Applicability of modeling tools to tackle conservation problems is key for conservation planning. However, modeling papers regarding real-world conservation issues are scarce. Here, we combined two modeling tools to identify priority areas in the Brazilian Atlantic Forest, focusing on the last large-bodied frugivorous bird in the region, the red-billed curassow (Crax blumenbachii). We used population viability analysis (PVA) to determine (1) the minimum viable population size under different hunting scenarios; and (2) the minimum critical forest patch size required to maintain viable populations. We used ecological niche modeling (ENM) to identify remnants that retain suitable environmental conditions to ensure the long-term persistence of this species. We overlapped the outputs from PVA and ENM models to identify priority areas for curassows. Under our best-case scenario, 56 individuals would suffice to maintain a viable population and 71 forest patches located within the species' known range are above the critical size of 3141 ha. In the worst-case scenario, at least 138 individuals would be required to maintain a viable population in forest patches larger than 9500 ha, corresponding to only 20 Atlantic Forest fragments within the species range. Among these, 17 presented median habitat suitability values higher than 0.70, eight of which were selected as priority areas for law enforcement and nine as priority areas for reintroduction. We encourage conservation biologists and

We calculated a genetically based minimum viable population size of the red-cockaded woodpecker (Picoides borealis) using a formula derived from Hill (1972) and life history data from a long-term study. Based on published criteria for maintenance of genetic variability, a red-cockaded woodpecker population must contain 509 breeding pairs to be considered viable. It is likely that no existing population contains 509 breeding pairs. Genetically based estimates of population viability may not be valid, but if they are adopted as in the recovery plan for the red-cockaded woodpecker, the area required for a viable population would be >25,450 ha. The estimates of population size and area required for a viable population are considerably higher than those contained in the species' recovery plan (U.S. Fish and Wildl. Serv. 1985). J. WILDL. MANAGE. 52(3):385-391 A viable population is self-sustaining over a long period. Population viability is a critical issue in conservation, but how viability should be assessed is unclear. The most commonly used methods are (1) determining the probability, based on demography and population size, that a population will become extinct over a predetermined number of years (Shaffer 1983, Shaffer and Samson 1985); (2) determining the size of naturally occurring, stable populations of a species (Shaffer 1981); and (3) determining if a population is large enough to maintain its genetic variability (Franklin 1980, Lehmkuhl 1984). These 3 methods address di

Abstract While conservation management is increasingly turning towards an ecosystem-level framework, the focus on a small subset of surrogate species has recognised merit given insufficient time, resources, and expertise. The kaka ( Nestor meridionalis ), a large threatened New Zealand parrot, is an iconic, visible species in lowland forests. As kaka populations are sensitive to mustelid predation and habitat loss, kaka can act as both a flagship and indicator species for healthy lowland forest ecosystems in New Zealand. To ensure the sustained protection of kaka over a sufficient area, this research aims to estimate the minimum viable population (MVP) size of kaka in the Eglinton Valley, Fiordland, and the management required for population persistence. A post-breeding census, stochastic, age structured Leslie matrix model was developed to estimate the population size having a 95% probability of persistence over 100 years. Scenarios modeling current and alternate management regimes, uncertain life-history traits, and environmental unpredictability were run. The most ‘realistic’ scenario resulted in an MVP size of 258 kaka (155 adults). Maintaining current levels of predator control appears essential to ensure kaka population persistence. An area of >500 km 2 is proposed to maintain the MVP of kaka based on detailed information on home range size and territory overlap derived from radio-tracking studies. As one of a group of surrogate species in lowland forest ecosystems, kak

Abstract Estimating minimum viable population and reserve size is a fundamental cornerstone of conservation biology—but these estimates require representative demographic parameters. For example, “Benchmark” Grizzly Bear (Ursus arctos) Management Units in British Columbia (BC) are defined as unhunted and naturally regulated populations that can serve as population sources to surrounding hunted areas and provide information on natural population processes. Such benchmarks should have a very small probability of becoming threatened (N 1 2 K, 3 4 K, and K. Results indicated that 200–250 bears were required for a sufficiently small probability (P 20 years. Reserve sizes varied from 8556 km2 to 17,843 km2 depending on population density in each benchmark. These minimum viable populations and reserve sizes would protect approximately 12% of the estimated provincial grizzly bear population and would cover approximately 5% of the landmass of BC.

Abstract A population viability analysis (PVA) was conducted to assess the minimum viable population (MVP) of the Atlantic Forest spiny rat Trinomys eliasi, a species threatened by habitat loss and restricted geographical distribution. Objectives were to suggest quasi-extinction thresholds, estimate minimum areas of suitable habitat (MASH) and MVPs, and compare results with the species’ current status. The computer package VORTEX was used. The model predicted sizes of 200 animals to achieve demographic stability, but buffering declines in genetic variability required populations of 2000 animals. Estimated MASHs were approximately 250 and 2500 ha for demographic and genetic stability, respectively. Mortality rate and mean litter size were the most sensitive parameters to changes in model assumptions. The protection of known populations and the search for extant populations are the first steps in conservation. T. eliasi's issue could help protecting the coastal shrubland ecosystem of Rio de Janeiro state. Observing IUCN's criteria for listing threatened species, it is suggested that T. eliasi should be ranked as vulnerable in red lists.

Abstract A procedure is described to estimate viable population size and the area of habitat needed to support an endangered stream fish population. Monte Carlo simulations were used to evaluate population fates with stochastic demography and random variation simulated to cause age class 0 failures in some years. Viable population was defined in this paper to be large enough to have less than a 10% chance of extinction in 100 years and to have a long‐term effective size of at least 500 breeding adults, although the method could be applied for any assumed extinction rate and effective size. Using data for Rio Grande cutthroat trout ( Oncorhynchus clarkii virginalis ) in an age class model, it was inferred from simulations that minimum viable population size was 2750 fish, which would require 2.2 ha of habitat at median density of the subspecies in New Mexico streams. Minimum viable population size occurred at the highest survival rate of young of year and no population‐wide year class failures. Viable population size, and hence required habitat size, increased as the failure rate for age class 0 increased or when the survival rate from age 0 to 1 declined. This suggested that managers should avoid managing for smallest possible viable population size and instead plan for much larger population sizes to accommodate temporal variation in demography and habitat quality. Decreased survival rate of young of year caused the stable age class distribution to be skewed toward the age c

A non-spatial agent-based model is used to explore how marriage behaviors and fertility affect the minimum population size required for hunter-gatherer systems to be demographically viable. The model incorporates representations of person- and household-level constraints and behaviors affecting marriage, reproduction, and mortality. Results suggest that, under a variety of circumstances, a stable population size of about 150 persons is demographically viable in the sense that it is largely immune from extinction through normal stochastic perturbations in mortality, fertility, and sex ratio. Less restrictive marriage rules enhance the viability of small populations by making it possible to capitalize on a greater proportion of the finite female reproductive span and compensate for random fluctuations in the balance of males and females.

represents a minimum viable population for any one taxon all the time. Rather, viable population size depends … populations 166-8 viable population size 150-4 viable population strategies 165—72 viable population theory 17-18 … ecological ideas Minimum viable population sizes (MVP): genetic considerations Minimum viable population sizes

the minimum viable population size, shown as stars, was defined as the population size at … relatively small distance is required in many cases to prevent contamination. Experiments … probabilistic element (Shaffer, 1981): ‘[A] minimum viable population for any given species in any