Family Planning for Puerto Rican Parrots
To help the endangered Puerto Rican parrot, I recently took my everyday scientific advising of animal populations from my Chicago office to the dense, green rainforests of Puerto Rico. My colleagues at Lincoln Park Zoo and I have been working with the dedicated staff at two aviaries in on the island since 2006, making a perfect match of our population management expertise and their husbandry skills.
This was my fifth trip to Puerto Rico to analyze the collective data of every hatch, death and family tree of these birds. We worked on our laptops in the aviary office within El Yunque National Forest as a couple hundred Puerto Rican parrots screeched and squawked from their homes just outside. Our intention with this trip, as with the others before it, was to help this species continue its path away from extinction.
The history of these parrots is like that of many animal populations brought back from the brink by humans. Biologists began a recovery program with a woefully small group of individuals (less than 20 birds) struggling to live and reproduce in what was left of their wild habitat. The original causes of the parrots’ decline included habitat loss from deforestation, hunting to protect crops and nest robbing for the pet industry. Hurricanes, competition with other species for nest cavities and predation by red-tailed hawks continue to hinder the parrots’ success in the wild.
That’s not to say the species hasn’t experience an incredible comeback. Since a U.S. Fish and Wildlife Service recovery program brought the last remaining birds into captivity in 1972, the population has grown to nearly 400 birds in two aviaries in Puerto Rico and an estimated 100 birds released or hatched in the surrounding wild.
My contribution to the project is to help the aviary staff translate their detailed records on each bird’s life into a summary that helps them closely monitor the size and stability of the population. I also use these life histories to provide feedback on which parrots should be paired for breeding each year.
In fact, while working in Puerto Rico, I had the unique pleasure of receiving immediate feedback on my work from the birds themselves. As I pored over the genetic and demographic “values” of the prior year’s breeding pairs, I spotted the very pair I had just decided to leave together going into their newly prepared artificial nest cavity for the breeding season ahead. A reliable breeding pair indeed!
Success stories like this aren’t something I deal with on a daily basis in my Population Management Center work. Fortunately, most species cared for and managed by zoos haven’t come as close to extinction as the Puerto Rican parrot has, so our goals of keeping these populations healthy, while important, don’t carry the weight of preserving the last individuals of an imperiled species.
However, with common zoo species like tigers, rhinos and polar bears, good stewardship has become even more important as we see their wild counterparts face new threats and steeper declines than we could have expected when we first started managing them decades ago. The successes of the Puerto Rican parrot give us hope, even as endangered species continue to need our care.