Lead Hazards within the Range of the California Condor’
نویسنده
چکیده
The prevalence of lead in Golden Eagles (Aquila chrysaetos) occurring within the recent historical range of the California Condor (Gymnogyps californianus) was determined by analyzing blood samples from 162 Golden Eagles captured between June 1985 and December 1986 at three sites. We found no significant differences between sex and age classes in blood lead levels nor were there differences between residents and migrants. Significant differences were found between months with the highest blood lead levels occurring during the fall/winter period. Approximately one-third (35.8%) of the Golden Eagle population sampled had elevated blood lead levels, values similar to those reported for freeflying California Condors. Given this rate of exposure, if the proposed releases of California Condors back to the wild are to succeed, whether in their former range or elsewhere, any potential for lead poisoning must be reduced. It is essential that we identify the sources of the lead, the seasonal and geographic distribution of these sources, and develop management strategies to reduce or eliminate the hazard.
منابع مشابه
Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures
Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threa...
متن کاملSpatiotemporal patterns and risk factors for lead exposure in endangered California condors during 15 years of reintroduction.
Large-scale poisoning events are common to scavenging bird species that forage communally, many of which are in decline. To reduce the threat of poisoning and compensate for other persistent threats, management, including supplemental feeding, is ongoing for many reintroduced and endangered vulture populations. Through a longitudinal study of lead exposure in California condors (Gymnogyps calif...
متن کاملResource Selection by the California Condor (Gymnogyps californianus) Relative to Terrestrial-Based Habitats and Meteorological Conditions
Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook ...
متن کاملReducing Lead on the Landscape: Anticipating Hunter Behavior in Absence of a Free Nonlead Ammunition Program
Lead is a neurotoxin that has been documented to affect many forms of wildlife, and has been identified as a limiting factor in a population of California Condors in Northern Arizona. The Arizona Game and Fish Department provides vouchers for free nonlead ammunition to hunters selected to hunt within the distribution of California Condors, with the intention of having fewer lead-laden offal pil...
متن کاملComment on "Ammunition is the principal source of lead accumulated by California condors re-introduced to the wild".
The endangered California Condor (Gymnogyps californianus) was reduced to a total population of 22 birds by the end of 1982. Their captive-bred descendants are now being released back into the wild in California, Arizona, and Baja California, where monitoring indicates they may accumulate lead to toxic levels. Fragments of ammunition in the carcasses of game animals such as deer, elk, and feral...
متن کامل