Patterns and Underlying Mechanisms of Amphibian Response to Habitat Fragmentation

EPA Grant Number: U916208
Title: Patterns and Underlying Mechanisms of Amphibian Response to Habitat Fragmentation
Investigators: Hawley, Tanya J.
Institution: University of Miami
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $106,845
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2003) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Natural and Life Sciences , Biology/Life Sciences


Forest fragmentation is occurring globally and results in the direct loss of habitat for wildlife and the modification of remaining forest patches. Research suggests that anurans may have a heightened sensitivity to environmental change and that their health can be used as an indicator of ecosystem health. Therefore, anurans can be used as an excellent model to examine the effects of forest fragmentation. Many studies have examined the general impact of fragmentation on amphibians, but little progress has been made in understanding the mechanisms underlying species-specific responses. The worldwide declining amphibian phenomenon places urgency on the need to understand the mechanisms so that conservation efforts can mediate population declines. The objectives of this research project are to: (1) examine the spatial patterns and mechanisms related to amphibian response to forest fragmentation; and (2) enhance our understanding of the amphibian response to fragmentation and produce management recommendations that will improve the ability of protected areas to maintain anuran diversity.


First, I will investigate spatial patterns of diversity indices in relation to microhabitat characteristics important to amphibians. Geographic information systems will be used to examine these relationships in fragments, matrix, and undisturbed forest habitats. I will establish which species are vulnerable to fragmentation effects and which can maintain viable populations in fragments. In addition, I will test whether the species present within fragments represent a random subset of species present in undisturbed forest. This will allow the placement of species into ecological types by traits relating to life history.

Second, I will examine experimentally the mechanisms that dictate how ecological species types respond to environmental changes that occur as a result of fragmentation. Behavioral, physiological, and ecological mechanisms will be uncovered to understand the pathways by which vital rates are altered, and the fate of individual species within a fragmented habitat will be determined. As changes in demographic vital rates occur, there are three possible outcomes for individuals of a species in a fragment: mortality and eventual local extirpation of the species, persistance of individuals as a nonbreeding population (because of a lack of suitable breeding habitat), or persistance of individuals as a viable breeding population.

Supplemental Keywords:

fellowship, amphibian, anuran, habitat fragmentation, forest fragmentation, breeding habitat., Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Habitat, Ecology and Ecosystems, Biology, urban habitat, land use effects, habitat loss, anthropogenic stressors, habitat fragmentation, conservation biology, effects of fragmentation, forest fragmentation, amphibian population

Progress and Final Reports:

  • 2003
  • 2004
  • Final