Murres take extreme ledge-nesting to a whole new level. Unlike kittiwakes and cormorants, which build well defined nest bowls for their eggs from mud and vegetation, murres simply lay a single egg directly on bare rock, often on narrow exposed ledges that can be hundreds of feet above the water below. Most of the time one of the two parents keep the egg securely tucked away below the breast feathers, cradled in place by their feet. Parents have to switch incubating shifts, they fight with neighboring birds, and are sometimes flushed from their nest sites by predators. When these disturbance events happen, most eggs would simply roll off the edge of the cliff, but murre eggs are unique. They have an exaggerated teardrop shape, with one end pointier than the other, that causes the egg to roll in a circle. If the egg is left along, it generally stays in place. Unless of course the parents decided to lay on a slope...which happens. Then they fail.
Canon EOS 60D, Canon EF 17-40mm f/4L USM, ISO-400 f/4 @ 1/1600 sec.
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