Fernando L Sicuro, Luiz Flamarion B de Oliveira, Eduardo Ferreira, Oscar Rocha-Barbosa
The morphological plasticity of the Sus scrofa wild–domestic species complex is evident in both free-ranging morphotypes and domestic breeds. The Brazilian Pantanal feral hog (“porco-monteiro”) evolved after a long-term feralization process and represents a significant proportion of the mammalian biomass in the region. Its coexistence with native fauna brings several ecological impacts, which are mitigated by the Brazilian Pantanal wetland vastness and resource availability. They are a local subsistence game resource but also impact crops and pastures. Around the 2000s to mid-2010s, numerous European wild boar were introduced in Brazil to fulfill a demand for gourmet meat. Wild boar was also introduced to the Brazilian Pantanal as a game species and to breed with porco-monteiro feral hogs in a commercial venture to produce an even more exotic meat. The craze for wild boar meat has since dwindled, but their populations remain widespread and uncontrolled. Moreover, the full impact of the wild boar introduction on feral hog populations is still unknown. This study analyzes the skulls of porco-monteiro feral hogs from the 1990s, 2000s, and 2010s to assess possible morphological and functional variations along with skulls of wild boar and hybrids from Argentina, Uruguay, and Southern Brazil. The results indicate a trend of broadening of feral hog skulls at the coronal plane and a progressive reduction of the semispinalis capitis muscle scars over the decades. Biomechanical analysis denoted a decrease in head-elevation force that could affect the rooting performance of the latest feral hog morphotypes. Taken together, results show that wild boars likely influenced the evolution of the Pantanal feral hog skull. The magnitude of ecomorphological implications of these morphofunctional changes is unknown, as well as its effects in the Brazilian Pantanal wetland ecology.
{"title":"Invasive wild boar affected feral hog skull evolution over 25 years in Brazilian Pantanal wetland","authors":"Fernando L Sicuro, Luiz Flamarion B de Oliveira, Eduardo Ferreira, Oscar Rocha-Barbosa","doi":"10.1093/jmammal/gyae098","DOIUrl":"https://doi.org/10.1093/jmammal/gyae098","url":null,"abstract":"The morphological plasticity of the Sus scrofa wild–domestic species complex is evident in both free-ranging morphotypes and domestic breeds. The Brazilian Pantanal feral hog (“porco-monteiro”) evolved after a long-term feralization process and represents a significant proportion of the mammalian biomass in the region. Its coexistence with native fauna brings several ecological impacts, which are mitigated by the Brazilian Pantanal wetland vastness and resource availability. They are a local subsistence game resource but also impact crops and pastures. Around the 2000s to mid-2010s, numerous European wild boar were introduced in Brazil to fulfill a demand for gourmet meat. Wild boar was also introduced to the Brazilian Pantanal as a game species and to breed with porco-monteiro feral hogs in a commercial venture to produce an even more exotic meat. The craze for wild boar meat has since dwindled, but their populations remain widespread and uncontrolled. Moreover, the full impact of the wild boar introduction on feral hog populations is still unknown. This study analyzes the skulls of porco-monteiro feral hogs from the 1990s, 2000s, and 2010s to assess possible morphological and functional variations along with skulls of wild boar and hybrids from Argentina, Uruguay, and Southern Brazil. The results indicate a trend of broadening of feral hog skulls at the coronal plane and a progressive reduction of the semispinalis capitis muscle scars over the decades. Biomechanical analysis denoted a decrease in head-elevation force that could affect the rooting performance of the latest feral hog morphotypes. Taken together, results show that wild boars likely influenced the evolution of the Pantanal feral hog skull. The magnitude of ecomorphological implications of these morphofunctional changes is unknown, as well as its effects in the Brazilian Pantanal wetland ecology.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"8 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The daily activity pattern of animals can be classified as diurnal, nocturnal, crepuscular, and cathemeral reflecting strategic decisions to maximize mating and foraging while reducing predation risks and thermal constraints. Among monomorphic mammals, competition for resources and gender-related differences in physiology and reproductive strategies may translate into different activity patterns of males and females. Therefore, to understand the daily activity pattern both aboveground and belowground of the semifossorial rodent Clyomys laticeps, we tested the following hypotheses: (1) males and females differ in their diel activity patterns; (2) males are active for longer periods than females due to a promiscuous mating system and female site fidelity; and (3) higher maximum temperatures restrain C. laticeps activity. The study was carried out in the Serra de Caldas Novas State Park (Goiás, Brazil) in the Cerrado biome. The activity of C. laticeps was recorded using the telemetry technique over 5 days and nights (twice in each season, rainy and dry, between 2019 and 2021). Clyomys laticeps activity was bimodal, with 2 peaks around dawn and dusk, resembling a crepuscular pattern. Temporal segregation in male and female activity patterns was restricted to the dry season, when female activity was more diurnal than males who were mainly nocturnal. Intersexual competition for resources or male-avoidance behavior by females during the dry food scarcity season could contribute to this pattern, although it may also be explained by gender-related differences in thermal tolerances. Overall, males were active for longer periods than females, probably as a strategy to increase mating opportunities among the former and site fidelity in the latter. Finally, temperature imposed major constraints on C. laticeps activities who preferred milder temperatures and avoided being active in temperatures above their thermoneutral zone.
动物的日常活动模式可分为昼行性、夜行性、昼伏夜出性和昼行性，这反映了动物在减少捕食风险和热限制的同时最大限度地进行交配和觅食的战略决策。在单形哺乳动物中，对资源的竞争以及与性别有关的生理和繁殖策略的差异可能会转化为雌雄不同的活动模式。因此，为了了解半浮游啮齿类动物Clyomys laticeps在地上和地下的日常活动模式，我们测试了以下假设：（1）雄性和雌性在昼夜活动模式上存在差异；（2）由于杂交交配系统和雌性对地点的忠诚度，雄性比雌性活动的时间更长；（3）较高的最高温度会抑制C.这项研究在塞拉多生物群落的 Serra de Caldas Novas 州立公园（巴西戈亚斯州）进行。使用遥测技术记录了 C. laticeps 在 5 个昼夜（2019 年至 2021 年间，雨季和旱季各两次）的活动。Clyomys laticeps的活动呈双峰分布，在黎明和黄昏前后出现两个高峰，类似于昼伏夜出的模式。雌雄活动模式的时间分隔仅限于旱季，此时雌性活动多于雄性，而雄性主要在夜间活动。在食物匮乏的旱季，雌性对资源的争夺或雌性对雄性的回避行为可能是造成这种模式的原因，但也可能是与性别有关的热耐受性差异造成的。总体而言，雄性比雌性活跃的时间更长，这可能是为了增加前者的交配机会和后者对地点的忠诚度。最后，温度对拉蒂斯蛙的活动造成了很大的限制，拉蒂斯蛙更喜欢温和的温度，并避免在温度超过它们的中温区时活动。
{"title":"Thermal constraints and gender-related differences in the activity patterns of the monomorphic rodent Clyomys laticeps","authors":"Ingrid Paixão, Claire Ferrando, Natália Leiner","doi":"10.1093/jmammal/gyae099","DOIUrl":"https://doi.org/10.1093/jmammal/gyae099","url":null,"abstract":"The daily activity pattern of animals can be classified as diurnal, nocturnal, crepuscular, and cathemeral reflecting strategic decisions to maximize mating and foraging while reducing predation risks and thermal constraints. Among monomorphic mammals, competition for resources and gender-related differences in physiology and reproductive strategies may translate into different activity patterns of males and females. Therefore, to understand the daily activity pattern both aboveground and belowground of the semifossorial rodent Clyomys laticeps, we tested the following hypotheses: (1) males and females differ in their diel activity patterns; (2) males are active for longer periods than females due to a promiscuous mating system and female site fidelity; and (3) higher maximum temperatures restrain C. laticeps activity. The study was carried out in the Serra de Caldas Novas State Park (Goiás, Brazil) in the Cerrado biome. The activity of C. laticeps was recorded using the telemetry technique over 5 days and nights (twice in each season, rainy and dry, between 2019 and 2021). Clyomys laticeps activity was bimodal, with 2 peaks around dawn and dusk, resembling a crepuscular pattern. Temporal segregation in male and female activity patterns was restricted to the dry season, when female activity was more diurnal than males who were mainly nocturnal. Intersexual competition for resources or male-avoidance behavior by females during the dry food scarcity season could contribute to this pattern, although it may also be explained by gender-related differences in thermal tolerances. Overall, males were active for longer periods than females, probably as a strategy to increase mating opportunities among the former and site fidelity in the latter. Finally, temperature imposed major constraints on C. laticeps activities who preferred milder temperatures and avoided being active in temperatures above their thermoneutral zone.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"28 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nhan T T Nguyen, Caitlin P Wells, Dirk H Van Vuren
Dispersal is common in mammals and can have an important role in shaping demography, genetics, distribution, and social structure. Dispersal entails potential costs but also potential benefits, and the dispersal decision is thought to be conditional; the potential disperser assesses prospects for success at its current location and disperses to improve its fitness. However, the costs and benefits of dispersal, as well as factors influencing the dispersal decision, are not well known. We used trapping and observation to study dispersal in the Golden-mantled Ground Squirrel (Callospermophilus lateralis), a species for which dispersal is largely unknown. We characterized the dispersal process by evaluating dispersal timing and distance, assessed factors that might influence the dispersal decision, and analyzed the fitness cost of dispersal after settlement. We found that most dispersal occurred during the summer of birth, as is expected for a small-bodied sciurid. However, some squirrels delayed dispersal until early in their yearling summer. Dispersal was male-biased in dispersal tendency, and it was also male-biased in dispersal distance, but only over shorter dispersal distances. The dispersal decision for juvenile females appeared to originate as soon as 10 days after they emerged from the natal burrow, and the decision was not associated with body mass or several measures of competition. Instead, dispersal of juvenile females was associated with the number of littermate sisters, with each sister present increasing the likelihood of dispersal by 26%. Littermate sisters might be a cue foretelling the effects of kin competition the following year. We did not find a significant difference in lifetime reproductive success between philopatric and dispersing females after settlement, suggesting that for golden-mantled ground squirrels, any cost of dispersal is experienced primarily during the transience phase.
{"title":"Dispersal of the Golden-mantled Ground Squirrel (Callospermophilus lateralis)","authors":"Nhan T T Nguyen, Caitlin P Wells, Dirk H Van Vuren","doi":"10.1093/jmammal/gyae106","DOIUrl":"https://doi.org/10.1093/jmammal/gyae106","url":null,"abstract":"Dispersal is common in mammals and can have an important role in shaping demography, genetics, distribution, and social structure. Dispersal entails potential costs but also potential benefits, and the dispersal decision is thought to be conditional; the potential disperser assesses prospects for success at its current location and disperses to improve its fitness. However, the costs and benefits of dispersal, as well as factors influencing the dispersal decision, are not well known. We used trapping and observation to study dispersal in the Golden-mantled Ground Squirrel (Callospermophilus lateralis), a species for which dispersal is largely unknown. We characterized the dispersal process by evaluating dispersal timing and distance, assessed factors that might influence the dispersal decision, and analyzed the fitness cost of dispersal after settlement. We found that most dispersal occurred during the summer of birth, as is expected for a small-bodied sciurid. However, some squirrels delayed dispersal until early in their yearling summer. Dispersal was male-biased in dispersal tendency, and it was also male-biased in dispersal distance, but only over shorter dispersal distances. The dispersal decision for juvenile females appeared to originate as soon as 10 days after they emerged from the natal burrow, and the decision was not associated with body mass or several measures of competition. Instead, dispersal of juvenile females was associated with the number of littermate sisters, with each sister present increasing the likelihood of dispersal by 26%. Littermate sisters might be a cue foretelling the effects of kin competition the following year. We did not find a significant difference in lifetime reproductive success between philopatric and dispersing females after settlement, suggesting that for golden-mantled ground squirrels, any cost of dispersal is experienced primarily during the transience phase.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"32 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Insectivorous bats play an essential role as predators in natural ecosystems and contribute to pest control in agricultural landscapes. However, characterizing diets of specific bat species is difficult using conventional methods that cannot capture detailed dietary information. In this study, we used metabarcoding of the cytochrome oxidase I mitochondrial gene to analyze fecal samples of Myotis velifer and provide insight into the seasonal variation of diet from a colony located in the Chihuahuan Desert region of Texas. After filtering sequence reads, we recovered and analyzed 706 molecular operational taxonomic units (MOTUs) in the diet of M. velifer. We found 484 taxa (species and genus level) belonging to 11 insect orders in 66 fecal samples collected from March to October 2021. The orders containing the most MOTUs were Diptera (n = 353), Lepidoptera (n = 160), and Blattodea (n = 59). In their diet, we identified important insect crop pests, non-native insects, and substantial consumption of mosquitoes. Dietary composition shifted throughout seasons. Bats captured in summer months consumed the highest diversity of arthropod orders, and those captured in the spring consumed more diet items but were less diverse in arthropod orders. Our results uncovered 2 additional orders consumed by M. velifer, Blattodea and Odonata, that have not been previously described in their diet.
{"title":"Cave Myotis (Myotis velifer) consume diverse prey items and provide important ecosystem services","authors":"Katheryn V Fitzgerald, Loren K Ammerman","doi":"10.1093/jmammal/gyae102","DOIUrl":"https://doi.org/10.1093/jmammal/gyae102","url":null,"abstract":"Insectivorous bats play an essential role as predators in natural ecosystems and contribute to pest control in agricultural landscapes. However, characterizing diets of specific bat species is difficult using conventional methods that cannot capture detailed dietary information. In this study, we used metabarcoding of the cytochrome oxidase I mitochondrial gene to analyze fecal samples of Myotis velifer and provide insight into the seasonal variation of diet from a colony located in the Chihuahuan Desert region of Texas. After filtering sequence reads, we recovered and analyzed 706 molecular operational taxonomic units (MOTUs) in the diet of M. velifer. We found 484 taxa (species and genus level) belonging to 11 insect orders in 66 fecal samples collected from March to October 2021. The orders containing the most MOTUs were Diptera (n = 353), Lepidoptera (n = 160), and Blattodea (n = 59). In their diet, we identified important insect crop pests, non-native insects, and substantial consumption of mosquitoes. Dietary composition shifted throughout seasons. Bats captured in summer months consumed the highest diversity of arthropod orders, and those captured in the spring consumed more diet items but were less diverse in arthropod orders. Our results uncovered 2 additional orders consumed by M. velifer, Blattodea and Odonata, that have not been previously described in their diet.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"20 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bruce D Patterson, Terrence C Demos, Laura Torrent, Amanda L Grunwald, Cecilia Montauban, Julian C Kerbis Peterhans, Molly M McDonough, Carl W Dick, Michael Bartonjo, M Corrie Schoeman, Luis A Ruedas, Javier Juste
Roughly a third of all horseshoe bat species (Rhinolophidae: Rhinolophus) are found in Africa, where a recent continent-wide genetic survey suggested the presence of both undescribed and apparently invalid species. Here, we focus on the R. landeri species complex and the recent elevation of R. lobatus Peters, 1852, to species rank. That action created ambiguity in the taxonomy of East African members of the group—are both R. landeri Martin, 1838, and R. lobatus sympatric in East Africa or is another, unnamed species present there? Here, we refine genetic, morphological, and behavioral characterizations of R. landeri and its erstwhile synonyms with samples from the vicinity of their type localities. The distribution of R. landeri appears to be limited to Central and West Africa; existing genetic records attributed to this species from Mali clearly represent another taxon. We marshal genetic evidence for the species-level distinction of R. dobsoni Thomas, 1904, from Sudan, which was previously considered a synonym of R. landeri. We reject R. axillaris J. A. Allen, 1917, as a synonym of the R. landeri complex, provisionally regarding it as a valid member of the landeri species group. Finally, we demonstrate that East Africa is home to a fourth species of the landeri complex that is named herein. Final resolution of the systematics of this species complex awaits expanded characterizations (especially of genetics, vocalizations, and noseleaves) and studies of variation in regions of contact.
大约三分之一的马蹄蝠（Rhinolophidae：Rhinolophus）物种分布在非洲，最近的一项全非洲遗传调查表明，非洲存在未被描述和明显无效的物种。在这里，我们重点讨论 R. landeri 种群以及最近将 R. lobatus Peters, 1852 提升为种的问题。Landeri Martin, 1838和R. lobatus在东非是否为同域物种，还是存在另一个未命名的物种？在这里，我们利用模式产地附近的样本完善了 R. landeri 及其过去的同义词的遗传学、形态学和行为学特征。R. landeri 的分布似乎仅限于中非和西非；马里现有的该物种遗传记录显然代表了另一个分类群。dobsoni Thomas, 1904 的种级区分提供了遗传学证据，该种以前被认为是 R. landeri 的异名。我们拒绝将 R. axillaris J. A. Allen, 1917 作为 R. landeri 复合体的异名，暂时将其视为 landeri 种群的有效成员。最后，我们证明东非是 landeri 复合体第四个物种的故乡，该物种在此被命名。该物种群系统学的最终解决有待于进一步的特征描述（尤其是遗传学、发声和鼻叶）以及对接触地区变异的研究。
{"title":"Systematics of the Rhinolophus landeri complex, with evidence for 3 additional Afrotropical bat species","authors":"Bruce D Patterson, Terrence C Demos, Laura Torrent, Amanda L Grunwald, Cecilia Montauban, Julian C Kerbis Peterhans, Molly M McDonough, Carl W Dick, Michael Bartonjo, M Corrie Schoeman, Luis A Ruedas, Javier Juste","doi":"10.1093/jmammal/gyae085","DOIUrl":"https://doi.org/10.1093/jmammal/gyae085","url":null,"abstract":"Roughly a third of all horseshoe bat species (Rhinolophidae: Rhinolophus) are found in Africa, where a recent continent-wide genetic survey suggested the presence of both undescribed and apparently invalid species. Here, we focus on the R. landeri species complex and the recent elevation of R. lobatus Peters, 1852, to species rank. That action created ambiguity in the taxonomy of East African members of the group—are both R. landeri Martin, 1838, and R. lobatus sympatric in East Africa or is another, unnamed species present there? Here, we refine genetic, morphological, and behavioral characterizations of R. landeri and its erstwhile synonyms with samples from the vicinity of their type localities. The distribution of R. landeri appears to be limited to Central and West Africa; existing genetic records attributed to this species from Mali clearly represent another taxon. We marshal genetic evidence for the species-level distinction of R. dobsoni Thomas, 1904, from Sudan, which was previously considered a synonym of R. landeri. We reject R. axillaris J. A. Allen, 1917, as a synonym of the R. landeri complex, provisionally regarding it as a valid member of the landeri species group. Finally, we demonstrate that East Africa is home to a fourth species of the landeri complex that is named herein. Final resolution of the systematics of this species complex awaits expanded characterizations (especially of genetics, vocalizations, and noseleaves) and studies of variation in regions of contact.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"52 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Social monogamy is rare in mammals, but in those species in which it occurs, individuals frequently engage in extra-pair copulation (EPC). Numerous hypotheses have been proposed to explain EPC, but relatively few field studies have examined factors influencing EPC in socially monogamous mammals. Prairie voles (Microtus ochrogaster) are a socially monogamous rodent in which extra-pair paternity (EPP) is common. Using genetic data from a 3-year study of a natural population of prairie voles, we investigated whether the negative consequences of inbreeding and the structure of social units (male–female pairs vs. groups; adult sex ratio within groups) were factors affecting EPC. We found strong evidence that genetic similarity between males and females that produced offspring via EPC was less than that between social partners, as would be expected if avoiding inbreeding depression influenced the occurrence of EPC. Social unit structure was also a factor involved with extra-pair parentage. Contrary to our expectations, the greater the proportion of females in the group, the lower the chance of EPC resulting in offspring production by females, and, similarly, the chance of EPP by males declined as the proportion of males within the group increased. However, neither males nor females were more likely to produce offspring from EPC when they were living in pairs versus groups. One implication of these results is that EPC may be influenced more by female behaviors, such as mate choice, than male mate guarding. Overall, our results suggest that the proximate factors influencing EPC in prairie voles are complex but include the cost of inbreeding depression and the structure of social units.
{"title":"Influence of genetic similarity and social setting on extra-pair parentage in prairie voles","authors":"Brian Keane, Martin H H Stevens, Nancy G Solomon","doi":"10.1093/jmammal/gyae097","DOIUrl":"https://doi.org/10.1093/jmammal/gyae097","url":null,"abstract":"Social monogamy is rare in mammals, but in those species in which it occurs, individuals frequently engage in extra-pair copulation (EPC). Numerous hypotheses have been proposed to explain EPC, but relatively few field studies have examined factors influencing EPC in socially monogamous mammals. Prairie voles (Microtus ochrogaster) are a socially monogamous rodent in which extra-pair paternity (EPP) is common. Using genetic data from a 3-year study of a natural population of prairie voles, we investigated whether the negative consequences of inbreeding and the structure of social units (male–female pairs vs. groups; adult sex ratio within groups) were factors affecting EPC. We found strong evidence that genetic similarity between males and females that produced offspring via EPC was less than that between social partners, as would be expected if avoiding inbreeding depression influenced the occurrence of EPC. Social unit structure was also a factor involved with extra-pair parentage. Contrary to our expectations, the greater the proportion of females in the group, the lower the chance of EPC resulting in offspring production by females, and, similarly, the chance of EPP by males declined as the proportion of males within the group increased. However, neither males nor females were more likely to produce offspring from EPC when they were living in pairs versus groups. One implication of these results is that EPC may be influenced more by female behaviors, such as mate choice, than male mate guarding. Overall, our results suggest that the proximate factors influencing EPC in prairie voles are complex but include the cost of inbreeding depression and the structure of social units.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"75 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Animals living in seasonal environments have adopted a wide array of tactics used to deal with seasonal resource scarcity. Many species migrate between habitats to reach areas where food resources are more plentiful as an attempt to address energetic demands through foraging. We assessed the winter behavioral adaptations of Caribou (Rangifer tarandus), a large ungulate inhabiting Arctic and sub-Arctic regions known for seasonal resource scarcity. Movement rates of Caribou are the lowest of the year during winter, revealing 1 mechanism individuals use to reduce energy expenditures. However, migratory individuals moved nearly twice as much as nonmigratory individuals during winter, suggesting that migratory individuals rely more upon income (forage), whereas nonmigratory individuals rely more upon capital (bodily reserves). Lichens are the primary winter forage for large, migratory herds of Caribou, and migratory individuals experienced more than 2.5 times greater lichen cover than nonmigratory individuals. We documented that both groups slowed their movement in areas of greater lichen cover, suggesting increased foraging time in these areas. Movement rates were greater near villages, which may be suggestive of disturbance, but the effect was weak. Overall energy saved by reduced movement rates was modest. However, energy savings were 11% of daily body energy lost or 47% of the demands of early pregnancy, which potentially could affect individual condition and/or fetal growth if not offset by increases in forage intake.
{"title":"Behavioral adaptation to seasonal resource scarcity by Caribou (Rangifer tarandus) and its role in partial migration","authors":"Kyle Joly, Matthew D Cameron, Robert G White","doi":"10.1093/jmammal/gyae100","DOIUrl":"https://doi.org/10.1093/jmammal/gyae100","url":null,"abstract":"Animals living in seasonal environments have adopted a wide array of tactics used to deal with seasonal resource scarcity. Many species migrate between habitats to reach areas where food resources are more plentiful as an attempt to address energetic demands through foraging. We assessed the winter behavioral adaptations of Caribou (Rangifer tarandus), a large ungulate inhabiting Arctic and sub-Arctic regions known for seasonal resource scarcity. Movement rates of Caribou are the lowest of the year during winter, revealing 1 mechanism individuals use to reduce energy expenditures. However, migratory individuals moved nearly twice as much as nonmigratory individuals during winter, suggesting that migratory individuals rely more upon income (forage), whereas nonmigratory individuals rely more upon capital (bodily reserves). Lichens are the primary winter forage for large, migratory herds of Caribou, and migratory individuals experienced more than 2.5 times greater lichen cover than nonmigratory individuals. We documented that both groups slowed their movement in areas of greater lichen cover, suggesting increased foraging time in these areas. Movement rates were greater near villages, which may be suggestive of disturbance, but the effect was weak. Overall energy saved by reduced movement rates was modest. However, energy savings were 11% of daily body energy lost or 47% of the demands of early pregnancy, which potentially could affect individual condition and/or fetal growth if not offset by increases in forage intake.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"75 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Danielle M Blumstein, Jocelyn P Colella, Ernst Linder, Matthew D MacManes
Availability of food resources is an important driver of survival. Populations must either relocate or adapt to persist in environments where food availability is changing. An optimal diet balances energy gain, water regulation, and nutrition. We used flow-through respirometry to characterize metabolic phenotypes of the desert-adapted Cactus Mouse (Peromyscus eremicus) under diurnally variable environmental conditions that mimic that of the Sonoran Desert. We treated mice with 2 different energetically equivalent diets, a standard diet and a low-fat diet, and measured energy expenditure, water loss rate, respiratory quotient, weight, and electrolyte levels. Mice fed the low-fat diet lost significantly more water than those on the standard diet. Despite being desert-adapted, our results suggest that cactus mice may have limited capacity to tolerate water deprivation if optimal foods become less abundant. Given that climate change is predicted to modify the distribution of food items, understanding these links may have important implications for long-term population viability for desert and non-desert-adapted animals alike.
{"title":"High total water loss driven by low-fat diet in desert-adapted mice","authors":"Danielle M Blumstein, Jocelyn P Colella, Ernst Linder, Matthew D MacManes","doi":"10.1093/jmammal/gyae093","DOIUrl":"https://doi.org/10.1093/jmammal/gyae093","url":null,"abstract":"Availability of food resources is an important driver of survival. Populations must either relocate or adapt to persist in environments where food availability is changing. An optimal diet balances energy gain, water regulation, and nutrition. We used flow-through respirometry to characterize metabolic phenotypes of the desert-adapted Cactus Mouse (Peromyscus eremicus) under diurnally variable environmental conditions that mimic that of the Sonoran Desert. We treated mice with 2 different energetically equivalent diets, a standard diet and a low-fat diet, and measured energy expenditure, water loss rate, respiratory quotient, weight, and electrolyte levels. Mice fed the low-fat diet lost significantly more water than those on the standard diet. Despite being desert-adapted, our results suggest that cactus mice may have limited capacity to tolerate water deprivation if optimal foods become less abundant. Given that climate change is predicted to modify the distribution of food items, understanding these links may have important implications for long-term population viability for desert and non-desert-adapted animals alike.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"114 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142175863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Logan Whiles, Lisa A Shipley, Jocelyn R Akins, Roger G Christophersen, Jason I Ransom, Taal Levi, Daniel H Thornton
Declines in populations of small mammals associated with high elevations, e.g., marmots (Marmota spp.) and pikas (Ochotona spp.), have been attributed to both direct and indirect effects of environmental changes caused by humans. For example, populations of Olympic marmots (M. olympus) and Vancouver Island marmots (M. vancouverensis) have declined in response to increased predator access to high-elevation marmot habitats. In the North Cascades National Park Service Complex (NOCA), observed mean abundance of hoary marmots (M. caligata) declined by 74% from 2007 to 2016. Although these declines have been linked to harsh winter conditions, the role of predation and its association with decreasing snowpack has yet to be explored in this system. We noninvasively examined these predator–prey dynamics by coupling behavioral surveys of hoary marmots with indices of predation risk. We conducted 145 vigilance samples and 39 flight initiation distance trials to measure Hoary Marmot antipredator behavior. We derived a risk index for each predator by weighting its probability of use estimates (the probability of a predator–prey encounter) with its observed proportion of Hoary Marmot predation (probability of prey death given an encounter). We used genetic metabarcoding of vertebrate DNA from 413 predator scat samples to quantify predation on hoary marmots. We surveyed 9,930 trap-nights using 130 remote cameras to model predator probability of use near Hoary Marmot colonies. From camera traps and scat DNA, we detected 10 predator species in the study area, and we detected hoary marmots in the scats of 5 of these species. The proportion of observed Hoary Marmot predation was highest for coyotes (Canis latrans) at 50%. To our knowledge, we also report the first record of hoary marmots being consumed by Pacific martens (Martes caurina), which were also significant predators (proportion of observed predation = 32%). We expected predators with low-elevation habits to use sites with lesser snow persistence; this prediction was supported for coyotes but not for other typically low-elevation predators. We found estimated risk experienced by hoary marmots was highest from Pacific martens and lowest from Canada Lynx (Lynx canadensis). Contrary to our predictions and despite hoary marmots allocating >50% of their time to vigilance, neither estimates of predator risk nor human presence explained variation in marmot antipredator behavior. Based on the results from both our dietary and probability of use analyses, we expect coyotes to have an increasing effect on NOCA’s Hoary Marmot population as the climate warms and Coyote range continues to expand. Thus, our work highlights the need to better understand the effect of climate-driven shifts in predator–prey ecology in high-elevation systems.
{"title":"Predation risk for hoary marmots in Washington’s North Cascades Mountains","authors":"Logan Whiles, Lisa A Shipley, Jocelyn R Akins, Roger G Christophersen, Jason I Ransom, Taal Levi, Daniel H Thornton","doi":"10.1093/jmammal/gyae086","DOIUrl":"https://doi.org/10.1093/jmammal/gyae086","url":null,"abstract":"Declines in populations of small mammals associated with high elevations, e.g., marmots (Marmota spp.) and pikas (Ochotona spp.), have been attributed to both direct and indirect effects of environmental changes caused by humans. For example, populations of Olympic marmots (M. olympus) and Vancouver Island marmots (M. vancouverensis) have declined in response to increased predator access to high-elevation marmot habitats. In the North Cascades National Park Service Complex (NOCA), observed mean abundance of hoary marmots (M. caligata) declined by 74% from 2007 to 2016. Although these declines have been linked to harsh winter conditions, the role of predation and its association with decreasing snowpack has yet to be explored in this system. We noninvasively examined these predator–prey dynamics by coupling behavioral surveys of hoary marmots with indices of predation risk. We conducted 145 vigilance samples and 39 flight initiation distance trials to measure Hoary Marmot antipredator behavior. We derived a risk index for each predator by weighting its probability of use estimates (the probability of a predator–prey encounter) with its observed proportion of Hoary Marmot predation (probability of prey death given an encounter). We used genetic metabarcoding of vertebrate DNA from 413 predator scat samples to quantify predation on hoary marmots. We surveyed 9,930 trap-nights using 130 remote cameras to model predator probability of use near Hoary Marmot colonies. From camera traps and scat DNA, we detected 10 predator species in the study area, and we detected hoary marmots in the scats of 5 of these species. The proportion of observed Hoary Marmot predation was highest for coyotes (Canis latrans) at 50%. To our knowledge, we also report the first record of hoary marmots being consumed by Pacific martens (Martes caurina), which were also significant predators (proportion of observed predation = 32%). We expected predators with low-elevation habits to use sites with lesser snow persistence; this prediction was supported for coyotes but not for other typically low-elevation predators. We found estimated risk experienced by hoary marmots was highest from Pacific martens and lowest from Canada Lynx (Lynx canadensis). Contrary to our predictions and despite hoary marmots allocating >50% of their time to vigilance, neither estimates of predator risk nor human presence explained variation in marmot antipredator behavior. Based on the results from both our dietary and probability of use analyses, we expect coyotes to have an increasing effect on NOCA’s Hoary Marmot population as the climate warms and Coyote range continues to expand. Thus, our work highlights the need to better understand the effect of climate-driven shifts in predator–prey ecology in high-elevation systems.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"11 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William J McShea, Olivia Cosby, Andy J Boyce, Valentine Herrmann, Rosalina Ragai, Paul Y Imbun
The correlates of mammal species richness and community associations along elevation gradients have resulted in conflicting results within tropical systems. We surveyed the terrestrial mammal and gallinaceous bird community (>200 g body size) along transects at 4 mountain sites in Malaysian Borneo using camera traps to assess structuring of the mammal community along the elevation gradient. Between 2015 and 2021, we surveyed Bukit Lanjak (elevation 1,300 m) in Sarawak (Lanjak Entimau Wildlife Sanctuary; LEWS) and Mts. Kinabalu, Tambuyukon, and Magdalena (up to 2,400 m) in Sabah, with a total sample effort of 20,600 camera nights. We detected 48 species of mammals and 9 species of large terrestrial birds. There was mostly a common species pool across the sites, with only 9 species detected solely in LEWS and 5 species only in Sabah. Over our limited elevation range, no species were detected across the entire elevation range and no common species were confined to the highest elevation sites in Sabah or LEWS (>1,000 m). A species richness curve for each location indicated a slight peak at ~1,000 m for LEWS, but the mid-elevation peak was not evident at Sabah. The individual response curves of relative abundance to the elevation gradient for 15 species with sufficient detections were similar across sites (1 exception—Malaysian Porcupine) with 6 species showing no correlation with elevation, while 4 species increased and 4 species decreased in detections with elevation. A multivariate analysis of species detections found herbivores at lower elevations and mesocarnivores at higher elevations, while species of the same foraging guilds differed in body size at the same elevation. As opposed to studies focused on smaller vertebrate species (i.e., rodents, songbirds), larger mammal and terrestrial bird communities in these mountains did not form unique communities along the elevation gradient but did structure according to the functional traits of foraging guilds and body size.
{"title":"The structure of terrestrial mammal communities along an elevation gradient in the tropics.","authors":"William J McShea, Olivia Cosby, Andy J Boyce, Valentine Herrmann, Rosalina Ragai, Paul Y Imbun","doi":"10.1093/jmammal/gyae087","DOIUrl":"https://doi.org/10.1093/jmammal/gyae087","url":null,"abstract":"The correlates of mammal species richness and community associations along elevation gradients have resulted in conflicting results within tropical systems. We surveyed the terrestrial mammal and gallinaceous bird community (>200 g body size) along transects at 4 mountain sites in Malaysian Borneo using camera traps to assess structuring of the mammal community along the elevation gradient. Between 2015 and 2021, we surveyed Bukit Lanjak (elevation 1,300 m) in Sarawak (Lanjak Entimau Wildlife Sanctuary; LEWS) and Mts. Kinabalu, Tambuyukon, and Magdalena (up to 2,400 m) in Sabah, with a total sample effort of 20,600 camera nights. We detected 48 species of mammals and 9 species of large terrestrial birds. There was mostly a common species pool across the sites, with only 9 species detected solely in LEWS and 5 species only in Sabah. Over our limited elevation range, no species were detected across the entire elevation range and no common species were confined to the highest elevation sites in Sabah or LEWS (>1,000 m). A species richness curve for each location indicated a slight peak at ~1,000 m for LEWS, but the mid-elevation peak was not evident at Sabah. The individual response curves of relative abundance to the elevation gradient for 15 species with sufficient detections were similar across sites (1 exception—Malaysian Porcupine) with 6 species showing no correlation with elevation, while 4 species increased and 4 species decreased in detections with elevation. A multivariate analysis of species detections found herbivores at lower elevations and mesocarnivores at higher elevations, while species of the same foraging guilds differed in body size at the same elevation. As opposed to studies focused on smaller vertebrate species (i.e., rodents, songbirds), larger mammal and terrestrial bird communities in these mountains did not form unique communities along the elevation gradient but did structure according to the functional traits of foraging guilds and body size.","PeriodicalId":50157,"journal":{"name":"Journal of Mammalogy","volume":"31 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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