GE/BI307 Mar 10, 2007 Outline Reserve Design: The SLOSS debate and Beyond 1. Island theory and the SLOSS question. 2. Point and counterpoint 3. Beyond SLOSS: what have we learned about reserve design?
1. Island theory and the SLOSS question. Touching off the debate: Diamond J. 1975. The island dilemma: lessons of modern biogeographic studies for the design of natural reserves. Biological Conservation 7:129-146. Species-Area relationship predicts larger areas contain more species. ‘bigger is better’ Taken at face value, this suggests that 1 large reserve should contain more species than several smaller ‘SL better than SS’ reserves totaling the same area.
‘closer better’
‘circular better than linear’ ‘connected better than isolated’
‘minimize edges’
Other key ‘pro-SL>SS paper: Contrarians: Simberloff DS, Abele LG. 1976. Island Biogeography theory and conservation practice. Science 191:285-286. Terborgh J. 1976. Island Biogeography and conservation: Strategy and Limitations. Science 193:1029-1030.
Daniel Simberloff – Lawrence Abele – U. Tennessee (via Fl. State) Florida State University
1 Simberloff argument: Response from Diamond:
When z<1 (always the Larger areas are more likely to contain the wide-ranging case) half the area species that are often most threatened. preserves more than half the species. The sum of species in small areas may exceed a large area, but may be composed of generalists and weeds. Thus, two reserves of ½ area may contain more than the species in the full area.
What key assumption does this depend on?
Why several small can be better than single large:
1. Habitat diversity. 2. Focal species conservation, e.g Cape Floral Province Cape Floral Province: -68% of species are endemic -53 species of endemic Proteacea species restricted to 1 or 2 populations -Each population occupies 5 km2 or less, contains less than 1000 individuals. -A few large parks would completely miss many of these species. -Many smaller, scattered parks would be more effective in this case.
Whatever the merits of Diamond’s geometric reserve design recommendations, all would agree that these simple rules have been adopted uncritcally (e.g. 1980 World Conservation Strategy, “I suspect workers are growing more weary of it than World Conservation Union) approaching any agreement on its resolution”
– Craig Shafer Nature Reserves: Island Theory and Conservation Practice 1990
I wholeheartedly agree…
2 Beyond SLOSS Types of focal species:
Consensus: 1. Keystone species: many others depend on it (e.g. Beaver) 2. Umbrella species: large range protects many other species (bear) Strategies for conservation depend on the group of species under 3. Flagship species: public appeal (e.g. great blue heron) consideration and specific circumstances. (shift to autecological 4. Indicator species (frogs) focus from synecological focus). 5. Vulnerable species: Endangered Species List.
Corralary: There has been a shift away from Equilibrium Theory and toward Minimum Viable Population/ Minimum critical size analysis.
Large reserves are desirable, but well-managed small reserves have an important role in protecting focal species of value.
Recognizing the importance of buffers and corridors for focal species: Marine reserves: •Most island biogeography theory has been applied to conservation of terrestrial habitats, not marine.
•Aquatic reserves largely under-studied. -Dispersal mechanisms, characteristics largely unknown. - Pollution may have more subtle/widespread effects in aquatic systems than in terrestrial
Effective corridors must be designed with care – e.g., many animals move along riparian zones but not other pathways.
Conservation strategies Humans and Nature Apart: -Primack “Protected areas are a seductively simple way to save nature from -The role of humans humanity. But sanctuaries admit a failure to save wildlife and natural habitat where they overlap with human interests, and that means 95% or more of the earth’s surface. Conservation by segregation is the Noah’s Ark solution, a belief that wildlife should be consiged to tiny land parcels for its own good and because it has no place in our world. The flaw in this view is obvious: those land parcels are not big enough to to avert catastrophic species extinciton by insulratization or safe enough to protect resources from the poor and the greedy. Simply put, if we can’t save nature outside protected areas, not much will survive inside; if we can, protected areas will cease to be arks”.
D. Western et al. 1989.
3 Case study: Marine Reserve Design
Key challenges to marine reserve design: Focus area: Gulf of California.
-Almost no application of an increasing body of theory of large 1st step: Gather data on habitats and species. marine reserves.
-Some theory suggests need to protect >20% of habitat for fisheries, but no agreement on how much habitat needed to protect biodiversity.
-No consensus on how to maintain ecological links (connectivity) between reserve elements.
A priori goals:
1. Protect 20% of each representative habitat 2. Protect 100% of rare habitats & areas with highest species richness. 3. Protect ecosystem function by protecting larval sources and larval connectivity through dispersal (keep food chain from collapsing)
Thus, this is habitat and community focused more than focused on single species.
4 Methodological Approach: 1. Make an educated guess about larval dispersal: 100 km max. A. Gather Spatial Information on: 2. Use sophisticated geometric optimization model: 1. Fish diversity as a function of geography (latitude, depth predict 66% of fish diversity) “Spatially explicit simulated annealing algorithm (SITES/SPEXAN) 2. Area of each habitat Interfaced with a GIS system (ESRI Arc View).” 3. Larval sources (diving and interview fisherman) “This algorithm designs and analyzes portfolios of sites from a B. Create maximum reserve map preserving all diversity, then universe of territorial units… attempts to meet predefined, whittle it down based on: quantitative conservation goals using as few sites as possible”
- smallest number of reserves that meet % protection - constrained by 100 km distances between any 2 units. goals and ensure larval connectivity.
Many possible combinations of reserve number, size, and separation distance. How to optimize?
Biologically and socio- Biologically optimal network economically optimal network.
-includes overlay of fishing intensity maps.
.
Key result: This approach did not significantly decrease the number Key benefits of this approach: of desired conservation goals -objective method (more politically defendable)
-Stepwise procedure (biologically optimal -> socially acceptable) presents policy makers with ability to weigh costs and benefits, set priorities.
Key limitation: based on shaky information of dispersal distances. Likely to affect marine reserve designs for a long time.
5 Case study from New Guinea: (Diamond 1986)
Important to keep in mind: 1. Political Geography/zoning, as in most other cases, looms large, but particularly interesting in New Guinea:
- Irian Jaya under strong centralized govt. (Indonesia). Top- down control over land use/zoning. Relatively easier to implement national nature reserve system.
- Papua New Guinea – much more political power rests in local communities, tradition of freedom from higher authority. Nature reserves will depend much more heavily on local decisions.
Diamond focuses on Irian Jaya.
shrews Sorex vagrans, vagrant shrew
Sorex palustris, water shrew
Mustela erminea, short-tailed weasel
Marmota flaviventer, yellow-bellied marmot
Long-tailed Vole, Microtus longicaudus
Golden-mantled Ground Squirrel Northern Pocket Gopher, Spermophilus lateralis Belding’s Ground Squirrel Thomomys talpoides (Spermophilus beldingi)
Unita chipmunk Eutamias umbrinus
6 Neotoma cinerea, Bunker's Woodrat
Zapus princeps, western jumping mouse
American Pika, Ochotona princeps Lepus townsendi, snowshoe hare
Case study: Marine Reserve Design Key challenges to marine reserve design:
-Almost no application of an increasing body of theory of large marine reserves.
-Some theory suggests need to protect >20% of habitat for fisheries, but no agreement on how much habitat needed to protect biodiversity.
-No consensus on how to maintain ecological links (connectivity) between reserve elements.
Focus area: Gulf of California.
1st step: Gather data on habitats and species.
7 Black coral Rodoliths – ‘unanchored’ coral algae
Broomtail grouper – commercially important, large ranging Goliath grouper – commercially important, large ranging
8 A priori goals: Methodological Approach:
1. Protect 20% of each representative habitat A. Gather Spatial Information on: 2. Protect 100% of rare habitats & areas with highest species richness. 1. Fish diversity as a function of geography (latitude, depth 3. Protect ecosystem function by protecting larval sources and predict 66% of fish diversity) larval connectivity through dispersal (keep food chain from 2. Area of each habitat collapsing). Focus on large commercial fish. 3. Larval sources (diving and interview fisherman)
B. Create maximum reserve map preserving all diversity, then Thus, this is habitat and community focused more than focused on whittle it down based on: single species. - smallest number of reserves that meet % protection goals and ensure larval connectivity.
Many possible combinations of reserve number, size, and separation distance. How to optimize?
Biologically optimal network 1. Make an educated guess about larval dispersal: 100 km max.
2. Use sophisticated geometric optimization model:
“Spatially explicit simulated annealing algorithm (SITES/SPEXAN) Interfaced with a GIS system (ESRI Arc View).”
“This algorithm designs and analyzes portfolios of sites from a universe of territorial units… attempts to meet predefined, quantitative conservation goals using as few sites as possible”
- constrained by 100 km distances between any 2 units.
Biologically and socio- economically optimal network. Key result: This approach did not significantly decrease the number of desired conservation goals -includes overlay of fishing intensity maps.
.
9 Key benefits of this approach: Important to keep in mind: -objective method (more politically defendable)
-Stepwise procedure (biologically optimal -> socially acceptable) presents policy makers with ability to weigh costs and benefits, set priorities.
Key limitation: based on shaky information of dispersal distances. Likely to affect marine reserve designs for a long time.
Case study from New Guinea: (Diamond 1986) GE/BI 307 April 10, 2007 1. Political Geography/zoning, as in most other cases, looms large, but particularly interesting in New Guinea: Minimum Viable Populations and Population Viability Analysis - Irian Jaya under strong centralized govt. (Indonesia). Top- down control over land use/zoning. Relatively easier to 1. What is MVP? implement national nature reserve system. 2. What factors determine MVP? 3. What is PVA? - Papua New Guinea – much more political power rests in local 4. How are PVA’s conducted? Case study. communities, tradition of freedom from higher authority. Nature reserves will depend much more heavily on local decisions.
Diamond focuses on Irian Jaya.
1. What is MVP? 1. What is MVP?
Shafer 1981: “A MVP for any given species in any given Related to Minimum Dynamic Area: habitat is the smallest isolated population having a 99% chance of remaining extant for 1000 yrs despite the Once MVP is estimated, characteristic population densities (# foreseeable effects of demographic, environmental, and individuals per area) can be used to determine minimum genetic stochasticity, and natural catastrophes” area requirements.
- Not a fixed quantitative definition; other percentages and Similar to the Insular Distribution Function described earlier time periods may be used. (but that function includes isolation)
- Analagous to flood control measures. Plan for extreme events rather than mean conditions.
10 1. What is MVP? 1. What is MVP?
Thus, MVP ‘inverts’ a core question addressed by the Estimates range from 500-10,000, but single numbers can be equilibrium theory: (and have been) very misleading.
Instead of: “How many species exist in X area?” But there have been interesting and suggestive observations… MVP asks: “How much area is needed for Species X?”
2. What factors determine MVP? Bighorn sheep, SW US Deterministic factors: logging, hunting, pollution, etc. 50 individuals appears Things we can control. to be a threshold for century scale survival. Stochastic factors:
No single cause - Genetic problems associated with low population apparent – likely several sizes (genetic drift, impoverishment, factors. inbreeding depression)
What are possible - Demographic fluctuations (variation in birth, death factors? rates and offspring gender distribution)
(figures from Primack) - Environmental stochasticity (catastrophes, floods, drought, fires, etc.)
Often these factors add to the genetic extinction vortex.
More on demographic effects: More on demographic effects:
Recall effective population size: Not just the number of breeding animals matters, but the sex ratio as well.
Ne = 4x Nm x Nf/(Nm + Nf) Ne = 4x Nm x Nf/(Nm + Nf) This is for breeding animals, not all animals!
Age, health, behavior (e.g. monogamy vs. polygamy) may all affect breeding patterns.
Effective populations can therefore be much smaller than actual populations.
E.g. 1000 alligators may only have 10 animals, 5 male, 5 female that are of the right age and health to breed. Effective population is 10, not 1000.
11 Consider elephant seals: plausible case – 6 breeding males, More on demographic effects: 150 breeding females. Assume 6 males mate with 25 females each. Effective population can be computed over generations:
Ne = t/(1/N1 + 1/N2 + 1/N3 +…)
Where t= number of generations Nx = Ne at year x.
Example: 5 generations of endangered butterfly, with 10, 20, 100, 20, and 10 breeding individuals.
Ne = 5/(1/10 + 1/20 + 1/100 + 1/20 + 1/10) = 5/(31/100) = 16.1
Note: if there were 500 individuals in year 3, we would get only 16.6. Plugging into the above, this leads to an effective population Thus, effective population sizes integrated over time are impacted much of 23, not 156. more by the “lean” years – “population bottleneck” Thus, polygamy is discounted in Ne, and reflects the limited genetic variation due to unequal sex ratio.
Example of “genetic bottleneck” – Lions in Ngorongoro Crater, Tanzania
Stomoxys calcitrans Biting fly 1961-62
12 Ominous telltales, sperm from crater males (middle and right) show abnormalities when compared with a normal sample. Reproductive physiologist David Wildt and his colleagues at Washington's National Zoo found structural deformities in more than half the sperm of each male tested, strong evidence of inbreeding. The continuous decline of genetic diversity since 1969 is perhaps linked to a falling reproductive rate.
photo credits: David Wildt and Jo Gayle Howard, source: National Geographic, July 1992, p.133
Recall genetic extinction The 50/500 “rule” (Soule and Gilpin): Vortex from before. Add: A variety of breeding studies suggested that inbreeding Demographic stochasticity depression becomes a major factor driving extinction in sexually reproducing populations less than 50 (effective pop. Environmental Size). Stochasticity
And that the genetic impoverishment (loss of alleles) occurs Thus, Situation can get below effective population sizes of 500. Even worse.
Including genetic, This rule has been taken very literally and was sometimes used Demographic, and to justify not protecting very small populations because they Environmental factors were considered doomed. (Simberloff complaint). All together is done In Population Viability Never intended to be taken so literally. Analyses
Case study: Rhinos – all extremely African black rhino 3. What is Population Viability Analysis? endangered - A much more integrative framework for determining MVP. Sumatran rhino - Goal: determine in an integrative manner how deterministic and genetic, demographic, and environmental factors together determine the probability of extinction for a population, and thereby African Northern guide practical, specific conservation strategy. white rhino
- Spurred by very practical problems (Gilpin and Soule) Javan Rhino – how to save specific species in specific situations. Indian rhino - how to justify conservation of species at even very low numbers (beyond the 50/500 rule).
- No standardized methodology at present, case by case.
13 Paraceratherium, Eurasian grasslands, 10,000 yrs ago
Context: Rhinos used to exist not only in Africa and Asia, but Europe and N. America.
Extinct from N. America ~ 5 Mya
teleoceras, North America 4-17 mya
Coelodonta antiquitatis, Wooly Rhino, Eurasia
Facts: African White Rhinos (ceratotherium Extant Rhinos: Two overriding threats: Habitat destruction simum) and poaching. -Northern and southern sub-species Rhinos present a very compelling case study because: -Northern sub-species much Rarer (50 individuals) - they are all very endangered -about 11,100 remaining - Each species has unique problems, allowing comparison -Largest species of Rhino and contrast to Population Viability Analysis and -Least endangered of Rhinos conservation strategies – one solution does not fit all. -Grazer, lives in long and short Grass savannahs. How is this the case? First lets review some of the key features of each species…
14 Facts: African Black Rhinos Facts: Indian Rhino (Rhinoceros unicornis) (Diceros bicornis) Bicornis = “two horns” -Best success story: from under 200 (early 20th century) to 2400 today. -Poaching remains a threat. -About 3610 currently remaining. -Mostly aquatic grazer – most amphibious of all rhinos. -In 1970, about 65,000 -Low point: 2300 in 1992-3 -Fragmented into isolated populations of ~75 -Anti-poaching laws enacted. -Browser, eats leaves and branches of shrubs And trees.
Facts: Javan Rhino (Rhinoceros sondaicus) Facts: Sumatran Rhino (Dicerorhinus sumatrensis)
-Rarest of all species: less than 60 animals in only 2 locations – -Most endangered of all species: fewer than 300 individuals in very vietnam and indonesia. small and fragmented populaitons. -weak protection against poaching. -Numbers declined by 50% in last 15 years. -Smaller than indian rhino -No sign of stabilizing population numbers. -Adaptable eater – both browser and grazer – mostly along -Habitat: dense tropical forest, mostly browser from a great variety of watercourses. plant species.
Sumatran rhino
Past and present While inbreeding depression is the most immediate concern, the distributions. situation differs among the species in interesting ways. This impacts PVA and conservation strategies. Habitat loss and poaching. For example, Indian Rhino shows high levels of genetic diversity (heterozygosity) even though its population numbers are low. Fragmented populations – big risk of genetic . impoverishment .
15 Nepalese sub-species of Indian Rhino declined to 100 individuals, Contrasting situation: with 30 breeding. African Black Rhino: six living subspecies, very low genetic Population has recovered to 400. variability within subspecies – much more concern about inbreeding depression than Indian rhino for same population size. How could this species have retained genetic diversity even though it clearly went through a population bottleneck? Can we thus assume that the Indian Rhino is in better shape to avoid Answer not entirely clear. Speculation: high mobility of this extinction compared to the African black Rhino? species (moves relatively long distances) may have provided enough gene flow to maintain heterozygosity. Not so easy…
Lesson: low population sizes do not always lead to genetic impoverishment. Species-specific traits need to be considered. .
.
Another major contrast: Differing conservation strategies:
Indian rhino under much more pressure from habitat loss. Humans Emphasize genetic enrichment in Black Rhino now settle almost all of the land occupied by Indian Rhinos, and - move individuals between populations (gene flow) they have no opportunity to expand back (unless humans go away) - Bring all or most black rhinos together in a single breeding population. African Black Rhino not losing habitat nearly as much. Much of its - risk losing micro-environmental adaptations though range is still open. Indian Rhino: prioritize habitat protection more than genetic diversity.
. Sumatran Rhino: 4 scattered populations, genetic evidence suggests 1 (Borneo) is far different from the other 3. If possible, manage Borneon population separately for breeding/conservation.
Sumatran Rhino relocation - 2005 GE/BI307 April, 2007
Population Viability Analysis Exercise
(Example from Primack – Essentials of Conservation Biology)
16 The Scenario:
Endangered toad, formerly widespread, now occupies a small, isolated mountaintop.
At present, 10 toads.
Mountaintop can accommodate a maximum of 20 toads.
Toads complete life cycle in 1 year.
Form monogamous mating pairs.
Each pair can produce 0 to 5 offspring (all equally likely, determine by coin flip)
Sex of offspring is random (coin flip)
GE/BI307 Apr 19, Possible Extensions: 2007
1. Alter carrying capacity (from max of 20 to 15, or 30) Population Viability 2. Introduce environmental disturbance by imposing Analysis: 50% mortality in year X due to a drought. 3. Alter range of offspring allowed due to increases or A current example decreases in food. with critically 4. Polygamy, longer breeding life span. endangered 5. More demographics: infant, juvenile, adult, elderly Orangutans age distributions, mortality rates. 6. Introduce inbreeding depression into reproductive fitness.
Outline “it is probably the vast extent of the unbroken and equally lofty forest 1. Background on Orangutans which is the the principal attraction to the Orangutan. These forests are 2. Setting up the PVA model its open country, the place best adapted to its mode of life, where it can 3. Demonstration simulation. roam in every direction with as much facility as the Indian in the prarie 4. Summary of key results or the Arab in the desert. The dry grounds are more requented by man, 5. Conclusions and Conservation more cut up by clearings and by low second-growth jungle, in which Implications progression is more difficult, where it is exposed to danger, and where probably its favorite food is less abundant”
- Alfred Russel Wallace On the habits of the Orangutan of Borneo 1856.
17 Current Distribution General features:
•Most arboreal of all great apes – makes new tree nests every Sumatran (Pongo abelii) Bornean night - can’t live out of forests IUCN: critically endangered 2003 (Pongo pygmaeus) IUCN: endangered 2003 •Loves swamp forest, can also live in dryland forest.
•Eats fruit, insects, leaves, meat
•Usually considered solitary, but wide variety of cultures. Some very gregarious
•Major threats: habitat destruction, pet trade.
Demographic features:
•Females: reach puberty age 10, reproductive from 15-50. Gestation period ~ 250 days.
•1 born at a time; birth interval 7-9 yrs. Females can produce at most 4 surviving offspring. Infant mortality to age 1: 9%
•Females stay put; males wander.
•Young weaned/carried until about 4 yrs; independent at 6-7 yrs.
•Males: sexually maturity around 12 yrs old, full maturity with secondary sexual characteristics takes another 10-20 yrs.
•Lifespan: Avg. 45 yrs in wild, up to 59 in captivity
Large genetic Differences: differences imply longer separation -Large genetic distance (as much as is than simply last ice considered in different species in age. other primates like chimps) Large river basins may have been -But produce healthy, viable hybrids barriers even during in captivity. last ice age.
-Sumatran compared to Bornean: Fur: lighter, denser, longer. Faces: lighter, narrower Overall, more gracile, and shorter thumbs, larger toes.
Large genetic and cultural difference informs conservation strategies – manage populations separately
18 Estimated total population (both species): 20,000 50% reduction in population in last ten years. Major threats: illegal logging, pet trade Accelerated due to civil Unrest (Suharto Regime Collapse 1998)
Culture reflected by differential tool use
What conservationists are up against: an almost impossible political backdrop.
19 Orangutan Population Viability Vortex model development for Sumatran Orangutans Analysis Commission by IUCN Conservation • Vortex was used to integrate all 4 kinds of extinction Breeding Specialist Group threats:
Final Report August 2004. 1. Deterministic = habitat destruction due to logging 2. Stochastic = Genetic, Demographic, Environmental. Goals: Overarching: “ensure that orangutan populations are viable and secure for the next 1000 years. We will accept 0% risk of extinction over 1000 years”
1. Determine if wild populations still viable. 2. Determine how many separate populations are viable. 3. Identify priority areas for conservation action.
Goals 1 and 2 addressed using VORTEX
Vortex model Some Demographic inputs development for Sumatran Orangutans
• Used 30+ year observational data set on demographics, habitat needs.
•Baseline model performed first – in the absence of any future habitat destruction.
•Human impact scenarios added in subsequent simulations (by altering carrying capacity).
Vortex model development for Sumatran Orangutans Some key results:
•500 simulations run Baseline model (no continued logging, no environmental •1000 year runs (sounds long, but only 20 generations!) disturbances): populations above 250 appear to escape •Definition of extinction: 1 sex remaining. genetic problems and demographic stochasticity) •Inbreeding depression: yes (4.06 lethal equivalents – obtained from genetic studies at zoos)
A lethal equivalent is the mean number of lethal allelles per organism. For example, 4 allelles each with 25% lethality = 1 lethal equivalent.
•Mating system: short term polygyny
Note 250 is a precarious number and would likely lead to extinction after 1000 yrs. Also note 50 yrs is a very short time (~ 2 generations), so 0 PE is not very meaningful in this time frame.
20 Logging: Some Orangutan habitats in Sumatra exposed to up to 20% annual deforestation rates. Busy table; bottom line: Even much lower rates compound to large habitat loss over just a few generations. Logging must pretty much All populations cease in existing Orangutan habitats. extinct at 1000 yrs unless NO logging.
(assumes lost forest is not restored).
A dire situation when one considers current logging rates.
Let’s take a look at results from a couple of the extremes (in red boxes).
Sealuwah is likely too far gone for even reforestation to Other extreme: W. Leuser – only cessation of logging help long term survival. Additional intervention is likely allows long term viability and even then, only to 1000 to be necesssary. yrs.
21 Summing up: all Sumatran Orangutans Key Conservation Considerations:
-Pretty simple message: logging must cease to avoid extinction. Ceasing logging after 5 years may allow larger populations to persist long term. No evidence that any action is being taken.
-Essentially, same message for Borneo
-250 individuals sustainable in short term, 500 in long term.
-Of 13 isolated habitats, only 7 have more than 250.
-Of these 7, 6 are subject to 10-15% logging
-Smaller populations linked by occasional exchanges could contribute to overall metapopulation stability.
Conservation Recommendations based on Vortex: General Take Home Messages:
1. Stop illegal logging -PVA offers us an objective, quantitative tool to assess the viability 2. Stop road building of endangered species, based on concepts of biogeography and 3. Connect East and West Leuser conservation biology. 4. Forest rehabilitation -threats mount.
Other recommendations: -In combination with tools including GIS and Remote Sensing, -continue funding for existing conservation projects there are excellent opportunities for professional or academic -World Heritage status for Leuser Ecosystem careers in Biogeography -Education outreach programs -Ecotourism (post-war option) -Helicopter patrols for rapid enforcement -these careers are sorely needed as global extinction threats -Develop/encourage local NGO’s mount. -Incentives for people to move out of Leuser Ecosystem -Work closely with local governments, tribal leaders -International and national media campaign. -Sustainable income activities for local people
The Puzzle of the Pronghorn and Pleistocene Rewilding
Applied Conservation Biogeography GE/BI307 April 25, 2007
22 “In 1915, after the American pronghorn was almost hunted to extinction, there were only 15,000 animals. Today, there are less than 700,000, but some pronghorn are still Kingdom: Animalia on the brink of extinction.” - National Wildlife Federation Phylum: Chordata Subphylum: Vertebrate Class: Mammalia Order: Artiodactyla (even-toed ungulates (hoofed mammals)) Family: Antilocapridae Genus: Antilocapra (sub) Species: American, Sonoran, Oregonian, Mexican, Penninsular (baja) (only 300-500 sonoran left!)
Family Antilocapridae (pronghorn antelope) Family Bovidae (antelopes, cattle, gazelles, goats, sheep, and relatives) Family Camelidae (camels, llamas, and relatives) Family Cervidae (deer) Family Giraffidae (giraffes and okapis) Family Hippopotamidae (hippopotamuses) Family Moschidae (musk deer) Family Suidae (hogs and pigs) Family Tayassuidae (peccaries) Family Tragulidae (chevrotains and mouse deer)
An aside…
Conservation of pronghorns has been benefited tremendously by “Gap Analysis”
Procedure: map known range of a species, correlate to climate, soils, topography, vegetation
Use geospatial info (GIS, remote sensing) to locate suitable areas for which animals may exist but have not been documented, where they may have once been located, and where they may be successfully introduced or re-introduced.
23 Continuing threats include: Eyesight/hearing extremely acute. Habitat fragmentation Illegal hunting The pronghorn is the second fastest land animal in the world, almost as fast as the Grassland conversion to crops cheetah. It is the fastest in the Western Hemisphere. Habitat degradatation by grazing livestock Ranchers’ intolerance
60 MPH – faster than wolves, coyotes, thompson’s gazelle. No N. American predator that can match adult’s speed/endurance.
Why is this animal in N. America?
American cheetah – Acinonyx trumani Extinct by 13,000 years ago Should we bring back the Cheetah? Arguments for re-wilding
-restore ecological/evolutionary interaction with pronghorns
-African species very closely related to extinct American species
-African species highly endangered
-Ecotourism benefits/alternative economy in depressed great plains.
24 More general proposal for re-wilding N. America More general proposal for re-wilding N. America Rationale: almost all conservationists in N. America have sought to return species/habitats to pre-columbian times (1492) Symbols represent horses (Equus caballus and E. asinus in black; E. przewalskii and E. hemionus in grey), Bolson tortoises, The reality is that N. America has been highly camelids, cheetahs, Asian (grey) and African (black) elephants, and lions. a, The disrupted by loss of megafauna from 13000 years likely timescale and area required to restore proxies for extinct large vertebrates. b, ago – a snapshot in evolutionary time. Conservation value and ecological role (interactivity with other species) on the landscape. c, Potential economic/cultural Large scale changes in N. American landscapes value versus potential conflict. (e.g. loss of grasslands due to woody encroachment) may be a vestige of pleistocene overkill. Thus, restoring megafauna may actually be a more desirable conservation goal.
Bolson tortoise, Gopherus flavomarginatus. Camels browse woody shrubs unpalatable to livestock grazers – Largest extant N. American reptile – 50 kg may help to reduce woody encroachment into Great basin grasslands Bactrian Camel, Camelus bactrianus, extremely endangered, restricted to Gobi desert
Extinct Camel, Camelops hesternus
AMERICAN LION panthera leo atrox AFRICAN LION panthera leo leo Other endangered species in N. America may benefit from re-introduction of mega-mammals:
e.g. California Condor, a pleistocene relict
25 More controversial: Re-wilding: Lots of recent press Introduce niche replacers, even if they weren’t a part of the “near-time” complement of large mammals. e.g. Members of the Rhino family lived in N. America until about 7 million years ago.
Perhaps grazing/browsing rhinos were replaced by ground sloths.
No close replacement for ground sloths – could Rhinos fill the niche?
Ecological Arguments against re-wilding:
-introduced species are not genetically the same -Disease transmission -Unexpected ecological consequences
Proponents acknowledge risks, propose initial introduction in highly controlled habitats.
Perhaps unlikely to have same risk of uncontrollable growth as introduction of smaller animals (e.g. cane toads in australia)
control beetles that were destroying sugarcane crops
northern quoll Dasyurus hallucatus
To learn more: Re-wilding: Expanding and realizing www.rewilding.org the Concept
Google Josh Donlan 1. Rewilding outside of N. America: case studies Twilight of the Mammoths: Ice age Extinctions and the Rewilding of America 2. Mega-linkages: barrier removal for wildlife – Paul S. Martin, University of California Press, 2005
26 Science May 16, 2005
-Not just a reserve park, but a Case study #1: test of function of megafauna in ecosystem processes and global change. Re-wilding Siberian Steppe -Did megafauna maintain high productivity grasslands (and the 500 GT Carbon in boreal soils) that have vanished, replaced by low productivity heath/moss?
-Can they return moss/heath to carbon sequestering grassland?
Musk Oxen – introduced during Cold War to US FWS
Less than 5000, restricted to northern China
Wood Bison Bison bison athabascae
Yakutian horses: help reduce the effects of global warming by stabilizing vast expanses of grassland?
27 Pleistocene Park. This territory in the Republic of Yakutia is roughly an even split of meadow, larch forest, and willow shrubland. This Siberian region could become the venue for a reconstituted ecosystem that Case study #2: vanished 10,000 years ago. CREDIT: S. ZIMOV Re-wilding Oceania’s depleted avifauna
Rationale:
Polynesian “Future Eaters” and Europeans Late Niuafo’ou devestated Oceania’s birdlife
But there are many tiny, forested, Niuafo’ou: inhabited, forest uninhabited islands/islets with few exotics degraded, cats, rats (cats, rats, pigs). Late: uninhabited, forested
Introduce endangered birds into these habitats – in some cases of which are within their pre-historical range.
Re-wilding: Expanding and realizing the Concept
1. Rewilding outside of N. America: case studies
2. Mega-linkages: barrier removal for wildlife Megapodius pritchardii Polynesian megapode Once widespread in Pacific; now in 1 tiny island in Tonga “critically endangered” – most severe rating – IUCN World Cons. Union
28 Critter Crossing: an example from Banff National Park
“Highway mitigation in Banff National Park, Alberta, is the only large-scale complex of wildlife mitigation passage structures in the world.” - Parks Canada
elk, deer, moose, wolves, cougars, black bears,
Banff grizzly bear
29 •8-foot-high fencing on both sides of the highway •28 miles (45 km) of the highway • 22 underpasses - arched culverts, box culverts, and open-span bridges •two 164-foot-wide (50-meter-wide) overpasses.
Good for animals and good for people too! …and 35 months of monitoring animals' back-and-forth movement The fence has cut ungulate (hooved animal) roadkill by 96 percent… through the crossing structures has demonstrated that both ungulates and carnivores are using them.
Crossing designed to be near the animals' natural travel. Carnivores - structures close to stream corridors or drainage areas.
30 Ungulates: structures far from carnivores and with a clear view of the A work in progress: still learning structures' entrance more: -black bears and cougars climb over the fence. -eliminate dandelions (a delicacy for black bears) on the highway side of the fence, place additional wire mesh at a 90-degree angle on top of the fence. -stricter limits on human activity near the Banff crossing structures - a strategy to increase the low numbers of large carnivores (especially wolves and female grizzlies) using the structures
The grandest scale of rewilding: megalinkages Different responses by wildlife - How often they are used and how well they are accepted by wildlife varies between species and geographic area, and the reasons why are unclear.
Design specifications - There are recommended minimum dimensions for some ungulate species, but the needs of wide-ranging species are vague.
Influence of human activity - Our work in Banff has shown that human activity can influence how animals use passages.
Crossings for all species - Practically all of the research conducted to date has focused on single-species, such as elk or deer, and limited attention has been paid to multiple species or wildlife communities (e.g. large mammals).
Cost-effectiveness - Crossing structures are expensive, but a large research void exists in determining cost-effective designs
Parks Canada. .
One night every spring, most of Amherst's migrating salamanders use Closer to home… these tunnels to get to vernal pools where they mate and lay their eggs.
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