Tracking movements in an endangered capercaillie population using DNA-tagging
Data files
Dec 11, 2023 version files 19.78 KB
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all_locations.csv
9.10 KB
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caper_moves_esurge.csv
1.60 KB
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max_dist_movements.csv
6.43 KB
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README.md
2.65 KB
Abstract
Knowing the location and movements of individuals at various temporal and spatial scales is an important facet of behavior and ecology. In threatened populations, movements that would ensure gene flow and population viability are often challenged by habitat fragmentation. Also in those endangered populations capturing and handling individuals to tag them, or to obtain tissue samples, can present additional challenges. DNA tagging, i.e. non-invasive individual identification of samples, can reveal movement patterns. We used fecal material genetically assigned to individuals to indirectly track movements of a large-bodied, endangered forest bird, Cantabrian capercaillie (Tetrao urogallus cantabricus). We wanted to know how the birds were using the fragmented forest landscape, and whether they showed fidelity to display areas. We used multi-event capture-recapture models to estimate fidelity to display areas among three consecutive mating seasons. We identified 127 individuals, and registered movements of 22 females and 48 males. Most observed movements were as expected relatively short, concentrated around display areas. We did not find differences in movement distances between females and males within mating seasons, or between them. Fidelity to display areas among seasons was 0.62 (± 0.12 SE) for females and 0.77 (± 0.07 SE) for males. The best CR model suggested no sex or season effects. Several longer movements, up to 9.9 km, linked distant display areas, demonstrating that Cantabrian capercaillies were able to move between different parts of the study area, complementing previous studies on gene flow. Those longer movements may be taking birds out of the study area, and into historical capercaillie territories, which still include substantial forest cover. The non-invasive DNA tagging approach provided a much larger sample size than would have been feasible with direct tracking. Lack of information on the social status of individuals and timing of movements are some disadvantages of DNA tagging.
README: Tracking movements in an endangered capercaillie population using DNA-tagging
https://doi.org/10.5061/dryad.b8gtht7kh
This dataset contains the information on the individual birds identified, and the relative positions of their captures and recaptures. The coordinates have been shifted to a non-geographical reference, although maintaining the original dimensions, to comply with the Spanish guidelines for treatment of information on endangered species.
Description of the data and file structure
- all_locations.csv: this is a comma-separated dataset that contains all locations of individuals (column indv) included in the study. The coordinates (fields x_relative and y_relative) resulted from shifting the original coordinates to a non-geographical reference, although maintaining the original dimensions, which would allow repeating the spatial treatment of the data. Also included are fields year (year of the Spring survey) and sex. In the latter males are coded as M, females as F.
- max_dist_movements.csv: this is a comma-separated dataset that contains the locations to and from corresponding to maximum distance movements registered for each individual. Fields indv and sex are as above. Field unique_id identifies each movement. Field scope identifies whether the movement was recorded within a mating season, or between mating seasons. Fields year_from and year_to identify mating seasons. Fields x_relative_from, y_relative_from, x_relative_to, y_relative_to identify the relative coordinates (see above) for those movements.
- caper_moves_esurge.csv: This is a comma-separated dataset, where each line corresponds to individual capture-recapture histories of Cantabrian capercaillie, as used in multi-event modeling software E-SURGE, and following its notation. Fields H:c1, H:c2, H:c3, correspond to capture sessions of Spring 2009, 2010 and 2011, respectively. Coding in those fields corresponds to possible events of the CR multi-event model, indicated as follows:
1 - Captured in t in the same site as at t-1
2 - Captured in t in a different site as at t-1
3 - Captured in t but not captured in t-1 (thus no movement information)
0 - Not captured (thus no movement information).
Field S: indicates the sample size of each capture session (=1, since each row corresponds to the encounter history of a single individual). Two classes of individual were considered (males and females), and are coded as group effect in field $COV:sex.