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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 Mártir, Baja California; for the wolf, we identify a string of suitable sites along the Sierra Madre Occidental of western Mexico. We discuss the limitations of this approach, identifying ways in which the models illustrated could be made more realistic and directly useful to reintroduction programmes.

The entire population of the California Condor ( Gymnogyps californianus) probably contains fewer than 50 individuals (Wilbur 1976(Wilbur , 1978. Within its recorded history the species has shown a continual decline in numbers. During the past decade there has been an especially alarming decrease in condor recruitment. Between 1968 and 1975 the entire population averaged only 1.5 young fledged per year with a maximum of two produced any single year (Wilbur 1978).Mortality factors which historically have reduccd the condor population (Koford 1953) cannot account for the observed recent decrease in productivity. Lowered reproductive success in numerous other bird species in recent years has been associated with eggshell thinning caused almost exclusively by p,p' DDE, the principal metabolite of DDT (Cooke 1973, Stickel1975, Peakall 1975). In this paper we document thinning and other structural changes in California Condor eggshells, verify the presence of DDE in the thin eggs, and suggest that the "DDT syndrome" has contributed to lowered nesting success. Comparisons are made to the changes induced by the experimental feeding of DDE to the structure of eggshells of another falconiform species, the American Kestrel (F&o sparverius) . MATERIALS AND METHODSDuring the late 1960' s, a former U.S. Fish and Wildlife Service biologist, Fred C. Sibley, regularly visited all condor nests thought to have been used recently in order to monitor reproductive activity. During his visit to each nest, Sibley strained the loose substrate from the floor of the cavity through a fine-meshed screen. Sharp rocks, bone fragments and other debris which might pose a danger to an egg were removed, and all eggshell fragments he found were collected. Between 1966 and 1969, he obtained at least eight samples of eggshell fragments of known year of origin from six different condor nest sites, and he made them available to us for study. In addition, Eben McMillan provided 11s with shell fragments of a broken condor egg that he found in a nest in 1964. Wilbur and John Borneman collected fragments from another nest in 1976, and a party directed by Wilbur secured four more samples in November 1977. In order to detect changes in shell thickness, these fragments and intact California Condor eggshells in the Western Foundation of Vertebrate Zoology collection were measured with a model 35 PS Federal bench comparator thickness gauge, or with a modified Starrett Model 1010 M micrometer. We attempted to measure only specimens that had intact shell membranes tightly affixed to the true shell. However, some samples of fragments totally lacked shell membranes. To the measured thickness of these we added 0.10 mm, the mean thickness of normal California Condor eggshell membranes, as compensation. Whole eggs were measured on the egg equator through the blow-hole near the middle of one side, whereas we couldn' t tell what part of the eggshell the fragments came from. Condor eggshell fragments taken in 1896. 1922. -1964, 1966, 1967 and i969, and those of control...

BackgroundThe harpy eagle (Harpia harpyja) is the largest Neotropical bird of prey and is threatened by human persecution and habitat loss and fragmentation. Current conservation strategies include local education, captive rearing and reintroduction, and protection or creation of trans-national habitat blocks and corridors. Baseline genetic data prior to reintroduction of captive-bred stock is essential for guiding such efforts but has not been gathered previously.Methodology/FindingsWe assessed levels of genetic diversity, population structure and demographic history for harpy eagles using samples collected throughout a large portion of their geographic distribution in Central America (n = 32) and South America (n = 31). Based on 417 bp of mitochondrial control region sequence data, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and South America, although haplotype diversity was significantly higher for South America. Historical restriction of gene flow across the Andes (i.e. between our Central and South American subgroups) is supported by coalescent analyses, the haplotype network and significant F ST values, however reciprocally monophyletic lineages do not correspond to geographical locations in maximum likelihood analyses. A sudden population expansion for South America is indicated by a mismatch distribution analysis, and further supported by significant (p<0.05) negative values of Fu and Li's DF and F, and Fu's F S. This expansion, estimated at approximately 60 000 years BP (99 000–36 000 years BP 95% CI), encompasses a transition from a warm and dry time period prior to 50 000 years BP to an interval of maximum precipitation (50 000–36 000 years BP). Notably, this time period precedes the climatic and habitat changes associated with the last glacial maximum. In contrast, a multimodal distribution of haplotypes was observed for Central America suggesting either population equilibrium or a recent decline.SignificanceHigh levels of mitochondrial genetic diversity in combination with genetic differentiation among subgroups within regions and between regions highlight the importance of local population conservation in order to preserve maximal levels of genetic diversity in this species. Evidence of historically restricted female-mediated gene flow is an important consideration for captive-breeding programs.

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