Backyard Wildlife
- Thread starter Canuck from Kansas
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Backyard Wildlife, 2024 November 2. Bird tales on plumage. Part 1 of 3. I don’t need the National Weather Service to tell me when there is snow in the mountains. Instead, if I see varied thrushes in my yard, I know that it is snowing at higher elevations. Yesterday, a small flock of varied thrushes joined the local mixed-species winter feeding flock to glean pine seeds and other food from the yard outside my window. While the low-light conditions required a 4000 ISO (normally, I shoot at 1000 ISO) to have reasonable shutter speeds, I managed to capture some nice images of these of very beautiful, but often elusive (until they are not…) birds.
These relatives of the American robin are very distinctive. Males have a bright burnt-orange chest and eye-stripe, a black band on the chest dividing the burnt-orange and a black head. In addition, they have two orange wing bars on their wings. There are also other patches of orange on their wing feathers.
Females are similar, but more washed-out. The dark areas of the female plumage are more gray / brown and the burnt-orange color is less intense.
These orange colors are caused by carotenoid pigments that are deposited in the feathers as the feathers develop. These pigments are often acquired through the bird’s diet, not synthesized by the bird itself. Carotenoids (along with the green pigment chlorophyll) are naturally produced by green plants as part of their light-trapping pigment package that powers photosynthesis. Carotenoid pigments can be red, or orange, or yellow. Differences in the chemical structure of various carotenoids means different carotenoid absorb some wavelengths of sunlight, but reflect others - the color we see. The orange carotenoid pigments in male varied thrushes absorb most wavelengths (that is, colors) of sunlight but reflect out orange wavelengths.
[The red, orange, and yellow colors of the fall foliage are due to the presence of these carotenoid pigments. These pigments have always been present in green leaves; however, during the growing season, their impact on leaf color has been masked by the more-abundant green-reflecting pigment chlorophyll. As deciduous plants prepare to drop their leaves in the fall, the plants stop the synthesizing chlorophyll which rapidly breaks down. Now, the carotenoid pigments, which have always been there, shine through.]
The black and brown colors are the result of melanin pigments deposited in the feathers. Melanin pigments tend to absorb all wavelengths of light. The coloration differences between male and female varied thrushes reflect sex-linked differences in the amount of carotenoid and melanin pigments deposited in the feathers. Interestingly, those bird feathers with higher levels of melanin are tougher – more resistant to abrasion.
Varied thrushes breed in mountain forests. But in my experience, they can be very elusive to see while on their breeding grounds. The males produce a loud distinctive flute-like whistle; they aren’t hard to find. But even if you know where the singer is, it will be out of sight, perched 10-15’ off the ground on a branch close to the trunk on the opposite side of a Douglas fir. And when you circle around the trunk for a clearer view, the bird will move to a different limb always on the side away from you. So, I am always pleased to see varied thrushes in my yard in winter because of their relative novelty and their beauty.
Part 2 of 3. A family of Steller’s jays moved into my area in late summer. I often see them bouncing quickly from branch to branch around the trees in the back yard. But they are quite active and hard to photograph (easier if you bribe them with a feeder stocked with peanuts apparently…). But yesterday afternoon, they joined the mixed-species feeding flock that passed through the yard and I managed some nice snaps of one individual.
The black color on the crest and head of a Steller’s jay is also caused by melanin pigments in the feathers absorbing all wavelength of visible light. But the blue coloration is NOT caused by a blue pigment. In fact, there are very few natural blue pigments. Instead, the blue coloration is due to how the feathers are constructed – a structural color. Air pockets within the feathers act like tiny prisms to split (refract) light into its component wavelengths (colors). The blue wavelengths are enhanced and reflected out to your eye (and my camera); other wavelengths of light are absorbed by melanin pigments deeper in the feather.
Part 3 of 3. I wasn’t paying too much attention to the smaller birds flitting around at the periphery while the varied thrushes and Steller’s jay were in view. I figured that they were just dark-eyed juncos, a very common species. When I finally flashed my bins on one of them at the base of a patch of salal, my initial impression was a sparrow, perhaps a song sparrow. But I then saw the bird more clearly and picked up a flash of yellow. And I clearly saw a white chin and black and white stripes on the head. This was not a junco, nor was it one of the other relatively common sparrows like a white-crowned sparrow or a golden-crowned sparrow, but a new species at my property, a white-chinned sparrow (Zonotrichia albicollis).
Unlike these other two Zonotrichia species, white-crowned sparrows are not common in Washington in winter. The species breeds in the Northeastern U.S., Great Lakes, and across Canada (absent from the far West). In winter, most birds migrate to the south: into the Mid-West, Mid-Atlantic, and Southern U.S. states. Some birds migrate to the Pacific Coast to reside in coastal California and Oregon. So, in the PNW you might encounter them on migration between their wintering grounds and their breeding grounds (and that may be the case for the bird that I photographed).
While I have seen this species in New England, I had never seen it in the PNW. That led me to look deeper into their biology, especially their strange reproductive biology. In both golden-crowned sparrows and white-crowned sparrows, the adult birds (especially in the breeding season) have black and white (white-crowned) or yellow (golden-crowned) stripes on the head. Juveniles have muted brown and white (white-crowned) or yellow (golden-crowned stripes on their heads. However, in white-throated sparrows, a breeding adult of either sex has either black and white stripes or white and brown stripes. Almost all bird chose mates that have the opposite coloration. Black-striped individuals of either sex are more aggressive (and less faithful) and brown-striped individuals are better nurturers of the young. In about 5% of pairing the partners have the same morphology; if the two parents are black-striped, they do a very poor job raising offspring as they spend most of their time fighting…. The color patterns are determined genetically. My bird is a black and white striped morph.
Steve
These relatives of the American robin are very distinctive. Males have a bright burnt-orange chest and eye-stripe, a black band on the chest dividing the burnt-orange and a black head. In addition, they have two orange wing bars on their wings. There are also other patches of orange on their wing feathers.
Females are similar, but more washed-out. The dark areas of the female plumage are more gray / brown and the burnt-orange color is less intense.
These orange colors are caused by carotenoid pigments that are deposited in the feathers as the feathers develop. These pigments are often acquired through the bird’s diet, not synthesized by the bird itself. Carotenoids (along with the green pigment chlorophyll) are naturally produced by green plants as part of their light-trapping pigment package that powers photosynthesis. Carotenoid pigments can be red, or orange, or yellow. Differences in the chemical structure of various carotenoids means different carotenoid absorb some wavelengths of sunlight, but reflect others - the color we see. The orange carotenoid pigments in male varied thrushes absorb most wavelengths (that is, colors) of sunlight but reflect out orange wavelengths.
[The red, orange, and yellow colors of the fall foliage are due to the presence of these carotenoid pigments. These pigments have always been present in green leaves; however, during the growing season, their impact on leaf color has been masked by the more-abundant green-reflecting pigment chlorophyll. As deciduous plants prepare to drop their leaves in the fall, the plants stop the synthesizing chlorophyll which rapidly breaks down. Now, the carotenoid pigments, which have always been there, shine through.]
The black and brown colors are the result of melanin pigments deposited in the feathers. Melanin pigments tend to absorb all wavelengths of light. The coloration differences between male and female varied thrushes reflect sex-linked differences in the amount of carotenoid and melanin pigments deposited in the feathers. Interestingly, those bird feathers with higher levels of melanin are tougher – more resistant to abrasion.
Varied thrushes breed in mountain forests. But in my experience, they can be very elusive to see while on their breeding grounds. The males produce a loud distinctive flute-like whistle; they aren’t hard to find. But even if you know where the singer is, it will be out of sight, perched 10-15’ off the ground on a branch close to the trunk on the opposite side of a Douglas fir. And when you circle around the trunk for a clearer view, the bird will move to a different limb always on the side away from you. So, I am always pleased to see varied thrushes in my yard in winter because of their relative novelty and their beauty.
Part 2 of 3. A family of Steller’s jays moved into my area in late summer. I often see them bouncing quickly from branch to branch around the trees in the back yard. But they are quite active and hard to photograph (easier if you bribe them with a feeder stocked with peanuts apparently…). But yesterday afternoon, they joined the mixed-species feeding flock that passed through the yard and I managed some nice snaps of one individual.
The black color on the crest and head of a Steller’s jay is also caused by melanin pigments in the feathers absorbing all wavelength of visible light. But the blue coloration is NOT caused by a blue pigment. In fact, there are very few natural blue pigments. Instead, the blue coloration is due to how the feathers are constructed – a structural color. Air pockets within the feathers act like tiny prisms to split (refract) light into its component wavelengths (colors). The blue wavelengths are enhanced and reflected out to your eye (and my camera); other wavelengths of light are absorbed by melanin pigments deeper in the feather.
Part 3 of 3. I wasn’t paying too much attention to the smaller birds flitting around at the periphery while the varied thrushes and Steller’s jay were in view. I figured that they were just dark-eyed juncos, a very common species. When I finally flashed my bins on one of them at the base of a patch of salal, my initial impression was a sparrow, perhaps a song sparrow. But I then saw the bird more clearly and picked up a flash of yellow. And I clearly saw a white chin and black and white stripes on the head. This was not a junco, nor was it one of the other relatively common sparrows like a white-crowned sparrow or a golden-crowned sparrow, but a new species at my property, a white-chinned sparrow (Zonotrichia albicollis).
Unlike these other two Zonotrichia species, white-crowned sparrows are not common in Washington in winter. The species breeds in the Northeastern U.S., Great Lakes, and across Canada (absent from the far West). In winter, most birds migrate to the south: into the Mid-West, Mid-Atlantic, and Southern U.S. states. Some birds migrate to the Pacific Coast to reside in coastal California and Oregon. So, in the PNW you might encounter them on migration between their wintering grounds and their breeding grounds (and that may be the case for the bird that I photographed).
While I have seen this species in New England, I had never seen it in the PNW. That led me to look deeper into their biology, especially their strange reproductive biology. In both golden-crowned sparrows and white-crowned sparrows, the adult birds (especially in the breeding season) have black and white (white-crowned) or yellow (golden-crowned) stripes on the head. Juveniles have muted brown and white (white-crowned) or yellow (golden-crowned stripes on their heads. However, in white-throated sparrows, a breeding adult of either sex has either black and white stripes or white and brown stripes. Almost all bird chose mates that have the opposite coloration. Black-striped individuals of either sex are more aggressive (and less faithful) and brown-striped individuals are better nurturers of the young. In about 5% of pairing the partners have the same morphology; if the two parents are black-striped, they do a very poor job raising offspring as they spend most of their time fighting…. The color patterns are determined genetically. My bird is a black and white striped morph.
Steve
Great pics and, ,of course, an exceptional commentary.
Interesting that you would post on the varied thrush. I had the first one of the fall show up yesterday in Normandy Park, a male.
Interesting that you would post on the varied thrush. I had the first one of the fall show up yesterday in Normandy Park, a male.
Always fun to find a mantis.
Buzzy
I prefer to call them strike indicators.
We were at Ocean Shores over the weekend; twice I had to stop for a doe crossing the road being followed by a buck with intent...........
All our pond guys seem to have bedded down for the winter - Ducks must have headed south, bee a few weeks now since we've had them, though there are some on the lake still.
Rarely get deer wandering all the way into our fenced backyard (they have to either hop a 4' gate or stroll through the 20' breezeway between house and garage), but these two were out there a few days ago. They seemed unimpressed with our statuary - which makes them smarter than the neighbor's terrier
Apparently little fear of the big cat...
This guinea fowl wandered into our yard twice this morning. He ran off the first time. The second time it ended up next to the chicken run in a pinch point. My daughter and I cornered and captured it. We are waiting to hear if any neighbors are missing one. They have odd looking faces at best.
