نتایج جستجو برای: captive breeding and re
تعداد نتایج: 16860702 فیلتر نتایج به سال:
Captive breeding is used to supplement populations of many species that are declining in the wild. The suitability of and long-term species survival from such programs remain largely untested, however. We measured lifetime reproductive success of the first two generations of steelhead trout that were reared in captivity and bred in the wild after they were released. By reconstructing a three-ge...
The Japanese crested ibis is an internationally conserved, critically threatened bird. Captive-breeding programs have been established to conserve this species in Japan. Since the current Japanese population of crested ibis originates only from 5 founders donated by the Chinese government, understanding the genetic diversity between them is critical for an effective population management. To di...
A total of 114 captive elephants (6 Asian; 108 African) from 43 private institutions or North American zoos accredited by the Association of Zoos and Aquariums were sampled and evaluated to investigate genetic status. Because previous analyses of the captive collection indicated potential cytonuclear dissociation between mitochondrial DNA (mtDNA) sequence and microsatellite nuclear DNA genotype...
About 10 per cent of birds' eggs fail to hatch, but the incidence of failure can be much higher in endangered species. Most studies fail to distinguish between infertility (due to a lack of sperm) and embryo mortality as the cause of hatching failure, yet doing so is crucial in order to understand the underlying problem. Using newly validated techniques to visualize sperm and embryonic tissue, ...
Captive groups of primates often exhibit higher rates of aggression than wild, free-ranging groups. It is important to determine which factors influence aggression in captivity because aggression, particularly intense aggression, can be harmful to animal health and well-being. In this study, we investigated the effect of ground substrate as well as season, rank, age, and group size on rates of ...
This study observed the captive culture of Carassius auratus and Cyprinus carpio in Potohar region, Punjab, Pakistan. Captive culturing both species was conducted up to one-month post hatchlings. The sample size 180 (90 goldfish 90 koi carp) kept cemented raceways under optimum conditions. period from October 2019 April 2020. natural breeding season for 25th January 5th February end 11th March,...
High among-individual variation in mating success often causes problems in conservation breeding programs. This is also the case for critically endangered European mink and may jeopardize the long-term maintenance of the species' genetic diversity under the European mink EEP Program. In this study, breeding success of wild and captive born European minks at Tallinn Zoological Garden are compare...
Approximately 26 billion animals, spanning over 10 000 species, are kept on farms and in zoos, conservation breeding centers, research laboratories and households. Captive animals are often healthier, longer-lived and more fecund than free-living conspecifics, but for some species the opposite is true. Captivity is a very long way from the ideal 'common garden' often assumed by evolutionary and...
The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programme...
Captive breeding programs are widely used for the conservation and restoration of threatened and endangered species. Nevertheless, captive-born individuals frequently have reduced fitness when reintroduced into the wild. The mechanism for these fitness declines has remained elusive, but hypotheses include environmental effects of captive rearing, inbreeding among close relatives, relaxed natura...
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