- Once the female robin begins incubating, she rarely leaves the nest for more than 5-10 minutes at a time. There have been a few occasions when we've witnessed Mrs. Robin leaving the nest for 15 or 20 minutes at a stretch, and who can blame her for needing a break every now and then? But overall, she seems to be a devoted mother, and most of her excursions don't last more than five or ten minutes.
- Female robins turn their eggs several times each day, in order to keep the eggs at a constant temperature and prevent the little ones from sticking to the inside of the shells. I think we've witnessed Mrs. Robin turning her eggs a few times, although it's hard to tell for sure, because she usually has her back to the camera.
- Robin eggs need heat in order to develop properly. A robin's body temperature is typically around 104 degrees. However, a robin's feathers usually feel cool to the touch, due to the insulation that the feathers provide. So, with all of this insulation, how can the mother share her body heat with the eggs? The answer is that the female has a featherless spot on her stomach, called a brood patch. When the female is ready to sit on the eggs, she parts her outer feathers, allowing her hot stomach to come in direct contact with the eggs.
- The male robin rarely sits on the eggs, but he hangs out near the nest so that he can come to the mother's assistance if she calls for help. Occasionally, the male robin will even bring worms for the female robin to eat. I guess this is the avian equivalent of the human father-to-be who runs to the store late at night to fulfill his pregnant wife's desire for mint-chocolate chip ice cream topped with anchovies. Bill and I had become a bit concerned, because we never saw Mr. Robin during the first few days of incubation. What if he turned out to be a deadbeat dad, leaving Mrs. Robin all alone with four hungry mouths to feed? Or -- even worse -- what if he had decided to run off with that shapely red-breasted robin who lives across the street? Just when we were beginning to worry, Mr. Robin made a brief appearance on the robincam. We were quite relieved to discover that he hadn't left Mrs. Robin.
Saturday, April 23, 2011
What to Expect When Your Robin is Expecting
Now that Mrs. Robin is in full-time incubation mode, I thought I would share a few interesting facts about the incubation process.
at 5:27 PM