Enrichment reduces stereotypical behaviors and improves foraging development in rehabilitating Eastern Pacific Harbor Seals (Phoca vitulina richardii)

There is empirical support for the efficacy of enrichment in decreasing stereotypical behaviors and increasing naturalistic behaviors in laboratory, agricultural, and zoological settings. However, little research has been done on the possible value of enrichment in facilitating appropriate behavioral development of rescued wildlife in rehabilitative captivity. Eastern Pacific harbor seal pups (Phoca vitulina richardii) often […]

Optimal marine mammal welfare under human care: Current efforts and future directions

Marine mammals include cetaceans, pinnipeds, sirenians, sea otters and polar bears, many of which are charismatic and popular species commonly kept under human care in zoos and aquaria. However, in comparison with their fully terrestrial counterparts their welfare has been less intensively studied, and their partial or full reliance on the aquatic environment leads to […]

Carnivorous mammals: nutrient digestibility and energy evaluation

Abstract Estimating the energy content is the first step in diet formulation, as it determines the amount of food eaten and hence the concentration of nutrients required to meet the animal’s requirements. Additionally, being able to estimate the energy content of a diet empirically known to maintain body condition in an animal will facilitate an […]

Urinary cortisol sampling: a non-invasive technique for examining cortisol concentrations in the Weddell seal, Leptonychotes weddellii

Abstract 10.1002/zoo.20088.abs This study investigated the feasibility and validity of using non-invasively collected ice urine samples to measure cortisol concentrations in Weddell seals. Radio-immunoassays were used to determine urinary cortisol, and spectrophotometric assay was used to determine creatinine concentrations. This allowed for urinary cortisol/creatinine ratios (UCCR) to be compared between pure urine and urine collected […]

Absorption and Ocular Deposition of Dietary Lutein in Marine Mammals

Cataracts and ocular disease are common lesions of marine mammals in zoological collections. Lutein, an oxygenated carotenoid, may have therapeutic or prophylactic effects on ocular disorder. Therefore, this study examined the ability of marine mammals to absorb dietary lutein. Two preliminary trials examined lutein in two forms (beadlet or ester) in a small sample size […]

Behavior and body mass changes of a mother and calf Pacific walrus (Odobenus rosmarus divergens) during the suckling period

The behavior of a 13-year-old female Pacific walrus and her first calf is described during the first 7 months of the 19-month suckling period. The calf vocalized before 62% of suckling sessions. The mother immediately responded after 84% of vocalizations; after 44% she allowed a suckling session. The number of suckling sessions per 24-h period […]

Serum estradiol and progesterone profiles during estrus, pseudopregnancy, and active gestation in Steller sea lions

While the proximate driver behind the decline of the Western stock of Steller sea lions (Eumetopias jubatus, >80% since 1970s) is likely multifactorial, the population reduction may have been powered by a decrease in fecundity. A harvest of Steller sea lions in the 1970s and 80s revealed a 30% reduction in the proportion of pregnant […]