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(commission) chibi sparrows doing a big winter dig 🌰🍂🍃

#bird art #my art #bird artist #artists on tumblr #birds #fox sparrow #eastern towhee #white-throated sparrow #chipping sparrow #dark eyed junco

It's World Sparrow Day, and what a nice chance to show this guy again, a favorite from this winter - the Fox Sparrow! I love it when the native Sparrows pop up, they are always a surprise because they barely ever visit feeders. Spring is a good time to look out for them and learn how to ID them, they are migrating.

#birds #birdlovers #backyard birds #birds of michigan #birds of north america #native Sparrows #Wold Sparrow Day #Fox sparrow #nature #birdwatching #ostdrossel

Fox Sparrow (Passerella iliaca). Family Passerellidae, order Passeriformes.

This was my first time ever seeing one, and I've been obsessed ever since. In winter when we get a rare snow that lasts more than a day, I would get a few more species at/around my feeders that didn't typically come around. I had this little one several days in a row while the snow persisted.

Oklahoma, USA. February 2021.

#fox sparrow #passerellidae #passeriformes #sparrow #birds #bird #bird photography #bird photos #birding #wildlife #birdwatching #wildlife photography #animals #oklahoma

One of the data points we take during prep is skull ossification. Baby birds start out with a thin single layer skull and as they age they develop a thicker two layers skull. Most orders of birds have a fully ossified skull when they fledge from the nest but passerines take a bit longer, so it can give us a lot of information about how old a bird is.

This Fox Sparrow died by hitting a window in December, and from the outside appeared identical to an adult bird, but because of the presence of a bursa near the cloaca and this partially ossified skull, I know it was a first year bird.

Incredibly, banders can determine skull ossification on a live bird by looking through the thin skin. I'm not entirely sure how they pull that off, because I typically have to remove the brain and look through the skull in the light to feel confident that I'm actually looking at a partially ossified skull. I do so many non-passerines that I don't get enough practice.

In the first photo, I circled the window section that appears transparent compared to the rest of the skull. I also included a diagram of the skull ossification process under the break.