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Comparison of adult census size and effective population size support the need for continued protection of two Solomon Island endemics

Citation

Cowles, Sarah A. et al. (2021), Comparison of adult census size and effective population size support the need for continued protection of two Solomon Island endemics, Dryad, Dataset, https://doi.org/10.5061/dryad.q573n5tht

Abstract

Because a population’s ability to respond to rapid change is dictated by standing genetic variation, we can better predict a population’s long-term viability by estimating and then comparing adult census size (N) and effective population size (Ne). However, most studies only measure N or Ne, which can be misleading. Using a combination of field and genomic sequence data, we here estimate and compare N and Ne in two range-restricted endemics of the Solomon Islands. Two Zosterops White-eye species inhabit the small island of Kolombangara, with a high elevation species endemic to the island (Z. murphyi) and a low elevation species endemic to the Solomon Islands (Z. kulambangrae). Field observations reveal large values of for both species with Z. kulambangrae numbering at 114,781 ± 32,233 adults, and Z. murphyi numbering at 64,412 ± 15,324 adults. In contrast, genomic analyses reveal that Ne was much lower than N, with Z. kulambangrae estimated at 694.5 and Z. murphyi at 796.1 individuals. Further, positive Tajima’s D values for both species suggest that they have experienced a demographic contraction, providing a mechanism for low values of Ne. Comparison of and Ne suggests that Z. kulambangrae and Z. murphyi are not at immediate threat of extinction but may be at genetic risk. Our results provide important baseline data for long-term monitoring of these island endemics, and argue for measuring both population size estimates to better gauge long-term population viability.

Methods

Five files are uploaded:

1) Field data (Bird ID, transect, sex, GPS point of capture): Cowles_etal_Zosterops_Dryad

2) Point count data for Z. kulambangrae: Z_kulambangrae_5-26-20.csv

3) Point count data for Z. murphyi: Z_murphyi_5-26-20.csv

4) Processed genomics file containing 1508 SNPs used to measure Ne: filt_miss75_final_recode

5) ReadMe file containing author information, data collection information, and descriptions of the datasets

Funding

American Ornithological Society, Award: Van Tyne Research Award

American Philosophical Society, Award: Lewis and Clark Fund

Society for Integrative and Comparative Biology (SICB), Award: GIAR

University of Miami, Award: Kushlan, Savage, and Evoy Funds

University of Miami, Award: Aresty Chair in Tropical Ecology

National Science Foundation, Award: 11-44155

National Institutes of Health, Award: GM133412