RESEARCH ARTICLE The Puerto Rican Parrot Reintroduction Program: Sustainable Management of the Aviary Population

Abstract

Joanne Earnhardt.!" Jafet Velez-Valentin.? Ricardo Valentin;' Sarah Long,4 Colleen Lynch,5 and Kate Schowe1

1 Department of Conservation and Science, Lincoln Park Zoo, Chicago, Illinois

2 US. Fish and Wildlife Service, Iguaca Aviary, Rio Grande, Puerto Rico 3 Puerto Rico Department of Natural and Environmental Resources, Ramey Station, Aguadilla, Puerto Rico

"Population Management Center, Department of Conservation and Science, Lincoln Park Zoo, Chicago, Illinois

5 Animal Care Department, Lincoln Park Zoo, Chicago, Illinois

The cornerstone of the recovery plan for the critically endangered Puerto Rican parrot (Amazona vitatta) is an actively managed, long-term reintroduction program. One captive population distributed across two aviaries in Puerto Rico is the sole source for release but its ability to persist as a managed resource has not been evaluated since 1989. We conducted an assessment for sustainable management of the aviary population while harvesting for release. To assess demographic rates such as population growth, vital rates, and age/sex structure, we compiled a studbook database on all living, dead, and released individuals in the aviary population. Using an individual-based risk assessment model we applied population specific data based on the management period from 1993 to 2012 to simulate future aviary population dynamics and evaluate future potential production. We modeled four potential management strategies to harvest parrots for proposed releases; these scenarios vary the number of parrots and the life stage. Our simulations revealed that the aviary population can be simultaneously managed for sustainability and harvesting of parrots for release. However, without cautious management, overharvesting can jeopardize sustainability of the aviary population. Our analysis of the aviary breeding program provides a rare opportunity to review progress relative to conservation program objectives after four decades of active management. The successful growth of the aviary population and its ability to serve as a sustainable source for reintroductions supports the 1973 decision to build a breeding program from a small population of 13 parrots. Zoo Biol. XX:XX-XX, 2014. © 2014 Wiley Periodicals, Inc.

 INTRODUCTION

Reintroduction programs for any species are risky, complex conservation actions, but these programs may be even more of a challenge when captive populations are the sole source of individuals for release [Kleiman, 1989; Seddon et al., 2007; Snyder et al., 1996; Wilson et al., 1994]. For captive populations, managers must consider changes in genetic structure, loss of behavioral competency, and sustainability of the captive population [Earnhardt, 2010; Leus and Lacy, 2009; McPhee, 2004]. Due to challenges inherent to reintroduction efforts and a need to manage wisely, scientists and managers have attempted to assess individual factors contributing to potential success or failure of a release program. Most of the species-specific case studies have focused on factors such as management of threats in the wild, methodology for releases, monitoring after releases, evaluation of release programs, and adaptive management of wild populations [Seddon et al., 2007]. Few published case studies exist evaluating sustainability for the source popula- tion (wild or captive) when individuals are harvested for release; this is true even when captive populations are the sole source for recovery [but see Coonan et al., 2010; Earnhardt et al., 2009]. The IUCN Reintroduction Guidelines [1998] and other publications caution managers against jeopardizing the sustainability of a source population [Earnhardt, 2010; Kleiman, 1989]. Sustainability, defined by Lacy [2012] as "management of the resource in a manner that does not deplete its value for the future" is a well-recognized demographic and genetic challenge for captive populations. In our study, we evaluate past progress as well as current status and generate a computer model to assess sustainability of the captive source population as it contributes to the reintroduction program of the Puerto Rican parrot (Amazona vittata), an iconic and high-profile conservation species.

Conservation actions taken on behalf of the Puerto Rican parrot have a four-decade history. At one time these parrots were abundant and widespread, estimated near 1 million birds, but due to diverse threats including habitat loss and fragmentation, the wild population declined to 13 parrots by 1975 [Snyder et al., 1987]. In 1973, managers made a decision to establish an aviary population with chicks and eggs taken from the small remaining wild population [U.S. Fish and Wildlife Service, 1982, 1999, 2009]. The long-term management objective was to breed these birds and harvest from a future (i.e., larger) captive population for a reintroduction program. For reintroductions based on captive breeding programs, concerns exist that captive programs can (1) be costly, (2) direct funds away from habitat restoration, (3) alter genetic structure of future wild populations, (4) compromise natural behavior of the species, and (5) have low likelihood of success [Earnhardt, 2010; Griffith et al., 1989; Leus and Lacy, 2009; McPhee, 2004; Snyder et al., 1996; Wilson et al., 1994]. Yet for some highly endangered species like the Puerto Rican parrot, managers have no alternate options as a reintroduction program based on captive breeding may be the only viable recovery solution, despite the risks.