Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
Today’s photos come from physicist and origami master Robert Lang, taken from his home office in California. Robert’s captions and ID’s are indented, and you can click on the photos to enlarge them.
These birds are a good demonstration of a biological “rule”, which has some exceptions: if one sex in a species is more colorful, decorated, or prone to display or call than the other sex, or to fight with other members of the sex for reproductive access to the other sex the pugnacious or elaborate sex is male. That is, of course the result of sexual selection. (As I said, there are some exceptions, like seahorses and pipefish, but given their reproductive system [look it up], they’re really exceptions that prove the rule.)
Bird Sexual Dimorphism
These photos were taken from my office desk looking out the window to the back garden, which has a small fountain. It attracts a lot of birds (as well as the occasional bobcat, coyote, and bear). In this batch, I’ll show some birds which differ markedly in coloration between the male and female of the species.
The female has a lot more yellow on her; here you see them together:
Next, the Nuttall’s Woodpecker (Dryobates nuttallii). First, the female (all-black head):
And then the male, with a red patch on the head:
Next, a Black-headed Grosbeak (Pheucticus melanocephalus). Lots of orange on the male:
But a much more subdued female:
Then, one of my favorite visiting birds: the Hooded Oriole (Icterus cucullatus). Its brilliant yellow makes me think of something tropical, rather than the near-desert of Southern California:
And, once again, the female has more subdued coloration:
I’ll close with two visiting couples: House Finches (Haemorhous mexicanus) and Hooded Orioles, both male and female of each on the fountain:
I couldn’t resist putting up a short video of Robert’s origami work. Remember, each figure is made from a single sheet of paper. And check out his folded American flag on his Wikipedia page!
It’s Sunday, and that means a spate of themed bird photos from John Avise. It’s also a special day, for it’s the 150th straight weekly contribution from John. I can’t believe it’s been three years! Anyway, plaudits to Dr. Avise for his contribution and swell photos: he tells me he has plenty more. John’s narrative and captions are indented, and you can enlarge the photos by clicking on them.
Egret Plumes
During the breeding season, egrets (in the family Ardeidae) grow special plume feathers that cascade down from the back, breast, head, and neck. In the late 19th and early 20th centuries, hunters killed egrets by the thousands to supply these plume feathers for fashionable women’s hats. So serious was this depredation that some Egret species were driven to the brink of extinction.
But, thankfully, both protective legislation (notably the 1918 migratory Bird Act Treaty) and changing fashions rescued these special birds just before it was too late. Today, the happy result is that these spectacular creatures remain quite common for us to marvel at. This week’s post shows the full breeding plumages of two egret species that had been especially sought-after by the old millinery industry: the Snowy Egret (Egretta thula) and the Great Egret (Ardea alba). I took all of these photographs here in Southern California.
Today’s selection of photos comes from reader Kevin Krebs. His notes an IDs are indented, and click on the photos to enlarge them. At the bottom Kevin asks readers to consider donating to the wildlife organization for which he volunteers.
Here is a selection of bird photos I’ve taken during the last few months in and around Vancouver, BC.
Northern Saw-whet Owl (Aegolius acadicus) — These tiny owls (with the larger females generally no more than 8” in length) are also one of the most common owls in North America. Despite this, there are still many gaps in our knowledge about them as they are secretive, nocturnal, and have irregular movement patterns.
American Dipper (Cinclus mexicanus) — A unique and charming bird found in Western North America down through Central America. While they may appear drab, they are remarkable as North America’s only aquatic passerine. They dive and bob around in rushing streams, even in the cold of winter. Photos don’t really do them justice, and I recommend watching this short video to see one in action. As you might guess, they have many adaptations for their specialized lifestyle.
JAC: Do watch the video. The bird is amazing!
American Dipper (Cinclus mexicanus) — The same bird poised to dive into the pond.
Spotted Towhee (Pipilo maculatus) — A common but eye-catching bird of the West, Spotted Towhees are almost always found in dense brush, noisily kicking away at leaf litter to reveal insects and invertebrates that make up a large part of their diet.
Cackling Goose (Branta hutchinsii) — At first glance, it’s easy to quickly misidentify these birds as Canada Geese (Branta canadensis). In fact, they were considered conspecific with their larger cousins until 2004 when they were split into their own species. As soon as you spot one of these geese next to their larger cousins, the size difference is obvious.
Canvasback (Aythya valisineria) — Sometimes referred to as the ‘aristocrat of ducks’ due to the male’s sophisticated-looking plumage, Canvasbacks are the largest North American diving duck. I was lucky to get a photo of this male who made a surprise appearance at a local park.
Cooper’s Hawk (Accipiter cooperii) — Cooper’s Hawks are crow-sized hawks that can be found across North America. They commonly breed in suburban and even urban landscapes and specialize in hunting smaller birds and mammals. They are especially adept at high-speed flight through wooded areas in pursuit of their prey.
Merlin (Falco columbarius) — Merlins are small (9”-12″ body length) and fierce falcons found throughout the forests and prairies of the Northern hemisphere. Powerful and fast, they hunt small to medium-sized birds which they often catch in flight.
Bald Eagle (Haliaeetus leucocephalus) — Common until the 1800s, being hunted for bounties until the 1950s and the destructive effects of DDT combined to make Bald Eagles a rarity by the mid-to-late 1900s. Bald Eagle numbers have been steadily increasing since the 1980s, making them one of North America’s conservation success stories. Something that always surprises people about these birds is that they don’t sound at all like their media portrayal. Bald Eagles are splotchy brown until they’re 4 to 5 years old. If you see a bird with a white head and tail like this one, you know it’s been around a while.
Black Oystercatcher (Haematopus bachmani) — An eye-catching bird of the West coast, often found in rocky intertidal zones. Like so many birds, their common name is a misnomer, as Black Oystercatchers rarely catch and eat oysters. Their main diet comprises marine invertebrates, generally bivalves and other mollusks, which their bill is adapted to pry open.
Great Blue Heron (Ardea herodias) — A familiar but also remarkably adaptable wading bird found through North and Central America. Great Blue Herons are formidable predators who take a variety of prey. Small fish and amphibians are their common diet, but they will eat any small animal that comes within striking range, including snakes, rodents, and even other birds. While their numbers seem to have remained stable, development of wetlands and areas near their large and raucous nesting colonies are potentially damaging for local subspecies.
Steller’s Jay (Cyanocitta stelleri) — A beautiful, curious, and vocal jay found in Western forests. Like many corvids, Stellar’s Jays readily habituate to (and take advantage of) human presence. Despite being common and relatively tame, there are still many questions about their demographics and breeding biology that remain unanswered. This bird belongs to the Coastal subspecies (Cyanocitta stelleri stellari) distinguished by an overall darker colours and the light blue stripes on its ‘forehead’.
Douglas Squirrel (Tamiasciurus douglasii) — While photographing birds, I sometimes meet other animals, so for the final photo, here’s a Douglas Squirrel, a native squirrel of the Pacific Northwest. Significantly smaller than the introduced Eastern Gray Squirrel, they are found in coniferous forests, as their diet mainly consists of fir, spruce, and pine seeds. This individual in a local park is extremely habituated to humans due to being fed, running right up to people’s feet to beg. While undeniably cute, feeding animals results in many potential harms to both wildlife and humans.
Kevin also asks readers to consider donating to the Vancouver Avian Research Centre:
As an aside: I volunteer with the Vancouver Avian Research Centre (https://birdvancouver.com) and we are currently having a fundraiser to help keep our station outfitted and running smoothly. I thought it couldn’t hurt to ask, as I believe strongly in the organization and our mission to protect birds.
Today we have some photos from Matthew Ware showing some lovely antelopes. Matthew’s captions are indented, and you can enlarge his photos by clicking on them.
These photos are from South Africa, either near Port Elizabeth or in the Kruger National Park area.
Resting Hartebeest (Alcelaphus buselaphus). I was told that it was called this because of the ‘Heart’ shape that the horns make. However, Wikipedia suggests that it is from the Dutch hertebeest, literally deer beast, due to its similarity to a European deer.
Hartebeest in profile.
Gemsbok or South African Oryx (Oryx gazella) in long grass. They are extremely adaptable and can survive extremely arid conditions. In various subspecies, the Oryx, is native all over Africa and the Arabian peninsula.
Gemsbok front on.
Adult Greater Kudu (Tragelaphus strepsiceros). They seem quite curious and not overly wary of humans – maybe that’s why they are a staple item on Game Park menus!
Greater Kudus, probably juveniles.
A pair of Waterbuck (Kobus ellipsiprymnus) Very distinguishable from behind as they have large white circles on their rumps.
Common Eland (Taurotragus oryx) This is the second largest antelope found in Africa after the Giant Eland.
Blue Wildebeest (Connochaetes taurinus). This is the Wildebeest seen in the annual ‘Great Migration’.
Blue Wildebeest close up.
Black Wildebeest (Connochaetes gnou) This is distinguished from the Blue by the upturned horns and the white tail. They are not as nomadic as the Blues.
Dear readers, we are in serious trouble, for the photo tank is nearly dry. If you have good wildlife pics (or landscape or travel photos), send them in—pronto. Thanks!
Today’s batch comes from UC Davis ecologist Susan Harrison. Her notes and IDs are indented, and you can enlarge the photos by clicking on them.
Fall Harvest
This fall, unusual numbers of Lewis’s Woodpeckers (Melanerpes lewis) descended upon some of our riparian oak woodlands around Davis, California. These spectacular birds live in loose social groups that shift locations over time. They catch flying insects rather than drilling for grubs like other woodpeckers, and in fall they also harvest and cache acorns. In early October they were busy at both activities.
Acorn gathering puts them in competition with the much commoner Acorn Woodpecker (Melanerpes formicivorus), which form close-knit colonies of related individuals that raise their young communally, and which create “granary trees” studded with thousands of stored acorns. In early October when the Valley Oak (Quercus lobata) acorns ripened, there was much chattering and chasing between the two woodpecker species.
By mid-November the hubbub seemed to have calmed, and the Lewis’s Woodpeckers already appeared to be eating cached acorns. I’ll be curious to see how the two species interact as winter progresses. Will there be cache robbing?
Lewis’s Woodpecker with a partly eaten acorn:
California Scrub-Jays (Aphelocoma californica) gather acorns and cache them in the ground, where sometimes the acorns turn into seedlings instead of bird food.
California Scrub-Jay with Oregon Oak (Quercus garryana) acorn:
This tiny Bushtit (Psaltriparus minimus) was in possession of a tiny acorn:
This Nuttall’s Woodpecker (Picoides nuttalli) was eating Poison Oak (Toxicodendron diversiloba) berries:
Overwintering birds have now arrived, including this White-Throated Sparrow (Zonotrichia albicollis), a species abundant in the eastern US but uncommon in California:
Neotropical migrants have left, except for a few late-lingering individuals like this Townsend’s Warbler (Setophaga townsendi):
Phainopeplas (Phainopepla nitens) are year-round residents of our oak-lined stream banks. They are found mainly in Mexico and Central and South America, and reach their northern range limit in our area:
White-Tailed Kites (Elanus leucurus) are another year-round resident that adds an exciting southern element to our local fauna:
Today’s photos come from Tony Eales in Queensland. His narrative and IDs are indented, and you can enlarge the photos by clicking on them.
Lots of beautiful beetles around at the moment. I’ve been checking the flowers of native plants and under the lights of the train station to see what is around locally. Here’s a selection
The most interesting find was this small beetle. I found it crawling on my desk at work. I suspect I accidentally transported it there on my clothing. While it is just a small brown beetle, it turns out that this is the single species Acanthocnemus nigricans, in its own family Acanthocnemidae. It is a pyrophilous beetle that congregates in recently burned areas and even attracted to bonfires. It has twin heat sensing organs beneath its pronotum that it uses to find fires. Originally a solely Australian species it has now spread to Europe, Africa, India and Southeast Asia. There was a small bushfire right near my house recently and and I think that’s why it ended up on my clothes and transported to my office. This shows the use of always carrying collection vials.
I’ve also come across a couple of longicorn beetles. One from the large robust Subfamily Prioninae. This one is a female Cacodacnus planicollis. The males have large mandibles for fighting each other, however even the smaller female jaws are not something I’d like to get my finger to close to.
The other longicorn was a member of the Subfamily Cerambycinae or typical longicorns. This is Coptocercus multitrichus, a pretty, medium-sized beetle associated with Eucalyptus forests.
The main reason I have been searching flowering trees and shrubs is to find jewel beetles. So far, I haven’t had a great deal of luck but I have found two species, neither feeding on flowers.
The other jewel I found was a new one for me, Hypocisseis suturalis. I found it on a Red Ash (Alphitonia excelsa) leaf, but it looked so much like a bird or gecko dropping I had to touch it to make sure it was an insect. I am used to another species of Hypocisseis that I regularly find on Red Ash so it was a bit of a surprise to find this new species on the same host plant.
Speaking of Red Ash, every year at this time I find Red Ash trees half stripped of their leaves and covered in feeding and mating small scarabs of the genus Diphucephala. This one is a male with enlarged extensions at the front of the head for male-male battles.
One beetle species I have been finding on flowers is this member of the Comb-clawed Darkling Beetle subfamily Alleculinae. This one is Lepturidea viridis.
Also on the flowers I have found many of this gorgeous metallic-blue Flower Weevil (Subfamily Baridinae), Ipsichora desiderabilis:
Of course weevils, as the most specious family of beetles, are everywhere. This one is Myllorhinus strenuus, a member of the True Weevils subfamily Curculioninae:
And this is a member of Subfamily Apioninae, the Pear-shaped Weevils, Rhynolaccus formicarius.
Today we have photos from regular Mark Sturtevant. His notes and IDs are indented, and you can enlarge the photos by clicking on them. I’ll remind readers to send in your good photos, as we’re running low.
Mark:
Here are some pictures of mainly arthropods, taken in 2021 as the weather began to finally warm near my habitat in eastern Michigan.
An early opportunity was a European paper wasp (Polistes dominula) that emerged from hibernation on the front porch. It was still quite cold, so she was motionless most of the time. After a long winter, I was glad to see her even though the species is invasive and problematic in the U.S. because it has reduced populations of the native paper wasps. These pictures are focus stacked from about 100 pictures each, taken with the assistance of a Helicon Fb tube. That is a device that lets you do rapid focus bracketing with a DSLR camera.
Next is a ground spider (Gnaphosidae), a family of free roaming spiders that include some ant mimics. This is Zelotes fratris. This too is focus stacked, but from a few pictures taken by hand. Note the red velvet mite photo bomb.
Here is a very young green frog (Lithobates clamitans), only recently transformed from a tadpole. Often mistaken for the closely related bullfrog, green frogs can be identified by the dorso-lateral ridge that you can see here. This youngster may one day grow to be the size of both of your fists put together.
The big event for the early part of the 2021 season was a possibly once-in-a-lifetime chance to photograph 17-year cicadas,Magicicada septendecim. Cicadas spend most of their lives as nymphs living underground, where they feed on sap from tree roots. “Periodical” cicadas include a 13-year species and the 17-year species. After those many years, the nymphs emerge en masse in biblical plague numbers, mate, lay eggs, and die over a period of several weeks. It is believed their reproduction cycle evolved to overwhelm predators who cannot grow their population in response. The 2021 season was due to have “Brood X” of the 17-year cicadas, which is the largest population of this species. Brood X extends over multiple states in the US, and one edge of this group extends into southern Michigan. So, with the help of the internet, which provided records about their last emergence, I made the long drive to a likely park to see this marvel. The trip was well rewarded with high thousands of cicadas.
Here are various pictures showing perching cicadas, and a bush with quite a few of them. Cicadas were flying everywhere, and collisions with them were pretty frequent. Males are especially distinct with their bright red eyes.
The eerie sound of thousands of cicadas filled the air over the field. But it was evident that there were far more of them in the trees that surrounded the park, since the trees were fairly deafening with their shrill, spooky music. Accounts from other areas of the Brood X emergence described even heavier population densities, where pretty much everything gets covered by them.
It’s the males who sing, and they do so by forcing air past a stack of vibrating membranes under a pair of “tymbal” plates on the abdomen. This picture showing the plates is blurry because the male was continually squalling in protest.
Here is a wide angle macro picture of a cicada posing with my good friend Gary Miller. Gary is an excellent macro photographer in his own right. It was not even summer, and this is one of my favorite pictures of the entire season.
I wanted to find a video that conveys what this natural wonder is like. This amateur recording is a very good match to what the emergence was like in this field, right down to the screaming trees in the distance:
Readers in the eastern U.S. may have direct experience with seeing a periodical cicada mass emergence, and if you’d like to make plans for seeing one, here is a map that can get people started.
It’s the Lord’s day, but also John Avise‘s day, for on Sunday we get a themed collections of bird photos from John. His narrative and captions are below, and you can click on the photos to enlarge them.
Don’t forget to send in your photos—we’re running low! Thanks.
Turkey Day:
I hope all WEIT readers are having a very happy Thanksgiving weekend. In slightly belated honor of Turkey Day, today’s theme is native birds with the word “turkey” in the common name. In North America, there are two such species: the Wild Turkey (Meleagris gallopavo), from which domestic turkeys are descended; and the unrelated Turkey Vulture (Cathartes aura). The Turkey Vulture probably got its name from its featherless head, like that of a Wild Turkey gobbler. Wild Turkeys can be found across most of the United States and Mexico, whereas Turkey Vultures range throughout the Americas. I won’t include photos of domestic turkeys, because most of you already know what they look and taste like.
Wild Turkey hen:
Wild Turkey adult male (gobbler or tom):
Wild Turkey young male:
Wild Turkey adults with juvenile (chick or poult):
Today’s photos come from reader Paul Edelman. Paul’s notes and IDs are indented, and you can enlarge his photos by clicking on them. I’ve put the links to birds on the Cornell site in the introduction.
My daughter and son-in-law gave me a present–the Bird Buddy www.mybirdbuddy.com The gadget is a bird feeder with a built-in camera that connects to the web. It will take pictures of the birds that come to the feeder and send them to your phone. It also attempts to identify them for you. The app is a bit kludgy and the AI-recognition is not very good (I think they are counting on the users to train it further, which is some of what makes the app itself annoying) but the pictures are really fun and give an unusual view of the birds. Here are the ones that have come to visit:
The Carolina Chickadee (Parus carolinensis) and the Tufted Titmouse (Parus bicolor) are the most common visitors. They are both very bold and will eat even when we are puttering around the deck. The next most common is the House Finch (Carpodacus mexicanus). We have tons of these, but they seem more interested in the tube-feeders than the Bird Buddy. Occasionally we will see a Northern Cardinal (Cardinalis cardinalis) climb up to it as well.
Less often we have seen the bigger birds: Blue Jay (Cyanocitta cristata), Northern Mockingbird (Mimus polyglottos), and European Starling (Sturnus vulgaris). They do not sit so comfortably which is fortunate because they eat too much and scare the smaller birds.
I also attach a picture of our newest visitor, the Red-breasted Nuthatch (Sitta canadensis). These appear rarely in our area and only when their food sources in the Smokey Mountains fall short. He has yet to visit the Bird Buddy but is a regular diner at our tube-feeders. I am hoping that their irruption signals that other unlikely birds, say Pine Siskins and the like, might also make an appearance.
We’re running low on photos, folks, so if you have some good ones, you know what to do. .
Today’s batch comes from Brian Cox, an instructor at Assinboine Community College in Manitoba (see his earlier photos here). Brian’s notes and IDs are indented, and you can enlarge the photos by clicking on them.
A crayfish claw jammed between dock boards in Kenora, Ontario, Canada. I don’t know the species of crayfish, but here are some possibilities.
Stilt sandpiper (Calidris himantopus) in my hometown of Brandon, Manitoba.
A neighbour threw his Christmas tree on a bonfire. I was able to capture the vibrant colours, but I can only guess at the tree species. Is it a white or black spruce? Perhaps a jack pine?
Capturing a red-tailed hawk (Buteo jamaicensis) in flight with a manual-focus zoom lens can sometimes come down to luck. My city is surrounded by farmer’s fields, prime hunting grounds from these hawks.
This red-tailed hawk was happily stripping pieces off a Northern pocket gopher (Thomomys talpoides) until I got too close. The image is a little out of focus…
And this gopher completely objects to the hawk’s lunch preferences.
I startled this North American porcupine (Erethizon dorsatum), but waited for it to find the right safety-tree to climb up. I think it gave me a little smile.
