Tuesday, February 26, 2013
Hope for Haiti's Montane Forests
Cornell Lab colleague Jim Goetz descended yesterday to Port-au-Prince, Haiti from the mountains in La Visite National Park. There we were joined by 3 biologists from Societe Audubon Haiti and 3 student trainees from the local Universite Quisqueya. Our primary goal was to revisit two remnant patches of broadleaf cloud forest that we had surveyed in 2005, and to re-evaluate their conservation status. Eight years earlier, our field work had painted a grim picture, as both sites suffered from unchecked local subsistence agriculture and wood extraction. We hoped the tables might now be turning, with recent international focus on Haiti's precarious ecological future and our collaborative effort with Jim to develop incentive mechanisms for local residents.
The past four days of intensive mist-netting and banding, point counts and careful observations yielded a mixed outlook for these two forest patches. On the hopeful side, both remnants persist and have lost less broadleaf habitat than we feared. However, both patches continue to steadily lose ground, as local farmers cut, clear and cultivate. At our lower (and larger) site, Berak, even more striking than the unabated decrease of forest cover was dramatic erosion caused by storms like Hurricane Sandy, whose torrential rains from the deforested slopes above had slashed 10 foot wide and deep gashes through Berak's steep ravine. At current rates of forest loss and erosion, the ecological integrity of these two tracts will soon exceed a tipping point. Immediate changes in local land use practices are the only hope that these cloud forests and their unique biological diversity can survive, let alone expand.
Surprisingly, our mist-netting did not reveal dramatic overall declines in resident birds and overwintering migrants using the two forest patches. We captured 65 individuals at the upper elevation (2000 m) site, La Visite, with 16 Green-tailed Ground Tanagers (8 in 2005) and 8 Black-throated Blue Warblers (2 in 2005) the two most abundant species in our nets. We found and managed to capture a single Bicknell's Thrush that was calling from a tiny broadleaf patch (2 birds occupied the site in 2005). Of real concern was the near absence of two rare and highly vulnerable cloud forest endemics, La Selle Thrush and Western Chat-Tanager. We detected only a single vocalizing individual of each species at the La Visite site, and we netted none. In 2005, we had 5 La Selle Thrushes (2 netted) and 8 Chat-Tanagers (none netted). It seems that true forest specialists like these may be the first to disappear when patch size and vegetation structure become compromised.
At Berak, which features a more extensive, diverse and well-developed wet forest at 1200 m elevation, we mist-netted 78 birds. Green-tailed Ground-Tanager again was the most abundant species, with 12 individuals banded (21 in 2005), followed by 9 Hispaniolan Emeralds (7 in 2005) and 6 Hispaniolan Spindalis (4 in 2005). Among migrants, 7 Ovenbirds (11 banded in 2005) and 6 Black-throated Blue Warblers (10 in 2005) were our most common captures. Highlights included single Sharp-shinned Hawks, Loggerhead Kingbirds and Swainson's Warblers. Most remarkable were recaptures of 3 individuals that we had banded in 2005 - 2 Narrow-billed Todies and a Western Chat-Tanager! These parallel our long-term banding results from the DR's Siera de Bahoruco, which also show pronounced longevity and site fidelity of resident birds. A surprising and disconcerting discovery was the complete absence of Bicknell's Thrush at Berak. In 2005, we had detected 8 birds there, netting 6 of these. On this trip, we surveyed the entire forest patch with playbacks during two dawns and a single dusk period, without a single response. After 20 years studying this species on Hispaniola, we know that wintering birds, which hold discrete territories, respond to playbacks, so I'm confident there were no Bicknell's Thrush at Berak during our three days there. Equally troubling was the drop in La Selle Thrush and Western Chat-Tanager numbers - in 2005 we detected 5 thrushes (1 netted) and 14 Chat-Tanagers (8 netted). This trip: no La Selle Thrush and only 3 Chat-Tanagers heard or seen (though we netted 4). Again, loss of forest structure and integrity seems a likely culprit.
Despite disturbing signs, we left the mountains with a solid measure of optimism. Jim Goetz is enlisting local farmers in a Payments for Ecosystems Services program, which provides incentives to allow forest recovery. Our local partner, Fondation Seguin, is strongly committed to working with Jim and VCE for the long-term conservation of a core ecological reserve surrounding these two forest patches. And, the young Haitians with whom we worked are passionate and eager to make a difference. They are the future of conservation in this country - their dedication and sense of purpose must carry the day.
For information about VCE's 2005 trip to La Visite National Park, see our 2010 paper in the Journal of Caribbean Ornithology 23:31-43
Posted by Chris Rimmer