Density influences accuracy of model-based estimates for a forest songbird
| Autor: | Jennifer L. Reidy, Jason W. Hunt, Jonathan L. Scalise, Christopher C. Warren, William Reiner, Lisa O'Donnell, Kelly Nesvacil, C. Craig Farquhar |
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| Rok vydání: | 2015 |
| Předmět: |
0106 biological sciences
education.field_of_study Distance sampling biology Population Endangered species Magnitude (mathematics) Woodland biology.organism_classification Mixture model 010603 evolutionary biology 01 natural sciences 010605 ornithology Songbird Statistics Environmental science Juniper education Ecology Evolution Behavior and Systematics |
| Zdroj: | Journal of Field Ornithology. 90:80-90 |
| ISSN: | 0273-8570 |
| DOI: | 10.1111/jofo.12116 |
| Popis: | Golden-cheeked Warblers (Setophaga chrysoparia) are endangered songbirds that breed exclusively in the Ashe juniper (Juniperus ashei )a nd oak (Quercus spp.) woodlands of central Texas. Despite being the focus of numerous studies, we still know little about the size of the range-wide breeding population and how density varies across the spectrum of juniper co-dominated woodlands. Models that have been tested and shown to be accurate are needed to help develop management and conservation guidelines. We evaluated the accuracy and bias of density estimates from binomial mixture models, the dependent double-observer method, and distance sampling by comparing them to actual densities determined by intensive territory monitoring on plots in the Balcones Canyonlands Preserve, Austin, Texas. We found that the binomial mixture models consistently overestimated density by 1.1-3.2 times (actual density = 0.07-0.46 males/ha), and the other two models overestimated by 1.1- 29.8 times at low density and underestimated by 0.5-0.9 times at high density plots (actual density = 0.01-0.46 males/ha). The magnitude of error for all models was greatest at sites with few or no birds ( |
| Databáze: | OpenAIRE |
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