Another entry in Abby’s Birdbrained Summer. Abby, the summer communication intern for the Coast Office of Audubon North Carolina, is visiting sites with Audubon’s field staff and our community of volunteers. After she goes into the field, she’ll post blogs detailing her experiences.
This week, Audubon staff and volunteers went to the Cape Fear River to band tern chicks. South Pelican Island was covered with Royal and Sandwich Tern youngsters roaming the beach en masse. About a week after hatching, a huge exodus of chicks left their nests to form a crèche. The slightly smaller Sandwich Terns are free to nest in the densely packed Royal Tern colony, and their chicks are not excluded from the crèche. The crèche is like a preschool for birds; only a few adults are responsible for educating and protecting the juveniles during the day while most of the adults transit back and forth, feeding their young. Tern chicks remain in crèche until fledging, approximately one month after hatching.
The crèche behavior made it easy for the 15 participants to corral the chicks. They walked behind the chicks, which were herded into a pen and temporarily held until they were banded. Each chick was outfitted with a silver bracelet provided by the U.S. Fish and Wildlife Service. This is the 30th year of tern banding on the Cape Fear River. Audubon North Carolina’s coastal biologist Lindsay Addison, said the bands “give demographic information about longevity,” as well as migratory patterns and population size. From banding, birders know that Royal Terns can live to be at least 28 years old.
Audubon North Carolina’s volunteer coordinator, Marlene Eader, was amazed by the chicks’ parents. “This is my fourth year banding the terns, and I think it’s such a great experience,” she said. “The parents feed their chicks in the holding pen; they know exactly where their chick is, even in a group of 3,000 birds.” Terns have the capacity to recognize the individual sounds of their offspring or parent. Parents will feed their young only, and even among the dense nests (as many as six will be in one square meter), the parent will recognize its egg.
This year, 2,234 Royal Terns and 682 Sandwich Terns were banded. Information about these chicks will be beneficial to conservationists, biologists and scientists for years to come.
Sources:
http://www.fws.gov/migratorybirds/SurveysMonitoringResearch/mntrtbl.html
http://bna.birds.cornell.edu/bna/species/700/articles/breeding
