Bird Monitoring Program Summary

Populations of some bird species in the area have declined over the past 25 years based on regional data from annual Christmas Bird Counts. Possible causes include habitat fragmentation, climate change, and food availability during el Niño years. The results will serve as the baseline for long-term monitoring of bird populations as well as guide our management decisions at the reserve.

At Bijagual Ecological Reserve, we census populations of the resident bird species throughout the year and migratory bird species from October to April. Birds caught in mistnests are measured and weighed to determine their health. All birds that can be identified (residents and migrants) and for which we have appropriate equipment will be banded. These data are compared to existing data from the past five years of banding conducted at the reserve and the much larger banding dataset from the Tortuguero Station. In addition, point counts are conducted to provide a more complete census of the bird community since not all birds are caught in mistnets. This work will directly contribute to our understanding of avian population sizes at the reserve and how they fluctuate over time. These data have important implications for conservation in determining how habitat, the land use matrix, and climate change may be affecting both migratory and resident bird populations.

History of Banding at the Bijagual Ecological Reserve

Banding first started at the reserve in December of 2011 with Dr. George Farnsworth and students from Xavier University. We have continued to capture and band birds every year during the course's annual visit as a way of demonstrating field techniques and basic bird biology. The reserve is a collaborator with the Costa Rican Bird Banding network, and all data collected from the reserve is shared with the network.

Mistnet & Banding Data (Dec 2011 - Oct 2016):
>First bird banded on 12/30/2011
>Number of captures since start: 264
>Total number of species: 48
>Total number of birds banded: 149
>Number of recaptures: 26
>Number of resightings of color-banded or uniquely banded birds: 64

Most frequently caught species (number of captures):
Long-billed Hermit (30)*
Wedge-billed Woodcreeper (27)
White-collared Manakin (21)
Stripe-throated Hermit (15)*
White-ruffed Manakin (15)
Chestnut-sided Warbler (14)
Wood Thrush (14)
Rufous-tailed Hummingbird (10)*
*We do not band hummingbirds



A total of 918 bird species are known to occur in Costa Rica, a relatively large number of species for a small area. It is estimated that approximately 25% of species occurring in Costa Rica are migrants from North America. These birds include raptors, vultures, waterfowl, shorebirds, hummingbirds and passerine species such as thrushes, warblers, orioles, and tanagers. There are also a handful of species that live and breed in Costa Rica half of the year before migrating to South America for the other half of the year.

At the Bijagual Ecological Reserve, at least 284 bird species have been observed to date: 31% of all species found in Costa Rica. We include only species that have actually been seen or heard within the reserve's boundary. This number continues to increase over time. Our staff, visiting ornithologists and participants of the annual Christmas Bird Count are continually adding species to the bird list. An eample of some species commonly seen at the reserve include: the Great Green Macaw, White-collared Swift that roost behind a waterfall, Agami Heron, Sunbittern, American Pygmy Kingfisher, toucans, manakins, motmots, four species of trogons and various hummingbirds.



Rain forests are defined as forest ecosystems characterized by high levels of rainfall, a closed canopy and high species diversity and are actually found widely around the world, including both temperate and tropical regions. Tropical rain forests typically occur in the equatorial zone between the Tropic of Cancer and Tropic of Capricorn, latitudes that have warm temperatures and relatively constant year-round sunlight. Tropical rain forests support the greatest diversity of living organisms on Earth. Although they cover less than 2 percent of Earth’s surface, tropical rain forests house more than 50 percent of the plants and animals on the planet. Rain forests provide important ecological services, including storing hundreds of billions of tons of carbon, buffering against flood and drought, stabilizing soils, influencing rainfall patterns, and providing a home to wildlife and indigenous people. Rain forests are also the source of many useful products. Every year an area of rain forest the size of New Jersey is cut down and destroyed. Throughout Latin America, deforestation is squeezing migratory birds into ever smaller wintering grounds, threatening their long-term survival.