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Oregon City, OR, United States

Raines J.A.,Dallas Zoo and Childrens Aquarium at Fair Park | Storms T.,Oregon Zoo
Journal of Zoo and Wildlife Medicine | Year: 2015

A captive Indochinese sika deer (Cervus nippon pseudaxis) was castrated at the age of 5 yr. The resultant abnormal antler growth over the next few years became difficult to manage from both the veterinary and husbandry standpoints. Using a commercially available trenbolone acetate and estradiol implant marketed for domestic cattle heifers, normal mineralization of the abnormal antlers was achieved along with the expected normal casting. The deer was then maintained for 6 yr using an annual implant regimen. © Copyright 2015 by American Association of Zoo Veterinarians. Source


Martin M.S.,PDX Wildlife | Shepherdson D.J.,Oregon Zoo
Conservation Biology | Year: 2012

Success of captive-breeding programs centers on consistent reproduction among captive animals. However, many individuals do not reproduce even when they are apparently healthy and presented with mates. Mate choice can affect multiple parameters of reproductive success, including mating success, offspring production, offspring survival, and offspring fecundity. We investigated the role of familiarity and preference on reproductive success of female Columbia Basin pygmy rabbits (Brachylagus idahoensis) as measured by litter production, litter size, average number of young that emerged from the burrow, and average number of young that survived to 1 year. We conducted these studies on pygmy rabbits at the Oregon Zoo (Portland, Oregon, U.S.A.) and Washington State University (Pullman, Washington, U.S.A.) from February to June 2006, 2007, and 2008. Before mating, we housed each female adjacent to 2 males (neighbors). Female preference for each potential mate was determined on the basis of behavioral interactions observed and measured between the rabbits. We compared reproductive success between females mated with neighbor and non-neighbor males and between females mated with preferred and nonpreferred males. Our findings suggest that mating with a neighbor compared with a non-neighbor and mating with a preferred neighbor compared with a nonpreferred neighbor increased reproductive success in female pygmy rabbits. Litter production, average number of young that emerged, and average number of young that survived to 1 year were higher in rabbits that were neighbors before mating than in animals who were not neighbors. Pairing rabbits with a preferred partner increased the probability of producing a litter and was significantly associated with increased litter size. In captive breeding programs, mates are traditionally selected on the basis of genetic parameters to minimize loss of genetic diversity and inbreeding coefficients. Our results suggest that integrating genetic information with social dynamics and behavioral measures of preference may increase the reproductive output of the pygmy rabbit captive-breeding program. Our findings are consistent with the idea that allowing mate choice and familiarity increase the reproductive success of captive-breeding programs for endangered species. © 2012 Society for Conservation Biology. Source


Whitham J.C.,Chicago Zoological Society | Wielebnowski N.,Oregon Zoo
Applied Animal Behaviour Science | Year: 2013

In recent years, zoos and aquaria have intensified efforts to develop approaches and tools for assessing the welfare of populations and individual animals in their care. Advances made by welfare scientists conducting studies on exotic, farm, laboratory, and companion animals have led to the emergence of a new perspective on welfare assessment in zoos. This perspective: (1) emphasizes the importance of supplementing resource-based assessments with animal-based approaches that require measures of the behavioral and/or physical state of individual animals, (2) focuses on the subjective experiences of individual animals, and (3) considers positive affective states. We propose that the zoo community also should increase efforts to integrate measures of positive affect into both population-level studies and tools for monitoring individual well-being. For years, zoo welfare researchers have conducted trans-disciplinary, multi-institutional studies to identify risk factors associated with poor welfare. In the future, large-scale research projects, as well as epidemiological studies specifically designed to examine the patterns of welfare issues within populations, should integrate behavioral, physiological, and biological measures of good well-being (e.g. play, exploratory behaviors, measures of immunological function). While the results of population-level studies can be used to refine animal care guidelines, individual animals should be monitored to ensure that their needs are being met. Furthermore, after determining how to elicit positive affective states in individual animals, the zoo community should attempt to promote these states by offering positive experiences. We describe two strategies that zoos can currently pursue to facilitate the occurrence of positive affective states: (1) provide animals with stimulating opportunities to overcome challenges, make choices, and have some level of control over their environments, and (2) promote appropriate and beneficial keeper-animal relationships. Ultimately, we hope that as welfare researchers gain a better understanding of how to assess and promote good well-being, zoos and aquaria can apply these findings to actively strive toward achieving the best possible welfare for all animals in their care. © 2013 Elsevier B.V. Source


News Article | April 22, 2016
Site: http://www.techtimes.com/rss/sections/environment.xml

Climate change is taking its toll on a majority of Earth's species — from habitat and to even their diet. Scientists from U.S. Geological Survey (USGS) studied the effects of climate change on polar bear's diet to assess the extent of adaptation and its effects on the overall health of bears. Zoo curator Amy Cutting acknowledged that climate change is indeed happening at an alarming rate. Understanding the bear's response to environmental changes will help them in making decisions that would protect the animals in the wild. Researchers from USGS used Oregon Zoo polar bears, Conrad and Tasul, to collect baseline information before studying bears in the Arctic regions. "Scientists and wildlife managers need to understand how polar bears are responding as sea ice retreats," said Cutting. "But polar bears are notoriously difficult to study in the wild. Direct behavioral observations are nearly impossible." The shift in the Arctic ice has significantly altered the diets of polar bears. Instead of consuming ringed seals, polar bears in East Greenland are now eating hooded seals. Does diet have health implications on polar bears? To understand how polar bears process their food, the USGS researchers used stable isotopes that are present in the animal's tissues and serves as their dietary signature. These chemical markers can reveal what and where the food was eaten. USGS wildlife biologist and study lead Dr. Karyn Rode said that the use of stable isotopes has allowed them to use blood and hair samples to see whether the polar bears changed its diet since the 1980s and the effect of the meal diversity in their health. To assist in data collection, Conrad and Tasul switched their diet between terrestrial and marine foods, dubbed by zoo staff the "surf-and-turf experiment." The researchers then compared new samples from their USGS archived samples from 25 years ago. Rode said the comparison includes how the bears processed the food. "It's not just that a 50 percent salmon diet shows up as 50 percent salmon in the body," Rode explained. "Some gets routed toward body fat, some gets stored and some is transformed directly to energy. I need to understand how the bear body processes food before I can understand how different diets may affect them." The study is not only helpful in understanding the diet of polar bears but also invaluable in terms of preserving their population. The International Union for Conservation of Nature (IUCN) stressed the gravity of threat to the polar bears existence. With only about 26,000 left, the IUCN included it in the 2015 Red List of Threatened Species. Since they depend on sea ice when they eat, IUCN said that melting ice forces the polar bears to starve longer as they hunt for food and starvation significantly affects the animal's reproductive abilities. The study was published in Physiological and Biochemical Zoology. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.


News Article
Site: http://www.reuters.com

An endangered Amur leopard, which was euthanized on Tuesday due to kidney disease and old age, is seen at the Oregon Zoo in an undated handout photo provided by the zoo. "Given that there are fewer than 300 of these animals left in the world, every passing feels particularly poignant," zoo curator Amy Cutting said in a statement. Before her death on Tuesday, Kia may have been the oldest of her subspecies on the planet, the zoo said. She gave birth to nine cubs, or 3 percent of the world population of Amur leopards, over her lifetime. "She had a good life, raised a bunch of cubs and was an excellent mother," said Cynthia Kreider, who leads the Association of Zoos and Aquariums' efforts to boost and preserve Amur leopards in the wild. Populations of the giant cat, which are only found in northern China and Russia's far east, have been decimated by poaching, inbreeding and fires, with fewer than 70 of the animals believed to live in the wild. Kia's cubs are now part of an effort to breed and preserve new generations of the animals, the zoo said.

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