|David Anderson, Ph.D|
|Louisiana State University|
|Canopy Bird Communities and Tropical Rain Forest: Implications for Conservation|
|Location: Pico Bonito National Park, Honduras|
|Species: canopy bird communities of the tropical rain forest|
|Abstract: This research examines the structure and organization of canopy bird communities in tropical rain forests and forest fragments of the Caribbean slope of Honduras. Canopy birds provide key ecological services, such as dispersal of seeds and pollen, yet their ecology remains mostly unknown. Likewise, effects of forest fragmentation on canopy bird communities have not been quantified. Of further conservation concern is that some canopy bird species are suspected of being sensitive to forest fragmentation, and several species are threatened or endangered in Middle America. This research will address questions regarding the effects of habitat disturbance on canopy bird communities, and on seed dispersal in forest fragments.|
Project Update: June 2006
This study is being conducted in Parque Nacional Pico Bonito on the north coast of Honduras. The importance of Parque Nacional Pico Bonito for migratory and resident avifauna has long been speculated but little studied. The park is known for its large size (107,090 ha), wide range of elevations (ranging from 50 to 2480 m), and extent and diversity of primary forests. This study represents the first, albeit preliminary, attempt at a systematic inventory of the park's avifauna. This study documented 217 bird species in five months of study in a small portion of the park. Further inventory work will undoubtedly reveal many more species, and should be focused on the following areas: elevations above 500 m, especially cloud forest; forests on the south side of the park south of the Cangrejal watershed, pine forests, and anthropogenic habitats near human habitation. Surveys will also need to be conducted throughout the year to encompass altitudinal movements of birds within the park.
One of the principal objectives of this project is to provide employment and training to Honduran staff in an effort enhance the capacity within Honduras to conduct scientific investigations. To this end, Luis Soto was hired at the beginning of the project. Luis graduated with a licenciatura in biology from the Universidad Nacional Autónoma de Honduras 2005. Luis was highly regarded for his experience in using mist nets and his ability to work in the field. Luis integrated into the project in mid-January and soon became indispensable. In addition to the time spent in his primary responsibilities of mist-netting and point counts, he received training in aural identification of tropical birds, orienteering, and access to the forest canopy.
Many valuable conclusions can be made about the avifauna of Pico Bonito. Many species detected during this study are considered indicators of primary forest, and disappear when confronted with forest fragmentation or hunting pressure. A list of such species I detected would include White Hawk (Leucopternis albicollis), Keel-billed Motmot (Electron carinatum), Great Curassow (Crax rubra), and Crested Guan (Penelope purpurascens). Plain Chachalacas (Ortalis vetula), another popular game species, also seem to be rather common. Pico Bonito contains several species of birds that are noteworthy because they have limited ranges in Honduras, are seldom reported, or because they are sought after by birders. Broad-billed (Electron platyrhynchum) and Keel-billed Motmots are a good example. Broad-billed Motmots occur in primary forests east of the Sula Valley; Keel-billed Motmots occur only in lowland broadleaved forests in northern Central America (Guatemala, Belize, Honduras, and Nicaragua). Crested Owls (Lophostrix cristata) are rarely reported for Honduras, but seem to be fairly common in Pico Bonito. Yellow-eared Toucanets (Selenidera spectabilis) are rarely seen in Honduras, are very popular with birders, and can be easily seen in the Cangrejal watershed at elevations higher than 400 m. Pico Bonito has a high proportion of Nearctic migrant species in its avifauna. Northern Central America in general is rich in terms of the number of species that migrate from North America during the northern winter. Pico Bonito's 51 documented species is a high number and merits conservation attention. At least nine species are migratory transients, which only occur in Honduras during migration between North and South America but do not overwinter here. Two of these, Cerulean Warbler (Dendroica cerulea) and Golden-winged Warbler (Vermivory chrysoptera) are of special conservation concern due to steep and unexplained population declines on the breeding range. In fact, at the level of Central America, Honduras is one of the three most important countries for the Cerulean Warbler. Twenty-one Cerulean Warblers were detected this year in fieldwork that occurred between Trujillo, Omoa, and Copán. Of these, 10 (48%) were detected in Pico Bonito.
Despite the presence of forest indicator species, some species are perplexing in their absence. Not a single large parrot in the genus Amazona was detected during the entire course of the study. Diurnal raptors were very scarce; six of the nine resident species represented in the inventory were observed on only one occasion. King Vulture (Sarcoramphus papa), another indicator of undisturbed primary forests, was seen only on three occasions. Large game birds, although present, exist in low numbers. Great Curassows and Crested Guans are fairly common to common in similar forests in the Moskitia, but both were observed only twice during this study. One case of a Great Curassow being shot by a hunter was documented during this study. The absence of large parrots and low numbers of raptors and game birds warrants further investigation. The intact primary forests of Pico Bonito should be an ideal refuge for these species, and their low numbers should be of concern. Amazona parrots are captured for the illegal pet trade. Large raptors are routinely shot by hunters, as was documented on one occasion during this study. Hunting dogs, men with .22 rifles, and gunshots are observed on almost a daily basis in the Cangrejal watershed. Empty .22 cartridges and platforms built in trees by hunters can be found along the trails of the park.