Empirical estimates of minimum viable population sizes for primates: tens to tens of thousands?

Harcourt, Alexander H.

doi:10.1017/s1367943002002287

Cited by 33 publications

(24 citation statements)

References 58 publications

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“…A minimum population size, at least 250 adults (Shaffer 1981, Nunney & Campbell 1993 but usually up to thousands of adults (Harcourt 2002, Brito & Figueiredo 2003, Reed et al 2003, Traill et al 2007, is needed in mammals to resist the minimal level of stochastic genetic diversity loss. The current population size of TWC humpback dolphins (fewer than 100 animals; Wang et al 2007, Yu et al 2010, is substantially lower than the lowest predicted limit of at least 250 adults, and genetic exchange with neighboring populations, e.g.…”

Section: Factors Affecting the Results Of Trend Projection And Statusmentioning

confidence: 99%

Population trends and vulnerability of humpback dolphins Sousa chinensis off the west coast of Taiwan

Huang¹,

Chang²,

Karczmarski³

2014

Endang. Species. Res.

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Predictive modeling of population trends can indicate the rate of population decline and risk of extinction, providing quantitative means of assessing conservation status and threats. Our study tests the rate of population change and risk of extinction of the Indo-Pacific humpback dolphin Sousa chinensis off the west coast of Taiwan, the only humpback dolphin population classified as Critically Endangered (CR) by the IUCN Red List of Threatened Species. Under the most optimistic assumptions, almost 60% of simulations (out of 250 replications × 5000 iterations) predicted that population decline will exceed 80% within 3 generations, while the mean estimate of population decline within 1 generation was > 50% of the current population numbers. Status classification performed using IUCN Red List Categories and Criteria Version 3.1 supported previous CR classification, while risk assessment models that factored in anthropogenic impacts further increased the estimated extinction risk. At an adult survival rate of 0.95, a modeled increment of annual bycatch rate by 1% of population size increased the probability of extinction within 100 yr by 7.5%; this increase was lower at a higher adult survival rate. The estimated extinction risk was greatest under the impact of habitat loss, reaching a hazardous level when habitat carrying capacity dropped to less than 50%, indicating that habitat fragmentation and alteration of coastal environments pose the greatest threats to this population, even if the cumulative sum of fragmented patches of habitat may superficially appear to be large.

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Section: Factors Affecting the Results Of Trend Projection And Statusmentioning

confidence: 99%

Population trends and vulnerability of humpback dolphins Sousa chinensis off the west coast of Taiwan

Huang¹,

Chang²,

Karczmarski³

2014

Endang. Species. Res.

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“…Harcourt 2002;Reed et al 2003). The purpose of the present study was to investigate growth and population parameters from Svalbard's harbour seals.…”

Section: Introductionmentioning

confidence: 99%

Growth and population parameters of the world?s northernmost harbour seals Phoca vitulina residing in Svalbard, Norway

Lydersen

Kovacs

2004

Polar Biol

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The harbour seals (Phoca vitulina) in Svalbard are the northernmost population of this species. The population size is thought to be less than 1,000 individuals; these animals reside principally within a national park on Prins Karls Forland on the west coast of Spitsbergen, Svalbard, at about 78°20¢N. The material presented in this study was collected from 367 livecaptured animals, aged based on growth layers read from stained, decalcified incisor sections (except for pups of the year). Standard length (F 1,246 =45.70, P<0.0001) and body mass (F 1,258 =25.28; P<0.0001) were both significantly influenced by sex when age was taken into account. Adult males are both longer [152.9±4.8 (SE) vs 140.1±2.0 cm, standard length] and heavier (104.0±5.0 vs 83.2±2.7 kg, body mass) than adult females in this population. Age at sexual maturity was assessed based on analyses of sex hormones. Testosterone levels in males showed an abrupt increase at 6 years of age, while estradiol levels in females increased from age 4. The reproductive rate of adult females was 0.93. The longevity of Svalbard harbour seals was short compared to harbour-seal populations from other areas. However, these seals are not exposed to terrestrial predation; there is no known mortality due to fisheries or hunting and their pollution burdens are low. Extreme seasonality and perhaps other harsh environmental conditions at the northern edge of this species' distribution may exert long-term low levels of stress that result in short life span, or there are currently unknown acute sources of mortality in this population. To our knowledge, this is the first study of population parameters on a pinniped species using cross-sectional, nonterminal sampling.

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“…MVP is important when decisions are made which can alter the available habitat, and consequently the species population and risk of catastrophic extinction (Harcourt 2002). Similar to the population growth, MVP was also calculated for each age class and sex based on females' population only, whereas males' populations were obtained based on sex ratio.…”

Section: Minimum Viable Population (Mvp)mentioning

confidence: 99%

Determination of long-tailed macaqueâ€™s (Macaca fascicularis) harvesting quotas based on demographic parameters

Santosa

Kusmardiastuti²,

Kartono

et al. 2012

Biodiversitas

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Santosa Y, Kusmardiastuti, Kartono AP, Rahman DA. 2012. Determination of long-tailed macaque's (Macaca fascicularis) harvesting quotas based on demographic parameters. . Harvesting quota of long-tailed macaques for breeding purpose should be set up based on demographic parameters. The objectives of this research were to determine demographic parameters affecting the set up of harvesting quota and the sustainable harvesting quotas of long-tailed macaque in Indonesia. This study was expected to provide useful information for consideration of setting up harvesting quotas for long-tailed macaque in Indonesia. This study was conducted in November 2009-Januari 2010 using the equation of Q = Nt-MVP. The results showed varied harvesting quotas for different age classes of long-tailed macaque with an average number of 5 for infant males, 3 for infant females, 5 for juvenile males, 4 for juvenile females, 6 for sub-adult males, 8 for sub-adult females and 2 for adult males. The dominant variable determining quota was survival rate.

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Empirical estimates of minimum viable population sizes for primates: tens to tens of thousands?

Cited by 33 publications

References 58 publications

Population trends and vulnerability of humpback dolphins Sousa chinensis off the west coast of Taiwan

Population trends and vulnerability of humpback dolphins Sousa chinensis off the west coast of Taiwan

Growth and population parameters of the world?s northernmost harbour seals Phoca vitulina residing in Svalbard, Norway

Determination of long-tailed macaqueâ€™s (Macaca fascicularis) harvesting quotas based on demographic parameters

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