corn residues. Only 14% (10 of 74) of PTT-marked migrant cranes stayed at stopovers for ≥5 days before arriving in the CPRV, which limited the contribution of sites south of the CPRV for fat accumulation needed for migration and reproduction. Body masses of cranes (after adjusting for body size [an index of fat]) at arrival in the CPRV varied widely among years (1998–2006), indicating the importance of maintaining productive habitats on the wintering grounds to condition cranes for migration and reproduction. Average rates of fat gain by adult females while in the CPRV remained similar from 1978–1979 to 1998–1999 but declined among males. Distances cranes flew to feedi
本研究对加拿大中部大陆沙丘鹤(Grus canadensis)进行了为期10年(1998-2007)的研究，通过鹤的繁殖关系(阿拉斯加西部-西伯利亚[WA-S]、加拿大北部-努纳武特[NC-N]、加拿大中西部-阿拉斯加[WC-A]和加拿大中东部-明尼苏达州[EC-M])确定了春季迁徙通道、主要中途停留地点和迁徙年代史。在内布拉斯加州的中央普拉特河谷(CPRV)，我们评估了沙丘鹤的分期年代学、食物习惯、脂肪储存和栖息地利用的影响因素。我们将我们的发现与1978-1980年间进行的普拉特河生态研究的结果进行了比较。我们通过监测169只带有平台发射终端(PTTs)的鹤，确定了繁殖团体使用的春季迁徙通道(为管理目的而指定的亚种群)。我们还用甚高频(VHF)发射机对CPRV中的456只起重机进行了标记和监测，以评估其停留的时间和模式、栖息地使用和运动。在CPRV中，估计42%和58%的鹤是大沙丘鹤(G. c. tabida)和小沙丘鹤(G. c. canadensis)，它们的平均停留时间分别为20天和25天(2000-2007年)。WA-S、NC-N、WC-A和EC-M群鹤的春季迁徙平均时间分别为72、77、52和53天，其中CPRV群鹤的春季迁徙平均时间为28、23、24和18天。尽管WA-S鹤在北普拉特河谷占鸟类总数的90%，但大部分WA-S亚群在CPRV定居显然是因为栖息地不足，无法支持更多的上游鸟类。在CPRV中，鹤的分期时间与到达时间呈负相关;92%的起重机停留7天。从20世纪80年代初开始，主要在普拉特河主河道开展了一项每年机械清除成熟林木和幼苗的计划，使鹤的栖息地分布在过去的20年里保持相对稳定。大多数鹤回到前几年的夜间栖息地点。与20世纪70年代一样，玉米残留物在CPRV中主导了沙丘鹤的饮食，尽管玉米残留物的直立作物显著减少。只有14%(74只中的10只)的ptt标记的迁徙鹤在到达CPRV之前停留≥5天，这限制了CPRV以南的站点对迁徙和繁殖所需脂肪积累的贡献。1998-2006年，到达CPRV的鹤的体重(在调整体型[脂肪指数]后)在不同年份之间变化很大，这表明在越冬地维持生产栖息地对鹤的迁徙和繁殖有重要意义。从1978-1979年到1998-1999年，CPRV中成年女性的平均增脂率保持相似，但男性的增脂率有所下降。在CPRV中，随着种植大豆的农田比例的增加和夜间栖息的鹤的密度的增加，鹤飞到取食地的距离增加。这些结果表明，随着景观中对鹤的价值有限或没有价值的栖息地的增加，更多的飞行时间和更高的维护成本可能会减少脂肪储存。据估计，每天有40%的使用发生在80号州际公路(I-80)以北，那里有不到5%的土地专门用于起重机保护。74%和40%的ptt标记的EC-M和WC-A起重机进行春季迁徙，包括在南达科他州东部平均分别停留11天和10天。NC-N、WA-S和WC-A亚群的鹤在萨斯喀彻温省中部和西部/阿尔伯塔省东部的平均生存期分别为25、17和12天。在离开内布拉斯加州后，这些群体中的雌性分别增加了450克、451克和452克的脂肪储备，强调了这些暂存区在为3个亚种群的繁殖做准备方面的关键作用。离开内布拉斯加州后，MCP鹤主要栖息在盆地湿地。这些湿地大多为私人所有，缺乏足够的保护，强调需要有效的法律和政策来确保它们得到长期保护。目前的管理目标是将MCP维持在目前的规模，并在北美大陆中部和西部的广大地区提供多样化的娱乐机会，这一目标的持续成功取决于MCP起重机在繁殖前继续在CPRV中储存大量脂肪的能力。为了使CPRV保持一个关键的脂肪储存地点，可能需要继续进行积极的通道维护(例如，清除木本植被)，同时建立最小流量。这些行动将有助于确保夜间栖息的栖息地保持足够分散，为鹤提供每日摄入的高能量食物，以储存主要脂肪，并限制风暴和疾病造成的高死亡率。2014年出版。这篇文章是关于美国的 政府工作，在美国属于公有领域。
{"title":"Spring migration ecology of the mid-continent sandhill crane population with an emphasis on use of the Central Platte River Valley, Nebraska\u0000 Ecologia de la Migracion de Primavera de la Poblacion Centro-Continental de la Grulla Canadiense con Enfasis en el Uso del Valle del Central Platte River en Nebraska\u0000 Écologie de la Migration Printaninière de la Population Mi-Continentale des Grues du Canada avec un Accent sur L'utilisation de la Vallée Centrale de la Rivière Platte, Nebraska\u0000 Экология Весенней Миграции Средне-Континентальной Популяции Канадского Журавля с Акцентом на Транзитной Остановке в Центральной Долине Реки Платт в Небраске","authors":"Gary L. Krapu, David A. Brandt, Paul J. Kinzel, Aaron T. Pearse","doi":"10.1002/wmon.1013","DOIUrl":"https://doi.org/10.1002/wmon.1013","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>We conducted a 10-year study (1998–2007) of the Mid-Continent Population (MCP) of sandhill cranes (<i>Grus canadensis</i>) to identify spring-migration corridors, locations of major stopovers, and migration chronology by crane breeding affiliation (western Alaska–Siberia [WA–S], northern Canada–Nunavut [NC–N], west-central Canada–Alaska [WC–A], and east-central Canada–Minnesota [EC–M]). In the Central Platte River Valley (CPRV) of Nebraska, we evaluated factors influencing staging chronology, food habits, fat storage, and habitat use of sandhill cranes. We compared our findings to results from the Platte River Ecology Study conducted during 1978–1980. We determined spring migration corridors used by the breeding affiliations (designated subpopulations for management purposes) by monitoring 169 cranes marked with platform transmitter terminals (PTTs). We also marked and monitored 456 cranes in the CPRV with very high frequency (VHF) transmitters to evaluate length and pattern of stay, habitat use, and movements. An estimated 42% and 58% of cranes staging in the CPRV were greater sandhill cranes (<i>G. c. tabida</i>) and lesser sandhill cranes (<i>G. c. canadensis</i>), and they stayed for an average of 20 and 25 days (2000–2007), respectively. Cranes from the WA–S, NC–N, WC–A, and EC–M affiliations spent an average of 72, 77, 52, and 53 days, respectively, in spring migration of which 28, 23, 24, and 18 days occurred in the CPRV. The majority of the WA–S subpopulation settled in the CPRV apparently because of inadequate habitat to support more birds upstream, although WA–S cranes accounted for >90% of birds staging in the North Platte River Valley. Crane staging duration in the CPRV was negatively correlated with arrival dates; 92% of cranes stayed >7 days. A program of annual mechanical removal of mature stands of woody growth and seedlings that began in the early 1980s primarily in the main channel of the Platte River has allowed distribution of crane roosts to remain relatively stable over the past 2 decades. Most cranes returned to nocturnal roost sites used in previous years. Corn residues dominated the diet of sandhill cranes in the CPRV, as in the 1970s, despite a marked decline in standing crop of corn residues. Only 14% (10 of 74) of PTT-marked migrant cranes stayed at stopovers for ≥5 days before arriving in the CPRV, which limited the contribution of sites south of the CPRV for fat accumulation needed for migration and reproduction. Body masses of cranes (after adjusting for body size [an index of fat]) at arrival in the CPRV varied widely among years (1998–2006), indicating the importance of maintaining productive habitats on the wintering grounds to condition cranes for migration and reproduction. Average rates of fat gain by adult females while in the CPRV remained similar from 1978–1979 to 1998–1999 but declined among males. Distances cranes flew to feedi","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"189 1","pages":"1-41"},"PeriodicalIF":4.4,"publicationDate":"2014-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6235137","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}
David W. Howerter, Michael G. Anderson, James H. Devries, Brian L. Joynt, Llwellyn M. Armstrong, Robert B. Emery, Todd W. Arnold
<div> <section> <p>The Prairie Habitat Joint Venture (PHJV) delivers conservation programs for the Canadian portion of the Prairie Pothole Region under the North American Waterfowl Management Plan. The PHJV Assessment was designed to evaluate biological assumptions and effectiveness of PHJV conservation activities. Our objectives were to 1) test whether waterfowl reproductive success increased in response to the full suite of PHJV habitat treatments, and 2) quantify the relationships between mallard (<i>Anas platyrhynchos</i>) vital rates and landscape variables. We focused on examining the association of mallard vital rates with covariates measured at the study-area scale. We collected information on vital rates from 3,214 radio-marked female mallards at 27 study areas mainly throughout the Aspen Parkland ecoregion of Manitoba, Saskatchewan, and Alberta in 1993–2000. We used a modeling framework and information-theoretic techniques to test hypotheses about putative effects of environmental covariates on adult female and duckling survival, nesting effort, and nest survival. Additionally, we constructed a stage-based matrix projection model of mallard population growth (<i>λ</i>) to estimate the sensitivities of population growth rates to variation in vital rates. Nest survival was positively related to the amount of herbaceous vegetation on study areas and total precipitation for the 12 months prior to nesting. Nesting effort was positively related to wetland inundation in July. Duckling survival was positively related to the proportion of seasonal wetlands holding water in July and negatively related to the number of days in June and July when the minimum air temperature dropped below 10° C. Adult female survival rate was positively related to both the proportions of grassland and wetland habitats measured at the study-area scale (65 km<sup>2</sup>), though these factors interacted such that the positive relationship with proportion of wetlands was strongest on study sites with high proportions of grassland. The stage-based projection model constructed using mean vital rates indicated that populations were declining (mean <i>λ</i> = 0.95, median <i>λ</i> = 0.98, 5th percentile = 0.68, 95th percentile = 1.38). Variance-stabilized sensitivities indicated that population growth was most responsive to variation in vital rates for after-second-year birds and that nest survival was the single vital rate to which populations were most sensitive. A prospective simulation revealed that, as expected, sensitivity to nest survival is likely to decrease at higher levels of nest survival. Despite evidence that nest survival was higher in PHJV habitat treatments than surrounding habitats, our a priori PHJV treatment index was unrelated to mallard vital rates estimated at the 65-km<sup>2</sup> scale. Although mallard populations were affected by several weather variables and land uses, efforts to increase po
{"title":"Variation in mallard vital rates in Canadian Aspen Parklands: The Prairie Habitat Joint Venture assessment\u0000 Variación en las estadísticas vitales del Ánade real en las zonas verdes de Aspen en Canadá: Evaluación del Proyecto Conjunto Hábitat de la Pradera\u0000 Variation des indices vitaux du Canard colvert dans les Forêts-Parcs à trembles Canadiennes: Évaluation du plan Conjoint des Habitats des Prairies","authors":"David W. Howerter, Michael G. Anderson, James H. Devries, Brian L. Joynt, Llwellyn M. Armstrong, Robert B. Emery, Todd W. Arnold","doi":"10.1002/wmon.1012","DOIUrl":"https://doi.org/10.1002/wmon.1012","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The Prairie Habitat Joint Venture (PHJV) delivers conservation programs for the Canadian portion of the Prairie Pothole Region under the North American Waterfowl Management Plan. The PHJV Assessment was designed to evaluate biological assumptions and effectiveness of PHJV conservation activities. Our objectives were to 1) test whether waterfowl reproductive success increased in response to the full suite of PHJV habitat treatments, and 2) quantify the relationships between mallard (<i>Anas platyrhynchos</i>) vital rates and landscape variables. We focused on examining the association of mallard vital rates with covariates measured at the study-area scale. We collected information on vital rates from 3,214 radio-marked female mallards at 27 study areas mainly throughout the Aspen Parkland ecoregion of Manitoba, Saskatchewan, and Alberta in 1993–2000. We used a modeling framework and information-theoretic techniques to test hypotheses about putative effects of environmental covariates on adult female and duckling survival, nesting effort, and nest survival. Additionally, we constructed a stage-based matrix projection model of mallard population growth (<i>λ</i>) to estimate the sensitivities of population growth rates to variation in vital rates. Nest survival was positively related to the amount of herbaceous vegetation on study areas and total precipitation for the 12 months prior to nesting. Nesting effort was positively related to wetland inundation in July. Duckling survival was positively related to the proportion of seasonal wetlands holding water in July and negatively related to the number of days in June and July when the minimum air temperature dropped below 10° C. Adult female survival rate was positively related to both the proportions of grassland and wetland habitats measured at the study-area scale (65 km<sup>2</sup>), though these factors interacted such that the positive relationship with proportion of wetlands was strongest on study sites with high proportions of grassland. The stage-based projection model constructed using mean vital rates indicated that populations were declining (mean <i>λ</i> = 0.95, median <i>λ</i> = 0.98, 5th percentile = 0.68, 95th percentile = 1.38). Variance-stabilized sensitivities indicated that population growth was most responsive to variation in vital rates for after-second-year birds and that nest survival was the single vital rate to which populations were most sensitive. A prospective simulation revealed that, as expected, sensitivity to nest survival is likely to decrease at higher levels of nest survival. Despite evidence that nest survival was higher in PHJV habitat treatments than surrounding habitats, our a priori PHJV treatment index was unrelated to mallard vital rates estimated at the 65-km<sup>2</sup> scale. Although mallard populations were affected by several weather variables and land uses, efforts to increase po","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"188 1","pages":"1-37"},"PeriodicalIF":4.4,"publicationDate":"2014-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5835383","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}
Kevin L. Monteith, Vernon C. Bleich, Thomas R. Stephenson, Becky M. Pierce, Mary M. Conner, John G. Kie, R. Terry Bowyer
<div> <section> <p>Vital rates of large herbivores normally respond to increased resource limitation by following a progressive sequence of effects on life-history characteristics from survival of young, age at first reproduction, reproduction of adults, to adult survival. Expected changes in life-history characteristics, however, should operate through changes in nutritional condition, which is the integrator of nutritional intake and demands represented primarily by the deposition and catabolism of body fat. Elucidating seasonal patterns of nutritional condition and its relative influence on individual and population performance should improve our understanding of life-history strategies and population regulation of ungulates, provide insight into the capacity of available habitat to support population growth, and allow assessment of the underlying consequences of mortality on population dynamics. We acquired longitudinal data on individual female mule deer (<i>Odocoileus hemionus</i>), and linked those data with environmental and population characteristics. Our goal was to provide a nutritional basis for understanding life-history strategies of these large mammals, and to aid in the conservation and management of large herbivores in general. We studied a migratory population of mule deer that overwintered in Round Valley on the east side of the Sierra Nevada, California, USA, and was subject to a highly variable climate and predation from a suite of large carnivores. We intensively monitored nutritional and life-history characteristics of this population during 1997–2009 as it recovered from a population crash, which occurred during 1985–1991. Deer in Round Valley migrated to high-elevation summer ranges on both sides of the crest of the Sierra Nevada (Sierra crest), where a rain shadow resulted in a mesic and more forested range on the west side compared with xeric conditions east of the Sierra crest. Average survival of neonatal mule deer to 140 days of age during 2006–2008 was 0.33 (SE = 0.091), but was lower for neonates on the west side (0.13, SE = 0.092) compared with those on the east side (0.44, SE = 0.11) of the Sierra crest. Birth mass and nutritional condition of mothers had a positive effect on survival of young; however, those effects were evident only for neonates born east of the crest where predation pressure was less intense compared with the west side. Black bear (<i>Ursus americanus</i>) predation was the main cause of mortality for west-side young (mortality rate = 0.63, SE = 0.97) compared with canid and felid predation for east-side young (0.29, SE = 0.076). Mean autumn recruitment of young during 1997–2008 was lower for females on the west side (0.42, SE = 0.037) than for females on the east side (0.70, SE = 0.041) of the crest, and was affected positively by March ingesta-free body fat (IFBFat) of individual females. At the level of the population, ratios of young-to
{"title":"Life-history characteristics of mule deer: Effects of nutrition in a variable environment\u0000 Características de historia de vida del ciervo mulo: el Efecto de la nutrición en presencia de un medio ambiente variable\u0000 Traits Biodémographiques chez le Cerf Mulet: Effets de la Nutrition dans un Environnement Variable","authors":"Kevin L. Monteith, Vernon C. Bleich, Thomas R. Stephenson, Becky M. Pierce, Mary M. Conner, John G. Kie, R. Terry Bowyer","doi":"10.1002/wmon.1011","DOIUrl":"https://doi.org/10.1002/wmon.1011","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Vital rates of large herbivores normally respond to increased resource limitation by following a progressive sequence of effects on life-history characteristics from survival of young, age at first reproduction, reproduction of adults, to adult survival. Expected changes in life-history characteristics, however, should operate through changes in nutritional condition, which is the integrator of nutritional intake and demands represented primarily by the deposition and catabolism of body fat. Elucidating seasonal patterns of nutritional condition and its relative influence on individual and population performance should improve our understanding of life-history strategies and population regulation of ungulates, provide insight into the capacity of available habitat to support population growth, and allow assessment of the underlying consequences of mortality on population dynamics. We acquired longitudinal data on individual female mule deer (<i>Odocoileus hemionus</i>), and linked those data with environmental and population characteristics. Our goal was to provide a nutritional basis for understanding life-history strategies of these large mammals, and to aid in the conservation and management of large herbivores in general. We studied a migratory population of mule deer that overwintered in Round Valley on the east side of the Sierra Nevada, California, USA, and was subject to a highly variable climate and predation from a suite of large carnivores. We intensively monitored nutritional and life-history characteristics of this population during 1997–2009 as it recovered from a population crash, which occurred during 1985–1991. Deer in Round Valley migrated to high-elevation summer ranges on both sides of the crest of the Sierra Nevada (Sierra crest), where a rain shadow resulted in a mesic and more forested range on the west side compared with xeric conditions east of the Sierra crest. Average survival of neonatal mule deer to 140 days of age during 2006–2008 was 0.33 (SE = 0.091), but was lower for neonates on the west side (0.13, SE = 0.092) compared with those on the east side (0.44, SE = 0.11) of the Sierra crest. Birth mass and nutritional condition of mothers had a positive effect on survival of young; however, those effects were evident only for neonates born east of the crest where predation pressure was less intense compared with the west side. Black bear (<i>Ursus americanus</i>) predation was the main cause of mortality for west-side young (mortality rate = 0.63, SE = 0.97) compared with canid and felid predation for east-side young (0.29, SE = 0.076). Mean autumn recruitment of young during 1997–2008 was lower for females on the west side (0.42, SE = 0.037) than for females on the east side (0.70, SE = 0.041) of the crest, and was affected positively by March ingesta-free body fat (IFBFat) of individual females. At the level of the population, ratios of young-to","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"186 1","pages":"1-62"},"PeriodicalIF":4.4,"publicationDate":"2014-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6032760","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}
J. David Wiens, Robert G. Anthony, Eric D. Forsman
<div> <section> <p>The federally threatened northern spotted owl (<i>Strix occidentalis caurina</i>) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (<i>S. varia</i>). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The range expansion by barred owls into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered recovery efforts for northern spotted owls. We investigated spatial relationships, habitat use, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA, during 2007–2009. Our overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between these previously allopatric owl species. Our study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745-km<sup>2</sup> study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2–4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but interspecific space sharing was largely restricted to broader foraging areas in the home range with minimal spatial overlap among core-use areas. We used an information-theoretic approach to rank discrete-choice models representing alternative hypotheses about the influence of forest conditions, topography, and interspecific interactions on species-specific patterns of nighttime resource selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yr) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (greater for spotted owls) and slope conditions (steeper slopes for spotted owls), but we found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest t
{"title":"Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon\u0000 Interacciones competitivas y repartición de recursos entre S. occidentalis caurina y Strix varia en el Oeste de Oregon\u0000 Interactions concurrentielles et partages des ressources entre les chouettes tachetées du nord et les chouettes Rayées à l'Ouest de l'Oregon","authors":"J. David Wiens, Robert G. Anthony, Eric D. Forsman","doi":"10.1002/wmon.1009","DOIUrl":"https://doi.org/10.1002/wmon.1009","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The federally threatened northern spotted owl (<i>Strix occidentalis caurina</i>) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (<i>S. varia</i>). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The range expansion by barred owls into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered recovery efforts for northern spotted owls. We investigated spatial relationships, habitat use, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA, during 2007–2009. Our overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between these previously allopatric owl species. Our study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745-km<sup>2</sup> study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2–4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but interspecific space sharing was largely restricted to broader foraging areas in the home range with minimal spatial overlap among core-use areas. We used an information-theoretic approach to rank discrete-choice models representing alternative hypotheses about the influence of forest conditions, topography, and interspecific interactions on species-specific patterns of nighttime resource selection. Spotted owls spent a disproportionate amount of time foraging on steep slopes in ravines dominated by old (>120 yr) conifer trees. Barred owls used available forest types more evenly than spotted owls, and were most strongly associated with patches of large hardwood and conifer trees that occupied relatively flat areas along streams. Spotted and barred owls differed in the relative use of old conifer forest (greater for spotted owls) and slope conditions (steeper slopes for spotted owls), but we found no evidence that the 2 species differed in their use of young, mature, and riparian-hardwood forest t","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"185 1","pages":"1-50"},"PeriodicalIF":4.4,"publicationDate":"2014-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5695344","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}
Rachel C. Cook, John G. Cook, David J. Vales, Bruce K. Johnson, Scott M. Mccorquodale, Lisa A. Shipley, Robert A. Riggs, Larry L. Irwin, Shannon L. Murphie, Bryan L. Murphie, Kathryn A. Schoenecker, Frank Geyer, P. Briggs Hall, Rocky D. Spencer, Dave A. Immell, Dewaine H. Jackson, Brett L. Tiller, Patrick J. Miller, Lowell Schmitz
<div> <section> <p>Demographic data show many populations of Rocky Mountain (<i>Cervus elaphus nelsoni</i>) and Roosevelt (<i>Cervus elaphus roosevelti</i>) elk have been declining over the last few decades. Recent work suggests that forage quality and associated animal nutritional condition, particularly in late summer and early autumn, influence reproduction and survival in elk. Therefore, we estimated seasonal nutritional condition of 861 female elk in 2,114 capture events from 21 herds in Washington, Oregon, Wyoming, Colorado, and South Dakota from 1998 to 2007. We estimated ingesta-free body fat and body mass, and determined age, pregnancy status, and lactation status. We obtained estimates for most herds in both late winter–early spring (late Feb–early Apr) and in autumn (Nov–early Dec) to identify changes in nutritional condition of individuals across seasons.</p> <p>Body fat levels of lactating females in autumn were consistently lower than their non-lactating counterparts, and herd averages of lactating elk ranged from 5.5% to 12.4%. These levels were 30–75% of those documented for captive lactating elk fed high-quality diets during summer and autumn. Body fat levels were generally lowest in the coastal and inland northwest regions and highest along the west-slope of the northern Cascades. Adult females in most herds lost an average of 30.7 kg (range: 5–62 kg), or about 13% (range: 2.6–25%) of their autumn mass during winter, indicating nutritional deficiencies. However, we found no significant relationships between spring body fat or change in body fat over winter with winter weather, region, or herd, despite markedly different winter weather among herds and regions. Instead, body fat levels in spring were primarily a function of fat levels the previous autumn. Thinner females in autumn lost less body fat and body mass over winter than did fatter females, a compensatory response, but still ended the season with less body fat than the fatter elk.</p> <p>Body fat levels of lactating females in autumn varied among herds but were unrelated to their body fat levels the previous spring. Within herds, thinner females exhibited a compensatory response during summer and accrued more fat than their fatter counterparts over summer, resulting in similar body fat levels among lactating elk in autumn despite considerable differences in their fat levels the previous spring. Level of body fat achieved by lactating females in autumn varied 2-fold among herds, undoubtedly because of differences in summer nutrition. Thus, summer nutrition set limits to rates of body fat accrual of lactating females that in turn limited body condition across the annual cycle.</p> <p>Pregnancy rates of 2- to 14-year-old females ranged from 68% to 100% in coastal populations of Washington, 69% to 98% in Cascade populations of Washington and Oregon,
{"title":"Regional and seasonal patterns of nutritional condition and reproduction in elk\u0000 Patrones regionales y estacionales en el estado nutricional y la reproducción del alce\u0000 Tendances régionales et saisonnières observées sur l'état nutritionnel et la reproduction du wapiti","authors":"Rachel C. Cook, John G. Cook, David J. Vales, Bruce K. Johnson, Scott M. Mccorquodale, Lisa A. Shipley, Robert A. Riggs, Larry L. Irwin, Shannon L. Murphie, Bryan L. Murphie, Kathryn A. Schoenecker, Frank Geyer, P. Briggs Hall, Rocky D. Spencer, Dave A. Immell, Dewaine H. Jackson, Brett L. Tiller, Patrick J. Miller, Lowell Schmitz","doi":"10.1002/wmon.1008","DOIUrl":"https://doi.org/10.1002/wmon.1008","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Demographic data show many populations of Rocky Mountain (<i>Cervus elaphus nelsoni</i>) and Roosevelt (<i>Cervus elaphus roosevelti</i>) elk have been declining over the last few decades. Recent work suggests that forage quality and associated animal nutritional condition, particularly in late summer and early autumn, influence reproduction and survival in elk. Therefore, we estimated seasonal nutritional condition of 861 female elk in 2,114 capture events from 21 herds in Washington, Oregon, Wyoming, Colorado, and South Dakota from 1998 to 2007. We estimated ingesta-free body fat and body mass, and determined age, pregnancy status, and lactation status. We obtained estimates for most herds in both late winter–early spring (late Feb–early Apr) and in autumn (Nov–early Dec) to identify changes in nutritional condition of individuals across seasons.</p>\u0000 \u0000 <p>Body fat levels of lactating females in autumn were consistently lower than their non-lactating counterparts, and herd averages of lactating elk ranged from 5.5% to 12.4%. These levels were 30–75% of those documented for captive lactating elk fed high-quality diets during summer and autumn. Body fat levels were generally lowest in the coastal and inland northwest regions and highest along the west-slope of the northern Cascades. Adult females in most herds lost an average of 30.7 kg (range: 5–62 kg), or about 13% (range: 2.6–25%) of their autumn mass during winter, indicating nutritional deficiencies. However, we found no significant relationships between spring body fat or change in body fat over winter with winter weather, region, or herd, despite markedly different winter weather among herds and regions. Instead, body fat levels in spring were primarily a function of fat levels the previous autumn. Thinner females in autumn lost less body fat and body mass over winter than did fatter females, a compensatory response, but still ended the season with less body fat than the fatter elk.</p>\u0000 \u0000 <p>Body fat levels of lactating females in autumn varied among herds but were unrelated to their body fat levels the previous spring. Within herds, thinner females exhibited a compensatory response during summer and accrued more fat than their fatter counterparts over summer, resulting in similar body fat levels among lactating elk in autumn despite considerable differences in their fat levels the previous spring. Level of body fat achieved by lactating females in autumn varied 2-fold among herds, undoubtedly because of differences in summer nutrition. Thus, summer nutrition set limits to rates of body fat accrual of lactating females that in turn limited body condition across the annual cycle.</p>\u0000 \u0000 <p>Pregnancy rates of 2- to 14-year-old females ranged from 68% to 100% in coastal populations of Washington, 69% to 98% in Cascade populations of Washington and Oregon,","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"184 1","pages":"1-45"},"PeriodicalIF":4.4,"publicationDate":"2013-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5903297","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}
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