The Effect of Habitat Alteration on Migratory Land Birds in a West Mexican Tropical Deciduous Forest: A Conservation Perspective

I compared point count census data from both short and tall second‐growth sites with counts taken from a nearby undisturbed tropical deciduous forest in coastal Jalisco, Mexico. Each of the second‐growth sites differed significantly from the undisturbed forest in its bird composition Much of the change can be attributed to the improvement of conditions for some guild members (e.g., seedeaters) and the removal of adequate conditions for others (eg., trunk‐foragers, Nit‐eaten). Nonetheless, there was a significant difference in the effect on migrant us. Resident species that was independent of foraging guild; longdistance migratory species were significantly more likely to increase in abundance as a result of disturbance than were resident species Thus; many migratory species in western Mexico may benefit from the human‐caused creation of midsuccessional habitats. It is important to note however, that this conclusion may not apply to more intensely disturbed habitats and does not apply to all migratory species In addition without information on the habitat and geographical distribution of migrants in winter, and habitat‐dependent mortality rates, we cannot draw conclusions about the had‐scale effects on the species that showed population changes in response to habitat disturbance.