Conservation Examples Population Viability Analysis - Butterflies and Restoration Indicator Species - Good idea? Hotspots Endangered Species Part of declaring a species endangered involves doing a Population Viability Analysis (PVA) A population is not considered endangered if it has 95% chance of persisting for 100 years. Once a species is declared endangered, it gets a “recovery plan” What will be done to help it When is it considered “recovered” 1 Courtesy of Eli Meir. Used with permission. Fender’s Blue Butterfly Pretty butterfly that lives in western Oregon Lays eggs on Kincaid’s Lupine Kincaid’s Lupine only grows in “old growth” prairies Prairies are prime land for farms, suburbs, shopping malls, universities… Both Kincaid’s Lupine and Fender’s Blue Butterfly were recently listed as endangered species. Sources: Schultz and Hammond (2003) Conservation Biology 17:1372-1385. Schultz (1998) Conservation Biology 12: 284-298 E. Crone, pers. comm. 2 Population Viability for Fender’s Blue Data: Yearly population census in different patches Assume: Density independent growth No observer error No exceptional years Use exponential growth equation N(t+1) = N(t) + (r + ε) N(t) ε = error term 3 Growth rate and variance for Fender’s Blue Site Ownership Protected status Number of censuses Average population size c Population growth rate ( ) Variance in population growth rate (1 2 ) Butterfly Meadows d Private Unprotected 8 412 1.06 0.122 Fern Ridge – Eaton Lane Public Protected 9 5 2.66 1.461 Fern Ridge – Spires Lane Public Protected 9 22 1.92 1.338 Fir Butte Public Protected 8 54 1.61 0.861 Willow Creek- Bailey Hill Private Protected 9 77 1.34 0.692 Willow Creek- Main Area Private Protected 9 738 1.15 0.387 Willow Creek- North Area Private Protected 9 43 1.56 0.918 Basket Butte Public Protected 8 589 1.12 0.436 Gopher Valley Private Unprotected 8 10 0.99 0.468 McTimmonds Valley Public Unprotected e 9 11 2.02 1.715 Mill Creek Public Unprotected e 10 17 1.31 0.607 Oak Ridge Private Unprotected 9 149 1.21 0.448 Avg. growth rate = 1.49 Avg. variance = 0.79 (for sites with > 25 butterflies = 0.54) Chance of Persistence 4 Multiple Patches = Metapopulation Chance of survival with no colonization is: survival anywhere = 1 - Π (1 - survival i ) i Chance of survival WITH colonization will be higher Metapopulation can survive even when all patches will Individually go extinct 5 Prairie Restoration Measure Flight paths Chance to leave lupine area Daily time budget Lifespan Model different habitat configurations and ask which increases survival the most. Fender’s Blue Butterflies: Live ~ 10 days Fly ~ 2.3 hours / day Disperse within lupine ~ 3 m 2 /s Disperse outside lupine ~ 15 m 2 /s Weakly bias flight towards lupine patches Butterfly might go 0.75 km within lupine 2 km outside of lupine Historically, patches ~ 0.5 km apart Now patches 3 - 30 km apart 6 Other Examples of Recommendations Spotted Owls Save old growth trees Sea Turtles Protect the adults, forget the eggs Sea Otters Based PVA on risks of oil spills, recommend number and area for recovery Problem Fender’s Blue study: 8 years dedicated study by grad student, TNC personnel Undergraduate field assistants Lots of volunteers Impossible to do for very many species 7 Indicator Species A well-studied species whose protection will also protect many other less weel-studied species. What makes a good indicator? 8 Hot Spots Places with high biodiversity, especially many endemic species 9 Brooks et al., (2002) Habitat loss and extinction in the hotspots of biodiversity. Conservation Biology 16: 909-924. Save Hotspots to Save Diversity? Myers et. al. claim that 1.4% of land area contains 44% of vascular plants and 35% of vertebrates Save 1.4% and you save a good bit of world’s biodiversity Myers et al., (2000) Biodiversity hotspots for conservation priorities. Nature 403: 853-858. 10 Looks good, but… Conclusions Tools of ecology help guide small, local decisions At large scale, tools of ecology also offer guidance, but no easy answers. 11