Conservation genetics of threatened Red-billed Tropicbirds and White-tailed Tropicbirds in the southwestern Atlantic Ocean

Abstract

ABSTRACT Seabirds are of considerable conservation significance due to their key role in ecosystems and their generally high level of threat, especially from invasive species in breeding sites and as a result of bycatch during commercial fishing activities. We examined the genetic diversity, evidence for a bottleneck, and effective population size (Ne) of Red-billed Tropicbirds (Phaethon aethereus) from the Abrolhos Archipelago and White-tailed Tropicbirds (P. lepturus) from Fernando de Noronha Archipelago, both in the southwestern Atlantic Ocean. In addition, intraspecific genetic distance was assessed between 2 Red-billed Tropicbirds breeding on Fernando de Noronha and the larger population on Abrolhos, and between 5 White-tailed Tropicbird individuals breeding on Abrolhos and the breeding population on Fernando de Noronha, to identify relict populations. From 11 microsatellite loci, observed heterozygosity was 0.471 for White-tailed Tropicbirds and 0.267 for Red-billed Tropicbirds. Additionally, Ne was...