Earlier this summer, aquarists Austin Brayton and Jackie Anderson camped on a remote island in Maine to assist with Project Puffin, an Audubon Society project designed to restore populations of these clownish little seabirds. In this post, Austin takes us on surveys for terns on Seal Island.

June 20, 2014 
Tern studies

Jackie and I helped gather data for two major tern studies: tern productivity and a tern feeding study. The tern productivity study involves monitoring the growth and survival of tern chicks in specific study plots. The nests are checked daily and chicks are banded shortly after they hatch so that you can keep track of individuals. These chicks are then weighed and measured every other day.

Banding a tern chick

The tern feeding study involves observing specific nests from a blind within the colony and identifying and counting the food items (small fish and shrimp) that are fed to the chicks by the parents.

View from the blind: Arctic Tern and chick

Chicks from the nests being observed are marked with non-toxic ink in order to identify them.

It was fascinating to observe the terns during the feeding study. Each pair that I observed had a slightly different method of chick-rearing. Some pairs seemed to take turns going out to fish while in other pairs one parent remained at the nest while the other fished. There was also lots of drama – terns squabbling over territory and even killing neighboring chicks, and chasing away “teaser” males that would come into the colony showing off a fish they had caught in order to attract females. Data from both the productivity and the feeding studies will be used to monitor how changes in the environment, such as from climate change, overfishing or increases in predators like gulls, impact the health of the tern colony.

-Austin

Earlier this summer, aquarists Austin Brayton and Jackie Anderson camped on remote islands in Maine to assist with Project Puffin, an Audubon Society project designed to restore populations of these clownish little seabirds. In this post, Austin and Jackie take us on surveys for terns.

June 15, 2014 
Tern census and the first tern chicks

Today was a busy day on Seal Island as we performed a census to estimate the number of pairs of terns (Artic and Common) that nest on the island.  We got a late start on the census as it rained heavily overnight and the vegetation was damp until 10 AM.  We don’t enter the colony in damp cold weather because the eggs and chicks might get cold if the parents are scared away from the nests.

Preparing for the tern census

Entering the tern colony is always an adventure as the terns are very aggressive, calling noisily and swooping down to try and peck your head, as well as pooping on you as they fly by.  They have evolved this behavior to deter predators that could otherwise easily prey upon the tern eggs and chicks which are in very simple nests on the ground.

Island Supervisor Julia Gulka, surrounded by terns

You will notice the funny hats that we are wearing – having pin wheels or sticks attached to your hat helps keep the terns from pecking you directly on the head!  After being pecked bloody one day, I upgraded my hat with a cardboard liner and two branching sticks duct-taped to the sides of the hat like antlers.

We spent all day performing multiple transects of the colony, walking side by side  and counting the number of Arctic and Common Tern eggs (while being continuously dive-bombed by the adult terns).

The best part was seeing the first day-old tern chicks.

Day-old tern chick

We also counted eggs in one plot going in one direction and marked their locations and then did a census of the same plot walking in another direction and counted the eggs again to see how many we missed and determine our margin of error.  We missed 8 out of 200. Not too bad!

— Austin

Tern egg and chick

Meanwhile on Matinicus Rock, we conducted our census over the next three days, June 17–June 19. We counted tern nests and how many eggs were in the nest. Additionally, we counted nests of laughing gulls, Eider and black duck. We divided the island into sections and walked up and down each section an arm’s length apart so that we didn’t miss anything.

Jackie during census on Matinicus Rock

--Jackie