The concepts of longevity (longest lived) and life expectancy (typical age at death) are common demographic parameters that provide insight into a population. Defined as the longest lived individual, longevity is easily calculated but is not representative, as only one individual will live to this extreme. Longevity records for North American Asian elephants (Elephas maximus) and African elephants (Loxodonta africana) have not yet been set, as the oldest individuals (77 and 53 years, respectively) are still alive. One Asian elephant lived to 86 years in the Taipei Zoo. This is comparable to the maximum (though not typical) longevity estimated in wild populations. Calculation of life expectancy, however, must use statistics that are appropriate for the data available, the distribution of the data, and the species' biology. Using a simple arithmetic mean to describe the non‐normally distributed age at death for elephant populations underestimates life expectancy. Use of life‐table analysis to estimate median survivorship or survival analysis to estimate average survivorship are more appropriate for the species' biology and the data available, and provide more accurate estimates. Using a life‐table, the median life expectancy for female Asian elephants (Lx=0.50) is 35.9 years in North America and 41.9 years in Europe. Survival analysis estimates of average life expectancy for Asian elephants are 47.6 years in Europe and 44.8 years in North America. Survival analysis estimates for African elephants are less robust due to less data. Currently the African elephant average life expectancy estimate in North America is 33.0 years, but this is likely to increase with more data, as it has over the past 10 years. Zoo Biol 23:365–373, 2004. © 2004 Wiley‐Liss, Inc.
Strategic collection planning is a relatively new concept for zoos. Until recently, personal preference, availability, and competition determined which species or subspecies were acquired. In the last few years, however, there have been attempts to employ systematic criteria for taxon selection that better serve conservation objectives. Planning currently occurs at three levels: global, regional, and institutional. The current planning process is reviewed and recommendations are made for ways the process might be improved. An efficient, economical, and effective collection planning process is critical if modern, professionally managed zoological institutions are to make a significant impact on wildlife and ecosystem conservation. Rather than selecting taxa solely on the possibility of a future reintroduction, serious consideration should be given to the ability of a species or subspecies to contribute to more immediate conservation goals, including public education, fund raising to support field conservation, and scientific research. Because resources are limited, perhaps zoos should focus their long-term breeding programs primarily on flagship species-that is, those that have the potential to excite public attention and help to protect habitat and other taxa-rather than on a broad array of species that are currently endangered. o 1995 Wifey-Liss, Inc. A strategic collection plan can be defined as a set of objectives for the composition of animal collections in zoos. This would typically include the number and type of species or subspecies as well as the number of individuals to be maintained. It may also include a proposed time schedule for implementation. Such plans can be formulated at three different levels: global, regional, and institutional [Foose and Hutchins, 19911. An institutional plan outlines the goals for a specific zoo's collection, which may be determined by the institution's mission statement, budget, current and proposed facilities, climate, and so forth. A regional plan focuses on the goals for an entire geographical region with an organized, cooperative breeding program (e.g., the North American AZA Species Survival Plano). A global plan is intended to integrate various regional plans, once they exist, into a coherent whole [IUDZG and IUCNlSSC CBSG, 19931. Strategic collection planning is a relatively new concept for zoos. Until recently, personal preference, availability, and competition determined which species or subspecies were acquired [Thomas, 1987; Diebold and Hutchins, 19911. In the last few years, however, there have been attempts to employ more systematic criteria for taxon selection that better serve conservation objectives [Bruning, 1990;Hutchins and Wiese, 1991; Foose et al., 1992bl. To assist its member institutions in the selection of appropriate taxa, the American Zoo and Aquarium Association (AZA) formed specialized committees called Taxon Advisory Groups, or TAGs [Hutchins and Wiese, 19911. Similar committees have been established in other regions of the world, includin...
In a review of the evidence for reduction in the severity of inbreeding depression in Speke's gazelle [Templeton and Read, pp. 241–261 in Genetics and Conservation: A Reference for Managing Wild Animal and Plant Populations, C.M. Schoenwald‐Cox, S.M. Chambers, B. MacBryde, and L. Thomas, eds., Reading, MA, Addison‐Weley, 1983; Templeton and Read, Zoo Biology 3:177–199, 1984] a flaw was found in the statistical analysis. Reanalysis of the 1983 data showed no significant reduction in the severity of inbreeding depression. An updated analysis using data from the 1992 Speke's Gazelle North American Regional Studbook [Fischer, St. Louis, St. Louis Zoological Park, 1993] also showed no significant reduction in the severity of inbreeding depression. While there is empirical evidence suggesting reduction in the severity of inbreeding depression in captive populations is possible through reduction of the founder base, maintenance of genetic variation must remain the primary goal of genetic management strategies for captive populations of exotic wildlife. Zoo Biol 16:9–16, 1997. © 1997 Wiley‐Liss, Inc.
Data collected on life-history parameters of known-age animals from the northern (NR) and southern resident (SR) killer whales (Orcinus orca) of the eastern North Pacific were compared with life-history traits of killer whales located at SeaWorld (SEA) facilities. For captive-born SEA animals, mean age and body length at 1st estrus was 7.5 years and 483.7cm, respectively. Estimated mean age at 1st conception was different (P < 0.001) for the combined data from both northern and southern resident (NSR) free-ranging populations (12.1 years) compared to SEA (9.8 years), as was the estimated mean age at 1st observed calf (SEA: 11.1 years, NSR: 14.2 years, P < 0.001). Average calf survival rate to 2 years of age for SEA animals (0.966) was significantly greater (P = 0.04) than that for SR (0.799). Annual survival rate (ASR) for SEA increased over approximately 15-year increments with rates in the most recent period (2000–2015 ASR: 0.976) improved (P < 0.05) over the first 2 periods of captivity (1965–1985: 0.906; 1985–2000: 0.941). The SR (0.966) and NR ASR (0.977) were higher (P ≤ 0.05) than that of SEA until 2000, after which there were no inter-population differences. Based on ASR, median and average life expectancy were 28.8 and 41.6 years (SEA: 2000–2015), 20.1 and 29.0 years (SR), and 29.3 and 42.3 years (NR), respectively. The ASR for animals born at SEA (0.979) was higher (P = 0.02) than that of wild-caught SEA animals (0.944) with a median and average life expectancy of 33.1 and 47.7 years, respectively. These data present evidence for similar life-history parameters of free-ranging and captive killer whale populations and the reproductive potential and survivorship patterns established herein have application for use in future research concerning the overall health of both populations.
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