Counts of unique females with cubs in the Apennine brown bear population, 2006–2014
| Autor: | Elisabetta Tosoni, Gianluca Mastrantonio, Paolo Ciucci, Roberta Latini, Luigi Boitani |
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| Rok vydání: | 2017 |
| Předmět: |
small populations
0106 biological sciences demography Capwire Chao estimator distance-based criteria females with cubs FWC counts Italy Ursus arctos marsicanus Monitoring Population Management Monitoring Policy and Law 010603 evolutionary biology 01 natural sciences Animal Science and Zoology Nature and Landscape Conservation Ursus education education.field_of_study Policy and Law biology Adult female Small sample Small population size biology.organism_classification Management 010601 ecology Geography Conservation status Population study Demography |
| Zdroj: | Ursus. 28:1-14 |
| ISSN: | 1938-5439 1537-6176 |
| DOI: | 10.2192/ursu-d-16-00022.1 |
| Popis: | Brown bears (Ursus arctos marsicanus) in the Apennines, central Italy, survive in a precarious conservation status but the reproductive performance of the population has never been formally assessed. Each year, from 2006 to 2014, we conducted surveys of females with cubs (FWC) to estimate the minimum number of female bears that reproduced and annual productivity in this bear population. We discriminated unique family groups based on simultaneity of sightings, presence of individually recognizable bears, and ad hoc distance-based rules developed using Global Positioning System relocations from 11 adult female bears in our study population. To estimate the true number of FWC from unique counts, we applied 2 estimators (Chao2, Capwire) known to handle heterogeneity in sighting probabilities relatively well at small sample sizes. Annually, we estimated 1–6 ( = 3.9 ± 1.5 SD) unique FWC and tallied a minimum of 3–11 ( = 7.4 ± 3.0 SD) cubs in the population. No temporal trend in FWC was observed and the... |
| Databáze: | OpenAIRE |
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