Parasitism and Migration: Like other warblers, the palm warbler is a migratory species. They spend the summer breeding in Canada ranging from Newfoundland, westwards to North Eastern British Columbia and the North West Territories. Come fall, they migrate south to the south eastern coast and the west coast of the United States, along with much of Central America and many Caribbean Islands. On one island in particular, Hispaniola, palm warblers have been shown to be infected with the ectoparasite, scaly leg mite (Knemidokoptes jamaicensis). These mites mainly effect warblers in lower elevations where the habitat is more desert, or scrub like. In these areas, warblers are more likely to roost communally causing infection rates to be higher. These mites have adapted to avian hosts and can cause a decrease in muscle mass in the bird's pectorals along with physiological stress to the host. This has become such an irritant to the birds that individuals recorded to have been infected, have not returned to the area afterwards. The presence of parasites can have a large influence on bird behaviour, more specifically their migratory habits.
Sources:
Latta, Steven C. "Effects of a Scaly-Leg Mite Infestation on Body Condition and Site Fidelity of Migratory Warblers in The Dominican Republic." Oxford Academic, The Auk, 1 July 2003, academic.oup.com/auk/article/120/3/730/5561997?login=true. Accessed 9 Feb. 2022. "Palm Warbler." The Cornell Lab, Cornell University , 2019, www.allaboutbirds.org/guide/Palm_Warbler/maps-range. Accessed 9 Feb. 2022. |