Mission: To promote the appreciation of wildlife and increase harmony between humanity and nature.

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Saturday, November 26, 2016

Flamingo Fantasy

Yesterday morning, Union Bay was filled with sunshine. The common mergansers seemed to enjoy it almost as much as I did.

There was bathing and wing-flapping by the male...

...and the female mergansers. Not only are the heads and backs of the females different colors than the males, the females apparently get their hair done at a stylish salon instead of the buzz-cut barber shop which the males frequent.

Although the males do have their moments. When a male sits in the sunshine and curves his neck into an elegant 'S' shape, I must admit he cuts a fairly fine looking figure.

Earlier in the week, when the sun was hiding behind clouds of grey, I spent some time watching the mergansers and fantasizing I was someplace sunny with sandy beaches and pink flamingos. While mergansers are obviously not flamingos, they do have at least one thing in common, besides being birds. Both species have feathers which may be in part colored pink by the food they eat.


Oddly, not all of the merganser's white or whitish feathers have this pink or salmon coloring. 

It made me wonder if the wing feathers grew when the merganser was not eating the color-enhancing food or if their bodies simply produce both white and salmon colored feathers at the same time.

In spite of the color differences between the genders, their shapes are almost identical, especially when the females lay down their stylish head feathers. In our Master Birder Class we were taught that ignoring a bird's colors and focusing on their shape can sometimes actually make identification easier.

In addition to color differences on the head and back, the female common mergansers also seem to have less of the salmon coloring. Their undersides are much more white. I doubt that this has to do with dietary differences because the males and females are usually close together and they appear to be feeding on the same schools of fish.

In this photo, the foremost female does show a hint of a salmon tinge but it is clearly less extensive than in the males. In case you were wondering, my answer is no, I do not think the females eat less salmon. Plus, nothing I have read links the color of salmon meat to the salmon colored feathers on the mergansers, but it did make me wonder.

I ended up reading somewhere that a blue-green algae can induce flamingos to have a richer pink color. If that is true, then I suspect that the color of the food which the mergansers eat does not directly correlate with the coloring in their feathers. In fact, I suppose the differences in the head feathers of the male and female mergansers may actually prove that point. I wonder how the genetics in their bodies, and ours too, allow us to eat the same foods and yet produce different colored feathers, hair or skin.

In the case of the mergansers their gender genetics and body color genes must be very closely associated. Obviously, it is not the same with humans, but it does make me wonder would our society be better or worse if our color differences were gender based. My conclusion is that it is not how we look, but rather how we think and act which will determine whether our society improves or not.

Regardless of how the process works, there is no doubt that the mergansers love fish. Whenever a bird surfaces with food, its colleagues watch very closely. If the fish is large or awkwardly held, the others begin to close in. They obviously hope the fish will be dropped and they can pickup a free meal. Usually, within a second or two the first bird tips its head up and the fish disappears.

Whenever one merganser dives...

 ...the others quickly follow suit. It seems a bit like the old saying, 'Monkey see, Monkey do'. It may actually be very logical, if one bird spots a fish there may be more passing by. Plus, with multiple mergansers underwater they can surround a school of fish and cut off their escape routes.

I suspect as soon as their heads dip below the surface they are focused on food.

Their webbed feet give the initial dive a powerful boost and also propel them underwater.

It is easy to imagine how human divers came up with the idea for flippers.

One moment there can be a dozen mergansers floating offshore and seconds later there are only ripples fading across the surface.

I often think of the pattern of a bird's colors as being perfectly symmetrical. A closer look shows subtle differences, just like a human face. I wonder if these patterns help them to recognize their mates during breeding season.

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By the way, common mergansers are cavity nesters. Since they cannot create their own holes in trees they must search for those created by others. They are one of the dozens of creatures who depend primarily on pileated woodpeckers for dry, spacious nesting sites. In turn woodpeckers depend on us to leave dead, standing nature trees which they can easily excavate to find food and create the cavities which they ultimately leave behind for others. 

A squirrel taking shelter in an abandoned flicker nest in a dead cottonwood on Foster Island.

The preferred trees for woodpeckers, at least around Union Bay, are alder, cottonwood and willow. From a human perspective these are softwood trees which are not highly valued. However, every one of these dead trees which we leave standing - especially near water - makes life around Union Bay richer by increasing the reproduction of birds and other wildlife.

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The larger splash on the left may indicate that the merganser is making a steering adjustment to chase after a fish.

If we had the time, equipment and inclination we could analyze the diving splashes of mergansers. I suspect the angle and size of the splash may indicate the direction and speed of the diving bird.

All of these photos were taken at the east end of Montlake Cut.

I counted more the two dozen mergansers in the area. It seems to me that they settle in around the entrance to Union Bay every winter. I suspect that Montlake Cut provides a bottle neck which increases the density of fish and makes their feeding more efficient. 

Since I cannot supply you with flamingo photos from Union Bay, I will end this Thanksgiving weekend post with a final pinkish merganser photo.


I hope you had a Happy Thanksgiving! 

Larry







Saturday, November 19, 2016

A Genetic Treasure

Seeing this sparrow could not have been more startling if the clouds had suddenly parted and a sparkling shaft of sunlight had illuminated the bird.

I have seen hundreds of sparrows near the mouth of Arboretum Creek. In almost every case, they are always one of these smaller, darker song sparrows.

In fact just moments before, I watched this song sparrow shake off unwanted berry parts while it consumed the core of this brilliantly bright red fruit.

To suddenly see this bird, with its vibrant head stripes and its perfect little white bib, was a shock. Instantly, I suspected it was a bird I had never seen before.

Its behavior reminded me of a spotted towhee. At first glance one might assume that the bird in this photo is simply standing and listening. Actually, it is in the process of grabbing leaves with both feet and using all of its strength and body weight - about one ounce - to throw the leaves behind it. This energetically expensive hunting strategy has its rewards.

There are often even smaller creatures hiding, hunting and feeding under the leafy debris. Feeding wild birds is just one of the many reasons for leaving autumn leaves under the bushes and trees in our yards. Over the winter, the heat from the decomposing leaves will warm the living plants. In the spring, the nutrients from the leaves will augment the floral proliferation.

It turns out that this little bird with the calico back is very common if you are east of the Mississippi, in much of the southern half of the United States or if you happen to visit Canada in the Spring. 

Seattle Audubon's online application, Birdweb, says that these little birds are uncommon to rare in Washington. If you follow the link to Birdweb, be sure to listen to the soft and melodic song of one of these white-throated sparrows.

One of our local song sparrows began following the visitor as it worked its way through the standing grass and fallen leaves.

In addition to its many other colors, the visiting sparrow has two bright yellow patches just above the black stripes between its eyes and beak. These small black areas are called the 'lores' so the yellow spots above them are appropriately termed the 'supraloral' areas. The bright color is supplied from plant foods which the birds eat.

As sparrows crush seeds with their beaks, the unwanted husks are often pushed up and out onto their upper mandibles.

This little bird was so effective at turning over leaves and exposing food...

...that the song sparrow, with its full load of husks, was following precisely in its footsteps.

I believe the two small 'twigs' sticking out of the sparrow's mouth may previously have been the antennae of a tiny creature it just consumed.

I love the way the three colors of feathers seem randomly mixed on the bird's back. I suspect if we had a bird in hand, we would find the feathers are actually symmetrically arranged, but as it moves and twists the feathers constantly shift.

When I got home and started reading about white-throated sparrows, I found a whole new area of interest.

It turns out this single species is comprised of two different color morphs. One of which has white stripes on its head - like this bird - and one of which has tan stripes. The fourth photo on Birdweb shows an example of a darker, tan-striped bird.

My first thought after reading about the two morphs, was to assume that each type was in the process of evolving into its own species.

As I continued to read, I soon discovered an even more surprising situation.

The research summarized in the Birds of North America (please see the citation below) explains that the two different morphs almost always breed with birds of the other morph. White-striped males are apparently visually attracted to the tan-striped females. While the females of both morphs seem to prefer the tan-striped males. This may be because the tan-striped males are more invested as parents. 

Oddly, since the genetics are nearly constantly and evenly mixed, the young birds from either mix of parents tend to be about one half tan-striped and one half white-striped. Apparently, this ongoing mix of color morphs may continue indefinitely without either morph becoming a new or separate species. I have never heard of anything like this before.

This strangely balanced situation reinforces my awe at the bewildering array of behaviors and species in nature. I personally believe that this is the result of millions of years of evolution. On the other hand, if you believe this is the handiwork of an all-powerful creator, it should change very little about our respective views of nature. In either situation, the diversity of wild creatures around us should be considered an incredible treasure to be protected and conserved. 

Larry


Recommended Citation

Falls, J. B. and J. G. Kopachena. (2010). White-throated Sparrow (Zonotrichia albicollis), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/whtspa









Saturday, November 12, 2016

A Birding Challenge

I do the majority of my birding around Union Bay. Birding locally keeps me in touch with the wildlife in my neighborhood while minimizing both my travel time and my contribution to global warming.

This week's post is an exception to the rule. Near the end of April, my wife and I went on a very special family trip. We stayed in a well known U.S. city. Your challenge is to guess the city. You can use the bird photos and my comments in this post as hints. For example, the city where we stayed has a population of less than two hundred thousand people.

The angel-like bird in the previous photo is a Least TernMy impression was that the tern was searching the water for food. When our guide, Preston, stopped to cool off for a moment, I thought the tern came even closer. Maybe the small bird was hoping to catch a creature startled by Preston's water adventure.

I am including links to All About Birds for each bird species. The Cornell birding guide contains range maps for the birds which may help you focus-in on the correct part of our country. Once in a while a bird may disregard its 'normal' range. I have attempted to mention this each time it has happened.

This Laughing Gull was more successful than the tern in securing food. I am surprised that everything about the gull's coloring indicates it is prepared for breeding season - except its bill which has not yet turned red. My best guess is this might be a younger bird and its bill would be the last visible portion of its body to achieve a mature breeding color.

 On the other hand, this American Oystercatcher certainly had a bright colorful bill.

The Piping Plover had colorful bills as well, but their smaller size made their tiny little beaks a bit less obvious. Sadly, All About Birds says all populations of this bird are consider threatened or endangered. It might be wishful thinking, but hopefully since we spotted these birds outside their normal breeding range we might be observing a slight expansion in their territory and maybe a first step toward recovery. A more pessimistic possibility would be that they are wandering far and wide searching for food and a safe place to breed.

Speaking of wandering, this Ruddy Turnstone was about halfway between a possible wintering location in Brazil and its breeding site in the Arctic. No wonder it looked tired. Coastal locations (and inland waterways like Union Bay) are critical migration stops for a wide variety of birds. The 'development' of wetlands and coastal areas should always be very carefully considered.

Just like the gull we saw earlier, this Willet also found a small crab. I do not know the crabs in this area but I am guessing that the light coloring of the crab may indicate a Fiddler Crab or possibly even a Blue CrabNote: I just noticed that the Willet was still in a wintering location.

The Willet struggled to find the correct angle to consume the crab. Part of the problem might be related to Willets having sensitive tips on their bills. This helps them to feel around under the sand and find food which they cannot see. This adaptation enables them to feed in the dark of night which doubles their food finding time. Given their special feeding skills, one would expect that Willets will survive global warming, however their weakness may be that they build their nests at ground level.


Before leaving the mystery city I also visited a nearby Wildlife Refuge a few miles to the north. One of the first birds I saw was this Great Blue Heron - our Seattle city bird. I doubt this particular bird had ever been to Seattle.

The Osprey is another familiar species for those of us who have been spending time watching Lacey and Chester around Union Bay.

The Black-bellied Whistling Duck was a complete surprise for me.

I found the posturing of the Boat-Tailed Grackle a clear indicator that spring was in the air.

Great Egret reminded me of The Egret which visited Portage Bay earlier in the year. If you look closely you can see a hint of the green colored lore between the eye and the beak. This coloring only develops during breeding season.

 I had to spend sometime with my bird guide to identify this Glossy Ibis, especially...

 ...given the somewhat similar shape of the Wood Stork.


When I spotted this unknown dragonfly I immediately thought of Dennis Paulson. Given the location, I suspect Dennis' book Dragonflies and Damselflies of the West would be unlikely to contain this species.

The Black-necked Stilt did not seem to mind the freshwater at the Wildlife Refuge.

Can you see any obvious differences between these Snowy Egrets and the Great Egret? In addition to their bill colors, their lores are also different. I must admit I find the striking colors of the Snowy Egrets very attractive.

The crisp delineation of black versus white in the Gull-billed Tern is also quite striking. Breeding season in a warm climate certainly provides some beautiful birds.

The Sora strolling along the shoreline was a quickly passing surprise. According to its range map, it should have been much further north by this point in the breeding season.

 The female Red-winged Blackbird tried to help me feel at home...

...however the signs which said 'Do Not Disturb The Alligators' - not to mention their actual physical presence - did add a certain level of unease and excitement to the birding adventure.

The beautiful coloring of a nest building Green Heron provided a familiar sight and had a soothing effect.

Cattle Egrets are a reminder of nature's amazing achievements. In our Master Birder Class I believe Dennis mentioned that the Cattle Egrets appear to have made their way from Africa to South America - all on their own. I wonder if they blew over in a strong wind, island-hopped or rode over on large ship. In any case, after arriving, the Cattle Egrets have certainly fanned out into all warm and available habitats.

The bird on the left is an Anhinga. The bird on the right is a young Cormorant. The head does seem unusually light compared to the young Double-crested Cormorants I have seen around Union Bay, but it does not look like any other species of cormorant to me.

In regards to this birding challenge I am positive that the correct answer will show up fairly quickly in the comments section below. I hope you have fun trying to figure out the location. One last hint - while the two birding sites were both relatively close to the city in question, the locations were in two different states.

Have a great day on Union Bay...where nature lives in the city!

Larry