Lecture 15. Biology 5865 Conservation Biology. Ex-Situ Conservation

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Theodore Osborne
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1 Lecture 15 Biology 5865 Conservation Biology Ex-Situ Conservation

2 Exam 2 Review Concentration on Chapters 6-12 & 14 but not Chapter 13 (Establishing New Populations) Applied Population Biology Chapter 12 Methods for Studying Populations Published literature peer-reviewed Unpublished literature gray literature Fieldwork Monitoring populations Inventories and surveys Demographic studies Population Viability Analysis Metapopulations Long-term Monitoring of Species and Ecosystems

3 Four Interacting Factors Contributing to Species Extinction (Hunter 2002) 1. Demographic stochasticity - uncertainty due to random variation in reproductive success and survivorship at the individual level requires estimates of population size, age, sex, age structure (effective population size), natality and mortality rates all of these are generally not available for most populations - why? 2. Environmental stochasticity - random variation in variables that measure habitat quality Requires data on how the environment affects populations, reproduction, etc. - usually neglected in PVA analyses 3. Catastrophes - form of environmental stochasticity, but generally are discrete events (hurricanes, tornadoes, blizzard, drought) generally specifically modeled depending on the species, environment, etc. 4. Genetic stochasticity - random variation in the gene frequencies of a population due to genetic drift, bottlenecks, inbreeding, and similar factors

4 MVP and PVA Minimum Viable Population (MVP) and estimated via Population Viability Analysis (PVA) Evolved out of Risk Assessment which is commonly used in the insurance industry and now a wide variety of industries, federal and state government agencies provides a probability framework for consideration of the degree of risk.

5 Population Viability Analysis What is the probability that species X will go extinct after 100 or 1000 years? Remember that all populations will go extinct - it is just a question when and why? When will populations go extinct? As population size decreases the greater the probability it will go extinct in a given period of time, The longer the time span, the greater the probability of extinction. Why do species populations go extinct? Threats to biological diversity How can these threats be managed

7 From Meffe and Carroll (1994)

9 Zoos, Aquaria, and Gardens Ex-situ Conservation US zoos and aquaria attract more visitors each year than the combined attendance at US professional baseball, basketball, hockey, and football games Zoos maintain over 500,000 individuals of terrestrial vertebrates primarily representing 7,400 species and subspecies of mammals, birds, reptiles, and amphibians 2000 World Conservation Monitoring Centre listed 17 species of plants and 34 species of animals that survived only in captivity Zoos are important places for captive breeding programs, yet only about 10 % of the 274 species of rare mammals kept by zoos have sustaining captive populations (Ralls and Ballous 1983); hence, zoos still collect much of their stock from wild populations Capacity of the world s zoos could only support 1,000 of the world s 20,000 species of birds, mammals, reptiles, and amphibians

10 Ex-situ Conservation Continued - 2 Genetic variability - individuals represent a small portion of the population gene pool, is the gene pool representative of the range of environmental conditions upon which the species could be released at a later time Continuity - a) continuous flow of money to maintain the populations, and b) stability of the country to maintain the facilities - e.g., former Soviet Union, political unrest in developing countries such as Africa Concentration - susceptibility of the entire zoo, arboretum, garden, aquarium, etc. to a catastrophe such as a hurricanes, tornados, earthquakes, epidemics, or war Size factor huge bias toward charismatic mega-vertebrates - little attention paid to plants, insects, etc.

11 Ex-Situ Conservation continued -- 3 Despite these limitations for some species, zoos etc. may represent the only hope to save the species for example Pere David s deer mentioned by Hunter (2002) - disappeared from the wild about 3,000 years ago and is unlikely to be reintroduced to its native habitat in northeastern China because the wetlands have been converted to agricultural areas The Jurassic Park (Crichton book) phenomenon reviving a species based on the recovery of fragments of DNA will this become a reality? Should we have DNA Banks for Endangered Species????

12 Science 2008

Biodiversity and Extinction. Lecture 9

Biodiversity and Extinction. Lecture 9 Biodiversity and Extinction Lecture 9 This lecture will help you understand: The scope of Earth s biodiversity Levels and patterns of biodiversity Mass extinction vs background extinction Attributes of