Wildlife at Escanaba Lake, Wisconsin

August 12, 2023 • 1:50 pm

by Greg Mayer

I’m going to try to post some of my own wildlife photos while Jerry is not in a position to post readers’ wildlife photos. (We can look forward to Jerry’s posts of Galapagos wildlife photos, which we eagerly await!) To start, here are some pictures from a field trip  I took to Vilas County, Wisconsin, last summer with colleagues from the University of Wisconsin Zoological Museum in Madison. These pictures are from our visit to Escanaba Lake, where the Wisconsin Department of Natural Resources has a small field office that conducts careful surveys of the fish in the Lake.

Escanaba Lake, Wisconsin, 23 July 2022.

We went out with DNR fisheries biologist Greg Sass, who showed us some of the research being carried out by the DNR. Greg got his PhD at Madison, where he is affiliated with the Center for Limnology.

Escanaba Lake, Wisconsin, 23 July 2022.

Part of the DNR’s research involves fyke net surveys:

Escanaba Lake, Wisconsin, 23 July 2022.

Here are some of the fish found in the Lake. My ichthyological expertise is minimal, so the IDs will be to family only; feel free to volunteer species IDs in the comments. [Added: see species IDs by Mark R in comment #2.] Centrarchidae:

Escanaba Lake, Wisconsin, 23 July 2022.


Escanaba Lake, Wisconsin, 23 July 2022.


Escanaba Lake, Wisconsin, 23 July 2022.

A large Bullfrog (Rana catesbeiana) tadpole also turned up:

Escanaba Lake, Wisconsin, 23 July 2022.

But the highlight for me was that Northern Water Snakes (Nerodia sipedon) were very common at the boat launch. There were little ones:

Escanaba Lake, Wisconsin, 23 July 2022.

And big ones:

Escanaba Lake, Wisconsin, 23 July 2022.

Measuring the big one– about 44 inches, total length:

Escanaba Lake, Wisconsin, 23 July 2022.

Sometimes, the big and little hung out together:

Escanaba Lake, Wisconsin, 23 July 2022.

The biggest ones were under and around an overturned boat:

Escanaba Lake, Wisconsin, 23 July 2022.

The snakes were so common, I told Greg it would be a great place for someone to do a thesis on their population biology and behavior. Some more water snake photos:

Escanaba Lake, Wisconsin, 23 July 2022.
Escanaba Lake, Wisconsin, 23 July 2022.
Escanaba Lake, Wisconsin, 23 July 2022.

This being Wisconsin and all, we had dinner the night before at a supper club, accompanied, for most of us, by brandy old fashioneds:

Brandy old fashioneds (mostly) at Marty’s Place North, now sadly closed.

Readers’ wildlife photos

July 14, 2023 • 8:15 am

Today sees the return of Robert Lang, physicist, origami master and, today, photographer.  Robert’s narration is indented, and you can click on the photos to enlarge them.

More local animals

The Los Angeles basin is a vast urban/suburban metropolis, but its natural boundaries of ocean and mountains are abrupt with sharp transitions created by water and steepness. The northern boundary is formed by the San Gabriel and San Bernardino Mountains (collectively, the Transverse Ranges) and they rise steeply from many back yards along the range. My studio is about 20 feet from the edge of the Angeles National Forest; this gives rise to many wildlife encounters, both at the studio and on the trails that climb up from the back property line. Most of these pictures are fairly recent.

One from last fall that I’ve been saving for RWP is this California Tarantula (Aphonopelma sp.). Probably a male, because he was out and about; in the fall, the males go on walkabout looking for females (who mostly stay hidden in their burrows):

Then we turn to a couple of reptiles. The Western Fence Lizard (Sceloporus occidentalis) is one of the most common lizards around; just walking down the front steps, I’m likely to see one (although it’s rare that they stay still enough to be photographed). They are highly variable in color, and the same lizard can appear either light or dark. In the morning, they are dark to absorb the sun’s rays; then in the afternoon, after they’ve warmed up, they lighten their skin and their lovely iridescence becomes visible:

I was pleased on a recent hike to see a Blainville’s Horned Lizard (Phrynosoma blainvillii) at an elevation of about 4000 feet. They used to be more common in the San Gabriels, but earlier in the previous century their numbers were reduced by collectors gathering them for the curio trade, and they’ve never fully come back. I really should have taken a wide-angle photo of this one; it would have been a great candidate for the “Spot the …” series, as it was so perfectly camouflaged against the sand and gravel I nearly stepped on it:

Another reptile that I’m glad I didn’t step on was this Southern Pacific Rattlesnake (Crotalus oreganus helleri), who was stretched out across the trail. He was pretty chill, though; didn’t budge as we approached, and so we gingerly stepped past. A nice set of rattles on that one!

We have three kinds of squirrels around; ground squirrels, gray squirrels, and the (introduced) Fox Squirrel (Sciurus niger). The local rattlers are happy to dine on any of them.

We also have both crows and ravens; crows are more common down in the neighborhoods, while ravens like this Common Raven (Corvus corax) dominate up in the chapparal. This one is perched on the top of one of last year’s blooms from the Whipple Yucca (Hesperoyucca whipplei):

Larger creatures sometimes come visit the meadow behind the studio. A not infrequent visitor is the coyote (Canis latrans). Although this one was (barely) within the National Forest, they come far down into the adjacent neighborhoods, where they find plentiful food in the form of dropped fruit, loose garbage, and the occasional domestic animal whose owners ill-advisedly allow them to roam free:

Another frequent large visitor is the California Mule Deer (Odocoileus hemionus californicus). This time of year, the bucks are in velvet, like this one. We had a very wet spring, so there is a lot of browse in the mountain canyons and not much to lure them into the meadow, but in the fall, when the acorn crop starts to fall, they’ll be visiting twice a day:

In much of California, the urban/wilderness interface usually exists in one of two states: (1) recovering from the last wildfire; (2) stocking up for the next wildfire. A year ago we had a relatively small wildfire just across the canyon; fortunately, it was a cool day with not much wind, and the fire crews held it to just a few acres:

I spent the afternoon watching the firefighters dragging hoses for hundreds of yards up the ridges while helicopters and fixed-wing aircraft dropped water and fire retardant. I am in awe of the firefighters, who were clambering up cliffs that I wouldn’t even try to scramble under the best of circumstances, while they were wearing and/or carrying 50 pounds of kit and dragging hoses. Within a few hours, they had things under control. The drifting smoke and red fire retardant gave things an almost surreal appearance as they were mopping up:

That was a year ago. One thing about the chaparral is it recovers quickly from fire (indeed, many plants rely on it), and after this spring’s wet rains, the formerly bare ground is covered in new growth, and the burned bushes have resprouted. They’re getting ready for the next fire, which is bound to happen sometime; it’s the nature of this bit of Nature.

Readers’ wildlife photos

July 13, 2023 • 8:15 am

Today we have part 2 of Tony Eales’s recent safari to Botswana (part 1 is here). Tony’s narrative is indented, and you can enlarge the photos by clicking on them.

Botswana Safari Part II

After we left the Okavango Delta camp, we moved northeast into the Moremi Game Reserve, still mostly in the delta. Being winter, the nights were cold and mornings brisk but the days warmed up nicely. It was strange to Australian eyes to see a forest in a landscape much like Australia but with deciduous trees. There’s only one species of deciduous tree native to Australia so it looked very off to our eye. In addition, the forest looked like it had been trashed by heavy machinery and had regrown from broken trunks and suckers. Of course, the heavy machinery in question was elephants—major shapers of the habitat.

Here’s an African bush elephant breaking off a piece of a Mopane tree. it will chew the bark off and throw away the stick:

Here’s a baby begging for food from mum. There were so many baby elephants around when we were there all of them acting in the most cute and silly ways:

Moremi was perhaps my favourite place, it was varied with pools and swamps as part of the delta as well as large grasslands, forests and thickets. one shallow waterhole in particular was a haven for birdlife with two species of pelicans and African Skimmers (Rynchops flavirostris) both of which were on my bucket list for Africa. here’s a shot of a skimmer with Great White Pelicans (Pelecanus onocrotalus) in the background:

It was here that I realised that if you looked closely at most of these large waterholes, you’d see the eyes and nose of (Southern African) Nile Crocodiles (Crocodylus niloticus ssp. cowiei) poking out. We also saw many out basking on the banks.

Also nearby, we got great close-up views of the famous Marabou Stork (Leptoptilos crumenifer):

Close to the Third Bridge Camp Site we saw zebra (Chapman’s Zebra Equus quagga ssp. chapmani), wildebeests (Connochaetes taurinus ssp. taurinus), ostriches (Struthio camelus ssp. australis) and a lone young spotted hyena (Crocuta crocuta) moving quickly through:

My son—this trip was a combined 18th and 21st present for him—was absolutely in love with the mongooses. We mainly saw Banded Mongoose (Mungos mungo ssp. ngamiensis) and Slender Mongoose (Herpestes sanguineus):

And of course, no one can leave a safari without the obligatory photo of the Lilac-breasted Roller (Coracias caudatus ssp. caudatus). A jaw-droppingly beautiful bird.

I’ll finish with a pic of a giant herd of Cape Buffalo (Syncerus caffer ssp. caffer) that we saw in amongst dead leadwood trees near sunset. It made for some stunning photos.

Readers’ wildlife photos

June 24, 2023 • 8:15 am

Here is part 3 of a set of photos taken by reader Daniel Shoskes on his trip to Africa (see earlier photos here and here). The species IDs are not given, so I’ll provide links when I’m fairly sure of them. You can enlarge the photos by clicking on them. The narration is short and sweet:

Here are photos from our trip to Africa. Started in Livingstone Zambia, traveled through Zimbabwe, and into Botswana.

Victoria Falls (from a helicopter):

Vervet Monkey (Chlorocebus pygerythrus):

Lions (Panthera leo):

Nile crocodile (Crocodylus niloticus):

Termite mound. These are grass-eating termites and the mounds can be huge and take decades to make:

Sausage Tree (Kigelia africana):

Baby African bush elephant (Loxodonta africana):

Common warthogs (Phacochoerus africanus):

Lioness eating a baby elephant carcass:

Baboon holding its tail [JAC: probably a Chacma Baboon, Papio ursinus]

Vulture [JAC: probably a Cape vulture, Gyps coprotheres]:

Readers’ wildlife photos

June 20, 2023 • 8:15 am

We have a new batch of photos from reader Larry Powell.  His captions and IDs are indented, and you can enlarge the photos by clicking on them.

Here are some pictures, mainly of amphibians and reptiles, from a trip I took a few years ago to southeastern Arizona to help a friend with some fieldwork. A busman’s holiday for me, as I saw a lot of amphibian and reptile species I’d never encountered in the field, and got to spend some time in beautiful country with good company.

First off, one for the entomologically-inclined – what I believe to be Giant Mesquite Bugs (Thasus neocalifornicus). We found aggregations of these large impressive insects on mesquite bushes (of all places) while looking for lizards on the Appleton-Whittell Research Ranch. Going by the red banding on the legs, these are females. There’s a nice account of this species here.

This Mojave Rattlesnake (Crotalus scutulatus) was waiting outside when we left our field headquarters one morning. It’s apparently quite a dangerous species, with potent venom, but this individual appeared to be fairly phlegmatic.

I believe that this is a Western Patch-Nosed Snake (Salvadora hexalepis), going by the number of upper labials – the large scale on the end of the rostrum identifies it to genus; but there’s more than one species in that corner of Arizona. This one was encountered on the gravel road leading to the highway.

We were in Arizona during what’s called the monsoon season (June – September), and got caught in some spectacular thunderstorms. After one, the dry wash near our field headquarters filled overnight, with standing pools crowded with spadefoot toads, which spend most of their adult lives buried but breed explosively when the rains come. This individual is a Couch’s Spadefoot toad (Scaphiopus couchii) that I removed from the breeding festivities for a portrait.

There are four species of horned lizards (Phrynosoma) found in the SE corner of Arizona, and I’d hoped to see one or more that I’d never seen in the wild. However, the only individual I encountered was this neonate Greater Short-horned Lizard (P. hernandesi), which belongs to the species I’ve been working on in Alberta for years. Still nice to see, though.

From the Sonoita Valley we moved up to the Chiricahua Mountains, and here we encountered this Madrean Alligator Lizard (Elgaria kingii), hidden under some wood litter. This individual is regenerating its tail.

The Chiricahuas constitute a sky island archipelago, high enough in elevation to harbour life zones not typical of the surrounding desert. We spent our time there in the deciduous forest and coniferous forest biomes, which were at just the right temperature from my point of view. Common at higher elevations was Yarrow’s Spiny Lizard (Sceloporus jarrovii); a subadult is shown here. This species is viviparous. They are very quick on their feet.

Another, less conspicuous high-elevation lizard in the Chiricahuas is the Slevin’s Bunchgrass Lizard (Sceloporus sleveni). Despite being mainly found at high elevations, this species is oviparous. Like S. jarrovi, they are exceedingly nimble.

Readers’ wildlife photos

June 17, 2023 • 8:15 am

We have several contributors today, whose notes and IDs are indented. Click on the photos to enlarge them.

First, some photos of owls living in Dobrzyn.  Can you ID them? (To me it looks like a juvenile, and note that it has a mustache.)

This is what Malgorzata says, “Yesterday evening Andrzej posted 3 pictures of an owl which Paulina took. We have 4 owls as lodgers this year, probably parents and two young. We are not sure where their nest is but it is in our garden.” Andrzej’s caption:

Paulina’s late night owl hunting (in Polish: “Nocne polowanie Pauliny na sowy.”)

From Charles Sawicki, in Fargo, North Dakota:

A few years ago I raised native leaf cutting bees (family Megachilidae), that normally live in hollow plant stems, and discovered that their population is severely limited by a lack of nest sites. Identification of the particular species requires examination, under magnification by an expert. [JAC: the bees provision each cell for the larvae with pollen or a mixture of nectar and pollen. You may have these bees in your yard, and can just use straws and a container to rear many of them.]

These bees build little cells blocked at the ends with leaf pieces and bee secretions. Each cell is about 0.6 inches long and contains pollen and an egg that eventually develops into a bee. The straws were held in 4-inch plastic pipes, and held about 12 cells each. In year 1 I had only three full tubes, in year 2, 32 tubes and in year 3 there were 305 filled tubes. As can be seen in the first picture, near the center, the bees sometimes cut out pieces of pink flowers instead of leaves. These photos were taken in year 3. The first photo shows bees in the process of filling straws. The second photo shows filled straws in one pipe.

These bees can also make their pipes by rolling cut-up leaves. Here are some leaf-cutter cells from Bangalore India (photo from Wikipedia):

From Robert Woolley:

My favorite wildlife photo is attached. It’s an Eastern copperhead snake  (Agkistrodon contortrix) on a tree stump in the Joyce Kilmer Memorial Forest, in western North Carolina. There’s a sneaky second copperhead visible on the left, which I didn’t even know was there until I got home and looked at the photos.

From James Sutzer:

Here’s a few photos of an Eastern racer (Coluber constrictor)  I found passing through my backyard yesterday. Looks like he needed a drink. Later I watched him climb a tree in my front yard. Haven’t seen him since.

Man rescues Indian cobra trapped in a fishing net, gives it a big drink of water

June 9, 2023 • 1:20 pm

The Indian or spectacled cobra (Naja naja) is widespread in South Asia, and is the “classical” cobra that Westerners are familiar with from wildlife shows, movies, Kipling stories, etc. The one shown in this video got itself trapped in a fishing net. Fortunately, a skilled snake handler was around and, after giving the snake a long drink of water, pinned its head and then proceeded to free it from the net, releasing it back where it was found.

My favorite part is where the snake greedily guzzles water from a plastic bottle. It must have been plenty thirsty! As in all Dodo videos, things end well, and so this is your Friday heartwarmer.

The YouTube notes:

This king cobra [see Note by GCM below] was found trapped in a fishing net on New Year’s Day near a rice paddy in East India. When the local villagers found the trapped snake, they called in snake rescuer Mirza Arif. Arif uses scissors to cut the fishing net off, but not before giving the cobra sips of water from a Sprite bottle to quench his thirst. After being freed from the net, the snake was later released near where he was found.

[Note by GCM: Youtube wrongly identifies this as a king cobra  (Ophiophagus hannah), also native to Asia, which is the world’s longest venomous snake, with extremely toxic venom. The key to identifying it correctly are the markings on the neck, which sometimes resemble glasses (hence “spectacled”), and sometimes a monocle; there are various cobras with these marks, some split off as separate species.

The guy in the video, BTW, shows real skill and knowledge in handling the snake. A lot of online videos show people doing stupid and dangerous things with venomous snakes, but this guy is appropriately prudent!]

The NYT oversells a new report of a “virgin birth” in crocodiles

June 8, 2023 • 9:30 am

This is an example of science reporting that’s misleading—not because it gets the facts wrong, but because it oversells a rather mundane finding as a potentially important insight into the life of the extinct dinosaurs.  And no, there’s nothing in the original paper—about a single “virgin birth” in a crocodile (really a “stillbirth”)—to suggest the Big Sell: that dinosaurs could have reproduced via “virgin births”, too. Dinosaur Jesus probably didn’t exist.

So here we have one new paper from the Royal Society’s Biology Letters; click on first screenshot below to read (the pdf is here) reporting the occurrence of parthenogenesis in one crocodile in one zoo. The NYT Trilobite reports about it in the second screenshot below (I found it archived here).

Parthenogenesis is a form of asexual reproduction that occurs without the fusion of a sperm and an egg. It occurs across various animal taxa, and can arise in different ways.  Here’s what Wikipedia says about its distribution (note that it doesn’t occur naturally in mammals).

Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea and parasitic wasps) and a few vertebrates (such as some fish, amphibians, reptiles and birds).

Parthenogenesis can occur in a variety of ways, often after hybridization between species that produces an individual whose chromosomes can’t pair properly during meiosis (cell division producing sexual gametes). That mispairing increases the likelihood that an unfertilized egg in a hybrid can have a full chromosome complement and develop into an offspring. But in most other cases, like this one, asexual reproduction occurs as a modification of non-hybrid meiosis.  That’s what apparently happened in this case.

The authors report that an 18-year-old American crocodile (Crocodylus acutus) in a reptile park in Costa Rica laid a clutch of 14 eggs. Candling of the eggs (holding them up to the light) revealed that seven apparently contained embryos (or dense spots), but none developed to hatching. One fetus, however, almost made it, and when the egg was dissected it contained a single female. Here’s the photo from the paper: mom on top and the fetus at the bottom. There was clearly something wrong with the baby as it failed to hatch, and I suspect it was simply screwed up.

(From paper): Figure 1. (a) Adult American crocodile, Crocodylus acutus. Photo courtesy of Q. Dwyer. (b) Stillborn fetus of American crocodile, Crocodylus acutus, Parthenogen. Photo courtesy of Q. Dwyer.

Genetic analysis of the fetal DNA compared to mom’s showed that they were pretty much genetically identical, with the fetus being, in effect, a clone of the mother.

How did this happen? If you don’t need the details, skip this next part between the lines.

DNA results from the paper suggest that the fetus came from fusion of two of the products of meiosis. Here’s a diagram of how a female produces an egg (or a male produces a sperm) during meiosis (figure from Wikipedia). It entails doubling of each of the chromosomes in a sperm or egg precursor cell followed by two bouts of cell division.  The circle on the extreme left is of the precursor gamete cell in a species having four chromosomes, with two copies of each of two different chromosomes (remember, we have two pair of every chromosome).  Then each pair doubles, which happens during normal cell division (mitosis) as well as in meiosis (second circle).

But then meiosis begins in gonadal cells: instead of each doubled chromosome splitting and going to a new cell, producing two genetically identical cells (this is normal cell division), the chromosome twins of each pair, now doubled (and having reshuffled bits from meiotic “recombination”), go into separate cells (third circle from left).  This is the first phase of meiosis, or “meiosis I”.  Now we have two daughter cells, each containing two chromosomes that are doubled but connected by the centromere. The chromosome number is really two, not four, because these doubled chromosomes (called “chromatids”) are going to go to different cells.

During “meiosis II”, the doubled chromosomes of each pair split, with each going to a new cell, so instead of two pair of joined chromosomes, we simply get two single chromosomes.  The chromosome halves can sort out independently of each other, which is called “segregation”, and is one way to recombine existing genes. In the end, a cell with four chromosomes has, though doubling and then two  cell divisions, produced a “haploid” cell with only two chromosomes. These final cells have only one instead of two copies of each chromosome pair. They are the gametes: eggs and sperm, and are shown on the extreme right.  This happens in eggs and sperm, and when they fuse, the normal chromosome number is restored. You can see that when this happens in both sexes, you get novel combinations of parental genes—one of the likely reasons why sex evolved.

Now, how did this produce the parthenogenic crocodile fetus?  In females, usually only one of the four products of meiosis goes on to form the haploid egg, with the other three cells being segregated into “polar bodies” that eventually die. But sometimes a polar body will fuse with the egg cell, restoring the normal chromosome complement and producing a diploid individual having two copies of each chromosome.  It’s a bit more complicated than this , but the result is that a female can produce a normal diploid offspring without being fertilized. This is simply because two of the halved cells that would normally become egg cells fuse with each other.

Using DNA sequencing, the authors confirmed that this is what happened (the formal process is called “automictic parthenogensis with terminal fusion”). But the diploid fetus, which would normally go on to form a crocodile that would hatch, was somehow inviable.

Note that this is the first report of parthenogenesis in a crocodile. (Since the mother was 18 and had been alone since she was two, it was extremely unlikely that the fetus came from her storing sperm after being inseminated sixteen years before, as some animals can store sperm for a substantial period.)

So far so good. And the NYT article below gets the details and facts right. Where it goes off the rails is instantiated in the sub-headline.  (The big headline is wrong, too: this is NOT a “virgin birth” but a virgin stillbirth. No new croc entered the world. 

Because crocodiles are related to the extinct dinosaurs, author Greenwood (and the authors of the original paper), suggest that this is a case of “facultative parthenogesis that could also have occurred in dinosaurs! Dinosaurs could have reproduced asexually! T. rex could have produced baby T. rex copies without having to mate! Note the subheadline above, mentioning “Jurassic Park”.)

The article also says this:

So, did dinosaurs do it, as the discovery of parthenogenesis in crocodiles suggests? Parthenogenesis is best confirmed with DNA analysis, a process that has allowed scientists to tell it apart from delayed conception, where a female stores sperm for as long as six years before using it to fertilize eggs. Without the ability to retrieve dinosaurs’ and pterosaurs’ DNA, which does not persist in fossils, certainty is not available.

“We’ll never be able to prove they could do it,” Dr. Booth said. “But it suggests they had the ability.”

My response is “no, it doesn’t.”

But at least both the authors and the journalist say we can’t prove that there were Jesus-saurs, but I’d go further and argue that this is speculation far beyond what’s warranted from the data—speculation prompted by the desire to jazz up what is a decent but not terribly exciting result. In fact, I’d say that because the single dead offspring represents a bug and not a feature of croc reproduction, it says absolutely nothing about the likelihood that dinosaurs reproduced asexually, much less that they did so “facultatively”—as a regular evolved feature of their lifestyle.

First of all, this isn’t really “facultative parthenogesis,” which refers to species that can produce normal offspring sometimes via sexual reproduction and sometimes asexually. (That might be an evolved property, allowing an individual to pass on its genes when populations are sparse and there is nobody around to mate with.)

This isn’t what’s going on with crocs.  What we see here is probably a rare developmental screwup (it hasn’t been reported before, despite there being many captive crocs), an anomaly that is an evolutionary dead end.  Rare parthenogensis has been seen in other species too, including birds (see below), but in those species results in largely inviable or infertile offspring.  True “facultative parthenogenesis” isn’t common, but does occur in some creatures like lizards. And it’s not a bug, but an evolved feature.

Below I show the family tree of some vertebrates, including the dinosaurs, birds, lizards (one of the “squamates” along with snakes), and the crocs. (This slide was created by my friend Phil Ward, who teaches evolution at UC Davis.) You see that the crocs are related to dinosaurs, but not as closely related as are living birds, which are a group (“clade”) phylogenetically embedded within the now-extinct dinosaurs.

The upshot is that a rare occurrence of asexual reproduction, especially when it leads to a dead or sterile offspring, says nothing about the likelihood of facultative parthenogenesis in a relative. After all, birds are more closely related to dinosaurs than are crocs, and a couple of birds have reproduced asexually (turkeys can produce fertile offspring this way, though rarely, and California condors have also done it). But nobody goes shouting from the rooftops “dinosaurs could have reproduced asexually” because of a few rare cases in birds.  Quite a few lizards reproduce normally by parthenogenesis, but you don’t hear people extrapolating from lizards to dinosaurs, either.  Even some fish reproduce parthenogenetically, so why not write that “because fish are related to dinosaurs, dinos could also have reproduced parthenogenically.”?  It’s all pilpul.

The facts in the NYT report are accurate, including the caveat that we can’t test the asexual-dino hypothesis, but the author couldn’t resist bringing in the dinosaur angle—without any good reason to do so.  What will happen is that people will ignore the fact that the single parthenogenic crocodile fetus was stillborn (or “stillhatched”), was probably just a rare developmental anomaly, and go away instead with the lesson that “DINOSAURS COULD HAVE REPRODUCED BY CLONING THEMSELVES!!!”.

Readers’ wildlife photos

May 26, 2023 • 8:15 am

Today’s photos come from Larry Powell of Calgary; his captions and IDs are indented, and you can enlarge the photos by clicking on them.

Here are some photos of amphibian and reptile species that are found in Alberta. Most of our species are widely distributed through western North America, and reach their northern (or eastern) range limits here. We don’t have a very diverse herpetofauna, and the species we do have must deal with long cold winters.

Some of these (Prairie Rattlesnake, Greater Short-horned Lizard, Long-toed Salamander) are species that I’ve conducted ecological research on in Alberta, and the others are individuals that I’ve come across during various field projects.

Tiger Salamander (Ambystoma tigrinum) – A large and amiable salamander found over much of Alberta’s prairies, but seldom seen, as it spends most of its time underground. This one was found right at the western margin of its Alberta distribution, at the eastern edge of the Front Range:

Long-toed Salamander (Ambystoma macrodactylum) – This is our other salamander species, found in the mountains. It’s much smaller than the Tiger Salamander, but also spends most of its time underground:

Three Long-toed Salamanders from the same population in the Front Range, showing the great variability in dorsal colouration and pattern. This species exudes a toxic secretion from glands in the skin, and from a ridge of glandular tissue down the dorsal side of the tail, that is both sticky and irritating, so the bright yellow blotching is presumably warning colouration:

Wood Frog (Lithobates sylvaticus) – This is a cold-adapted species found in the boreal forest across Canada. It overwinters by allowing its extracellular fluids to freeze, and limits damage to cellular structures through cryoprotectants. This individual was found in the Front Range:

Leopard Frog (Lithobates pipiens) – This species was formerly widespread and abundant in the Alberta Prairies, but almost disappeared in the late 1970s. There doesn’t seem to be any satisfactory explanation for this. They are still locally common in spots, however – this individual was found in a dugout in the deep southeast of the province, in relatively undisturbed short-grass prairie:

Great Plains Toad (Anaxyrus cognatus) – A handsome and charming toad that reaches its northern limits in southeastern Alberta, where it occurs in great numbers in spots (mainly the sandy areas around the South Saskatchewan River). The breeding call sounds like a miniature jackhammer, and breeding congregations are audible for a long distance:

A Great Plains Toad in the hand:

Bullsnake (Pituophis catenifer sayi) – Bullsnakes are found over the short-grass prairie region of southeastern Alberta, mainly near rivers. They are unusual in being oviparous – most Alberta reptiles are viviparous. This specimen was encountered by the South Saskatchewan River, north of Medicine Hat. Bullsnakes spend a lot of time underground, hunting rodents in their burrows – note the large rostral scale, thought to be used in burrowing:

Prairie Rattlesnake (Crotalus viridis) – Another species of the short-grass prairie in the southeast of the province. Like Bullsnakes, their distribution is associated with drainage channels – they hibernate communally in the bedrock exposed in these situations, and travel considerable distances during the warmer months to and from their dens. This individual is a subadult, encountered on a road at the edge of the Cypress Hills:

Greater Short-horned Lizard (Phrynosoma hernandesi brevirostris) – This is our only lizard, found in scattered locations across the southeast corner of the province. They are remarkably cold-hardy. This is a large adult female I’m holding – males are quite a bit smaller. The species’ viviparity is probably part of the reason for this sexual size dimorphism:

Another Greater Short-horned Lizard – this individual is a member of the northernmost population of this species in the world, located about 30 km north of Medicine Hat. It’s a subadult female: