Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment
For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare, such as ‘establishment’: a hypothetical process whereby repetition increases behaviour’s predictability and resistance to change. If such hypotheses are correct, […]
Stereotypic behavior in Asiatic black and Malayan sun bears
The stereotypies of individually caged Asiatic black bears (Ursus thibetanus) and Malayan sun bears (Helarctos malayanus) were studied in detail. Stereotypies were performed by 27 of the 29 subjects, were primarily locomotory in form (e.g., pacing), and occupied on average 18% (standard error of the mean (SEM)=2.5) of daylight hours. Stereotypy levels during the night […]
Global analysis of factors affecting the outcome of freshwater fish introductions
As humans move species around the globe, biotic homogenization decreases diversity. It is therefore crucial to understand factors influencing invasion success at a global scale. I analyzed factors predicting establishment of freshwater fishes transferred internationally based on 1424 cases of first introductions from one country to another as reported in FishBase, an encyclopedic database of […]
Determinants of vertebrate invasion success in Europe and North America
Species that are frequently introduced to an exotic range have a high potential of becoming invasive. Besides propagule pressure, however, no other generally strong determinant of invasion success is known. Although evidence has accumulated that human affiliates (domesticates, pets, human commensals) also have high invasion success, existing studies do not distinguish whether this success can […]
Individual differences in stereotypic behaviour predict individual differences in the nature and degree of enrichment use in caged American mink
Environmental enrichment (EE) reduces stereotypic behaviour (SB), but typically only partially. Using American mink (n = 17) as models, we tested the hypotheses that the effectiveness of EE reflects the degree to which subjects utilise it, and also the SB’s degree of ‘establishment’ (its frequency and within-bout predictability). In Non-Enriched cages, our subjects performed Carnivora-typical […]