How much can parentage analyses tell us about precapture dispersal?

Area of Science:

• Ecology
• Population Genetics
• Conservation Biology

Background:

• Estimating animal dispersal rates is crucial for population dynamics and conservation.
• Traditional field methods may underestimate dispersal, especially for young animals not captured at birth sites.
• Genetic methods offer potential for detecting 'pre-capture' dispersal and informing population structure.

Purpose of the Study:

• To compare the effectiveness of different genetic analyses (parentage, assignment) with traditional field methods for estimating dispersal in banner-tailed kangaroo rats (Dipodomys spectabilis).
• To assess the accuracy of genetic methods in detecting pre-capture dispersal and inter-population movements.
• To evaluate the influence of incorporating non-genetic information into genetic analyses for dispersal estimation.

Main Methods:

• Utilized a 17-year dataset of banner-tailed kangaroo rats.
• Compared genetic parentage analysis (cervus, MasterBayes) and genetic assignment (geneclass2) with mark-recapture data.
• MasterBayes incorporated genetic, spatial, and other non-genetic information.

Main Results:

• Both genetic assignment and parentage analyses detected pre-capture dispersal.
• Approximately 10% of adults in local populations were identified as immigrants.
• Inter-population dispersal was found to be slightly female-biased.
• MasterBayes's results aligned well with known dispersal characteristics (body mass, distance).

Conclusions:

• Genetic parentage analyses are valuable tools for estimating elusive demographic parameters like dispersal.
• Incorporating non-genetic data, such as distances between potential parents, enhances the accuracy of genetic dispersal estimates.
• Genetic methods provide crucial insights into population connectivity and movement patterns, complementing traditional ecological studies.