FW662 -- Population Dynamics 165FW662 -- Final Exam March 10, 19951. (20 pts) The following data collected on the Mexican Spotted Owl in New Mexico and Arizona, 1989-1993:number of pairs checked (n), mean, and standard deviation (SD) for number of young produced per pair, basedon formal monitoring methods.Year n Mean SD1989 61 1.246 0.9061990 20 0.200 0.4111991 79 1.177 0.9421992 99 1.172 0.9651993 85 0.882 0.968a. Compute the variance component for the year effect of the number of pairs fledged, plus a 95%confidence interval.b. Comment on other sources of variation that might exist in these data, what additional informationwould be needed to estimate these sources of variation..2. (20 pts) The endangered red-bellied toad has been extensively studied by the Colorado Division of Wildlife.About 100 adults remain in a population located in the Eagle Nest Wilderness . CDOW biologists havemonitored survival of adults and recruitment to the adult age class during the last 5 years, and provided thefollowing estimates (per capita rates) for the recovery plan.Year Recruitment Survival1989 0.624 0.731 1990 0.331 0.483 1991 0.580 0.552 1992 0.371 0.372 1993 0.476 0.425 Mean 0.476 0.513 The Group for Rabid Expression of Environmental Negativity (GREEN) hired a consultant that developed apopulation viability model based on these estimates. This model predicts a median persistence time of less than200 years. However, the Basic Logging And Concrete Korporation (BLACK) also hired a consultant (differentthan the GREEN consultant), and he also developed a population viability model. This model predicts a medianpersistence time of >200 years. You are hired by the Colorado Division of Wildlife to develop a positionstatement on these 2 models, and explain the differences in their predictions. Both models are provided in theFINAL2.WB1 spreadsheet. Explain what the differences are in the 2 models that causes their predictions to bedifferent. Which model would you select as the model the CDOW should support, if either? Why? What canbe done to improve the estimates of persistence?3. (20 pts) Critically review the conclusions of the attached paper:FW662 -- Population Dynamics 166Swenson, J. E. 1978. Prey and foraging behavior of ospreys on Yellowstone Lake, Wyoming. J. Wildl.Manage. 42:87-90.Do you accept the conclusions? If yes, discuss why the conclusions are valid. If no, suggest what is wrong, andsuggest additional work that might be needed.4. (20 pts) The attached Box 19 from Primack, R. B., 1993, Essentials of conservation biology, SinauerAssociates, Inc., Sunderland, MA., pages 261-262, suggests that remaining black rhinos should be mixed (“madepanmictic”) to increase genetic diversity and enhance the persistence of this species. Discuss this issue in somedetail (broader than just genetics) for the black rhino only. Do you agree or disagree with this recommendation?Give your arguments for both sides of the issue, and make a recommendation for rhino managers such as PeterGoodman (the Thursday pm seminar speaker about a month ago). If you can give a conclusive, persuasiveanswer, you can undoubtedly become both rich and famous (which means, I don’t know the real answer, but Ihopefully can recognize a really thoughtful one!).5. (20 pts) The black-tailed prairie dog (Cynomys ludovicianus) has received much attention in the news latelyas a possible Category 2 species under the Endangered Species Act, not because their own populations are indanger so much as because numerous other threatened or endangered species are dependent on prairie dog townhabitat. However, prairie dogs are viewed as pests by many ranchers and farmers and continue to beexterminated. Recent newspaper editorials have advocated that prairie dogs be more aggressively managed onpublic lands in order to avert future conflicts between private land rights and species management goals.However, the success of this strategy depends on knowledge of the relationship between prairie dog colonies onpublic land to those on adjacent private lands. Prairie dog colonies, or towns, may be considered patches; thus,they are a spatially divided population. a. (5 pts) If these patches represent a metapopulation in the classic sense of Levins, what do you thinkwill be the long-term effect on the metapopulation of continued extermination of patches onprivate lands?b. (5 pts) If the patches have a source-sink structure, what would the effect of exterminations be?c. (10 pts) If you could conduct a study of prairie dogs in both public and private patches (neithersubject to extermination during the study), what specific demographic parameters would youmeasure to determine which type of spatial structure (classic metapopulation or source-sink)that the prairie dog population exhibits? Give the parameters you would measure and thecharacteristics of each that would lead you to conclude which type of spatial structure youhave.Answers1.a. The most common mistake was to try to treat fecundity estimates as a binomial variable. You weregiven the SD of each estimate. Hence, you should have computed the SE of the estimate as , andSD/ nthe sampling variance of each estimate as . The correct answer is = 0.1792 with 95% CI(SD/ n)2F20.0583 - 1.5481.FW662 -- Population Dynamics 167 b. Other sources of variation you should mention are demographic, spatial, and individual heterogeneity.Some of you were pretty cleaver about coming up with other realistic sources: observers and techniques.Good job on thinking about the problem.2. Red-bellied toad = Bufo abdorubra. The GREEN model only has demographic variation. The BLACKmodel incorporates environmental variation with linked survival and recruitment rates. However, theBLACK model has a dreadful flaw -- when the population reaches only 2 individuals, it will never goextinct with the values in the table. Hence, it is totally unrealistic. If you missed this flaw, I took off5 points.3. This study lacks a manipulation to demonstrate cause and effect -- hence the conclusion of “lack ofcompetition with other piscivores” (including humans) is totally unfounded. Competition can only bedemonstrated via manipulation of competitor populations, or manipulation of the exploited resource.No measures of fitness, either reproduction or survival, were collected, so the conclusion that foodshortages were not a limiting factor is unsupported. To support this conclusions, a