Evaluating the conservation parameters for the critically endangered Montserrat Oriole (Icterus oberi).

摘要

The critically endangered Montserrat Oriole (MTOR; Icterus oberi), endemic to Montserrat, West Indies, faces extinction threats from habitat loss, invasive species, inter-specific competition, and climate change. I evaluated these threats from three perspectives: the genetic, the ecosystem and the human dimensions. I evaluated the genetic diversity of both wild and captive populations with an analysis of genetic structure and an evaluation of the need and potential for genetic rescue. I surveyed neutral genetic variation in 124 MTOR using AFLP techniques used to generate 210 loci. The captive and wild populations have similar levels of heterozygosity, but the captive population has no private alleles and shows elevated FIS when compared to wild birds. The founding members of the captive population only represented 3 of the 6 genetic clusters found in wild birds. To analyze threats at the ecosystem level, I used dynamic occupancy models to quantify the effect of survey, habitat, geographic, predator, and climate covariates on detection, occupancy, extinction and colonization probabilities of the MTOR between 2011 and 2014. Detection probability decreased on ridge tops and increased in valleys and areas with larger numbers of Heliconia clumps and higher Heliconia density. Highest MTOR patch occupancy occurred in mature forests with high canopy cover, relatively low tree density, and a high number of Heliconia clumps. Colonization increased and extinction decreased at higher elevations, suggesting possible climate driven altitude shifts. To evaluate the differences in oral- versus written-mediated pedagogy, students enrolled in two large undergraduate science courses at the University of Wisconsin-Madison, participated in the evaluation of a case study comparing life histories and threats for the MTOR and the vulnerable regional endemic Forest Thrush (FOTH; Turdus lherminieri). In each course, half of the class was given an oral presentation and half received written case scenarios, and then completed a survey. Students receiving the oral presentation showed higher levels of engagement than those receiving only the written lesson. Best predictors for MTOR concern and effort were IUCN status, invasive species, and population status. Best predictors for FOTH concern and effort included IUCN status, negative population trends, invasive species, and threat of hunting.