How do you conduct a census, for birds?

Obviously you can’t send out paperwork to every tern nest on the island and expected to receive exact information on the number of parents and their eggs that are on the island. So, you may be asking how exactly do biologists living on Seal Island NWR get an accurate count of the number of terns nesting on the island? Each year between June 12th and 20th we form a line and slowly tip toe through the tern colony shouting out the number of nests and eggs that we walk past. We ziz-zag across the island as a designated recorder furiously writes down the information. Nearly the whole time we are counting terns are consistently pecking and dive-bombing at you head. (Can we some how put a link to the video that I sent you?). At the end of the long day we tally up our totals. This year we had a total of around 2200 tern nests on Seal Island! Around 900 Arctic Terns and 1300 Common Terns.

Arctic Tern on Nest

Arctic Tern on Nest

To get an accurate count on Puffins we must use a different method as they burrow deep into the boulder berm. Each year we follow a select group of puffin burrows to estimate the number of puffins breeding around the island. This is completed by looking into a select number of burrows, in addition to observational stints from bird blinds. To get a good look into the burrows you often have to contort your body into uncomfortable positions just to get a glimpse. It is hard to say exactly how may puffins are breeding this year on Seal Island but, last year we estimated around 492 burrows!

Checking out  a Puffin Burrow

Checking out a Puffin Burrow


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