Where are the Aleutian Terns?

“Is everyone ready to depart?” asked the Bush plane pilot. “Yes!” Melissa and I say. At this point I was giddy and ready to depart in a bush plane for the first time. Imagine a life size toy airplane (even in red) with room for only four passengers to board. I was also excited to see the Copper River Delta (CRD) from the skies. I had only seen the CRD from hiking excursions during the weekend but this time I would be able to see more of it. To be exact we were heading more south towards Kayak Island. Fun fact: Kayak Island is known for where the first European, Georg Steller landed during a Russian expedition in 1741. Steller is a famous naturalist known for being the first to record detailed accounts of the fauna and flora of Alaska (Steller’s Jay and Steller’s sea lion are named after him). Knowing all this I was even more excited but besides the cool location this was no ordinary trip we were participating in something larger.

The purpose of this trip is part of the ongoing effort to monitor Aleutian Terns. It is part of an interagency project in North America that takes place in the Chugach and Tongass National Forests. Aleutian terns are considered a sensitive coastal colonial nesting seabird of Alaska and Eastern Siberia. Terns arrive to the CRD and Prince William Sound mid-April to the start of May to breed. A lot about these terns is unknown so a large part of the project is to find out more information about them such as population density and behaviors. We had to conduct aerial surveys by looking for tern colonies from previously known locations. I was in charge of photographing them while Melissa marked the locations on a map. Population trends are difficult to determine because of the tern’s tendency to form dispersive colonies. In other words Aleutian tern colonies tend to move around constantly and across large areas making it difficult to keep track of them. Nevertheless several papers (Buckley and Buckley 1979, Holtan 1980) speculate an increase in Aleutian tern usage of the CRD. Here comes the interesting part. It’s because of the 1964 earthquake! That’s right, the same earthquake that has had detrimental consequences on the Dusky Canada Goose breeding success. Except the lack of tidal flooding and increase of successional vegetation has provided ideal habitat for the terns. This makes sense why I was dive bombed a couple of times when I was nest searching for Duskys. Currently, the population of Aleutian terns is estimated to be from 9,000 to 12,000 and the ideal population number is 10,000 birds.

During the plane ride we were able to find a handful of tern colonies. We believe that they are Aleutian but from the sky you can’t determine the species since Arctic Terns breed here as well and they look identical from the air. From the ground you can identify them better because Aleutian Terns have a white forehead, black bill and legs while the Arctic Terns have red bills and legs. Therefore, this week or the upcoming week I will be to go out with a couple of co-workers and Melissa to conduct surveys from a boat. We will be going straight to the locations that we had seen them from the air. Although I won’t be able to see them from the sky I will appreciate that I won’t be nauseous from the tight turns and maneuvering from the bush plane. Hopefully the finicky terns will be there when we arrive!

Arctic Tern. Notice the black face mask , red bill, and red feet.

Aleutian Tern. Notice the white forehead with the partial black face mask as well as the black beak and feet.

Fun fact about Aleutian Terns! Their diets consist mainly of zooplankton, insects, and small fish and a main part of the courtship display from males is to feed females fish that they personally caught. Talk about a fishy attraction!

Hillary Chavez
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