Differences in an animal's spatial environment can have dramatic effects on the hippocampus, an area of the brain involved with spatial processing. Animals in spatially impoverished environments have decreased hippocampal attributes. However, we do not know if differences in the spatial environment differentially interact with territorial status, which also covaries with hippocampal attributes....

Stereotypies are commonly observed in zoo animals, and it is necessary to better understand whether ambient environmental factors contribute to stereotypy and how to affect animal welfare in zoo settings. This study investigated the relationships between stereotypic behaviors and environmental factors including ambient temperatures, humidity, light intensity, sound intensity and number of visit...

Slave-making ants are specialized social parasites that steal the young from colonies of their host species to augment their slave supply. The degree of parasite-host specialization has been shown to shape the trajectory along which parasites and hosts coevolve and is a prime contributor to the geographic mosaic of coevolution. However, virtually nothing is known about extrinsic influences on p...

In previous studies, children disoriented in small enclosures used room shape, but not wall colours, to find hidden objects. Their reorientation was said to depend solely on a "geometric module" informationally encapsulated with respect to colour. We argue that previous studies did not fully evaluate children's use of colour owing to a bias in the enclosures' design. In this study, disoriented ...

Predators can influence prey directly through consumption or indirectly through nonconsumptive effects (NCEs) by altering prey behavior, morphology, and life history. We investigated whether predatoravoidance behaviors by larval longtoed salamanders (Ambystoma macrodactylum) in lakes with nonnative trout result in NCEs on morphology and development. Field studies in lakes with and without trout...

Laboratory and in-stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not...

Sexual size dimorphism results when female and male body size is influenced differently by natural and sexual selection. Typically, in polygynous species larger male body size is thought to be favored in competition for mates and constraints on maximal body size are due to countervailing natural selection on either sex; however, it has been postulated that sexual selection itself may result in ...