It’s that time of the year again, when the bugs and the deer discover all the tasty plants in my garden. While the Japanese beetles ravage the leaves of the apple trees and raspberries, the deer fawns chow down on the wildflowers. I don’t mind them, though, they are pretty cute, and very shy.
The usual suspects have returned to the back yard this summer, but one of my favorites is still missing, the pretty little red foxes. So, here’s a glimpse of their visit to the backyard last year.
June 30, 2017: What a delight to see my favorite canids lounging in my Minnesota backyard this morning.
In addition to brief, one minute naps, there was quite a lot of scratching and grooming going on.
And when they stopped digging at their own fleas or whatever was itchy, they groomed each other.
I watched these two foxes for several minutes, but can’t figure out if they are a male-female pair, or two youngsters, or what. Male foxes are usually noticeably bigger then females, and these two seem to be identical in size. They do seem a bit small and skinny, so maybe they are younger, but this year’s kits would not be this big yet, having been born in late March, and just out of their den in early May. It’s a mystery.
Shot through the not very clean porch window at 500 mm —
This is a tale of “if at first you don’t succeed”, keep trying. Mr. and Mrs. Robin decided to build a nest above a light fixture on our garage.
It’s a very unstable platform, and every stick added seemed to fall between the lights to the ground.
But gradually, after a few sticks held in place, and with the addition of some critical flexible, long leafy material, a platform began to take shape, and the nest cup was added on top.
I hope it’s strong enough to hold the weight of several growing chicks.
It’s nice to see familiar wildlife in the backyard. These were my first (vertebrate) visitors since returning from May travels.
now if only the fox family would come to visit…
My neighbor called to tell me there was a big snapping turtle on his patio, so I went over to make friends. It was indeed a big one, maybe a female looking for a soft garden spot to lay some eggs. I decided to get down on turtle level to take some photos.
They are called snapping turtles for a good reason. Those toothless jaws can produce a powerful pinch, strong enough to tear flesh. And if they can’t nail you with a vicious bite, snappers will put a nasty gouge in your skin with those long, sharp toenails. Beware of picking one of these up!
Once the turtle got tired of watching me, it moved off the patio toward the garden, raising itself up on its toes to step over a hose. How does a beast whose eyes are at the top of its head know where it’s feet are in relation to an obstacle on the ground? Obviously, snapping turtles have a wider visual field than you might think.
A continuation of the discussion in the last post of why black accent or coloration is so widespread, especially in small birds…there are still more questions to answer.
For example, you would think that a boldly striped, black and white animal would be an easy target to spot against the homogeneous green or gold African savanna.
Disruptive patterns of black and white break up the outline of an animal’s body, making it difficult to detect them in a complex background. Maybe this is why a herd of zebra can be referred to as a “dazzle”?
Looking at a single chickadee against a plain white or tan or gray background makes them standout because of their bold black and white markings.
But finding them in their more typical, complex background of myriad tree branchlets and leaves is much more difficult.
Birds that live in complex environments like the dappled shade of a forest, or the complex vegetation of a wetland or grassland, often have complex feather patterns (especially dark and light) that more or less blend with their background, or at the least, make them difficult to detect until they move. Some of the boldest black and white patterns, like the stripes on a Kildeer’s breast, actually distract one’s eye from the outline of the bird’s body.
Some birds emphasize camouflage even more by combining spots of white or bands of dark and light on their feathers.
So, one of the answers to why so many birds, especially those residents that live in the northern temperate forests all year, adopt splotchy patterns of black or brown and white plumage is that they maximize their ability to hide in plain sight by being boldly invisible.
Adding to the white, gray, and brown monotone colors of the winter landscape now, the resident birds also seem to be mostly shades of black, white, and gray or tan. In fact, many of them use black as a primary “color” of their plumage. Is black somehow advantageous to birds in the winter?
I usually feel warmer with a dark colored sweater or jacket on a cold day, and we know that black absorbs and holds radiant heat energy much better than other colors. So, do birds utilize their dark brown/black feathers to stay warm?
Some birds, like Turkey Vultures, Anhingas, Cormorants, and Roadrunners, do use their dark plumage to advantage to warm up on cold mornings, basking with their dark feathers spread widely apart so heat can reach the skin below.
However, wind ruffling the feathers of a crow reveals a flaw in the idea that their black feathers are used to keep them warm. Their feathers are only black right at their tips, and are white-gray underneath; in fact their skin is pale as well.
This seems more like an adaptation to avoid overheating in summer sun, than conserving heat in winter cold. In summer heat, black feather surfaces would heat rapidly, becoming warmer than the surrounding air, and would enable the bird to actually unload heat produced internally, reflected through the whitish underlayer of feathers to their outer surface. This helps explain how large-bodied, dark-feathered Ravens can survive in hot, arid environments as well.
Assistance in regulation of body temperature might be one explanation for why so many birds have black feathers or black-tipped feathers, but there are a host of other possible explanations, as well. One likely possibility is that the melanin pigment that colors the feather dark brown to black (depending on its concentration) binds to the keratin protein in the feathers and strengthens them and helps them resist wear.
During feather development, granules of melanin are deposited in the helical strands of keratin protein that make up the filaments that are in turn packaged into the barbs and barbules that make up the feather. Melanin-enriched keratin has been demonstrated to make feathers stiffer, more durable, and resistant to abrasion. The outer (primary) flight feathers are the propellers in the generation of powered flight, making it essential for them to be stiffer and wear-resistant.
But what are the benefits of black plumage patterns in all the other birds we see in the winter landscape? Is black important for thermoregulation, resistance to wear, cryptic camouflage, something else…?
Your thoughts? What about all those other mostly black birds: Red-winged Blackbirds, Pileated Woodpeckers, Puffins, Anis, Petrels, Auks, Grackles and Cowbirds, Coots, Moorhens, Frigatebirds, Starlings, and more. Why black?
“Spike and the boys” — it’s not a new band, but a herd of White-tailed deer bucks that roam the backyard and beyond. There are three mature (big) bucks and three first-year bucks with tiny antler spikes protruding from their foreheads — hence “spikes”. They are browsing for anything edible in the backyard on this cold, snowy day.
Males lose 20-30 % of their body weight during the fall rut, as they follow the does around waiting for their opportunities to mate with them. That allows little time to eat, and consequently, they may enter the winter period of low food availability with less fat than they will eventually need to survive. Their winter browse on evergreens, leaves, and shrubs may not sustain them completely either, and they may continue to lose weight throughout the winter, despite trying to reduce their metabolism by being less active and lowering their body temperature and heart rate: lessons that the “spikes” will need to learn quickly.
The proximate (immediate) answer to the question of why cardinals are red is that they have a diet rich in carotenoid pigments (e.g., the pigment that makes carrots orange), and will incorporate those pigments into their feathers as they develop each year during feather molt. To read more about this process, click here to read an article from Bird Watching Daily that explains where feather colors come from.
But I’m interested in the evolutionary basis for why cardinals stand out among other species residing year-round in northern climates in retaining their bright red coloration instead of molting to more muted shades during the non-breeding season, like, for example American Goldfinches do. Cardinals undergo a post-breeding feather molt, just like other species, so why risk attracting predators with bright red, when you might escape notice with a dull brown plumage instead?
Does sexual selection (that is, female choice for the most beautiful male, as Richard Prum argues) play a role? Please see the yesterday’s Back Yard Biology post for more information about the importance of beauty in female choice.)
Some additional facts regarding male-female relationships in Cardinals and their close relatives, the Pyrrhuloxias of the southwestern U.S., might help to answer the question.
The first thing you notice from the illustration above is that the Pyrrhuloxia male and female look more alike than Northern Cardinal male and his mate do. Why might that difference have arisen in such closely related species? And does it have anything to do with female choice for brightly colored, beautiful males?
The second and interesting difference between the two species is that Pyrrhuloxia share a pair bond only during the breeding season, breaking up in the non-breeding season into loose, often mixed-species flocks of seed-eating birds that move around to find food in their dry, desert habitat. Each year, males vie for available females by staking out and advertising their territories, often very aggressively. In contrast, Northern Cardinals may maintain their pair bond year-round, often for multiple years, unless one of the pair dies, and the pair stays in the same general area in which they nested, year-round.
Female Cardinals are making a choice of more than just a breeding partner; they may be choosing a life partner and his residence (territory). Richard Prum might argue: what’s a male to do, but be the most beautiful thing she has ever seen? And if he is better looking than his neighbors, she stays with him through that year and the next. They raise multiple broods of young Cardinals together, and he passes on his good looks to the next generations.
This is an amazing high definition video of male and female Cardinals feeding their chicks (by FrontYardVideo).
In other words, it’s possible that their long-term pair bond and high fidelity to a territory year-round makes it possible for choosy female Cardinals to drive the accentuation of beauty (in this case, “redness”) in their male partners, to the extreme that male Cardinals never lose their red color during the year.
Morning coffee in hand, I ventured out to a somewhat chilly “sunroom” porch this morning and found a red fox sleeping nearby.
So I sat, camera in hand, and waited for the fox to wake up — for an hour and a half. It was a long nap, perhaps needed after a long night of hunting mice, or the like. It got boring watching the fox nap, so I opened the window for a close-up, clearer telephoto shot.