Source Population Response When Florida Scrub-Jay Family Groups Are Removed for Translocation

Conservation translocation studies typically focus on assessing the fate of translocated individuals at recipient populations, and assessments of the source population's capacity to recover from removals are rare. Our understanding of the population level-impacts of avian translocation remains limited because of the small sample sizes (i.e., number of territories) typically involved and because when breeding vacancies are refilled the identity of the colonizers is usually unknown. To address this information gap, we studied the impacts of translocating 13 territorial Florida scrub-jay (Aphelocoma coerulescens) family groups (31 individuals) from long-term study sites where most birds were color banded and of known age so the source of colonizers could be determined. Eleven of 13 (85%) vacated territories were colonized within 1-2 weeks and all family groups that occupied vacancies attempted reproduction in the year of the removal. Habitat quality appeared to affect reoccupancy for this early-successional scrub specialist, as the two vacated territories that remained unoccupied were in the two oldest forest stands (14 years since mechanical clearing). In most cases (8 of 13; 62%), vacancies were partially, or entirely, absorbed into existing neighboring territories. However, two vacancies were colonized by newly formed family groups created by adults and helpers from other territories within the same management stand, and another vacancy was colonized by an immigrant group. This mix of refilling mechanisms for this species suggests a complex interplay of habitat quality, territoriality, and availability of non-breeders on the landscape. Removing Florida scrub-jay family groups from a source population may reduce the number of breeding territories if non-breeding helpers are either unavailable in the landscape or unable to outcompete established neighboring territory holders for vacancies. More broadly, practitioners of avian translocation may benefit from considering habitat patch quality and the availability of non-breeding adults when selecting birds for removal for translocation.