Earlier this past week, I calculated that the Eastern bluebird (Sialia sialis) babies in my front-yard nest box were close to fledging. I knew approximately when mom had finished laying her eggs (four in total), so that I could guess when they reached normal fledging age (16-18 days after hatching). When I looked at the nest on 10 June, I saw that there were only three babies; I have no clue what happened to egg No. 4. But the three survivors were progressing well as mom and dad made frequent forays to gather caterpillars and insects for them.
Occasionally, the male and also the female bluebird, identifiable by her subtler coloring and her brood patch, would visit the suet and meal worm feeders for a fast food repast for themselves. It was hard work keeping their growing offspring fed!
They also had to let one of their older offspring from a previous brood know that they were no longer going to feed him, even when he begged.
As fledging time neared, mom and dad had to contend with other birds coming near the box. Dad was especially angry with a young starling (Sturnus vulgaris) who wanted to settle on top of the box. Starlings have been known to eat young birds and papa bluebird was obviously taking no chances! (I just caught the action out of the corner of my eye so the photos aren’t great but do give an idea of the argument!). The parents also chased away squirrels from the tree in front of the box, which alerted me to the fact that fledging was probably imminent since the parents become especially protective at this time. I started using a smaller camera with a very long zoom (but somewhat lesser photo quality) as they weren’t excited by me being too close either.
On Wednesday, I checked the box before going out for the morning and there were still three babies there. When I came home a few hours later, mama and papa were sitting on branches, with or without food, calling to their little ones to come on out. They would also fly to the box for a quick look inside.
Mama also repeated behavior I had seen last year – flying to the box, standing on top and then hovering in front of the hole as a form of encouragement. When she and dad left, I approached to take a look and discovered bluebird baby No. 1 had already flown away. This meant that the parents had to watch the first baby out in the trees somewhere, as well as their two lagging offspring in the box.
At one point, mother bluebird seemed a bit fed up – she flew over to the box (without food) and finally entered, staying inside for a good 60-90 seconds at least. I imagined her giving the babies a lecture about how they had to be courageous and willing to jump.
Her admonishments seemed to have had an effect; the babies began calling loudly from inside their birth home. Finally, after about 30 minutes, one poked its head out to take a look at the big wide world. Mom and dad seemed glad, waiting together in the tree to see how long it would take baby No. 2 to join them.
The baby looked around a lot, also staring at me; s/he went back inside and then looked out a few more times, finally taking the great leap into the outside world. Baby 2 was a very strong flier – not even alighting in the tree in front of the box but circling around to land high in a juniper and then in a tall oak tree behind the box.
Sibling No. 3 took a little while longer and mama bluebird again went to the box to give encouragement. The baby then spent a little more time observing the new environment and also made a strong flight out.
It rained that night and I hoped that the bluebird babies were ok; between the thunderstorms and a neighbor’s cat who comes to hunt birds in my yard, their environment seemed precarious for their first days of life. In the afternoon, I was happy to see papa bluebird feeding one of the three babies at the top of an oak tree. Mama was also flying around up there, so I assumed they were all hanging out in the high branches.
Thursday night, it rained heavily again for many hours; Friday was an easier day and night. I haven’t seen the fledglings again yet but have seen their parents coming for suet and meal worms and flying up to the oak tree, so I assume at least a couple are there. I look forward to seeing their speckled selves at the feeders along with their parents – and will be curious to see if their parents go for a third brood this year.