Fledged!

Our first chick has fledged! Earlier this week I watched a chick on the nest where the earliest egg was laid and the first hatch occurred this year. The oldest chick was flapping furiously and getting some good loft, hovering a foot or two above the nest. Some people call this “helicoptering”. It is a thrill to observe! I stayed for a long time but she was just not ready to make the big leap quite yet. She was 54 days old. This morning I returned and was delighted to watch her flying loops and returning to the nest and sticking her landings perfectly. Her sibling was not quite ready to go yet.

She would have been 55 days old on Tuesday, perhaps the day she fledged. That is a good average age for a first flight tho there can be quite a bit of variability in fledge dates, but I often use 55 as a good guess for when a juvenile might take that first flight. Alan Poole says in his new book that fledging occurs between 50-60 days.

Some people think that parents do something to encourage fledging but it is really a physiological readiness that causes the first flight. So what is really happening? Let’s talk about feathers. As our little friends have grown, we have seen them move from a down covered fuzz ball, to having little pin feathers poking out all over their bodies. As those feathers grew, the shaft was full of blood, so they are called “blood feathers“. As they approach 50 days, the blood begins to recede from the shaft. The feather stiffens and is finally capable of sustaining flight. They also have spent significant time flapping those wings to build muscle strength. When I was working on the reintroduction, and we had a hack box full of chicks, I had to determine when the chicks were ready for flight. I became very familiar with the pre-fledging behaviors described above. I also noticed that they would begin trying to self feed at this time. We also examined each birds flight feathers, watching as the shaft turned from a bluish, dark color to a white, slightly transparent color.

This phase of watching our nests can be very exciting! As I made the rounds to many nests today, I was looking for those pre flight behaviors, and I saw one other chick that was getting some good loft and floating up in the air above it’s nest. I am sure there are others around the metro too. I also take a deep breath because this is a treacherous time for the juveniles. Not all first flights go well. We will watch over them as much as we can. May all our young ospreys fledge successfully this year!