Hello from the island!
This past week has been by far the most exciting and most busy we’ve had yet. Black guillemot chicks have started to hatch, finding new ones every time we conduct our burrow checks. Every three days, we check one half of the island for our marked burrows, looking for the presence of eggs or newly hatched chicks. If there are chicks present, we have to fish them out of their burrows (sometimes when the mom is in with them!) and take measurements. The first measurement taken is weight, and for that we have a special scale in which we clip a “bird bag” (fancy term for a small drawstring cloth bag) to a cylinder scale and record its weight on how far the indicator goes. The newly hatched chicks only weigh roughly 30 grams, but don’t let that fool you; we came back to a chick just three days later and it nearly tripled in weight! The next measurement we take is wing chord, or the length from the most prominent point of the wrist joint to the most prominent point of the longest primary feather. This is taken using a special ruler, but it’s easy enough to record. After the measurements are taken, and if the chick is big enough, we place a size four US Fish and Wildlife Service metal band on its right leg using a pair of modified pliers specifically made for banding birds. The bands don’t interfere at all with any of the birds daily functions, and makes it rather easy to identify the specific bird from exactly what burrow and what year it was found if it were to be captured or re-sighted in the future.
Our tern chicks have also grown considerably since our last post, more than tripling their weight and starting to get their primary feathers! But that’s not the half of it, we have five more healthy chicks! They are all very well fed by their parents, who really don’t care for us handling their babies, constantly diving and pecking our heads (and pooping on us if we’re lucky). However, the chicks don’t make it very easy for us to find them; they often hide in the vegetation around the nest and blend in rather well, so searching for them is a very careful and mindful process. When we do find them, they get weighed the same way the guillemots do but do not get their wing chord recorded, simply due to the fact that it would be impossible for all the other islands to record that much data- there’s only 7 terns for us to measure, compared to Petit Manan with over 1,000 breeding pairs! (with an average of three eggs per nest, you can imagine why!)
As our chicks are growing more each day, there’s always someone that wouldn’t mind snacking on them, and here at Eastern Brothers that’s our new visitor: the peregrine falcon. We first were confused when woken up by the terns going crazy on Saturday morning, chipping and calling from one of the ravines. We weren’t quite sure what they were on about, but after getting to one of our morning survey points, we found a dead adult black guillemot predated on by the falcon.
We observed it flying from island to island with the terns fearlessly dive bombing it the whole way until it eventually left. We’ve seen it two other days after that, but it has been driven off the island quicker and quicker each time with no additional signs of predation. We’re hopeful that the terns keep on driving it away until eventually it moves on.
Until next week,
~Nate and Dawson, EBI 2016