Declines and turnover in resident birds during a decade in the Yeguare Valley, central Honduras

Abstract

I investigated population changes in 109 resident bird species from 2011 to 2020 in agricultural landscapes of the Yeguare Valley, on the Zamorano University campus. Multiple observers entered bird counts in the eBird database across three “hotspots,” resulting in 1,833 bird counts, more than 75% of which were contributed by a single observer (the author). Analysis of online eBird data summaries showed that seven resident species (6.4%) experienced significant and convincing declines in abundance over the decade. By 2020, three appeared to be locally extirpated: White-tailed Kite (Elanus leucurus), Orange-chinned Parakeet (Brotogeris jugularis), and Fan-tailed Warbler (Basileuterus lachrymosus). In contrast, 10 species that were scarce or absent at the start of the decade increased notably. Five of these occurred for only a few years before declining again and may also have become locally extirpated. Of the remaining five increasing species, three arrived after the first study year and persisted through 2020: Harris’s Hawk (Parabuteo unicinctus), Acorn Woodpecker (Melanerpes formicivorus), and Bat Falcon (Falco rufigularis). These species may contribute to community turnover. The total number of resident species recorded each year remained stable (104 ± 2 species), with three species lost and three gained. Because the landscape and climate changed little during the study period, multiple factors may underlie the observed patterns. Most declining species were insectivores, suggesting that reductions in insect prey played an important role. Only one resident species in the study area—the Orange-fronted Parakeet (Eupsittula canicularis)—is globally vulnerable but showed no significant trend during the decade.