Breeding season has commenced in the Seabird Aviary! A total of 16 eggs have been laid so far, from several of the six species currently residing there. It’s an exciting time for the Aquarium’s aviculturists—and for anyone who loves fuzzy little chicks, which is everyone—but breeding in the Aviary is a controlled operation for a number of reasons, not least of which is sheer living space.
“Most species mind their own business in the Aviary,” said CJ McCarty, Curator of Birds at the Aquarium. “But when nesting habitat is shared—for instance, both puffins and rhinoceros auklets nest in burrows—there can be territorial disputes that we must take into consideration when breeding season rolls around.”
Each spring, the first thing our aviculturists ask themselves is whether they are in need of or have room for any new birds in the Aviary. If there is no place for a chick from a certain breeding pair, the keepers will replace the couples’ egg with a similar looking plaster-filled dummy egg. This allows the birds to practice natural breeding behaviors without overpopulating the Aviary.
Secondly, the aviculturists see if there are any requests for birds from other facilities. This year, for instance, Oceanario de Lisboa in Portugal has requested two black oystercatcher chicks from the Aquarium. So our resident pair will rear their chicks to fledging age before we transport them to Portugal.
If the answer to either of the previous questions is yes, staff will refer to the regional studbook. What, one might reasonably ask, is a studbook? “A studbook is a tool we use to track and manage each individual of a species cared for in AZA [Association of Zoos & Aquariums]-accredited facilities,” said Charlee Jackson, an Aquarium aviculturist. “It documents the pedigree [genetic make-up] and demographic history [genetic representation] of each individual in a population—in this case, the region of North America. Based on this information, it charts all of the males and females and gives us a score for any pair combination.”
For the Aviary’s mated pairs, a close look at the studbook produces a score for a specific pair, based on their combined pedigree and history. The scores are on a scale of 1-5 (1= Will greatly improve genetic diversity of population; 5= DO NOT BREED). For the alcids, the Aquarium currently has studbooks for common murres and both of our puffin species, horned and tufted. Two pairs of murres and at least three pairs of tufted puffins are incubating eggs this year, as their studbook “score” is low enough to ensure that their offspring will improve genetic diversity of the overall population.
This year, in addition to the oystercatchers bound for Portugal, the Aviary is expecting a handful of chicks that will remain at the Aquarium, joining the resident population. Check back for updates on our new arrivals throughout the summer!
Information and photos by the Oregon Coast Aquarium