In the January 2008 issue of The Oryx, Dr. Joel Berger (of the University of Montana and the Wildlife Conservation Society) published an interesting short article on the likely local extirpation of white-tailed jackrabbits from the Yellowstone region - a cautionary tale about the potential problems of undetected extinctions and their potential ramifications cascading up through food webs. The current issue of the journal is freely accessible, so at least for now you can read the whole article here, and I've put the abstract below the fold. The paper itself has become a cautionary tale for a different reason however - because it appears that the jackrabbits weren't really extirpated after all, as shown by a number of local people! Bully for citizen science - and a little egg on the face of the scientist. Now isn't that a good easter story?
Oryx (2008), 42:139-142 Cambridge University Press
Copyright © Fauna and Flora International 2008
Undetected species losses, food webs, and ecological baselines: a cautionary tale from the Greater Yellowstone Ecosystem, USA
Large protected areas are often considered natural yet outside pressures may compromise ecological integrity. This paper points to a problem in assessing ecological baselines: what if species’ extirpations go undetected? I present a data set spanning 130 years that demonstrates the loss of white-tailed jack rabbits Lepus townsendii from two National Parks in the well studied 60,000 km2 Greater Yellowstone Ecosystem, USA. While these extirpations have been unnoticed until now, an ecological consequence may be elevated predation on juvenile ungulates. A critical challenge we face is how to apply better the concept of shifting baselines to the restoration of functional relationships when species' losses are undetected.
(Received November 29 2006)
(Reviewed February 09 2007)
(Accepted May 01 2007)
Key Words: Ecological baseline; extirpation; Grand Teton; Lepus townsendii; protected area; white-tailed jack rabbit; Yellowstone
c1 Northern Rockies Field Office, Wildlife Conservation Society and Division of Biological Sciences, University of Montana, Missoula, Montana 59812 USA. E-mail email@example.com
The White-tailed Jackrabbit (Lepus townsendii) is a not-inconspicuous-sized small mammal likely to be an important prey species for the canids (coyotes and wolves) of Yellowstone and Grand Teton national parks. And in parks as well known, well-protected, and well studied by scientists as these, something as large as a jackrabbit shouldn't really disappear unnoticed for too long, right? Yet, somehow, that is exactly what happened - or so Berger argues in the article: this species did go locally extinct, without raising much of a scientific eyebrow and that this may in turn have led to the coyotes shifting prey to eating young elk instead! Berger "chronicled L. townsendii disappearances by collating historical information, unpublished and published notes, and queries to professional biologists and naturalists who have (or had) worked in the Yellowstone Ecosystem for up to 5 decades (Appendix). I also checked records and queried databases of the American Museum of Natural History, the California Academy of Sciences, the Chicago Field Museum, the Burke Museum (Seattle), the Denver Museum of Nature and Science, and the Museum of South-west Biology (Albuquerque)."
Berger's analysis of the above data suggested that the jackrabbit disappeared from the region by the 1990s. He also used analyses of coyote scat samples from the 1930s to the late 1990s to show that the jackrabbit disappeared from the coyote's diet over that time period. So he concluded there was a local extinction (as was also concluded in a WCS workshop on jackrabbits in the Grand Teton in 2005), and went on to speculate about the potential effects of coyotes shifting to young elk as prey. He rounds off the brief article by discussing the potential for reintroducing jackrabbits to the parks to potentially help in "the establishment of dynamic ecological processes that were intact prior to extirpation". And points out the problem that the local extirpation may have left us with unreliable baseline data so that we may not actually know what the ecosystem was like prior to this extirpation - therefore we need to use shifting baselines in an adaptive management framework. "At a broader level the problems of species disappearance in the two parks in the Greater Yellowstone Ecosystem is not likely to be a unique episode restricted to this well studied region. A critical challenge we face is therefore how to apply better the concept of shifting baselines to the restoration of functional relationships when species' losses are undetected."
All well and good, the paper was reviewed and published in the Oryx, and the story was picked up not only in the blogsphere (e.g., here and here) and science outlets, but even the mainstream media, including NPR; but there was a problem. A few days after the paper was reported in the media, a local ornithologist saw a couple of jackrabbits in Yellowstone, and a handful of other locals furnished other evidence that they were not exactly extinct yet! All this has left Joel Berger with "egg on his face", and he now promises to publish a retraction in the next issue of the Oryx. Yet, he stands by his "study's broader point - that the rabbit's decline may have forced predators to turn to other food sources". More unfortunately, he leaves himself, and scientists in general, open to accusations of bias, hidden agendas, and worse.
Here are my lessons from this cautionary tale:
- Extinction (like most other negatives) is damn hard to prove, even on a local scale. The counterpoint, as seen in the infamous saga of the Ivory-billed Woodpecker's "rediscovery", is that non-extinction is equally hard to prove! So we should strive to use all means available to get the most reliable data.
- Scientists, even prominent ones, can make simple mistakes. In this case, it seems Berger drew upon a variety of evidence to analyze the status of jackrabbits - yet somehow failed to ask for the most direct data: current field observations!
- Standard peer-review can fail to catch some of these mistakes immediately. This article was peer-reviewed, yet no one apparently asked for more direct evidence from the author!
- Its funny how many of us accepted the conclusions of the paper and ran with the "cautionary tale" perhaps because it fits so nicely with our conservation paradigms - yet all Berger (and the rest of us) had to do was to ask ordinary people who live in the area if they'd seen the jackrabbits! How often, and why, do we forget that?
- Nevertheless, science remains (and must remain) open to non-peer review as well, so that even amateurs can point out the errors of the most eminent among us scientists. This is where citizen science has a crucial role to play, so we should all, especially in conservation biology, strive to use every possible set of eyes and ears to monitor wildlife and the environment. And given that many people are fascinated enough by nature to spend plenty of their own time and money watching wildlife, why not get some useful data out of their efforts as well? Isn't that a real win-win?
- And finally, scientists must be prepared to enjoy the occasional egg on their faces! Afterall, isn't the scientific method, ultimately, about us hurling empirical eggs at each other's pet hypotheses? So why should we keep the fun of that to ourselves? Why not share it with the public?
Joel Berger (2008). Undetected species losses, food webs, and ecological baselines: a cautionary tale from the Greater Yellowstone Ecosystem, USA Oryx, 42 (01) DOI: 10.1017/S0030605308001051