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Society for Conservation Biology: 2002 Annual Meeting

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Society for Conservation Biology: 2002 Annual Meeting


Society for Conservation Biology 16th Annual Meeting July 14-July 19 2002
co-hosted by DICE and the British Ecological Society


Abstracts for Conservation and Birds
Session Two

Wednesday 17th July, 13.30 - 15.00, Eliot Lecture Theatre 2

Chair: Glen Chilton




(BLOCK CAPITALS indicate the presenting author)


13.30 - 13.45
CHILTON, GLEN. Department of Biology, St. Mary’s College, 14500 Bannister Road, S.E., Calgary, Alberta, T2X 1Z4, Canada, <glen.chilton@stmc.ab.ca>.

LESSONS LEARNED FROM THE LONG-EXTINCT LABRADOR DUCK

If current management practices are to be successful, they should be based on a thorough understanding of the causes of past population declines and extinctions. The Labrador Duck bred in remote localities, and went extinct before much was known of its natural history. Even so, a thorough, critical examination of the literature has provided some important insights. There is no evidence that this bird or its eggs were harvested on its breeding grounds. Harvest on the wintering ground was likely to have had only a minor impact on its population dynamics. The only description of a nest, from Blanc Sablon, Labrador by Audubon, is likely an error. However, eggs in collections suggest that this species may have bred in even more remote situations, including western Greenland and in far northwestern Canada on the Beaufort Sea. We must therefore examine possible causes of decline in this species that are unrelated to human activities.

13.45 - 14.00
CAMPBELL, STEVEN P., Jack W. Witham, Malcolm L. Hunter, Jr., and Malcolm T. Jones. Department of Wildlife Ecology, 5755 Nutting Hall, University of Maine, Orono, ME 04469, USA, <Steve_Campbell@umenfa.maine.edu>.

LONG-TERM EFFECTS OF A GROUP-SELECTION TIMBER HARVEST ON THE BIRD COMMUNITY OF AN OAK-PINE FOREST IN MAINE

Much of the attention on population declines of Neotropical migrant birds has focused on the effects of clear-cutting and the attendant effects of fragmentation, but few studies have examined the effects of forest management practices that create small interior openings in a forest (i.e., group-selection harvests). At the Holt Research Forest in Arrowsic, Maine we have documented the effects of this type of harvest on bird abundance for 18 years (5 years pre-harvest and 13 years post-harvest). Abundances of all bird species in the 40 ha study area were determined by territory maps based on 16 visits in each breeding season. Of the 38 species of breeding birds abundant enough for analysis, only six showed a significant response to the timber harvest. The abundances of Ovenbird and Black-throated Green Warbler decreased in the harvested areas, while those of White-throated Sparrow, Common Yellowthroat, and Eastern Wood-Pewee increased in these areas. Notably, the Winter Wren which was previously absent from the forest appeared in harvested areas immediately following the harvest, apparently in response to remnant slash piles; subsequently it declined and disappeared. We conclude that group-selection harvesting favours gap species and disfavours a few forest species, while most species show little effect.



14.00 - 14.15
MULWA, RONALD, Leon Bennun and Callistus Ogol, Department of Ornithology, National Museums of Kenya, P.O. Box, 40658 Nairobi, Kenya, <kbirds@africaonline.co.ke> (RM), Zoology Department, Kenyatta University, P.O. Box 43844 Nairobi, Kenya (CO), BirdLife International, Wellbrook Court, Girton Road, Cambridge CB3 ONA, UK (LAB).

CONSERVATION STATUS OF TAITA WHITE-EYE IN THE FRAGMENTED TAITA HILLS FORESTS, KENYA

Taita White-eye, Zosterops (poliogaster) silvanus, is an Endangered bird species endemic to the highly fragmented forests of the Taita Hills and Mount Kasigau in south-east Kenya. Between November 1998 and September 1999 we counted Taita White-eyes along line transects (119 in total, covering 56.3 km) to establish current population status and distribution in their entire range. Censuses were conducted in all ten Taita Hills forest fragments where the birds occurred and the little-disturbed Mt Kasigau forest, some 50 kilometres south-east. The total global population of Taita White-eyes was estimated to be c. 7,100 birds. Mt Kasigau was the species’ main stronghold, holding 80% of the entire population at the high density of 26 birds/ha. In the Taita Hills, white-eye densities were consistently higher in the small than in the large fragments, but the small fragments held only three percent of the total population. It is not known if there is current population interchange between the Taita Hills and Mt Kasigau, which are separated by an extensive tract of unsuitable, semi-arid habitat.



14.15 - 14.30
TEJEDA-CRUZ, CESAR and William J. Sutherland. Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich, NR4 7TJ, UK, <Cesar.Tejeda-Cruz@uea.ac.uk>.

BIRD DIVERSITY IN COFFEE SYSTEMS: MIGRANT VS. FOREST SPECIES

Transformation of undisturbed tropical forest to an agricultural mosaic has meant the local disappearance, fragmentation and isolation of natural habitats. However, structurally complex production systems, such as coffee, might play an important role for biodiversity conservation. This has resulted in the promotion of "biodiversity friendly" coffee. This study aimed to analyse the role of coffee plantations in bird diversity conservation in southern Mexico. We conducted 245 bird point counts in five habitats. Tropical rainforest and rustic coffee, which uses native tree shade, held similar high diversity levels. Shaded monoculture, coffee planted under a specialised shade dominated by Inga trees, showed slightly lower diversity levels. Cloud forest held considerably less diversity. Finally, sun coffee, with no tree shade, had very low diversity. Both shaded coffee systems showed high richness and significantly higher abundances of migratory birds species. However, cloud forest and tropical rainforest held higher numbers and significantly higher abundances of sensitive and indicator species. Thus shaded coffee is important for migratory species and may play an important role maintaining local biodiversity, but may be detrimental for forest specialists. Semi-structured interviews with local farmers showed that there is a tendency to transform forest into coffee when prices rise.



14.30 - 14.45
BORKHATARIA, RENA R., J. Collazo, and M. Groom. Program in Ecology, Duke University, Durham, NC, 27708 <rrb8@duke.edu> (RRB), North Carolina Cooperative Fish and Wildlife Research Unit, North Carolina State University, Raleigh, NC 27695 (RRB, JC) and Dept of Zoology, University of Washington, Seattle, WA 98195-1800 (MG)

ECOLOGICAL AND POLITICAL IMPLICATIONS OF CONVERSION FROM SHADE TO SUN COFFEE IN PUERTO RICO


Biodiversity is greater in shaded coffee plantations than in sun plantations, yet many farmers are converting to sun for short-term economic gains. The environmental costs of sun coffee farming and farmers’ opinions have received little attention from local policy-makers. We used an integrative approach to determine reasons for coffee conversion in Puerto Rico and ecological services lost to farmers by conversion. By sampling birds, lizards, and insects in 3 sun and 3 shade coffee farms and using exclosures, we determined that insectivorous birds are more abundant in shaded coffee (p=0.002) and may provide a service to farmers by controlling insect outbreaks. A survey of 100 farmers revealed that the reasons for growing sun coffee were higher yields, recommendations by agronomists, and governmental incentives. Shade farmers were more satisfied than sun farmers (p=0.03) and most farmers indicated they would plant shade trees if provided with incentives. Farmers valued species that provide services to humans, but through conversion farmers lose valuable ecological services associated with biodiversity. We conclude that promotion of shade coffee serves the interests of the government and the coffee growers of Puerto Rico, particularly if biodiversity is valued equally with the social and economic factors involved in coffee production.


14.45 - 15.00
Discussion