Tara Smith posted Entry 1364 on August 23, 2005 08:14 AM.
Trackback URL: http://www.pandasthumb.org/cgi-bin/mt/mt-tb.fcgi/1362

Coming soon to Nebraska?

In the August 18th issue of Nature (1), Donlan et al. suggest a novel way to save certain species of megafauna: bring them to the North American wilderness. (CNN summary/commentary here).

It’s not as outlandish as it may sound. As they point out, North America had many similar species until 13,000 years ago, including mammoths, camels, cheetahs, and lions. While they acknowledge there are differences between modern species and those which existed once upon a time in America, they suggest that the modern species are proxies for their long-extinct cousins, and could be used to “re-wild” North America. The authors suggest a mutually beneficial relationship: portions of the Great Plains benefit from tourism dollars, while the animals benefit from increased habitat and a decreased threat of extinction. Win-win, right?

Potential pitfalls are mentioned. In addition to the “they’re not exactly the same” objection mentioned above, the authors mention other likely criticisms: disease, different habitats, and “unexpected ecological and social consequences of reintroductions.” They suggest moving animals onto large tracts of private land in order to study these possibilities prior to the final stage in their vision: “ecological history parks,” with perimeter fencing, allowing these large mammals to roam free over large stretches of the Great Plains. While I applaud their optimism and their passion, and while I’d love to be able to drive a few hundred miles and see animals like this in “the wild,” our history of moving animals around the world just ain’t that great, and often has unintended consequences.

First, “unexpected consequences.” The authors highlight the successful re-introduction of peregrine falcons in North America as a recent example of “proxy species” used to replace an extinct population. Indeed, 2500 captive-produced birds (Falco peregrinus) were released in the east beginning in 1974, and in the Midwest beginning in 1982 (2), and appear to have flourished. However, the time scales between elimination of the original population of peregrine falcons and re-introduction of new ones in comparison to the megafauna re-introduction differ by a factor of over 400. The decimation of the falcon population began in the late 1940s as a result of chlorinated hydrocarbon poisoning, and severe effects were seen by the mid-1960s. If we’re generous, we can say that a span of 30 years went by between the elimination of the bulk of the peregrine falcon population and the re-introduction of their cousins of different subspecies. In the case of the re-introduction of these large vertebrates, the time span is over 10,000 years; not a valid comparison, in my mind.

Additionally, our success with introductions of novel species into new areas has not exactly been high. One suggestion is that these animals will serve to control the “pests and weeds” that dominate the Great Plains landscape. Perhaps elephants can eat certain plants that threaten grasslands. This brings to mind other biological control agents—such as the cane toad in Australia , which were not only unsuccessful, but by most accounts, an environmental disaster. Granted, elephants are quite a bit easier to keep track of than toads, but ecological webs are tricky, and it’s difficult to predict what long-term effects the introduction of a new species will bring. Let me provide a graphic example. This is taken from the webpage of Mark Newman, a physicist at the University of Michigan who works with all different kinds of complex systems.

Don’t focus on the specific examples; the key is to see how inter-connected all of the individual species (the “hubs” or dots) are. (Another good example, with some more commentary, can be found here. ) When one hub is disturbed, it may have severe effects on the interactions at other levels. There’s a great chapter on this in Mark Buchanan’s book Nexus: Small Worlds and the Groundbreaking Science of Networks. (3) Buchanan quotes ecologist Kevin McCann (4):

The lessons for conservation are obvious: 1) if we wish to preserve an ecosystem and its component species then we are best to proceed as if each species is sacred; and 2) species removals (that is, extinction) or species additions (that is, invasions) can, and eventually will, invoke major shifts in community structure and dynamics.

The question then becomes—which is more important: maintaining the ecosystem of the Great Plains by preventing invasion of non-native species, or acting to prevent extinction of these large vertebrates, something which certainly is a concern to many ecologists? While I think overall this is a bad idea, I don’t have any concrete answers, and at least it’s heartening that the suggested plan is (supposedly) to proceed slowly.

My other concern is one Donlan mentions but glosses over: disease transmission. I’m a microbiologist, and my emphasis area is infectious disease epidemiology. Additionally, a major focus of the research center I’m involved with just happens to be zoonotic disease: disease which is transmitted between different animal species. So my first thought is, “what biological agents will these introduced species bring along with them?” And secondarily, “what biological agents will they encounter here, that they’ve not encountered in their native lands?” Certainly some of this has been experienced already, as these animals are present in zoos, circuses, and private refuges throughout the country, but there’s a difference in disease potential between animals housed in contained areas with regular medical care, and those roaming free in the wilderness, able to be in contact with a large variety of other species who’ve not been vaccinated and are not routinely screened for disease. A figure of 77,000 “large mammals” which “roam free” on Texas ranches is mentioned in the article; I’d love to see more data about these as they go forward with their idea. I’d hate to see some kind of pathogen native to elephants spread into, say, the wild deer population, and then spread to hunters, and then further into the human population, for example. Alternatively, it would be horrible to have a mass die-off of elephants due to an infection native wildlife have immunity against, and carry asymptomatically.

In the end, if this is carried out on private land, I’m not sure what could be done to stop them. I know some areas have laws against housing wild animals; I suppose other areas could impose them if it seems this is going forward faster than local authorities may like. But given the political climate of the United States, it seems that the enticement money brings often trumps the science that may support or derail such ideas. Donlan’s last thought in the Nature article states that they “…want to reinvigorate wild places, as widely and rapidly as is prudently possible.” As much as I’d love to take my kids on an “African” safari just a few hundred miles away, I hope prudence is more important than speed.

References:

(1) Donlan, J. Re-wilding North America. Nature. 2005 436:913-4.
(2) Tordoff, H.B.; Redig, P.T. Role of genetic background in the success of reintroduced Peregrine falcons. Conserv. Biol. 2001 15:528-32.
(3) Buchanan, M. Nexus: Small worlds and the groundbreaking science of networks. W.W. Norton and Company: New York. 2002.
(4) McCann, K.S. The diversity-stability debate. Nature. 2000 405:228-233.

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Comment #44436

Posted by Dark Matter on August 23, 2005 10:34 AM (e)

From the CNN article:

“Just when you think the world has gotten as weird as it can get, something like this comes along,” said Steve Pilcher, executive vice president of the Montana Stockgrowers Association.

“I wonder how many calves or lambs it would take to feed a family of lions for a month?” Pilcher mused. “We sort of know what it takes for wolves, but something tells me we would be in a whole new ball game.”

From reading the article, I don’t think this has been thought out very well. They would have to set up an entire food chain to support these predators.

If they push this thing through, does anybody else see this project being turned into a shooting gallery “canned” hunt thing to cull any excess predators?

Comment #44438

Posted by Harald Korneliussen on August 23, 2005 10:42 AM (e)

One thing is that big fauna is pretty easy to control. If you don’t mind killing them, that is. The Muskox was (re)introduced in the fifties into high mountain fauna in Norway, after having been extinct since the ice age. I quote from the “control programme for the muskox population of dovrefjell”:

“Experiences with the muskox in the fifty years that have passed since its intoduction to Norway, suggest that the species is not a threat to ecosystems or other species on Dovrefjell.”

So there’s one positive example. It’s an interesting article, pity I don’t have time to translate the full 28 pages. I can perhaps translate some more if someone is interested enough to mail me (020042 at stud hials no).

article

Comment #44440

Posted by Greg Peterson on August 23, 2005 11:28 AM (e)

It’s basically “Jurassic Park” with geography rather than chronology. Crichton might be a wanker when it comes to global climate change, but there were some pretty sage warnings about tampering with Mama Nature in JP.

Comment #44442

Posted by Jason on August 23, 2005 11:41 AM (e)

IMO, this is a counter-productive argument that takes us away from some important conservation efforts closer to home. I would think resources would be better spent on reintroductions of the herds of bison that used to roam these areas, or other more-recently extirpated species.

We certainly have no shortage of endangered species issues here in the US, and spending time debating over whether we should start importing African savannah species only distracts scarce resources away from these local issues.

This looks to me more like a “publicity stunt”, where the author knew this would generate a lot of press coverage along the lines of “Lions and elephants are coming soon to you!”

Comment #44444

Posted by Bayesian Bouffant, FCD on August 23, 2005 11:51 AM (e)

Where exactly are they proposing to do this? Kansas, perhaps? How many school board members would it take to feed a pride of lions for a month?
:o

Comment #44446

Posted by Gerard Harbison on August 23, 2005 12:03 PM (e)

Actually, as a Nebraska resident, I have a much more primal response: we’re not your !@#$% zoo!

Sure, the US megafauna was decimated after the last ice age (as were the Eurasian and Australian faunas previously, and those of virtually every island humans have ever landed on). But the Plains ecosystem is what it is; in fact, we’re seeing species like the mountain lion recolonize territory from which it had been exterminated, while southern plains species are gradually moving north. At latest count, I’ve seen 68 bird species on my acreage SW of Lincoln, as well as a diverse group of reptiles, mammals and amphibhians. In terms of large predators, we have coyotes out the wazoo, and my neighbors swear they’ve seen mountain lions. We need lions like we need a hole in the head.

Can’t these yobs go concentrate on something worthwhile, like saving the Hawaiian honeycreepers?

Comment #44448

Posted by TimW on August 23, 2005 12:25 PM (e)

There are some huge exotic wildlife parks in the USA now. Fossil Rim in Texas comes immediately to mind because I used to live only about 50 miles from it.

I don’t see how this suggestion is really any different than what these mega-size wildlife parks are already doing.

Comment #44450

Posted by Tara Smith on August 23, 2005 1:45 PM (e)

Seems to be a matter of scale. I’m not familiar with Fossil Rim, but just looking at their site, the park is either 1500 or 1800 acres (2 different claims on their website), and has ~1000 animals. Big, to be sure, but the authors of the Nature paper seem to be proposing both more animals and more land. One quote (my emphasis):

Many of these animals are already in captivity in the United States, and the primary challenge will be to provide them with naturalistic settings, including large protected areas of appropriate habitat and, in the case of carnivores, live prey.

They use words like “vast” and “great swaths” in the paper as well, so I’m guessing they’re hoping for a lot more than 1800 acres.

I also wonder if the animals at Fossil Rim fend for themselves, or are more zoo-like, in that keepers feed them regularly. Since they claim the animals “live peacefully,” I’m guessing that they’re not exactly letting the cheetah prey on the gazelle.

Comment #44451

Posted by Tara Smith on August 23, 2005 1:48 PM (e)

Oh, and I’m not sure Nebraska is even an area targeted, Gerald–they’re not any more specific than “the Great Plains” in any of the articles I’ve seen. So your birds may be safe yet. :) (And there have been mountain lion reports here in Iowa too; with some confirmed tracks and IIRC a few captures to boot).

Comment #44461

Posted by Bayesian Bouffant, FCD on August 23, 2005 4:13 PM (e)

Survey Confirms Sea Squirts in Maine

PORTLAND, Maine - A survey of Cobscook Bay has uncovered the presence of sea squirts, an invasive species that scientists fear could overwhelm valuable shellfish beds and alter the marine ecosystem, researchers said Monday…

Comment #44568

Posted by Dan S. on August 24, 2005 12:58 AM (e)

Before we start shipping the lions and camels, maybe we should try out the Buffalo Commons first? (Although presumably the Pleistocene rewilding folks feel that lions and elephants would promise to bring in enough ecotourism dollars to get it off the ground in a large-scale, well organized, top-downish way - something that the whole buffalo-commons-movement philosophy is not exactly on board with …

That food web image is astonishingly cool.

Comment #44600

Posted by HPLC_Sean on August 24, 2005 10:06 AM (e)

Moving these creatures into a new habitat is an astonishingly bad idea. I can’t believe that actual scientists are entertaining this notion given all of the examples of man’s incompetence at introducing new species to different environments.
The only real way to save endangered animals is to restore their native environment. Every biologist will tell you that habitat means everything to survival and evolution of species. Thinking that we can protect species from extinction by changing their environment is short-sighted junk science and flies in the face of everything we know about evolution.