Woodworth (1997) found the arrival of rains early in 1991 facilitated rapid initiation of breeding behavior by the PRVI in Guanica with increased opportunities for laying second clutches.
Maricao and Guanica can be considered the extremes of a gradient differing in elevation above sea level and habitat characteristics, but aspects of the biology of PRVI were similar in both populations.
Woodworth (1999) indicated that Guanica is a population sink for the PRVI due to high levels of nest parasitism and depredation.
Nesting success parameters of PRVI did not vary significantly before and after the hurricane, but a low return rate of color-banded adults was observed in 1999 suggesting that disappearance of individuals was related to the effects of the hurricane.
Nest parasitism was not found to threaten the PRVI in this study, but the Shiny Cowbird population may increase at Maricao if hurricanes facilitate their colonization by opening the canopy and altering microhabitat characteristics.
Thirty-six adult PRVIs were color-banded from 1998 to 2000 to facilitate behavioral observations.
This method was possible because juvenile PRVIs remain within their natal territories and are fed by adults for as long as 2 months after fledging (pers.
Counts were conducted in June 1998 (n = 30) and 1999 (n = 30) when PRVIs and most resident bird species were breeding.