Research: American Redstarts in Jamaica

by JulieCraves on September 24, 2006

Johnson, M.D., T.W. Sherry, R. T. Holmes, and P.P. Marra.  2006.  Assessing habitat quality for a migratory songbird wintering in natural and agricultural habitats. Conservation Biology 20:1433-1444.

This study examined American Redstarts (Setophaga ruticilla) in natural and agricultural habitats in Jamaica.  Redstarts are beautiful warblers that nest in North America and winter in the tropics (see map).

Four natural habitats were compared with two agricultural habitats: citrus groves and shade coffee plantations, which were shaded primarily by Inga vera, with understories of varying densities.

Measures of habitat quality for redstarts on the coffee farms was generally intermediate between the best and worst natural habitats.  Two measures, body mass and overwinter survival, were very similar in shade coffee and the best natural habitat. Body mass is especially important.  It indicates that enough food is available, and maintaining body mass is critical for later survival, even after departure from the wintering grounds.  This study estimated that a loss of 0.1 grams (a very tiny amount!) over the winter corresponded with a 6.8% reduction in annual survival probability.

The authors provide two caveats: First, this study focuses on a single species in a single region.  And importantly, there is no similar data to compare the quality of present coffee farms with the habitat from which they were carved. Although shade coffee farms can provide habitat for some species, they do not possess the complete suite of species or ecosystem functions as the original habitat.

The paper named the three shade coffee farms/areas that were used in the study.  None were in the eastern Blue Mountain region. One was in the western growing region, in James Hill, Westmoreland Parish.  Two were in the central highlands in Manchester Parish, Coleyville Farm and Baronhall Farms.  Most coffee is pooled and single estates are hard to find, but Baronhall (formerly Broomhall Estate) is apparently an exception.  I have been able to find various roasters offering this coffee.  Here is a review of Jamaica High Mountain, Baronhall Estate at Coffee Review.

Revised on November 14, 2019

Posted in Birds and other biodiversity,Research on coffee growing

Previous post:

Next post: