Publication Date

Summer 2021

Degree Type


Degree Name

Master of Science (MS)


Environmental Studies


Lynne Trulio


Belize, ecology, Hook-billed Kite, migration, Neotropical, raptor

Subject Areas

Ecology; Biology; Environmental science


The Hook-billed Kite (Chondrohierax uncinatus) is a specialized Neotropical raptor with a wide distribution that has received little research attention. The species is considered non-migratory across most of its distribution, but there are scattered records of Hook-billed Kite migration. The present research describes, for the first time, the largest southbound autumn migration of Hook-billed Kite in Belize and Mexico and evaluates the effects of environmental conditions on this phenomenon. Eight years of count data were collected in Belize and 25 years in Mexico. During a total of 3093.1 count hr from 2013-2020 in Belize, 39928 Hook-billed Kites were counted on their southbound autumn migration with a mean (±SE) annual count of 4991 ± 1083 kites/yr. In comparison, during a total of 42531 count hr from 1995-2019 at two count sites in Mexico, 3870 Hook-billed Kites were counted. The mean 95% seasonal passage window of Hook-billed Kites in Belize was 44.9 ± 2.5 d (n= 8) from 26 October to 9 December compared to 13 September to 11 November in Mexico. Precipitation on the breeding grounds had no influence on the timing or magnitude of the kite migration through Belize, whereas in Mexico, migration time occurred later as precipitation north of the count site increased. The present research provides critical ecological information, which can aid in identifying potential threats, conservation needs, and population status for Hook-billed Kites and other neotropical raptors.