Snail Kite survey on Lake Yojoa

immature male Snail Kite, Lake Yojoa, earlier photo from 29 January 2013

This past weekend, Roselvy and I participated in a survey of the resident Snail Kite population on Lake Yojoa in Honduras. We were invited by Robert Gallardo, author of the still to be published Field Guide to the Birds of Honduras.

The earliest reference in the scientific literature to the presence of Snail Kite (then called Everglades Kite) in Honduras is Stone (1932), who mentions that during a collection expedition organized in the summer of 1930 by the Academy of Natural Sciences of Philadelphia, this species was "quite common" at Laguna Toloa, "and one was also seen at Lake Yojoa" (Stone 1932). He also mentions a record from "Tigre Island" (i.e. Isla el Tigre, or Amapala, in the Gulf of Fonseca), but this earliest report (Sclater 1858), according to Monroe (1968), is in error. Taylor (1860), on a bird collecting trip through Honduras in the winter of 1857-1858, spent two days at Lake Yojoa in February of 1858, but did not report Snail Kite from there, or indeed any other Honduran site. By the 1960s, the species was "common" (Monroe 1968) at Lake Yojoa.

Forty-five years later, in 2013, the Snail Kite population of Lake Yojoa appears to number more than 600 individuals, possibly the largest concentration in Central America!

Most birders visiting Lake Yojoa, however briefly, will not fail to observe this locally common species, but exactly how common is it there? To answer this question, two teams in motorized boats set out early Saturday morning in opposite directions from El Cortijo del Lago, in the northeastern corner of the lake, covering the 43 km circumference of the lake. Robert Gallardo's team went northwest, while my team went south. We roughly divided the route in transects of about 5 km each, figuring each team would probably cover about 4 such transects before meeting up at the opposite side of the lake. It took us about four hours to survey the circumference of the lake in two teams. The count was generously sponsored by Gallardo's Field Guide project, which provided meals and housing at the Cortijo del Lago lodge this weekend, as well as boats and fuel. The idea was to duplicate the effort on Sunday, but that was not feasible due to poor weather conditions.

Lake Yojoa, Honduras. The arrows show departure and meeting up of the two teams

Each team scanned the vegetation, including trees, for perched Snail Kites, as well as the sky for flying birds. A total of 606 Snail Kites was counted by both teams combined; presumably a small number (less than 10 percent?) of birds hidden in the vegetation was missed. Very little local movement between sites was observed, and thus the percentage of double counts seems negligible or null.

from left to right: Malcolm Glasgow, John van Dort, Roselvy Juárez, John Chater (photo Robert Gallardo)

Our team, which included dedicated eBirders such as Roselvy and myself, counted all birds on the transects, although some species were so numerous that their numbers had to be estimated. Especially American Coot, American Wigeon, Fulvous Whistling-Duck, and Common Gallinule were present in the hundreds. 

two adult male Redheads

Good records included two adult male Redheads, a species scarce anywhere in Central America and with only a couple of previous records from the lake: two males seen and photographed on 21 January 2011, and a single male earlier this winter. Could Saturday's two males have been the same as those from January 2011?

Pinnated Bittern

Another bird new for me in Honduras was Pinnated Bittern. We spotted one in the reed beds between Honduyate and Rancho Bella Vista, while Gallardo's team had no fewer than four individuals on their transects! One of the Snail Kite survey participants, local bird guide Malcolm Glasgow, told me that he's observed this species on several occasions before at the lake, but five in one day seems a remarkable count.

Cited literature

Monroe, B. L., Jr. 1968. A distributional survey of the birds of Honduras. Ornithological Monographs, No. 7, 458 pp., American Ornithologists' Union.

Stone, W. 1932. The Birds of Honduras with Special Reference to a Collection Made in 1930 by John T. Emlen, Jr., and C. Brooke Worth. Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 84: 291–342.

Sclater, P. L. 1858. List of birds collected by Geo. Cavendish Taylor, Esq., in the Republic of Honduras. Proceedings of the Zoological Society, London: 356–360.

Taylor, G. C. 1860. On Birds collected or observed in the Republic of Honduras, with a short Account of a Journey across that country from the Pacific to the Atlantic Ocean, Ibis: 10–24.