What do population-level welfare indices suggest about the well-being of zoo elephants?

Abstract 10.1002/zoo.20303.abs To assess zoo elephants’ welfare using objective population-level indices, we sought data from zoos and other protected populations (potential “benchmarks”) on variables affected by poor well-being. Such data were available on fecundity, potential fertility, stillbirths, infant mortality, adult survivorship, and stereotypic behavior. Most of these can also be affected by factors unrelated to […]

Immunocontraception and increased longevity in equids

Abstract 10.1002/zoo.20109.abs Intensive population management by means of fertility control has been shown to change the age profile of a wild horse herd. The primary change has been an increase in the number and percent of older animals, as expected, but also the appearance of new and older age classes. An examination of direct effects […]

Reproduction of the lesser kudu (Tragelaphus imberbis) at Dvůr Králové Zoo

Abstract 10.1002/zoo.1430110205.abs Reproductive data on captive lesser kudus (Tragelaphus imberis) were collected from 1972 to 1990. The estrous cycles of two females were 21 and 22 days. Mean gestation length of 18 pregnancies was 244 ± 5.5 days (range = 235–256 days), and 71.2% of interbirth intervals (n = 146) were from 248 to 365 […]

Fitness and behavioral correlates of pre-stress and stress-induced plasma cortisol titers in pink salmon (Oncorhynchus gorbuscha) upon arrival at spawning grounds

Semelparous Pacific salmon (Onchorynchus spp.) serve as an excellent model for examining the relationships between life history, behavior and individual variation in glucocorticoid (GC) stress hormone levels because reproductive behaviors are highly variable between individuals and failure to reproduce results in zero fitness. Pink salmon (O. gorbuscha) were intercepted upon arrival at the spawning grounds […]

Culled early or culled late: economic decisions and risks to welfare in dairy cows

Involuntary culling (IC) is where a cow is disposed of due to injury, poor health or infertility. The main reasons for IC are infertility, mastitis and lameness. These reasons have differing age profiles in when they affect cows, cost variable amounts to treat and have an effect on the value of the cow at market. […]

Negative affective states and their effects on morbidity, mortality and longevity

Mortality rates are often used in population-level animal welfare assessments because they are assumed to reflect rates of disease or injury and other problems likely to cause poor welfare. High mortality is thus assumed to correlate with factors likely to cause negative affective states. Here, we argue that negative affective states are also related to […]

Life expectancy and longevity of varanid lizards (Reptilia:Squamata:Varanidae) in North American zoos

In zoos, life expectancy—the average lifespan of individuals within a population, and longevity—the maximum lifespan within a population, can be useful parameters for evaluating captive husbandry and animal welfare. Using life history and demographic data derived from regional studbooks, this study examined life expectancy and longevity in a total of 782 wild-caught (WC) and captive-bred […]

Demographics of polycystic kidney disease and captive population viability in pygmy hippopotamus (Choeropsis liberiensis)