You know what? You probably won’t even believe how our sixth banding session went. So maybe I just won’t even tell you about it.
PHSYCHE. Of course I will. 😀
It was an amazing day; we caught not just 20, not just 30, not even just 40 birds… but 49. Can you believe that?! I don’t even remember most of the morning – it was a blur of banding and net checks and scarfing down banana muffins at every hands-free-of-birds opportunity.
Here are the (epic) totals:
As you can see, only 5 were recaptures – so that’s 43 new birds total (one of the House Wrens escaped at the station just before banding – they often become fugitives in this way) in just 6 hours of mist netting. Pretty good capture rate, especially for just 8 nets!
Several net rounds ended in a scene like this:
Judging by the day, it’s probably safe to say that mid-July is the peak of fledging season for many species at Crossways; take a look at this fancy chart I made (but please, don’t be intimidated by its highly complex, scientific nature):
Of all the young birds (HYs and Ls), most were either Robins or Catbirds. In fact, I’m pretty sure that we caught ALL the robins. Not all the catbirds – there’s an endless supply of those.
I don’t have too many photos from the day, since there was little opportunity for anything but Extreme-focus Speed-banding. But here’s what I do have!
What does it mean when feathers are “in pin”?
When birds are either growing in or replacing feathers, the new feathers begin their development inside a keratin sheath, which can look like a pin (I don’t really see it though – they look more like tiny paintbrushes to me, but I suppose “the feathers are in paintbrush” doesn’t have the same ring to it…). The feathers are delicate when first forming, and need the protection of the sheathe. They also need a supply of nutrients for growth, and this they get from a blood vessel that circulates nutrients up to the emerging feathers. That blood supply is also what gives pin feathers their dark color.
As the feathers develop and become stronger, and no longer need as many nutrients for growing, that keratin sheathe will eventually disintegrate and peel away; the blood supply will recede and become centralized at the base of the feather shafts.
And the feathers will unravel into all their majesty.
Actually, that up there is a shot of the same bird’s wing that we caught during the last session, which was exhibiting the first prebasic molt. Look how much happened in two weeks:
It finished growing several feathers, and began replacing others. That’s a lot of change in a short amount of time!
Since we caught many, many Hatch Year and Local birds, we really had a chance to check out one of the interesting features of fledgling anatomy: the fleshy gape.
The ‘gape’ is where the upper and lower mandibles of the bill join (actually, it can more specifically be called the ‘gape flange’, while gape can refer to the edge of the bill as well as its interior).
Long ago, some young birds realized that since they‘re relying on their parents to feed them – and since their parents have to see their mouths clearly in order to put the food in the right place – having weird, fleshy, brightly colored mouth-corners was advantageous.
Now they all do it.
Such gapes of pink, red, orange, and yellow coloration attract a parent bird’s attention, encourage more feeding, and make the mouth more visible in low-light settings, such as might be found at a nest hidden in a dense thicket.
Young birds open their mouths (literally called “gaping”) in response to pretty much any stimulus. Seriously, I’ve monitored a lot of nests and the tiniest sound, the slightest brushing of vegetation near the nest with an errant arm, and they will FREAK. OUT. And insist that whoever or whatever is nearby immediately give them food.
Unlike people, birds have very thin skin, which means we can actually see the stored fat beneath by gently blowing their feathers apart. It appears yellow in coloration, unlike their muscle, which appears more reddish-purple. We check for fat in three main places: the furcular hollow (pictured – the hollow at the base of their throat); the wing pit (their armpits, to put it gently); and the base of their abdomens. Fat is scored on a scale of 0-7, where 0 is (can you guess?) nothing, and 7 is excessive or bulging.
*Note: blowing the feathers apart to check for fat doesn’t upset the birds or cause them any discomfort, but it can lead to a case of extreme lightheadedness in banders – the cure for this is quick consumption of some variety of pastry*
Birds have very high metabolisms and burn through fat so quickly that their scores can change throughout a day, depending on their activities. They are typically lower in the morning, after a night of not foraging, and higher in the evening, after a day of incessant foraging.
During the summer, birds tend to have lower fat scores. It’s really not until just before migration that we start seeing some real fatties (affectionately called ‘butterballs’), since they need plenty of stored fat to fuel them through their long flights to southern climes (or for local birds, to supply enough energy to keep them warm once the weather turns cold).
Birds are not the only winged creatures at Crossways; the grasses and wildflowers of the preserve attract an array of gorgeous Lepidoptera species. Red Admirals are one of the most common that we see each banding day:
Well, friends, that’s all for now. But let me just reiterate one very important thing before I go:
WE CAUGHT A LOT OF BIRDS.
Our last session was a bit slower, but there were a few gems. So check back soon for those highlights!