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.
If you have good photos or videos with a wildlive/biology theme, send them in.
Today we have a short but lovely video from reader Mark in Australia. His notes are these:
The birds in the video are Little Corellas (Cacatua sanguinea), an Australian cockatoo, filmed at Winchelsea, in the state of Victoria. My drone was hovering when the flock came from nearby to inspect the strange object in their airspace.
When my daughter was quite young I asked her if she had noticed the large flock of corellas that had moved into the area. She asked “Are they the birds that sound like ghosts?” I had to say yes. Their call is not harsh like a sulphur-crested cockatoo, but high pitched and sort of spooky.
If you want to hear their spooky calls, go to this video.
Today is the third and last set of photos sent last week, so I am of course in need of more. Send ’em if you got ’em!
The photos today come from reader Jan Malik. Jan’s IDs and notes are indented, and you can enlarge his photo by clicking on them.
In August I had to go to one of Mexico’s southern states for work (the usual story of Americans taking the jobs of hard-working Mexicans). The 12-hour shifts left little time for photography, and only toward the end of my assignment did I manage to spend a full three hours in a small nature preserve. The preserve is maintained by a certain state-owned company with an effective monopoly on oil exploration and processing in Mexico. Soon after entering, I realized that the preserve might well have been a money-laundering enterprise, but nonetheless, I went ahead trying to find interesting arthropods.
The white peacock butterfly (Anartia jatrophae), with a damaged wing, which probably occurred during a not quite successful pupation or immediately after, when the wings are soft and pliable and can get entangled in the exuviae or vegetation:
A leaf-cutter ant from the genus Atta—as evidenced by the sharp spines growing from its thorax. This may be Atta mexicana:
They were busy stripping bare a nearby ficus tree, which from my observations is one of their preferred foods, with supple leaves and twigs that are easy to cut:
More precisely, ficus is not the ants’ food, but raw material for their underground gardens, where they farm and tend to a fungus growing on plant matter, then eat the special tissue produced by the fungus. The fungus (Leucoagaricus gongylophorus) has lost the ability to thrive on its own and depends entirely on the ants for survival. In fact, a leaf-cutter ant’s nest is a consortium of at least three symbiotic organisms—ants, fungus, and bacteria growing on the ants’ exoskeleton, which secrete antifungal compounds to protect the garden from parasitic infections:
These ants are vegetarians (and often dreaded agricultural pests), but occasionally they may collect other arthropods, like this unfortunate caterpillar, which is being carried to an underground nest to be used as fertilized for the fungus:
I first became interested in the small creatures that live unnoticed under our feet after reading, decades ago, a popular science book by Bert Hölldobler and Edward O. Wilson, “Journey to the Ants,” which I highly recommend. The same team also wrote “The Leafcutter Ants: Civilization by Instinct,” which is still on my reading list. Perhaps that book contains the clue to this picture – how two or more ants with such tiny brains can organize their work so they can carry items to their nest together:
Leaving the ants alone, I went deeper into a subtropical grove, where by accident I spotted a supremely camouflaged tree trunk spider (family Hersiliidae), possibly from the genus Neotama. It was perfectly flush with the tree trunk; in fact, after looking away from it for a moment, I had trouble spotting it again. Normally it would have two “tails,” actually elongated spinnerets, at the end of its abdomen, but one of them had broken off on this individual:
Trying to photograph the cryptic spider, I brushed against another tree nearby and something—I thought moss or dirt—broke off. But, seeing several insects milling about around that spot a moment later, it turned out to be an encased termite tunnel, a section of which I had just destroyed. By the look of these nasute soldiers, they are from the genus Nasutitermes (spinning the taxonomic roulette wheel, it may be Nasutitermes corniger). They are completely blind and the first to lay down their lives in defense of their nest, trying to squirt a sticky liquid from their nozzle-like heads to ensnare invaders:
The termite tunnel led to a large bulbous nest. Some birds, like trogons and parakeets, use these structures for nesting—they breach the relatively fragile walls constructed from chewed plant material, saliva, and feces, then let the insects do the hard work of sealing the broken internal runways, thus acquiring a climate-controlled, safe nesting place:
Looking closer, there were two termite castes that appeared at the breach in their fortified tunnel: nasute soldiers, the bodyguards of the colony, and workers, here visible with lighter-colored heads and functional mandibles, trying to mend the breach. They must do it quickly, or marauding ants will invade the nest. Usually, after a breach in the defenses is mended, some straggler soldiers are left outside to die:
There was no shortage of ants in that neighborhood, for a few trees away I saw some turtle ant workers (genus Cephalotes, but I don’t know the species). They acquired the moniker “turtle” because of the soldiers’ flat, armored heads, which they use to block the entrances to their tree nests. They seemed to proceed with their business more deliberately, not in the feverish hurry expected of ants:
Some of them appeared to be carrying their larvae or pupae in their mandibles. These arboreal ants can reportedly control their fall to land back on the tree trunk and safely stick the landing:
This is possibly the spotted red bug (Pachycoris klugii), but they are highly variable so I may be wrong:
This tiny (about 5 mm) larva is probably a species from the bagworm family (Psychidae), which if everything goes well pupates into a small moth. It was crawling slowly, turning its armored head around, searching for anything palatable. The protective case is made from its own silk and plant debris. Adult males are winged, but females of many species stay inside their protective cases for life:
Another arthropod was a common spinybacked orbweaver (Gasteracantha cancriformis). I might have seen this species in New Jersey, but definitely in Texas. Unlike many squishy spiders, this one has a tough carapace and spines, making it a difficult morsel to chew or swallow whole. Its bright color may be an honest, warning signal to predators not of a foul taste or toxicity, but of the risk of choking or throat damage
Leaving the preserve, I spotted this butterfly, which could be a glassy-winged skipper (Xenophanes tryxus). The whitish spots on its wings are actually semi-translucent:
Please send in your wildlife photos as this is the last batch I have!
Today we have bird photos from Jan Malik showing avian denizens in the “wilds” of New Jersey. Jan’s IDs and descriptions are indented, and you can enlarge the photos by clicking on them. Note the DUCKS at the beginning and in the penultimate photo.
I’d like to present my natural backyard, the Meadowlands in New Jersey. This is an expanse of tidal marshes and phragmites reeds, formerly used as city dumps. It was more or less that desolate swath of land where Pete Clemenza instructed his enforcer: “Leave the gun, take the cannoli.” Nowadays, this land is in the process of active reclamation and on its way to becoming aquatic parkland.
In spring and summer, DeKorte Park is teeming with ducks; here are a male and a female Green-winged Teal (Anas carolinensis):
There is a large flock of Ruddy Ducks (Oxyura jamaicensis) that stays each year in the same cove:
Every year, many Northern Shovelers (Spatula clypeata) visit the marshes. Their bills certainly look like spatulas:
American Black Ducks (Anas rubripes) also move through the area and possibly even breed in more secluded areas. They are close cousins of Mallards, and hybridization occurs fairly often (as evidenced by the green brow on this male); however, the species manage to stay separate due to their selection of nesting sites and preferred diets:
There are too many wading birds to list, but here is a Killdeer (Charadrius vociferus):
Midges and mosquitoes can sometimes be a nuisance:
But we have an efficient pest control crew, like this Tree Swallow (Tachycineta bicolor):
Large wading birds are numerous; here is a Great Egret (Ardea alba).
A strong local colony of Ospreys (Pandion haliaetus) has a prominent presence here. As long as nesting platforms are available and polychlorinated hydrocarbons are absent, these birds will thrive:
Among songbirds, we have native sparrows, like this White-throated Sparrow (Zonotrichia albicollis):
As well as introduced ones, like this male House Sparrow (Passer domesticus), which has taken up residence in an all-American nesting box:
We have too many songbirds to show them all, but as a final one, here is an American Goldfinch (Spinus tristis):
Every summer, we have our crop of youngsters, like these American Robin (Turdus migratorius) chicks:
Or these ducklings—I think they may be Black Ducks, not Mallards:
I’ve realized now that I have collected too many bird pictures from this region and have short-changed all our lovely mammals, insects, turtles, shellfish, and fish—the latter, sadly, largely inaccessible to a photographer. But I would be remiss if I didn’t include this view, which has been visible on this specific September day for the last 25 years. The World Trade Center site’s light beam tribute is visible across the Hudson, and its aesthetic quality must not cloud our understanding of what it means: that on one sunny September morning in 2001, we were deprived of Francis Fukuyama’s comfortable utopia of universalism and thrown into Samuel Huntington’s world, where others look at our treasured values with disdain and a desire to destroy them:
Today I’m stealing (with permission) some photos from Professor Scott Ritchie of Cairns, Australia. Scott’s IDs and captions are indented, and you can enlarge his photos by clicking on them. (Scott’s Facebook page is here.). I’ve inserted the Latin binomials and links to the bird page.
I stupidly set the wildlife post to appear at 6:15 a.m. instead of the usual 8:15, and so you may have received an email that goes nowhere, as I reset the posting for the usual time.
At any rate, you’ll want to see Bruce Lyon’s photos and four videos of Arctic foxes that he took in Alaska, and that post is right below this one—at this link. Have a look.
Bruce Lyon has returned with Part 2 of his adventures with Arctic foxes, including photos and several videos. Bruce’s captions and narrative are indented, and you can enlarge his photos by clicking on them.
Here is a second batch of photos and videos of arctic foxes (Vulpes lagopus) on St Paul island. First batch here.
A parent resting by its den:
Below, a video from a couple of years ago of a very tame fox at the dump. Every time I went to the dump to check on some rosy-finch nests, this individual would run up very close to me and run circles around me, whining and barking and jumping up at me. I was amused and thought the fox was being friendly and curious but another biologist told me that this could be aggressive behavior—perhaps the fox was defending its den a bit too aggressively. That biologist had been bitten by foxes before:
This year we had a similar close encounter of the fox kind but this fox was at the harbor for the food and did not seem to have a den nearby. It seemed genuinely playful and curious and was particularly keen on nibbling my assistant’s rubber boots. Who doesn’t enjoy a chaw of boot rubber once in awhile?:
Earlier the fox in the above video had been munching on a clam that it probably got from the nearby pile of dredge material being scraped up from the floor of the harbor in a harbor improvement project. The dredge sediment seemed to be chock full of inverts like clams and seemed popular with at least a few foxes.
Back to the foxes with dens close to our lodging—one of these adults takes a large salmon tail to its pups:
If the pups are hidden in the den when a parent arrives with food the parent will sometimes just dump the food on the nearby beach for the pups to find later. The thick-billed murre carcass in the photo below was lying on the beach for some time before a pup finally discovered it:
Food fight or play? A couple of pups squabbled over a dead crab. I didn’t see much in the way of them eating the crab—either the crab was too far gone to be worth eating or the shell was a barrier:
A few photos of pups playing around the two dens near my lodging:
The pups do a lot of pouncing—here a pup pounces on a piece of cardboard:
Below, but it’s much more fun to pounce on a sibling:
Sometimes the squabbles among the pups seem like real fights. Below is a video of a family that had a den under a large metal CONEX container in town. Two of the pups seem to be having a serious fight, evidenced by the screaming. Normal play is not accompanies with this screaming. Perhaps these squabbles are used to establish dominance. Some studies have observed dominance hierarchies among the pups—the dominant individuals defend prey items and also take it from subordinates:
Here’s a video of the same family with a more playful scene:
Adult foxes that I at first thought were playing were more likely having a serious fight. This was near the harbor on a day when there were a lot of foxes hanging around, most of them peaceably. I saw these two foxes in the middle of the road, seemingly frolicking. One of the foxes was on its back in the typical dog submissive posture while the other was standing over it. All of a sudden the one standing went at the submissive one, which ran like hell, right towards me. Look at the glorious fluffy tail on the fleeing animal! My colleague Paula White, who has studied this population of foxes, tells me that fleeing subordinates often wave their tails in the face of the pursuers. Perhaps it is better to get bit on the tail than the butt? Waving a fluffy tail might also distract and confuse the chaser:
The “ducklings”—if you can call them that now that they’re fully feathered and miniature adults—are almost six weeks old: they hatched on July 25 and came to the pond the next day. All is well with them: they all seem healthy and lively, and they eat heartily, though Miss Duck allows the babies to eat before she does. It’s hard to get food to her as her brood tends to scarf it up.
The babies are already starting to flap their wings vigorously, as you can see in the videos below, and I expect that in about 2-3 weeks they’ll be trying to fly, and levitating a bit. I suspect that the “zooming” behavior you see below is both fun but also practice for taking off.
But first some photos. First, Miss Duck, the ever-attentive mom who is still monitoring the babies closely. She’a also starting to molt, and during this period she will be able to flap and levitate a bit, but when she molts her flight feathers she’ll be pretty much grounded for a couple of weeks.
First, Miss Duck on the water. I love this photo, what with the reflection and all. (I posted it the other day.)
On the edge of the pond, watching her brood. Notice that her foot is on the side and not underneath her:
And a glamour head shot. If she returns next year I’ll be able to recognize her by this distinctive beak pattern.
Here’s the brood crossing the sidewalk in the morning so I can feed them in the channel. As soon as they plop in the water (I won’t feed them on land), they immediately turn and face me, waiting for their duck pellets. They know the drill!
Make way for ducklings! You can see that Mom is still larger:
Sleeping on the water six days ago (iPhone photo). Mom is floating:
Often Miss Duck and the brood will get the “zoomies” after a meal. Usually initiated by Miss Duck taking off and flying a short distance in the pond, the ducklings go wild, zooming across the pond at high speed chasing Mom, as well as dunking themselves and swimming underwater. I’m convinced that, with Mom’s prompting, this behavior prepares them for flight. Notice how they often flap their wings during the exercise.
I’ll show two bouts. This first one took place after third breakfast a week ago (they get fed three times a day):
And here’s a vigorous case of the soomies yesterday:
The babies also “dabble” after meals. In the wild, they get most of their food by going butt-side up and thrusting their beak into the pond bottom, taking in some mud and then squeezing out the dirt but keeping the edible stuff (worms, other inverts, etc.). As I’ve shown before, ducks have “teeth”: serrations on their bill that allow them to get rid of the inedible stuff and keeping the food. In this way they’re like baleen whales.
Since the pond bottom is gravel and not dirt (a huge mistake in the pond design), the dabbling takes place in the dirt in the few pots of plants that they’ve put in the pond, which have dirt in them. Unfortunately, the plants cannot spread because the pond bed is gravel. It’s beyond my ken why they designed the pond this way, for it will prevent the luxurious growth of aquatic grasses and water lilies we were promised when the pond was reopened.
Here’s one duckling dabbling in an empty plant pot in mid-August. At this time they still had their duckling fuzz, but you can see the feathers coming in. Now they are fully feathered and fuzzless, but their flight feathers have a way to go.
And here’s a napping duckling with almost all the feathers grown in. There’s still a patch of fuzz on the butt and neck.
Ducklings napping on the edge of the pond. They always do this in the full group of four, and Miss Duck is among them, usually at one end of the line so she can watch them all. The “white” covering in the eye is their nictitating membrane.
The babies are starting to develop the speculum: the patch of blue secondary wing feathers that you can see on Miss Duck’s wing above. It is one of the landmarks of attaining adulthood. I’ve circled the nascent speculum in the first photo. Curiously, we’re not sure what this speculum is for. It’s present in both sexes, but could be the result of mutual sexual selection or selection for species recognition.
The nascent speculum is clear here:
The brood heading to one of the three Sacred Rocks to rest after a meal. There’s lot of dunking and preening before they settle down. Notice that Miss Duck gets up on the rock to let the babies know where to go.
DANGER! There is a nest of Cooper’s Hawks (Astur cooperii) in the quad, and the young hawks often inspect the pond. Miss Duck sees them before we do, and she warns the babies with a specific quack. They immediately become motionless. While I’ve seen the hawks fly low over the pond, they’ve never tried to take a duckling, thank Ceiling Cat.
These photos were taken three days ago by my friend Peggy Mason, a neurobiologist on Team Duck. The tree is adjacent to the Pond, but I let Peggy take a few pictures before I chased the hawk away.
The definitive ID comes from Bruce Lyon, who looked at the photos and said, “Yes I think it’s a Cooper’s. I had to double check that it was not a broad-winged hawk. Looks like it is molting its tail so it is shorter than typical and a long tail would indicate Coopers’.”
And we musn’t forget the turtles. We now have six of them. We originally had five but one died (I was told, without proof , that its shell was cracked when students were playing Frisbee with it). But then a student found a large red-eared slider on the Midway, far from the pond, and carried it over and let it jump in. That made five again. Then a smaller red-eared slider appeared, probably another willful introduction.
They are all well and many people come to watch them. A group of women who work in the Regenstein Library regularly visit, and they’ve named all the turtles after hamburger-ish sliders, like “Buffalo Chicken Wing” and “Beef”. Unlike me, they can recognize every turtle.
A few photos of our terrapins. Here are four sunning on the rocks and doing Turtle Yoga, stretching their limbs to catch the sun:
You can see why they call them red-eared sliders (Trachemys scripta elegans):
Finally, two videos showing the turtles. This first one also shows some of the seven species of fish we have in the pond. All are naturally-occurring (as are sliders and ducks), but there are four pesky goldfish that someone is going to remove and put in an aquarium.
This turtle is going after some leftover duck food, but they do get fed a healthy diet of turtle food (not by me):
This video shows how they swim around. They’re quite fast in the water when they’re in a hurry, in contrast to their slow ambling on land:
