Anna's Hummingbird - Calypte anna
A lot of migratory songbirds have returned to our area in the last few weeks. Some have traveled quite a distance from their winter habitat, to mate and raise their young here. I am always thrilled to see them return to our neighborhood!
It's mating time and many of the male birds are brilliantly colored and gorgeous! Studies have shown that most female birds prefer brightly colored mates! The bright colors of male birds are also indicators of the birds' health. Studies have shown that male bird color is lessened when they are in poor health. This would indicate to a female bird that the less colorful male wouldn't be a good choice for a mate. Birds rely on their coloration and feathers to communicate with others of their kind, especially during mating season. Color is also used in contests between males, over mates or territory. Conspicuous colors can help show that an area is already occupied, and the occupant is in good condition and prepared to fight!
It's mating time and many of the male birds are brilliantly colored and gorgeous! Studies have shown that most female birds prefer brightly colored mates! The bright colors of male birds are also indicators of the birds' health. Studies have shown that male bird color is lessened when they are in poor health. This would indicate to a female bird that the less colorful male wouldn't be a good choice for a mate. Birds rely on their coloration and feathers to communicate with others of their kind, especially during mating season. Color is also used in contests between males, over mates or territory. Conspicuous colors can help show that an area is already occupied, and the occupant is in good condition and prepared to fight!
Additionally, it's been recently discovered that birds can see more colors than we can. They can see all the colors we see, plus ultra-violet light! It turns out that some birds have special ultra-violet markings that we can't see, but birds can!! Even when it appears to us that both the male and female birds have the same coloring, the male might have ultra-violet markings that are visible to a potential mate!
Anna's Hummingbird - Calypte anna
Anna's Hummingbirds migrate up to our area from their winter
residence in the foothills, or from as far away as the Arizona desert.
What makes the different colors in bird feathers?
The following excerpts from https://www.audubon.org/news/what-makes-bird-feathers-so-colorfully-fabulous and https://academy.allaboutbirds.org/how-birds-make-colorful-feathers/ explain the source of the main colors in bird feathers.
"Structural Colors: Adding to the diversity of avian colors are colors produced by the structure of the feather. Instead of pigments, these colors are produced as light is refracted by the proteins in the feather. All hummingbirds have prism-like cells in their feathers of their neck, forehead, and back, which cause the metallic, iridescent sheen to their feathers. The iridescent colors are the result of the refraction of incident light caused by the microscopic structure of the feather barbules. The refraction works like a prism, splitting the light into rich, component colors. As the viewing angle changes, the refracted light becomes visible in a glowing, shimmering iridescent display. Many species of birds have feathers that exhibit iridescent colors."
Western Bluebird - Sialia mexicanus
Western Bluebirds spend the winter in the California foothills, across Arizona and New Mexico, or may even migrate down to Central America! A small number of them arrive in our neighborhood every spring to breed and raise their young.
"Not all structural colors are iridescent. Tiny air pockets in the barbs of feathers can scatter incoming light, resulting in a specific, non-iridescent color. Blue colors in feathers are almost always produced in this manner. Examples include the blue feathers of bluebirds, Indigo Buntings, Blue Jays and Steller’s Jays."
Cassin's Finch - Haemorhous cassinii
Cassin's Finches are not common in our area, but pass through here at this time of year. Some will breed at higher elevations in the western Sierra, but are more commonly found year-round in the Rockies and eastern Cascade Mountains.
"Pigmentation: Pigments are colored substances that can be found in both plants and animals. The coloration created by pigments is independent of the structure of the feather. Warm colors come straight out of the food birds eat. Carotenoids create most of the reds, oranges, and yellows in birds. There are more than 600 types of carotenoids, and they all require photosynthesis to make, so birds have to borrow them from plants and a few types of bacteria and fungi.
Birds cannot produce carotenoids on their own. For feathers with bright colors, birds must consume food items that contain these pigments, and the carotenoids circulate through the bloodstream and to the feather follicles. Birds' bodies do not have direct cellular control of synthesizing and depositing carotenoids; nor do they have control of the specialized feather structures, which react to the consumed carotenoids with a mechanism that is not regulated by specialized cells."
Red-breasted Sapsucker - Syraphicus ruber
Red-breasted Sapsuckers are found year-round on the west coast of Canada, Washington, and Oregon. Some are winter residents of California's coast and central valley, and come up to the western Sierra to breed.
Bullock's Oriole (male) - Icterus bullocki
Bullock's Orioles spend the winter in Guatemala. They migrate to California and the western U.S. to breed, a distance of approximately 3,000 miles!!!
Western Tanager (male)- Piranga ludoviciana
Western Tanagers spend the winter in Central America as far south as Costa Rica! In the spring, they migrate approximately 2,800 miles to their breeding grounds in western North America!
Yellow Warbler - Setophaga petechia
Yellow Warblers spend their winters in Central America, and even as far south as Columbia and Venezula in South America! In the spring they migrate approximately 3,500 miles to their breeding grounds across North America!!!
Yellow Warblers spend their winters in Central America, and even as far south as Columbia and Venezula in South America! In the spring they migrate approximately 3,500 miles to their breeding grounds across North America!!!
Brewer's Blackbird (male) - Euphagus cyanocephalus
Brewer's Blackbirds can be found year-round in the coast, foothills, and central valley of California. Others migrate down to Central America in the winter. In the spring, some of them migrate up to our area to breed, while most travel to central Canada to breed.
"Blacks and browns come from the same pigment that's in human skin. If you love the dark black of a crow or the brown stripes of an owl, you can thank a molecule called melanin: The same substance that provides color to our own skin and hair is also responsible for the darker colors on birds. Melanins are synthesized in the birds' bodies in special cells called "melanocytes," which work together with feather follicles to achieve a fine control of pigmentation. These colors are especially prevalent on birds’ flight feathers—for good reason. Melanin is very strong, and allows the hardest-working feathers to better resist wear and tear. That not only allows the bird to remain in tip-top shape, but according to a decades-old experiment, also allows it to be 4 to 9 percent more aerodynamic."
Olive-sided Flycatcher - Contopus cooperi
The Olive-sided Flycatcher travels approximately 5,000 miles one-way to reach our neighborhood, from its winter residence in Panama or the Andes Mountains in South America!!! Some will nest here, while others will travel farther north up into Alaska and Canada to breed!
Scorpion - Paruroctonus spp.
Like the Water Mite featured last week, scorpions are in the Arachnida Class, and have eight legs. They can inflict a nasty but not usually fatal sting. I found this one in our house! First one ever! Yikkes! Wikipedia states, "Scorpions are opportunistic predators of small arthropods, although the larger kinds have been known to kill small lizards and snakes. The large pincers are studded with highly sensitive tactile hair, and the moment an insect touches these, they use their chelae (pincers) to catch the prey. Depending on the toxicity of their venom and size of their claws, they will then either crush the prey or inject it with neurotoxic venom. This will kill or paralyze the prey so the scorpion can eat it." I caught this one in a jar and set it free outside. Hope it stays out there!
Like the Water Mite featured last week, scorpions are in the Arachnida Class, and have eight legs. They can inflict a nasty but not usually fatal sting. I found this one in our house! First one ever! Yikkes! Wikipedia states, "Scorpions are opportunistic predators of small arthropods, although the larger kinds have been known to kill small lizards and snakes. The large pincers are studded with highly sensitive tactile hair, and the moment an insect touches these, they use their chelae (pincers) to catch the prey. Depending on the toxicity of their venom and size of their claws, they will then either crush the prey or inject it with neurotoxic venom. This will kill or paralyze the prey so the scorpion can eat it." I caught this one in a jar and set it free outside. Hope it stays out there!
What's blooming?
What's happening in the Lakes Basin?
Are birds starting to make nests?
Where are the Bears?
Check back next week for the answers to these questions and more!
During these days of Covid-19 and uncertainty, I hope you are all healthy and coping with this unusual stress. Get out in nature while you have the time! It can be so healing!
Unfortunately you can no longer sign up to get my blog emailed to you.
Something changed at Blogspot.com. Oh well...
Your questions and comments are greatly appreciated!
Please email me at northyubanaturalist@gmail.com
No comments:
Post a Comment