Skip to main content
Advanced Search

Filters: Tags: reintroduction (X)

8 results (104ms)   

View Results as: JSON ATOM CSV
thumbnail
Captive breeding is increasingly being used to create supplies of endangered animals for release into natural habitats, but rearing strategies vary and debates arise over which methods are most efficient. We assessed postrelease behaviors and survival of three groups of black-footed ferrets, each with different prerelease experience. Eighteen ferret kits ≤60 days of age were moved with their dams from cages to 80-m2 outdoor pens with prairie dog burrows. These animals were compared to animals reared in standard cages (n=72), some of which were given experience killing prairie dogs (n=32). Ferrets were released onto white-tailed prairie dog (Cynomys leucurus) colonies in Wyoming, USA, in fall, 1992. Radio-tagged...
thumbnail
Alala, or Hawaiian Crow (Corvus hawaiiensis), were extinct in the wild since the early 2000s. The first effort to reintroduce captive bred Alala back into the wild was conducted at Puu Makaala Natural Area Reserve on Hawaii Island. The 2017 release cohort were released in two stages and were the only Alala in the wild. Using automated radio telemetry tracking towers (n=4) that were distributed around the release area, we tracked the birds from September 26, 2017, to May 19, 2018, to document early exploratory movement of these birds in the wild.
thumbnail
This study addressed the initial effects of a reintroduction of Gunnison's prairie dogs (Cynomys gunnisoni) on resident small mammal and plant communities on the Sevilleta National Wildlife Refuge (SNWR), New Mexico. In spring 1997, 60 prairie dogs (36.8 kg live mass) were introduced onto a former prairie dog colony in a desert grassland site. Small mammals and vegetation were sampled on both a treatment (reintroduction site) and a control site (without prairie dogs) before and after the prairie dogs were reintroduced. We tested for differences in small mammal and plant community change during the 1st year of the colony's existence using repeated measures analysis of variance. Although prairie dog biomass was ca....
Species reintroduction programmes, in prioritizing areas for reintroductions, have traditionally used tools that include measures of habitat suitability and evaluations of area requirements for viable populations. Here we add two tools to this approach: evaluation of ecological requirements of species and evaluation of future suitability for species facing changing climates. We demonstrate this approach with two species for which reintroduction programmes are in the planning stages in Mexico: California condor Gymnogyps californianus and Mexican wolf Canis lupus baileyi. For the condor, we identify three areas clustered in the Sierra San Pedro Martir, Baja California; for the wolf, we identify a string of suitable...
The scientific evidence that California condors (Gymnogyps californianus) are frequently sickened and killed by lead poisoning from spent ammunition supports the conclusion that current levels of lead exposure are too high to allow reintroduced condors to develop self-sustaining populations in the wild in Arizona and, by inference, in California. The evidence for lead poisoning and its source comes from the following sorts of data: 1) 18 clinical necropsies revealing high levels of lead in body tissues and (or) presence of lead shotgun pellets and bullet fragments in digestive tracts; 2) moribund condors showing crop paralysis and impending starvation with toxic levels of lead in their blood; 3) widespread lead...
Translocations are a common conservation technique; however, the feasibility and success of translocations are evaluated rarely. We translocated 57 trumpeter swans (Cygnus buccinator) from Idaho to previous termUtahnext term during 1996 to encourage migration to more southern wintering areas. We evaluated the feasibility and success of the translocation by studying biological and socio-political criteria prior to and during the translocation. Lack of support from governmental and non-governmental agencies did not allow additional translocations in subsequent years. Additional releases are needed, however, to increase the probability of swan returns to the release area. Our evaluation explores the possibility that...
We modeled populations of lynx (Lynx canadensis) and snowshoe hares (Lepus americanus) to determine prey densities required for persistence of lynx translocated to the southern portion of the species' range. The models suggested that a density of 1.1?1.8 hares/h is required for lynx persistence; these densities are higher than those reported for most hare populations across the USA. We found that lynx dispersal and density-independent mortality substantially increased the hare density required for lynx persistence. Reintroduction success was associated with number of release events, total number of animals released, and timing of release relative to the phase of the hare population cycle. However, no release protocol...
thumbnail
This study examined the reproductive biology of the Mariana Swiftlet over five annual cycles on the island of O‘ahu in the Hawaiian Islands. This introduced population used a human-made tunnel for roosting and nesting, and was studied as a surrogate to negate interference with the endangered populations in the Mariana Islands. Active nests (N = 478) were observed in every month of the year. Data recorded included: nest visit dates, date nests were identified, number of visits to each nest; nest stage, nest fate, nest failure status, number of rat traps present, number of rats captures, daily rainfall, and nest ages.
    map background search result map search result map Influence of prerelease experience on reintroduced black-footed ferrets (Mustela nigripes) Responses of small mammals and vegetation to a reintroduction of Gunnison's prairie dogs Nest success and predation data for Mariana swiftlets (Aerodramus bartschi), Hawai'i, USA, 2006-2010 Hawaii Island locations of reintroduced Alala from automated radio telemetry tracking system, 2017 cohort Responses of small mammals and vegetation to a reintroduction of Gunnison's prairie dogs Nest success and predation data for Mariana swiftlets (Aerodramus bartschi), Hawai'i, USA, 2006-2010 Influence of prerelease experience on reintroduced black-footed ferrets (Mustela nigripes)