Last Day at Fry's Landing

Short Banding Day

Yesterday's banding at Fry's Landing was interrupted some really strong wind gusts that made me look up  at the cottonwoods and wonder which branch was going to fall directly on top of our banding table. Thankfully, that didn't occur, but the high winds and threat of rain caused us to shut down banding at 10:30 AM.

With only 4 hours of banding, we only caught 18 birds (12 new, 6 recaps). We did catch this Yellow-bellied Flycatcher.

And a nice ASY male Indigo Bunting. It looks like he replaced all of his secondaries, but did retain the outer two greater wing coverts. If you scroll down to the bottom of my post from the 28th, there's another wing photograph of an SY male for comparison.

We do focus on the birds, but every now and then something else flies into our nets.

When caught, dragonflies will start chewing on the net, getting their mandibles so entangled that it's seldom possible to get them out in one piece. This individual was lucky, in that Ruth, Joan and Sam were willing and able to free it and then remove the remaining strands of mesh from its mandibles. Their patience and the judicious use of scissors (it was an old and much abused mist net) completed the first successful dragonfly extraction of the season.

Other wildlife activity in the area included several nesting turtles. This female was laying eggs right next to our net lanes. There were at least three other females in the area looking for a safe place to dig a nest.

Unfortunately, Most turtle nests end up feeding the local skunks and raccoons. This snapping turtle nest had been raided a day or so ago.

I saw at least two other nests that had been dug up, so I'm not terribly optimistic about the outcome for the nests that I did see being initiated. Turtles live for decades and there are masses of them in the bay. They don't need that many successful nests to maintain their populations, but it's still sad to see all that effort go to waste. And few things are cuter than a baby turtle. 

The best thing we can do to help the turtles and other small animals is avoid feeding raccoons, skunks and opossums, whether intentionally (feeding) or inadvertently (not disposing of our garbage properly). When more of them to survive on Presque Isle than the environment can support under normal circumstances means other species like these turtles suffer the consequences. 

Quality, not Quantity

Field Season doesn't recognize holidays, so today we banded at Erie Bluffs. This was the first day where the morning sun shone with that milky light that promises a hot and humid day to follow. I had the nets open by 6:30 AM, but closed down by 11 AM as temperatures were getting into the 80s (~30 deg C.) and it was getting too hot to handle birds safely. We still had a nice time under the shade of the tulip trees and caught 22 birds, 16 new and eight recaptures. 

It's going to be a good day when these two birds are in your first net run.

ASY Male Hooded Warbler

ASY Male Mourning Warbler

The Mourning Warbler taught me an important lesson about lighting: don't photograph a dark bird in the shade with a sunlit background. I promise the next photo of a MOWA will be prettier.

We finally caught one of these, which I've been waiting for a while now to have in-hand.

Yellow-bellied Flycatcher

Note the complete yellowish eye-ring. Least Flycatchers have a whitish eye-ring that's more teardrop shaped, Willow/Alder have an incomplete one, and Acadians have a thin white eye-ring. Yellow-bellies are also one of the later migrants, so are expected in late May.

We were lucky enough to catch Gray-cheeks and Veeries in the same net run, so I took a few comparative photos to illustrate the differences between them.

Veery (left) and Gray-cheeked Thrush (right)

Veery (left) and Gray-cheeked Thrush (right)

The Veery is much brighter colored and has less spotting on its chest. There's more to look for, but that's the easiest way to tell them apart. There was also a Veery singing next to our banding table, so now I've heard all of our thrushes in song this spring. It's nice to band back east.

These two weren't very happy about being photographed. It was almost as bad as getting a good picture of a two-year-old child.

Our one Swainson's Thrush was caught an hour later, so we weren't able to photograph all three of them together. Perhaps tomorrow.

Molt Indigo

Much of what I show on this blog relates to identifying, aging and sexing different bird species. One of the best ways to appreciate bird molts is to illustrate the process with a distinctive species.

Can you get more distinctive than this?

It takes two years for male Indigo Buntings to achieve this, their full adult plumage. If you look at the wings, you can see that the primary coverts (feathers just below the alula on the outer edge of the wing) are edged with blue. The greater coverts (immediately to the right of the alula) have broad blue edges. Even the flight feathers themselves show some bluish edging. This is because the adult birds replace all of their feathers after breeding, in what is termed their pre-basic molt (as an aside, molt terms can be rather confusing, a good review by Steve N.G. Howell is here). Depending upon the species, some birds will then replace many if not most of their body feathers in late winter in preparation for the breeding season. This is called their pre-alternate molt. There are many variations on this theme,

Indigo Buntings having one of the more complicated molt schedules. Juveniles fledge, then undergo a pre-supplemental molt where they replace most if not all of their body plumage. They then migrate south and undergo a complete pre-basic molt on the wintering grounds, replacing all their feathers. Finally, they undergo their first pre-alternate molt before heading back to the breeding grounds (or once they get there), replacing their secondary coverts, several inner secondaries and up to four tail feathers (more details here). During each of these molts, an individual bird may retain some of their older feathers, so by the time they return to the breeding grounds an SY bird may have retained juvenal and basic feathers, as well as the newly acquired alternate (breeding) plumage feathers.

This second-year (SY) male shows three different-aged feathers. His pale belly comes from retained juvenal feathers that weren't replaced during the pre-supplemental molt. The brown body feathers actually have blue bases, but the brown tips haven't worn off yet and block his true blueness. He has new secondary coverts, but some retained ones from his first pre-basic molt that are paler and more worn than the newer ones. All in all, he's a complicated individual.

Here's a nice view of his back. showing the difference in age and wear of his flight feathers. You can see that he's retained a few of his tail feathers but replaced several with darker, blue edged ones. He's kept some of his greater coverts, but replaced all of the median coverts (row of smaller feathers above the greater coverts)

So that's what I spend much of my time doing, trying to decide how old these birds are based on the shape, color and wear of their feathers. It's a lot of fun and similar to solving a puzzle, except that no one publishes the correct answers online the following day.

Here's a female Indigo Bunting, that I aged as an SY based upon different-aged coverts and replaced flight feathers.

Finally, this male added some confusion. I have no idea what went wrong with his molt, but I'm guessing some form of leucism?

That's all for tonight, more tomorrow.

P.S. Today (28 May) we netted another SY male, and since I had volunteers with me, one of them held its wing out so I could get this picture. Let's take a closer look at confusing bunting molt.

He retained his juvenal primary coverts, which is why they're uniformly pale. He did replace the outer six primaries during the pre-basic molt. Counting from left to right, you can see that the outer six flight feathers are darker than the next seven. Three of those seven feathers are primaries and the next four, squarer-tipped ones, are secondaries. After that come two secondaries that were replaced during the pre-alternate molt along with the three replaced tertials. It also seems as though he retained the outer 7 greater coverts and the 2 outer median coverts. All in all, a much more interesting wing than I thought when I photographed it earlier today.