Hispaniolan Birds Program Detail

What Species: Overwintering Neotropical migrants, including Ovenbird (Seiurus aurocapillus), American Redstart (Setophaga ruticilla), Black-throated Blue Warbler (Setophaga caerulescens), Common Yellowthroat (Geothlypis trichas); and permanent residents, including Black-crowned Palm-Tanager (Phaenicophilus palmarum), Green-tailed Ground-Tanager (Microligea palustris), Greater Antillean Bullfinch (Loxigilla violacea), and others.

Where: Mencia, Pedernales Province, Dominican Republic; in the buffer zone of the Sierra de Bahoruco National Park.

Who: Dr. Steven Latta (National Aviary), Danilo Mejía and Marisabel Paulino (Grupo Accion Ecologico).

When: 2003 – present

Why: Birds throughout the world are threatened by habitat change. On the northern breeding grounds, as well as tropical wintering sites, migratory birds face a variety of degraded habitats. Agricultural lands, scrub, and early-successional forests represent a large majority of available habitats in many regions. Yet, much of the published work on wintering migrants (as well as Caribbean residents) has focused on birds in mature, native, and presumably optimal habitats. The question of how migrants and other birds respond to these early-successional habitats, and the impact of habitat degradation on avian demography, should be of high interest to avian conservationists concerned with population trends.

Project Description and Current Status: Hispaniola supports more endemic bird species (those species found nowhere else in the world) than any other Caribbean island except Jamaica. Haiti and the Dominican Republic's contribution to global biodiversity has earned Hispaniola the highest ranking of biological importance in a worldwide assessment of bird protection priorities. While habitats of Hispaniola are vital to the survival of many endemic and migrant bird species, the rate of loss of these habitats is alarming. Some recent estimates place forest loss at greater than 90% in the last 20 years in the Dominican Republic, while in Haiti forest loss is nearly complete. Most forested areas remaining in the Dominican Republic are fragmented and under continuing heavy pressure.

In response to this crisis, the Dominican government has established protected areas in key locations around the country. The Sierra de Bahoruco National Park is a 800 km2 protected area in the extreme southwest portion of the country. The Bahorucos are an ancient chain of mountains that constitute a center of Hispaniolan endemism and are of extreme biological importance. The Dominican Republic recognized the biological uniqueness of the Bahorucos by creating the Sierra de Bahoruco National Park in 1983, and the United Nations recognized the Bahoruco-Enriquillo-Jaragua Biosphere Reserve in 2003. These mountains contain 29 of the 31 endemic bird species found on the island.

Photo: Dr. Steven Latta with Marisabel Paulino in the fieldPrevious studies of wintering migrants in the Sierra de Bahoruco focused on demographics, site fidelity, and survival in presumably optimal habitats. However, considerable amounts of native habitats have been converted to agriculture; on Hispaniola 72% of land cover is now agricultural crops, early-successional scrub, or pasture. Large portions of the Bahorucos have been converted to agricultural use through slash-and-burn practices, and other forested sites are selectively cut and the understory burned to promote forage for cattle grazing.

The effects of these practices on birds, and the use of these early- and mid-successional habitats by birds, has never been studied. Among agricultural habitats, only sun and shade coffee plantations have been investigated as bird habitat, with the conclusion that shade coffee in particular may indeed be comparable to some native habitats for wintering migrants. However, there has been no comparable work on migrants in early-successional scrub or regenerating broadleaf forests, nor has any work been conducted on how migrants use habitats recovering from agricultural disturbance.

Thus, for management planning efforts, there is a need to know how this most common form of habitat conversion affects bird demographics and survival, and how birds respond to regeneration of these habitats.

Here we seek to build upon our previous work and identify conservation priorities by studying demographic structure, habitat needs, and non-breeding biology of wintering migratory birds, and Hispaniolan endemic and permanent resident species, in regenerating broadleaf forest.

As a result of this work, we will provide management planning recommendations concerning the creation and maintenance of habitat in National Parks and buffer zones. This represents an on-the-ground management tool with immediate potential to conserve migratory and resident birds in the Dominican Republic.

Current Goals: (1) Determine relative abundance of migrant species occurring in early-successional habitats of 2, 5 10, and 20 years post-clearing, as well as in mature dry forest; (2) Describe the demographic structure of migrant populations in each habitat; (3) Determine body condition, overwinter site fidelity, and annual return rates for populations in each habitat; and (4) Use these data to assess habitat quality, winter population limitation, and the conservation implications of habitat change.

Recent Results: Over five winters we have invested more than 15,000 mistnet hours in each of the agricultural habitats.

  • More species and more individuals were captured in the 5 year old sites, but capture rates were more similar among the other habitats.
  • Ovenbirds were most abundant in the older habitats; Black-throated Blue Warblers were less abundant, but were still most common in the older habitats; and the American Redstart and the Common Yellowthroat were moderately common, but only in the youngest habitats.
  • American Redstart and Black-and-white Warbler females were much more prevalent than males.
  • Common Yellowthroats appear to favor densely scrubby sites, with site persistence at >75% and annual return rates of >55 percent in these habitats.
  • The 20 year-old forest may be adequate habitat for the Black-and-white Warbler, with site fidelity data comparing favorably to data from mature forest.
  • Preliminary results suggest that Ovenbirds may be able to successfully utilize the older of these regenerating forests.
  • Relatively low site fidelity in the 2, 5, and 10 year old habitats, suggest that this regenerating broadleaf forests may still be marginal for even female Black-throated Blue Warblers.

Funding: This project has been supported by The Nature Conservancy, U. S. Forest Service - International Programs, and PRBO Conservation Science.

Related Scientific Publications:

Latta, S. C. 2012. Avian research in the Caribbean: past contributions and current priorities. Journal of Field Ornithology 83:107-121.

Latta, S. C., and R. E. Ricklefs. 2010. Prevalence patterns of avian Haemospridia on Hispaniola. Journal of Avian Biology 41:25-33.

Latta, S. C. 2005. Complementary areas for conserving avian diversity on Hispaniola. Animal Conservation 8:69-81.

Latta, S. C. 2003. Effects of scaley-leg mite infestations on body condition and site fidelity of migratory warblers. Auk 120:730-743.

Latta, S. C., C. C. Rimmer, and K. P. McFarland. 2003. Winter bird communities in four habitats along an elevational gradient on Hispaniola. Condor 105:179-197.

Latta, S. C., and J. Faaborg. 2002. Demographic and population responses of Cape May Warblers wintering in multiple habitats. Ecology 83:2502-2515.

Latta, S. C., and J. Faaborg. 2001. Winter site fidelity of Prairie Warblers in the Dominican Republic. Condor 103:455-468.

Wunderle, J. M., Jr., and S. C. Latta. 2000. Winter site fidelity of Nearctic migrant birds in isolated shade coffee plantations of different sizes in the Dominican Republic. Auk 117: 596-614.

Latta, S. C., and M. Baltz. 1997. Population limitation in Neotropical migratory birds: Comments on Rappole and McDonald (1994). Auk 114:754-762.