Determinants of Home Range Size for Polar Bears (Ursus maritimus)

The mean home range size of female polar bears (Ursus maritimus; 125 100 km2 ± 11 800; n = 93) is substantially larger than the predicted value (514 km2) for a terrestrial carnivore of similar weight. To understand this difference, we correlated home range size and sea ice characteristics. Home range size was related to […]

A case of non-scaling in mammalian physiology? Body size, digestive capacity, food intake, and ingesta passage in mammalian herbivores☆

As gut capacity is assumed to scale linearly to body mass (BM), and dry matter intake (DMI) to metabolic body weight (BM0.75), it has been proposed that ingesta mean retention time (MRT) should scale to BM0.25 in herbivorous mammals. We test these assumptions with the most comprehensive literature data collations (n=74 species for gut capacity, […]

Body temperature and thermoregulation of Komodo dragons in the field

Komodo dragons from hatchlings (≈0.1 kg) to adults (≤80 kg) express the full magnitude of varanid species size distributions. We found that all size groups of dragons regulated a similar preferred body temperature by exploiting a heterogeneous thermal environment within savanna, forest and mangrove habitats. All dragons studied, regardless of size, were able to regulate […]

Agonistic Behavior in Freshwater Crayfish The Influence of Intrinsic and Extrinsic Factors on Aggressive Encounters and Dominance

Fighting success and dominance in crayfish depends on a variety of extrinsic and intrinsic factors. Most intrinsic factors studied to date are related to the physical size of the crayfish. Larger crayfish or those with larger chelae often have advantages in agonistic interactions. Age, sex, and reproductive status can influence the physical size of the […]

Relations between captive and noncaptive weights in anthropoid primates

Abstract 10.1002/zoo.1430130105.abs This study explores the relations between captive and noncaptive (literature-reported wild) adult weights in 53 anthropoid primate species. Based on recent studies of variation in growth among wild populations, it is expected that captive and wild weights are highly correlated. In addition, the lack of a relation between species size and captive and […]

The Relationship between Popularity and Body Size in Zoo Animals

Larger animals are more expensive to maintain in zoos than are smaller animals, and they breed at slower rates. Consequently, zoos could potentially contribute more to conservation efforts by concentrating on smaller-bodied species, but they could lose patronage if the zoo’s public prefers to see larger species. Therefore, we examined the relationship between the popularity […]

Maternal effects and the endocrine regulation of mandrill growth

Maternal effects can influence offspring growth and development, and thus fitness. However, the physiological factors mediating these effects in nonhuman primates are not well understood. We investigated the impact of maternal effects on variation in three important components of the endocrine regulation of growth in male and female mandrills (Mandrillus sphinx), from birth to 9 […]

Feeding and Resting Postures of Wild Northern Muriquis (Brachyteles hypoxanthus)

Increased body size in Brachyteles has been regarded as an important evolutionary adaptation that allowed a greater reliance on leaves compared to other more frugivorous Atelidae, but its association with muriqui positional behavior and substrate use is still unknown. Here, we present original data on the feeding and resting postures of the northern muriqui (Brachyteles […]

Effect of egg predator on nest choice and nest construction in sand gobies

Nest defence is a particularly costly component of parental care. The costs of nest-related behaviours are affected by the nest’s location, size and architecture; yet surprisingly little is known about how choice of a nesting site or nest characteristics are adjusted as a response to the threat of future nest predation. To address this topic, […]