June 27, 2011

Juv. House Finch

I don't know when you stop calling a bird a fledgling and start calling them a juvenile but either way, this is a very young bird. But then you could also call it a spring bird or a first summer bird or even a first year bird. Guess I'll just stick with "young" bird.  (Please read previous post to answer the about question.)

How do you spot a young bird???  Actually, I wasn't ready for this one since spring was so late but the birds didn't wait.  The first thing I think I notice is that soft fuzzy look a young bird has.  Also take a look at the corners of the mouth which are yellow.  The birds will loose this as the corners of the mouth close in to the adult stage.  On this bird you will notice that the corners appear to be just about closed.  Another sure sign of young birds is that they will be following an adult around.  You will see them flying close behind and slightly below the adult.  And the final sign of a young bird is that when it's near a parent, if is always begging for food and what I call "vibrating" where the whole bird seems to be in motion at one time.

This little bird is a juvenile since it was at the bird bath getting a drink and at the feeder getting a bite to eat all by itself.  But Dad was close by keeping a eye on things at the other feeder.  While Dad was there, a Pileated Woodpecker flew in. It didn't seem to bother Dad and when youngster saw Dad, it immediately flew over and started begging for food...wings down, tail up, and vibrating.  Sorry that the pictures are poor quality but the camera couldn't decide what to focus on and I was shooting in burst mode so didn't give it much chance to focus plus it looks like I moved (I was kind of hanging out a window shooting around the corner).

Fledgling vs. Juvenile

I have often made the comment that I didn't know when you quit calling a young bird a fledgling and started calling it a juvenile.

With all the resources of the Internet and the help of a lot of birding experts out there, I posed that question to Don and Lillian Stokes, authors of the "Stokes Field Guide to Birds of North America" and "Stokes Birding Blog". 

Here is my question: "When do you stop called a new bird a fledgling and start calling it a juvenile? Or would be be simpler to just call it a first spring or first summer or even a first year bird?"

Here is Don's response:

" There is a difference in describing the age of a bird and the stage of plumage it is in and behavioral stages. A fledgling is a behavioral stage; it is when young birds are out of the nest but still dependant on the parents for food. A fledgling is said to be in juvenile plumage, the first full plumage of a bird after being a nestling where it has natal down. Most small birds molt their juvenile plumage in their first few months and look much like the adult after that. But larger birds, like hawks can keep their juvenile plumage for their whole first year of life. The terms first spring or first year birds refers to a birds calendar age. They can also refer to a plumage if that plumage is distinct from other ages."

Well, that answered my question.  Thank you Don for the help.