The Bird Thead

[LFC]

Dec 15, 2022 14:47:49 GMT goldenvalley said:

Slow birding? LFC what do you think of this?

I do it all the time. My desk overlooks my feeders. I'll sit on my deck during spring and fall migration to see what appears. There are areas I love to go that provide both variety and in-depth time. On my last international birding trip to Honduras I planned 10 days and just 2 lodges so it was NOT what is sometimes called "slam-bam birding."

I've done more than my share of hard-core birding. I spent 3 weeks on Attu Island in the Aleutians, at the time the furthest west airstrip in Alaska. (The Coast Guard base there is now closed.) I competed in NJ Audubon's World Series of Birding, a 24-hr competition that raised money for conservation, for decades. From PA I've chased rarities in FL in a 3-day weekend, driving straight through the night. It was all fun. I move a lot slower now though some consider my love of pelagic (offshore) birding as hard-core, especially if they tend to get seasick!

[AnBr]

Dec 15, 2022 14:47:49 GMT goldenvalley said:

This sounds nice of course, but isn't travel away from your home part of the fun?

Why not both?

[LFC]

As a public service here is a recent comparison of affordable but nice quality binoculars.

[AnBr]

www.science.org/content/article/newfound-brain-structure-explains-why-some-birds-are-so-smart-and-maybe-even-self-aware

[goldenvalley]

[Bact PhD]

Invasive snail seems to be contributing to the resuscitation of an endangered FL bird:

www.npr.org/2023/03/14/1157862843/endangered-snail-kite-invasive-apple-snail-florida

In Florida's Everglades, few species are more closely tied to the habitat's health than an endangered bird, the snail kite. The Everglade snail kite is a raptor, similar to a hawk, that eats just one thing: snails.

Over the last century, as much of the Everglades was drained, the bird's population declined precipitously. But the kite has bounced back recently thanks to an exotic snail. It's a rare case of an invasive species having a positive impact.

[goldenvalley]

[LFC]

Wrong thread. That belongs in the Byrds thread.

[AnBr]

[AnBr]

[LFC]

White-throated Sparrows are common here in the East in winter. They aren’t particularly flashy but can be fairly nice looking. They have, however, a unique biology that, at the genetic level, effectively produces 4 different sexes. This is expressed in their mate selection.

Long ago, the X and Y sex chromosomes in mammals were probably just two normal chromosomes. They crossed over and put red tips on blue chromosomes and vice-versa. But at some point, the Y chromosome suffered an inversion: a huge stretch of it got flipped around. As a result, crossing over was impossible. And over the long term, the X and Y chromosomes became quite different.

Something similar happened with bird sex chromosomes. Long ago, one suffered an inversion. Crossing over became impossible, and over time, Z and W became quite different.

But white-throated sparrows go even beyond this. The changes on chromosome 2 have effectively doubled the number of sex chromosomes, from two to four. The overall result is four distinct sexes.

This is exciting for two reasons. One, the process of how mammals got our X and Y chromosomes is mysterious, because it took place so millions of years ago. But the situation with the sparrows is happening right now. We can actually watch sexual differentiation happening, which could teach us more about our own heritage.

The second reason for excitement is this. Normally we think about sex differences and barriers to reproduction in terms of anatomy. Two females can’t reproduce because they don’t have all the right parts between them. Same with two males.

But the emergence of the new sexes in the sparrow doesn’t involve anatomy. Anatomically, white-heads could still mate with white-heads and tan-heads with tan-heads. The parts still fit.

Instead, the reproductive barrier here involves behavior. It’s still driven by genes and chromosomes, but it’s behavior that’s segmenting the population and giving rise to the third and fourth sexes. These sparrows expand our notion of what biological sex even is.

And to me, that’s why this bird is so fascinating. Traditionally, scientists thought about biological sex in binary terms. Male or female, and that’s that.

Nowadays, we know that’s too simple. There are intersex people who don’t conform to that binary. What’s more, psychologists also now know that, above and beyond biological sex, there’s something called gender. It’s different from sex, and behavior plays a big role in it.

And it’s not just humans that display these nuances. Anatomy is part of the sparrow’s four sexes, certainly. You can’t escape that. But behavior is equally important.

As of now, biologists don’t know of any other animals with a four-sex reproductive schema. But that might be because they haven’t looked. Most birding books describe the white-throated sparrow as a “common” bird. In truth, it’s anything but. It’s extraordinary.

[AnBr]

[AnBr]

[goldenvalley]

Well...bird feeders

[goldenvalley]

Visitors to my pool yesterday

[goldenvalley]

It's World Penguin Day.  Who decides these things?  But anyway here's some photography

[AnBr]

Jim Wright
12m ·
Tree Swallow a fraction of a second before snatching its dinner from the surface of the pond

And it only took me 6 hours and 8671 shots to get this capture.

[AnBr]

Jim Wright said:

Stop doom scrolling for a few minutes and enjoy this image of a Sandhill crane mare and her two colts

(yep, that's what you call cranes. Males are called "roans")

Her mate made sure I didn't get too close, so I shot this image through the cattails with the big lens.

[AnBr]

[AnBr]

Jim Wright ·

Black Skimmer hitting a tide pool in the early morning sun. Navarre Beach, Florida.

Attachments:

[AnBr]

[AnBr]

Jim Wright
5m ·
Red-Shafted Norther Flicker

Went out for a walk in downtown Missoula. Brought my walking around camera along (because if I'm going for a walk, I'm walking around with a camera) and who do I see down by the river? This guy.

The Flickers I captured in Michigan last month were Yellow-shafted (yellow underwing and tail). Red-shafted are in the West from Alaska down to Mexico.

Happy to get both subspecies.

[goldenvalley]

Not a bird but wow!

[pnwguy]

So I had a similar experience rowing a kayak here on the Willamette river, just south of Portland. The Willamette flows into the Columbia. I was quietly rowing one peaceful summer morning when a sturgeon that was maybe 4 or 5 foot in length, leaped out of the water like that, about 20 feet from the bow of my kayak. I nearly lost my breakfast.

[goldenvalley]

Jun 27, 2023 22:31:15 GMT pnwguy said:

So I had a similar experience rowing a kayak here on the Willamette river, just south of Portland. The Willamette flows into the Columbia. I was quietly rowing one peaceful summer morning when a sturgeon that was maybe 4 or 5 foot in length, leaped out of the water like that, about 20 feet from the bow of my kayak. I nearly lost my breakfast.

There is a subgroup of non native carp in the Missouri River that gives aerial shows as you boat through the sloughs in and around Jefferson City MO.  One landed in my cousin's boat one day.  My kids were impressed that you can catch fish without a pole or net.