June - July 2016
We opened our nets for a total of 27 days over these two summer months and banded 1,112 new birds. We processed another 409 recaptured birds for a total of 1,521.
Our most common bird was a bit of a surprise this season-- we banded 270 Cedar Waxwings, well over our recent 5-year average of 85 per summer. The rest of our top 10 list included many local breeders: Gray Catbird (218), American Redstart (95), Red-eyed Vireo (83), Common Yellowthroat (81, pictured), Song Sparrow (69), Yellow Warbler (54), Eastern Phoebe (53), Black-and-white Warbler (46) and Ovenbird (37).
And breed locally they did... of the 1,521 birds that passed through our hands this summer, 608 (40%) were young, newly-hatched individuals.
One "breeder" that we were NOT expecting in our nets this summer was this well-worn adult female Tennessee Warbler captured July 22. As noted in our summer highlights from 2015, we rarely band individuals of this species during the breeding season. In fact, this was just our third banded at Powdermill during a summer season. The others were last year's adult male on July 23rd and we banded a second-year female on July 13, 2011.
Since Tennessee Warblers primarily breed in the boreal forest to our north, these individuals are likely “molt migrants”— birds that begin migration after breeding but before they replace the previous year’s feathers.
Note the wear and sun damage on the tips of the primary flight feathers on the spread wing of the Tennessee Warbler.
Tail feathers of the Tennessee Warbler; again, the extreme wear of the year-old central tail feathers is obvious.
Breeding birds (usually the females) lose the feathers on their breast so that heat can be transferred efficiently to the incubating eggs. This is know as a brood patch, shown here.
This Tennessee Warbler was just starting to re-grow the feathers on her breast
So, with all of this talk of breeding birds, we thought you might want to see some of that 40%- the young birds that found their way into our nets this summer, sometimes with a parent squawking in the bushes nearby or, sometimes the parent was also in the net! But don't worry- we return the young (and parents if captured together) right back to the net where we caught them so they can continue those interrupted life lessons.
In order of appearance then, we start with this Brown Thrasher from June 14th, one of 10 banded this summer.
One needn't look farther than the head to age this bird. The characteristic brightly-colored fleshy gape at the base of the beak facilitates feeding by the parents while the nestling in the nest.
Also, the gray eye indicates its newly-hatched status. Many young birds have light gray or brown eyes that change over the winter. By Spring, this thrasher's eye will be yellow.
Somehow these little warbler nestlings just raise the cuteness bar. Would you have recognized this Yellow Warbler without seeing its characteristic yellow tail and yellow-edged wings?
If you look closely around the beak, you can see that this individual has already started to replace those loose-textured downy feathers with more structured yellow feathers.
This Yellow Warbler was banded on June 16th, one of 54 banded this summer.
Some fledglings have not completely grown in their flight feathers yet when they leave the nest, as was the case with the Yellow Warbler. The feathers start out as just a sheath from which the plumage emerges.
Since a shorter wing makes for somewhat wobbly flying, we know that this individual didn't fly far before he landed in our net, so this bird was aged "local" rather than hatch-year.
The Yellow Warbler was also still growing in its tail. the very loosely-textured undertail coverts are another clue to its fledgling status.
Although this young Tufted Titmouse, banded the same day as the Yellow Warbler, was not particularly interested in posing for a picture, he did feel the need to show us that, though small, his attitude was large.
We don't mind, because it gives another good look at that bright fleshy gape at the base of the bill.
Also, this picture highlights another characteristic of some young birds-- a light-colored mouth lining. The adult titmice will have a dark mouth lining. This color difference will make it much easier to age these birds throughout the Fall.
This Titmouse was one of 13 banded this season.
By the time this House Finch showed up in our nets on June 23rd, it had lost most of its downy fluff. All except the two feather tufts above both eyes. This was one of just four of this species banded during the breeding season.
A "local" American Redstart with a lot of loose juvenal feathers that will gradually be replaced. Our third most commonly banded species (95 banded this summer), this individual was from June 30th.
Much less common than the Redstart above, this very young Cerulean Warbler was one of two we banded-- July 2nd and July 30th.
Although common breeders near the banding area (we banded 83 this summer), we don't often see Red-eyed Vireos this fluffy and brown. you can see the feathers on the head have already started to be replaced.
And no red eye, you say? This is another species that starts out with a juvenal eye color. The dark brown eye of this individual will change to red over the winter.
Hatch-year Red-eyed Vireo, July 28th.
True confession upfront-- this fledgling Kentucky Warbler was actually from the first week of August, but since he fits in so well with our other pictorial highlights this season, we took the liberty of including him here. We did band 21 Kentucky Warblers during the summer months of June and July.
A closer look at the head of the Kentucky Warbler. Note that the loosely-textured juvenal feathers are being replaced starting at the front of the head.
Feathers start out as "pin feathers," the short gray straw-like structures seen here. The feathers grow out from these small sheaths, which continue to provide nourishment as the feather grows.
The tail was almost fully-grown and the sheaths around the feathers are starting to curl up and break off.
Note that the upper-tail coverts are also in sheath.
Flight feathers and wing coverts are also still growing! The sheath, appearing dark as the feather is forming, supplies the blood and nutrients for feather growth.
We hope you enjoyed this look at some of our newly-banded fledglings. They make us smile with their pouty gapes, fluffy feathers and big attitudes. It is always a privilege to encounter these newly-hatched individuals and to continue the census of summer birds at Powdermill.
Check back soon for our Fall update to see what other cool birds we are photographing.
And in the meantime, good luck keeping the squirrels away from your bird feeder! We have a few red squirrels that regularly stop by for lunch!