For a few weeks this summer, I had house guests. A very efficient mother Robin built a little nest on my bathroom window ledge with sticks and strands plucked from my yard. I presume that her belief was that critters would not menace her or her babies at this altitude. She was an empty nester for a few days, and then her first egg appeared. Immediately I was in the encyclopedia, researching the gestation period of robins. I learned all sorts of random facts- like they usually lay 4 eggs, then incubate them all at once. Scientists conducted experiments where they kept removing an egg, and the mom kept depositing eggs, but would never nest. This was not the case with my robin. She peaked at 3 eggs. Then, determining that her nest was on the small side, she somehow reduced her maternal responsibility to one egg. In Janet world, she airlifted the other ovums to a surrogate. In reality, maybe a squirrel had eggs for dinner. I do not know.
The mother took up residence on her one little blue egg. She sat there, day and night. The summer storms, with their wind and rain, menaced her perch. Still, she sat. She never seemed to sleep- her neck swiveled, checking to be sure no jays or sparrows came near. Her mate hovered in the vicinity as back up. If she saw me through the bathroom window, she would fly off into the birch tree next to the window. One early morning I rose at 5 to see a squirrel ambling up the trunk, with bad intent. I opened my window and shooed it away, but the mother and father Robin seemed to have things in hand, dive bombing it into submission. If I cranked the window out, they squawked at me and flew toward the house, a la "The Birds" by Hitchcock. I did not want them to hurt themselves, nor did I want my eyes pecked out, and so I stopped butting in.
The consequence of my concern for this solitary egg was that I kept the blinds down in the bathroom. My personal appearance took a hit, as I applied makeup in a dark room with harsh overhead lights. I wasted hour after hour waiting to see the mother nesting, or the baby being born. I used a longer lens to snap pictures of this process. Eventually, Mother was more worried about her nestling than she was about me, and we made some eye contact. Then, voila! The baby arrived. It was hideous- just pinkness with a little down. Every day it morphed and grew until it resembled a living thing. Mom and Dad took turns pecking the hell out of my garden to find worms, which they would pre-digest and feed to Junior. The little one sprawled across the nest, waiting to be taken care of. Its neck arched and stretched until they filled its beak with nutrition. Baby was not as hesitant to make eye contact with me, but I remembered the psychological theory of imprinting, and I did not want the bird to attach to me. So I kept my distance.
Steve and I went to the lake for two days, and I worried about my foster family. When I returned home, I raced upstairs to check on my nestling.
The nest was there, clean as can be, but there was no sign of my Robin family. I checked outside, to see if there was a distressed fledgeling bird hopping about in the garden. Robins generally push their babies to leave the nest and practice flight plans on the ground, but this was a two story drop. I was not optimistic that some foul play had occurred. I am still sad to have missed the final step of my bird's development, but of course it allows me to create a lovely "happily ever after" for the red breasted family. The nest is still on the sill. Who knows? Maybe there will be another tenant. I'll let you know.
A PS. here- I received the kindest letter from a professor of biology about my bird saga. He answered many questions and made me somewhat hopeful about my little house guest. Ignorance is bliss. Here is his letter:
I'm writing to offer a bit of insight into your robin saga.
I started listening to Steve in elementary school on the South Side, and now, 25 years later, I'm an avian biologist/professor of biology, and still loving listening from New Jersey. Maybe you have it figured out more than Steve indicated, but here are my thoughts:
In terms of clutch size, 3 eggs is pretty common in robins, about half of all nests. Female birds make a complex set of trade-offs that determine how many eggs they lay, and for this female, at this nest, 3 was the optimal number.
The two missing eggs are a bit difficult to explain. Unless you've seen squirrels on the ledge, I think it is unlikely that a squirrel took the two missing eggs just because I'd expect a squirrel to take all three and to damage the nest a little. Crows and jays will definitely take robin eggs without altering the nest, and that particular nest is very visible to an aerial predator. One other slight possibility is that a female cowbird removed the eggs in preparation to lay one or two of her own eggs in the nest. This would explain why all three eggs did not disappear (because if they all disappeared then the female robin would abandon the nest).
The more recent picture of the nestling on your blog is probably just a few days from being ready to fledge. Robins fledge in a pretty immature physical state as a way to avoid being eaten in the nest. The fledgling could have probably fluttered safely to the ground. They have short wing and tail feathers when they fledge, usually enough to crash-land somewhere. After they fledge they continue to grow their wing and tail to fully-functional lengths. This may have been the most risky period of your grandbirdie's life, unfortunately because house cats are highly skilled at catching songbirds.
And lastly, if you want another robin to nest on your sill you should remove the old nest to make space for a new one, because they will not use the same nest twice. If you want to save the nest you can just put it in your freezer for a couple of weeks to kill any insects. I'm sure Steve would love that.
Take care and thanks for your contributions to the show over the years, and for keeping Steve going.
Department of Biology
The College of New Jersey
Isn't that he nicest thing, ever? I am touched beyond reality. And wiser. I obscured his last name just in case he wished for anonymity. I will never forget how kind he was.