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Understanding of resource requirements of vulnerable species is key for conservation planning. Here, we used stable carbon (δ 13 C) and nitrogen isotopes (δ 15 N) of hair from giant armadillos (Priodontes maximus) to understand individual resource use. We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pantanal and compared the resource use between sexes and age classes. We also assessed the relationship of isotopic values with individuals' body mass and the habitat type used. We observed a wide variation in resource use by giant armadillos, showing that individuals consume prey that feeds on distinct resources and occupies different habitat types, indicating that there is individual variation in foraging behavior. Most giant armadillos presented a mixed diet (C 3 /C 4 resources, forests/open areas), but a quarter of individuals had strictly C 4 diets (open areas). Males are more prone to forage on C 4 resources, presenting an isotopic niche 2.6-times larger than that of females. Subadults presented diets more associated with habitats with high arboreal cover (C 3 resources, forests), while adults foraged more in open areas (C 4 resources). This result is mirrored by the positive relationship between δ 13 C values and body mass, suggesting that larger giant armadillos tend to feed more in open areas. We observed that δ 13 C values decreased as individuals increased the use of habitats with high arboreal cover. We stress the importance of conserving the natural mosaic in the Pantanal landscape for the species persistence, given that giant armadillos require all habitat types to fulfill their dietary, spatial, and developmental needs., (© 2022 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

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., (© 2021 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)