This year the Central American Waterbird Census (CAWC) was implemented for the tenth year in a row. Started in July 2011, the CAWC is part of the International Waterbird Census, coordinated globally by Wetlands International. Since its initiation, the number of participants increased, reaching nearly 200 in 2020. Likewise, the number of participating sites and the number of birds has steadily increased over the years. The commitment of our partners in Central America and southern Mexico are the main drivers of this success.
Between the 15 of January and 15 of February 2020, a total of 222 sites were surveyed in Central America and southern Mexico. 305,051 individuals of 106 waterbird species were recorded. The majority of these waterbirds were Nearctic migrants (230,253 individuals), with ducks and shorebirds being the dominant species. A Little Gull (Hydrocoloeus minutus) was observed in Guatemala, representing the first record for the country and Central America in general.
A total of 30 species of Nearctic shorebirds were recorded, including three species considered resident and migrant in Central America – American Oystercatcher (Haematopus palliates), Black-necked Stilt (Himantopus mexicanus) and Wilson’s Plover (Charadrius wilsonia)-. 85,741 individuals were counted (74,603 when excluding the three species with both resident and migrant populations). The numbers of migratory shorebirds were lower than the previous year, just 28% of all waterbirds counted in comparison to the nearly 50% of the census of 2019. The most common species were the Western Sandpiper (Calidris mauri) with 27,522 individuals, Least Sandpiper (C. minutilla) with 6,822 individuals, and the Willet (Tringa semipalmata) with 6,453 individuals.
Central America Waterbird Census participants in Honduras Photo: ASHO
Two American Oystercatchers (H. palliates) observed in Nicaragua had bands. One of the individuals was banded in Georgia in 2018 and the other was banded in 2019 in New York. Most American Oystercatchers observed during the census belong to the resident population, however, based on the data gathered on banded birds, it is clear that a portion of the migratory population of the Atlantic coast of North America migrates to Central America. During the census in previous years, banded American Oystercatchers were also observed in Honduras and El Salvador around the Gulf of Fonseca.
Twelve sites proved to be of significant importance, qualifying for WHSRN status. All sites qualified based on the total number of a species counts surpassing the 1% threshold level, but none of the sites had more than 20,000 shorebirds. A total of 11 sites qualified as a key site based on the presence of significant numbers of Ch. wilsonia (presumed ssp. beldingi), and one site qualified on the basis of two species reaching the 1% threshold. Delta Estero Real in Nicaragua, one of the sites with significant counts of Ch. wilsonia, is already a WHSRN site of International Importance. Acuicola Real, a Shrimpfarm of SeaFood in Nicaragua, would also qualify as a WHSRN site of International importance based on significant counts of Ch. wilsonia. The other identified key sites all qualify as WHSRN sites of regional importance.
Shorebirds at Salinera Isla de Rico, El Salvador Photo: Gerson Rodríguez
In most participating countries, except for Belize, the census is aligned with the Point Blue Conservation Science’s Migratory Shorebird Project (MSP), which is a shorebird monitoring program along the entire Pacific coast of the Americas. It is carried out once a year during the same period as the CAWC. The CAWC and MSP started collaborating to be more efficient with funding and logistics (many sites are being monitored for both CAWC and MSP). This collaboration resulted in Guatemala becoming the country number 13 to join MSP, after starting CAWC participant in 2015. Consequently, more sites were covered, more participants were trained and more birds observed!
The WHSRN Executive Office is grateful to an anonymous donor who provided the funds for the tenth Annual CAWC. In past years, the census was funded by the Environment and Climate Change Canada. The final reports with the results of these former years can be downloaded on the Wetlands International website.
Volunteers will be back out again to count in July, and we also look forward to their efforts in February 2021.
Cover Photo: Western Sandpiper at the Gulf of Fonseca. Photo: Gerson Rodríguez.
