Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior...Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation,the giant anteater(Myrmecophaga tridactyla).We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah.We estimated the distance moved,area used,use of forest areas,and mean environmental temperature for each monitoring day of each individual.We modeled these data with Mixed Structural Equations—considering the possible interactions between our variables and controlling for sex and body mass.Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature,probably because of their low body heat production.It is possible that they reduce distance moved and area used by reducing the duration of activity.With decreasing temperature,forest habitats become warmer than open ones,besides buffer rain and chilly winds.Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation.However,decreasing movement can limit food access and,consequently,fitness.Therefore,we highlight the importance of forests as thermal shelters.With increasing frequency and intensity of extreme weather events,we showed the need to preserve forest patches to offer suitable conditions for tropical mammals’behavioral thermoregulation.In this context,policies favoring deforestation on Brazilian territory are especially worrisome.Finally,we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.展开更多
The matching habitat choice hypothesis posits that individuals actively choose those microhabitats that best match their specific phenotype to maximize fitness. Despite the profound implications, matching habitat choi...The matching habitat choice hypothesis posits that individuals actively choose those microhabitats that best match their specific phenotype to maximize fitness. Despite the profound implications, matching habitat choice has not been unequivo- cally demonstrated. We conducted two experiments to examine the impact of pigmentation pattern in the color polymorphic pygmy grasshopper Tetrix subulata on habitat choice in a laboratory thermal mosaic arena. We found no behavioral differences in the thermal mosaic among pygmy grasshoppers belonging to either pale, intermediate or dark natural color morphs. However, af- ter manipulating the grasshoppers＇ phenotype, the utilization through time of warmer and colder parts of the arena was different for black-painted and white-painted individuals. White-painted individuals used warmer parts of the arena, at least during the ini- tial stage of the experiment. We conclude that microhabitat choice represents a form of behavioural plasticity. Thus, even if the choice itself is flexible and not genetically determined, it can still lead to spatial genetic structure in the population because the phenotypes themselves may be genetically mediated [Current Zoology 58 （3）： 392--400, 2012].展开更多
In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nes...In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nests where they hatched in the evening and roosted there over night.This behavior lasted 6.7±4.3 nights(range=1–15;n=13)after the chicks hatched.At this stage,the hens became very vigilant to predators and human disturbance.If disturbed,they often abandoned the nests immediately and no longer returned thereafter.The ambient temperature at night during the early brooding period of Sichuan Partridge at our study site was^12.4°C.Our findings suggest that hen Sichuan Partridges may make trade-offs between nest predation risks versus the thermoregulatory needs of their young.展开更多
The multiple spatial and temporal parameters affecting cattle herd distribution and activity dynamics can significantly affect resource utilization but are not fully understood.The aim of this study was to determine w...The multiple spatial and temporal parameters affecting cattle herd distribution and activity dynamics can significantly affect resource utilization but are not fully understood.The aim of this study was to determine whether current animal tracking technology and spatio-temporal analysis tools can be used to integrate multi-scale information on herd distribution patterns as a function of seasonal forage production,periods of the day,animal activity,and landscape features.Positional and activity information of 11 free-ranging cows within a 31-member herd was obtained at 5-min intervals by using GPS collars for 1 year within a 457-ha ranch in the semi-arid rangelands of South Texas.Forage biomass was calculated with satellite imagery.Spatial analysis of cattle distribution and landscape features was conducted with GIS.Herd spread was greatest during the growing season.Throughout the year,during midday,the herd showed smaller spread and greater use of shade patches than any other time of day.Cattle also aggregated under trees in winter,particularly during the night.There was no statistically significant overall pattern of seasonal changes in the use of water and supplemental feeding areas,but a trend toward highest use during the winter.However,significantly different diurnal patterns in the use of supplemental feed and water were observed within each season.This study found a strong influence of shade patches relative to the influence of water and supplemental feeding areas on the diurnal and seasonal movement patterns of cattle in shrub-dominated rangeland.Although this study used only 11 tracked cows in a 31-member herd,the results indicated that techniques such as seasonal and diurnal GPS tracking,GIS,and remote sensing data enable evaluation of multiple spatial and temporal dynamics of cattle distribution and activity patterns.The smaller spread during the dry winter season associated with the observed aggregation of individuals in water and supplemental feeding areas,may aid in determining the most critical tim展开更多
基金This work was supported by the Brasilian Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPQ(133623/2017-3 to AG and 308934/2017-2 to GM)National Program of post doctorate of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES(PNPD 1694744 to ZO)São Paulo Research Foundation-FAPESP(2013/18526-9 and 2013/04957-8 to AB).
文摘Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation,the giant anteater(Myrmecophaga tridactyla).We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah.We estimated the distance moved,area used,use of forest areas,and mean environmental temperature for each monitoring day of each individual.We modeled these data with Mixed Structural Equations—considering the possible interactions between our variables and controlling for sex and body mass.Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature,probably because of their low body heat production.It is possible that they reduce distance moved and area used by reducing the duration of activity.With decreasing temperature,forest habitats become warmer than open ones,besides buffer rain and chilly winds.Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation.However,decreasing movement can limit food access and,consequently,fitness.Therefore,we highlight the importance of forests as thermal shelters.With increasing frequency and intensity of extreme weather events,we showed the need to preserve forest patches to offer suitable conditions for tropical mammals’behavioral thermoregulation.In this context,policies favoring deforestation on Brazilian territory are especially worrisome.Finally,we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.
文摘The matching habitat choice hypothesis posits that individuals actively choose those microhabitats that best match their specific phenotype to maximize fitness. Despite the profound implications, matching habitat choice has not been unequivo- cally demonstrated. We conducted two experiments to examine the impact of pigmentation pattern in the color polymorphic pygmy grasshopper Tetrix subulata on habitat choice in a laboratory thermal mosaic arena. We found no behavioral differences in the thermal mosaic among pygmy grasshoppers belonging to either pale, intermediate or dark natural color morphs. However, af- ter manipulating the grasshoppers＇ phenotype, the utilization through time of warmer and colder parts of the arena was different for black-painted and white-painted individuals. White-painted individuals used warmer parts of the arena, at least during the ini- tial stage of the experiment. We conclude that microhabitat choice represents a form of behavioural plasticity. Thus, even if the choice itself is flexible and not genetically determined, it can still lead to spatial genetic structure in the population because the phenotypes themselves may be genetically mediated [Current Zoology 58 （3）： 392--400, 2012].
基金This work was supported by the National Natural Science Foundation of China(31872961 and 31272330)the biodiversity survey and assessment project of the Ministry of Ecology and Environment of China(2019HB2096001006)the National Forestry and Grassland Administration of China.
文摘In this study,we report an unusual homing behavior of the Sichuan Partridge(Arborophila rufipectus)at the Laojunshan National Nature Reserve,Sichuan Province,China.Hen Sichuan Partridges led the chicks back to the nests where they hatched in the evening and roosted there over night.This behavior lasted 6.7±4.3 nights(range=1–15;n=13)after the chicks hatched.At this stage,the hens became very vigilant to predators and human disturbance.If disturbed,they often abandoned the nests immediately and no longer returned thereafter.The ambient temperature at night during the early brooding period of Sichuan Partridge at our study site was^12.4°C.Our findings suggest that hen Sichuan Partridges may make trade-offs between nest predation risks versus the thermoregulatory needs of their young.
基金Funding to C.Cheleuitte-Nieves was provided through Hispanic Leaders in Agriculture and the Environment(HLAE)fellowshipsthe Alfred P.Sloan Foundation,a Texas A&M University Graduate Diversity fellowshipa Department of Ecosystem and Management(Texas A&M University)Tom Slick fellowship.
文摘The multiple spatial and temporal parameters affecting cattle herd distribution and activity dynamics can significantly affect resource utilization but are not fully understood.The aim of this study was to determine whether current animal tracking technology and spatio-temporal analysis tools can be used to integrate multi-scale information on herd distribution patterns as a function of seasonal forage production,periods of the day,animal activity,and landscape features.Positional and activity information of 11 free-ranging cows within a 31-member herd was obtained at 5-min intervals by using GPS collars for 1 year within a 457-ha ranch in the semi-arid rangelands of South Texas.Forage biomass was calculated with satellite imagery.Spatial analysis of cattle distribution and landscape features was conducted with GIS.Herd spread was greatest during the growing season.Throughout the year,during midday,the herd showed smaller spread and greater use of shade patches than any other time of day.Cattle also aggregated under trees in winter,particularly during the night.There was no statistically significant overall pattern of seasonal changes in the use of water and supplemental feeding areas,but a trend toward highest use during the winter.However,significantly different diurnal patterns in the use of supplemental feed and water were observed within each season.This study found a strong influence of shade patches relative to the influence of water and supplemental feeding areas on the diurnal and seasonal movement patterns of cattle in shrub-dominated rangeland.Although this study used only 11 tracked cows in a 31-member herd,the results indicated that techniques such as seasonal and diurnal GPS tracking,GIS,and remote sensing data enable evaluation of multiple spatial and temporal dynamics of cattle distribution and activity patterns.The smaller spread during the dry winter season associated with the observed aggregation of individuals in water and supplemental feeding areas,may aid in determining the most critical tim
