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NEWS TIPS FROM THE October 2004 ISSUE OF CONSERVATION BIOLOGY the Journal of the Society for Conservation Biology
FOR IMMEDIATE RELEASEPlease mention Conservation Biology as the source of these items:
For PDFs of these papers or any Conservation Biology papers since 1992, please contact Robin Meadows at robin@nasw.org. Images are provided by the researchers; please contact them directly for more information. For more information about the Society for Conservation Biology
FOREST ELEPHANT FUTURE IN DOUBTConservation efforts based more on guesswork than facts
A new analysis shows that despite decades of conservation effort, most estimates of forest elephant populations are unreliable. Knowing how many forest elephants there are, and where they live, is key to deciding which populations are most important to protect. "The frequent repetition of crude guesses has created a false sense that we know more than we really do and has set back conservation of these species," say Stephen Blake and Simon Hedges of the Wildlife Conservation Society in the October 2004 Conservation Biology. Blake is the WCS African Forest Elephant Coordinator, and Hedges is the WCS Asian Elephant Coordinator. While no one really knows how many forest elephants are left, conservationists believe that they are in serious trouble due to poaching and habitat loss. For example, poaching appears to be common even in Central African national parks, and West African forest elephants have lost more than 90% of their range. Similarly, Asian elephants used to live all the way from Iran to India and China but are now found only in scattered populations in South and Southeast Asia. Most forest elephant surveys are poorly designed, out-of-date or both. Current survey methods include simply counting the elephants along roads or at water holes, which is not rigorous enough for estimating how many there are in a population. Moreover, "current" estimates for Central West African forest elephants are based on 15-year-old, incomplete data. Worse, the estimate for Asian elephants is 25 years old and even then was little more than an educated guess. "Conservationists and the media have repeated this estimate so often that it has come to be accepted as fact," say Blake and Hedges. Unreliable population estimates can misdirect conservation planning. For example, Sumatra's Bukit Barisan Selatan National Park was not chosen as priority site for elephant conservation in 1998 because the population was thought to be small. However, a 2001 survey revealed that the park actually has about 500 elephants, making the site critically important to elephant conservation in part because Sumatra has a subspecies found nowhere else.
Recognizing the need for rigorous forest elephant surveys, a systematic monitoring program was proposed in 1997 by CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). Called MIKE (Monitoring the Illegal Killing of Elephants), the program began in six Central African sites in 2003. Ultimately, MIKE is planned to encompass 55 African and 31 Asian sites. While promising, this is still not enough. Saving forest elephants will also require spending more money on their conservation needs, which include controlling both poaching and the illegal ivory trade. "At some point in the near future, the international community, including elephant range states, needs to decide if it wants forest elephants to continue to exist. If it does, then the funds for the protection of these species and their habitats need to be significantly increased," say Blake and Hedges. CONTACT: Stephen Blake: 301-650-0607, sblake@wcs.org
WEBSITES: WWF at Work in Africa (click on "Elephant Programme" in the box on the right)
WWF Forest Elephant Program
Forest Elephant Telemetry Maps
TROPICAL FORESTS CAN INCREASE CROP POLLINATIONForest fragments provide wild bees for coffee farmsThe European honeybees that are used to pollinate crops worldwide have declined recently, sparking an interest in using native pollinators. New research suggests that wild bees from tropical forest fragments can help coffee farms in two ways: by increasing pollination and by compensating for honeybee declines. "Exploring such economic links between forest preservation and coffee cultivation may help align the often-conflicting goals of conservation and agriculture," says Taylor Ricketts in the October 2004 Conservation Biology. Ricketts did this work while at Stanford University in California, and is now at the World Wildlife Fund in Washington DC. Crop pollination by wild bees is one of many natural processes that benefit people. Other such ecosystem services include water purification and flood control by wetlands. While it is hard to estimate the economic value of these services, crop pollination by wild bees is likely to be worth billions of dollars per year worldwide, says Ricketts. Wild bees' contribution to crop pollination is more important than ever now that European honeybees are declining in North American and elsewhere due to parasitic mites and pesticides. The key to protecting native pollinators is preserving their habitats, which provide both nest sites and food when crops are not flowering. Wild bees live in the forest in Costa Rica, where coffee is one of the most valuable crops. To see if tropical forest can provide pollination services to coffee farms, Ricketts studied bees in a 1,100 ha coffee farm near San Isidro del General, Costa Rica. The farm was flanked by two relatively large forest fragments (46 and 111 ha), and Ricketts assessed the bees' diversity, flower visits and pollen deposition at various distances from the forest fragments (50-1,600 m). Most of the 40 types of bees observed during the two-year study were native species; the only non-native type observed was the Africanized honeybee, which was also the most common. Ricketts found that bee diversity and activity were much higher at coffee farm sites near the forest fragments. For example, compared to sites that were 800 or 1,600 m from the forest fragments, sites that were 50 m away had roughly three times as many bee species, twice as many flower visits, and twice as much pollen deposition. He also found that native bees helped compensate for the sharp decline in Africanized honeybees that occurred between the first and second year of the study. After this decline, flower visits dropped by about half at sites that were 800 m from forest fragments. In contrast, sites that were 50 m away still had about 90% as many flower visits. This suggests that bee diversity can help stabilize pollination services, which is important because insect populations often fluctuate wildly. "As declines in European honeybees worry farmers elsewhere in the world, conserving a diversity of native pollinators may be considered especially valuable as a form of insurance against such declines," says Ricketts. In a companion paper in the August 24 PNAS, Ricketts and three colleagues showed
that native pollinators increased coffee yields by a fifth within about a kilometer
of the forest fragments. They estimate that the two forest fragments provided
the coffee farm with pollination services worth about $60,000/year during the
study period. "This value is commensurate with expected revenues from competing
land uses and far exceeds current conservation incentive payments," say Ricketts
and his colleagues. Taylor Ricketts: 202-822-3477, Taylor.Ricketts@WWFUS.ORG
SEA TURTLE-FRIENDLY BEACH LIGHTS DISTURB RARE MOUSELight pollution increases predation risk, deters foraging
The sea turtle-friendly lights that Florida has mandated for beaches may still disrupt behavior in other animals. New research shows that these long-wavelength lights can keep beach mice from foraging where and when they want. Artificial lights can increase the risk of predation and so are also likely to disrupt behavior in many other animals, including fish and birds, say Brittany Bird, Lyn Branch and Deborah Miller of the University of Florida, Gainesville, in the October 2004 Conservation Biology. Bird is now at the Wildlife Habitat Council in Detroit, Michigan. Light pollution is a growing problem that already affects nearly a fifth of the land worldwide, particularly coastal beaches and barrier islands. Artificial lights are infamous for discouraging adult sea turtles from landing on nesting beaches, and for keeping hatchlings from finding the sea. To protect the turtles, Florida requires long-wavelength lights on beaches. However, no one knows how these lights affect other at-risk species, such as the beach mouse. There are eight subspecies of beach mice in the coastal dunes of Florida and Alabama, and all are threatened or endangered except one: the Santa Rosa beach mouse. To see how the turtle-friendly lights affect the mice, Bird and her colleagues compared Santa Rosa beach mouse foraging in areas with and without long-wavelength lights (either one 18-W low-pressure sodium vapor light or two 40-W incandescent yellow bug lights, mounted on 10-foot pipes). The illuminated areas had a radius of 39 feet, and the researchers set trays of millet seeds at varying distances from each light source (0-52 feet) for the mice to eat at night. To see how much the mice had eaten, the researchers weighed how much millet was left the next day. Bird and her co-authors found that the turtle-friendly lights kept the beach mice from foraging at the nearest millet trays. While the mice foraged at virtually all of the trays in the dark areas, they foraged at only about 80% of those within 13 feet of the low-pressure sodium vapor lights, and at only about 65% of those within 13 feet of the bug lights. In addition, the bug lights kept the beach mice from harvesting as much millet as they did in the dark. The mice ate only a fifth as many seeds within 13 feet of the bug light source as they did in the dark. The low-pressure sodium vapor lights did not affect how much the mice harvested, possibly because they emit only yellow light while the bug lights emit a broader range of wavelengths. This study shows that it doesn't take much light to make beach mice avoid an area, which suggests that the effects of actual beach lights could be worse. "Taller, higher intensity lights and multiple light sources are common in substantial portions of beach mouse habitat and may have more pronounced impacts on mouse behavior," say Bird and her co-authors. CONTACT: Brittany Bird: 313-235-9627, bbird1976@yahoo.com
WEBSITES: The Night Sky in the World
Growth of Light Pollution in North America
University of Florida: Beach Mice
STRIPCOVER CROPS INCREASE SONGBIRDS IN COTTON FIELDSMore birds, same amount of cotton, lower cost
Wildfires in the western U.S. are bigger, hotter and scarier than ever due to fire suppression and other policies that have changed natural fire patterns. Today's fires can threaten wildlands and people alike, and a new analysis shows that reforming fire policies would help restore forests and rangelands while protecting people and homes. North American songbirds are having a harder time finding places to nest as agriculture intensifies, but crop production doesn't necessarily have to be at the expense of the birds. New research shows that Georgia cotton fields with stripcover crops can have up to 20 times more songbirds than conventional fields, with the same level of production at less cost. This makes "stripcover cropping not only a good choice for reducing negative impacts on wildlife and surrounding ecosystems, but also an economically valuable one," say Sandra Cederbaum, John Carroll and Robert Cooper of the University of Georgia, Athens, in the October 2004 Conservation Biology. Many of North America's grassland birds have declined over the last 30 years and agricultural intensification is a major factor. Tilling, planting and harvesting can kill birds, disturb nests, and reduce the cover where birds nest. In addition, pesticides can reduce the insects that birds eat. Of the major crops in the southeast U.S., cotton provides the worst habitat for birds. Conventional cotton fields are heavily sprayed with herbicides and insecticides, and are tilled so early and often that most nests established before the May planting are lost. However, there are two other systems for growing cotton that could benefit birds: conservation tillage, which leaves at least a third of the crop residue, and stripcover cropping, which leaves rows of the winter cover crop such as clover between the cotton rows early in the growing season. Cederbaum and her colleagues compared the abundance of birds and their insect prey in these three cotton-growing systems (conventional, conservation and stripcover) in the Upper Coastal Plain of Georgia. The researchers found that during the migration and breeding seasons, the density of songbirds in the stripcover fields was up to six times higher than on the conservation fields and up to 20 times higher than on the conventional fields. During much of the breeding season the stripcover fields also had more insects, many of which were beneficial. In addition, stripcover cropping entails less tilling and so gives birds more chances to nest. For example, early-nesting birds such as the horned lark can raise at least one brood before cotton planting. Besides benefiting the songbirds, Cederbaum and her colleagues found that clover stripcover cropping can benefit the farmers. They estimate that this method can decrease costs as much as $317/ha: less tilling means lower fuel and labor costs; clover produces nitrogen and so means lower fertilizer costs; and more beneficial insects means lower pesticide costs, which are about equal to those of tilling and fertilizer combined. Moreover, Georgia's clover stripcover fields have produced yields as high as or higher than the state average, showing that cotton production and conservation can go hand-in-hand.
CONTACT: Sandra Cederbaum: 706-542-9727, scederbaum@forestry.uga.edu scederbaum@forestry.uga.edu
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