The Shag's Feet

[1]cute or ugly?
[2]shags by night
[3]non-dainty female
[4]getting a bit big for the nest

Hello, I’m Katherine Herborn, a postdoctoral researcher at Glasgow and one of the seabird scientists on the Isle of May. I live here from April to June whilst my study species, the Shag, breeds on the Island.
Shags incubate their eggs with their feet. In a little over a month, this foot warming helps a few tiny cells grow into a hideous 35g chick, like this one[1]. We at Glasgow have been wondering whether a shag’s ability to keep it’s feet toasty, and nurture this growth, gets better or worse with age. To find out, I have temperature sensors in the nests of shag parents of various ages, from just 2 years old to an ancient 23.
As both parents share incubation duties, it is important to know which – the mother or father – is on the nest when I am recording egg temperature. To work this out, I have “shagcams” set up around the island to photograph my study nests once each minute, even at night [2]. You can tell the males and females apart by the colours of their leg rings (when they show them) or the shapes of their bills. Females are usually daintier. Occasionally though, less than dainty females are captured on camera..[3]
By now, in late-May, most of my eggs have hatched. So that’s part I of my study: the incubation phase, over. Next, I will see how the warmth of the early nest environment then effects growth in the chick. In the next 30 days, these tiny, wrinkly souls blossom into beautiful 1 kilo whoppers! Who still like to shnuggle up under mum and dad [4].