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.
Perhaps it lacks the gravitas of Matthew’s post, and it wasn’t narrated by David Attenborough, but it is in its own class of terror.
La vibora voladora…ja ja ja. Una experiencia única en el Vuelo Torreón-México, vuelo 231 de Aeroméxico. Eso si…Prioridad en aterrizaje. pic.twitter.com/qwDk6Wtszw
According to KTLA yesterday Aeromexico made this unwelcome discovery on a Sunday flight to Mexico. No-one was hurt and animal control took the snake into care once they reached their destination.
I think we can all agree that henceforth movies with suggestive names like Sharknado should be vehemently protested and banned if possible, because Mother Nature is clearly just taking these sorts of things as a suggestion.
It’s a bit late in the day, but I must announce that today is, at least in the USA, National Reptile Awareness Day. Happy Reptile Day to all! I must admit, as a herpetologist who joined all the major American herpetological societies while still in high school (1975), I had never heard of National Reptile Awareness Day before today. Reptiles Magazine, a fanciers outlet, is the only group I can find who are promoting it, although even they admit not to know how or when it started. Despite its obscurity, we’ll celebrate with a few reptile pictures.
First, a wild red-eared slider, a southern US turtle popular in the pet trade, and often released, but less often established, in places outside its native range, like Wisconsin.
Red-eared slider (Trachemys scripta elegans), Greenquist Pond, Somers, Wisconsin, 14 September 2016.
Next, my ball python Vivian, whom I’ve had for about 18 years.
Ball python (Python regius), captive, at alumni event at UW-Parkside, September, 2016.
A snapping turtle from UW-Parkside, at the same alumni event as Vivian.
And we’ll finish up with a series of eastern massasauga (Sistrurus catenatus catenatus) pictures; I believe all the pictures were taken in Cass, Michigan. They were taken by my former student Eric Hileman, who did his Ph.D. at Northern Illinois University with Rich King. Eric successfully defended his dissertation on the population ecology of massasaugas just this past Wednesday, and I was privileged to be able to attend. So we can all take this National Reptile Awareness Day as a day to send this joyous message to Eric: “Congratulations. Now get back to work.”
Today’s photos are by a father-and-son team, reader James Blilie and his 12-year-old son Jamie. The first batch is from Jamie, and James’s photos are at bottom. Their notes are indented:
These [first batch below] were all taken this summer by my 12-year old son Jamie. All were taken in Oregon and (mostly) Washington state, in June and July 2016. Most were taken on our place in rural Washington.
A western bluebird (Sialia mexicana), bringing chow for the kids
A dog-day cicada (Tibicen canicularis). Jamie caught it (and immediately released it) on our place. We have lots of these.
A house wren (Troglodytes aedon), taken on Orcas Island, WA.
This is (we think) a purple finch (Haemorhous purpureus).
I’ve mentioned in previous posts how I periodically engage in turtle or frog and toad “rescues”, taking animals that had fallen into human made traps, such as window wells and stairwells, and releasing them, sometimes after feeding them for a while in captivity to fatten them up prior to release. A couple of days ago I decided to stop and check a stairwell on my campus, the University of Wisconsin-Parkside, where I’ve previously found toads and a turtle, and sure enough I found a young American toad (Bufo americanus), about 30 mm in snout-vent length, hunkered down in some leaf litter at the bottom of the stairs. I took the little fellow’s picture with a lady bug, the type of beetle made famous by Jerry’s academic grandfather Theodosius Dobzhansky.
American Toad with ladybug in stairwell, University of Wisconsin-Parkside, Somers, Wisconsin, 16 August 2016.
The beetle of course was not trapped, and could just fly away when it wanted to. I checked the same stairwell again the next day. It had rained in the general area the previous night, which might encourage toads to be moving about– and thus fall down the stairs– but I wasn’t sure if it had rained on campus. There were two more American toads. These were smaller, about 18 mm snout-vent length. (A penny is about 19 mm in diameter.) These two were hopping about— they had just fallen in, and were in good shape. The toad from the previous day, although it looked good, may have been stuck in the stairwell for some days during a generally dry period, and was not active, but rather hiding in the leaf litter.
American Toads from stairwell, University of Wisconsin-Parkside, Somers, Wisconsin, 17 August 2016.
Here’s the stairwell, on the northern side of the Communication Arts building, in which the toads (and last year a painted turtle) got trapped. This year’s larger toad was under the leaves on the far right. Once they go down a step, they cannot climb back up, and they get ratcheted to the bottom.
Stairwell at UW-Parkside, NE corner of Comm Arts extension, 16 August, 2016.
I released these toads immediately after photographing them in Greenquist Woods, shown in the photo below, approximately under the large basswood leaves visible at the right. You can see how the ground slopes down to the left– just behind that screen of bushes is Greenquist Pond, which is where the toads breed, and the painted turtles live.
Greenquist Woods, University of Wisconsin-Parkside, Somers, Wisconsin, 16 August 2016.
Here’s Greenquist Pond looking north, with Greenquist Woods to the north and east, a lawn area (not well seen) behind bushes to the west, with a sidewalk and lawn edging to the south (from where the photo was taken).
Greenquist Pond, University of Wisconsin-Parkside, Somers, Wisconsin, 16 August 2016.
The smaller toads were recent transformlets from tadpoles this season. The 30 mm toad was a bit puzzling. Either it’s a transformlet from earlier this year which has grown quite a bit, or it’s a one year old from last year’s brood. It seems too small, based on my experience of toad growth in captivity, to be a year old, yet it seems odd to have in just one breeding season such a wide size range in the season’s transformlets (18 to 30 mm). I’ve not quite worked out the breeding phenology of the toads– perhaps I should figure this out.
After releasing the 30 mm toad in the woods the first day, I stopped at the Pond with the colleague who accompanied me, and there we found many small frogs that jumped in the water. At the size of those we saw, you need to get a good look at them to tell bull frogs (Rana catesbeiana) from Green frogs (Rana clamitans)– both species occur in the Pond. They all were diving quickly in the water, and we had no binoculars to get a close look at those that surfaced in the water, but one large individual sat still and let me approach. It was a large adult male green frog: a green frog, because the dorsolateral ridge extends from the eye over the ear and along the side toward the groin (in bull frogs, the ridge curls round the ear); and a male, because the ear is larger in diameter than the eye.
Large male Green Frog in Greenquist Pond, University of Wisconsin-Parkside, Somers, Wisconsin, 16 August 2016.
There are a lot of things to write about today, including a cool new paper on frigatebirds, birds that can stay aloft (without landing) for over two months. We’ll see how many we get to, as I have other work to do. In the meantime, here’s a “spot the ___” post, with the series initiated long ago by Professor Sir Matthew Cobb (that’s his new name since he was given a literary knighthood by the French for his books on the French resistance and the liberation of Paris).
This one isn’t too hard, but shows again how cryptic animals can be in the wild, and for good reasons. Reader Tom Hennessy sent this photo and some notes:
While I was in Shenandoah National Park in May taking photos of wildflowers and landscapes, I noticed a small toad in a meadow. As I tried to get a photo of it, it buried itself backward into the floor of the meadow.
Okay, spot it! (Click to enlarge; there won’t be a reveal as it’s too easy! But remember, predators don’t know it’s there, and so give the area only a cursory glance.)
As I’m traveling, I’ll post pictures that have arrived in the last several days. And, of course, those come from our prolific and talented contributor Stephen Barnard of Idaho:
I believe this is an Alligator Snapping Turtle (Macrochelys temminckii). I could be wrong, but it looks different from the common snappers I’ve seen. Photographed in Florida.
JAC: Instead of “Readers’ Wildlife” today, we’ll have a report on frogs by Greg Mayer, who’s just visited Costa Rica.
by Greg Mayer
Although quite cryptic on the forest floors it calls home, the smoky jungle frog (Leptodactylus pentadactylus) in the photo below is too obvious to be a candidate for “spot the frog”. This large species of frog (reaching over a 150 mm in snout-vent length) sports what in the military would be called “defense in depth”– a series of defensive behaviors and adaptations that help the frog avoid becoming someone else’s meal. The one in the photo below I encountered at the Lapa Rios Ecolodge, near the tip of the Osa peninsula, on my recent trip to Costa Rica.
Smoky Jungle Frog (Leptodactlyus pentadactylus), Lapa Rios Ecolodge, Osa, Costa Rica
It was a large individual (well over 100 mm), and we found it at night in the rainforest. Its first line of defense is that it’s quite hard to see against the variegated mixture of brownish leaves, twigs, and mud of the forest floor. (The red shine of the eye is more noticeable, but fortunately for the frog, natural predators don’t carry flashlights!) When first seen, the frog was sitting up at attention, but when we approached, it pushed itself down flat against the substrate, and as I moved around in front of it for a picture, it really pushed its face into the ground, making itself less noticeable.
Smoky Jungle Frog (Leptodactlyus pentadactylus), Lapa Rios Ecolodge, Osa, Costa Rica
Since all we wanted was pictures, the frog did not move to its further lines of defense. Had we provoked it, it would have assumed an elevated defense posture, with the back raised, also inflating its body and expelling air to make a hissing sound, similar to what is seen in some toads (Leptodactylus is not a true toad). I haven’t seen (or at least can’t recall seeing) this in Leptodactylus— the behavior was described in this species by Jaime Villa (1969)– but I have seen it in giant toads.
Elevated defensive posture of Leptodactylus pentadactylus (Villa, 1969: Fig. 6).
This of course draws a potential predator’s attention to the frog– having hidden, why would it now face up to its foe? This is where the next lines of defense come in. First, the frog is big, and this behavior makes it look even bigger. For some predators, the frog is a mouthful too far. Next, if the frog is touched, it exudes a copious and toxic mucus. This mucus induces a strong allergic response in humans, and presumably others, at least mammals if not all other vertebrates- intense sneezing, watery and itching eyes– the unpleasantness of which I can attest to from personal experience. It is said that people merely in the vicinity, who have not touched the frog, can, through aerial transmission of toxin droplets, get the same symptoms. The mucus can irritate the skin, and cause pain to any scratches or open wounds (which I fortunately did not have when catching the frogs). And the frog will also emit a loud, piercing shriek, which might well startle a predator into releasing its grip. Norm Scott reported that caimans were attracted to this cry, and even speculated that that was its function– to attract caimans to dispatch the frog’s predator– sort of like a bugle call to the cavalry!
More straight forward than the multi-layered defenses of the smoky jungle frog is the defense of poison dart frogs– aposematic, or bright, warning coloration, accompanied by very toxic skin secretions. We encountered two species at Lapa Rios. Phyllobates vittatus, with bright orange stripes, is a member of the genus which contains the three species of the poison dart frog family, Dendrobatidae, that are actually used by Indians to make poison darts.
Poison Dart Frog (Phyllobates vittatus), Lapa Rios Ecolodge, Osa, Costa Rica
We found three of them, during the day, along the Rio Carbonero. We also found three Dendrobates auratus along the paths at the Lodge itself, wandering about during the day, bold as brass, as is their wont. I’ve seen them quite abundant in other parts of Costa Rica, but we saw only three during 4.5 days at Lapa Rios. For neither species of dart frog was I able to get a very good picture; there’s a better picture of auratus in an earlier post, and, in another earlier post, more details and references on poison dart frogs. BBC Earth has a nice explainer on poison dart frogs, with links to interesting papers
Poison Dart Frog (Dendrobates auratus), Lapa Rios Ecolodge, Osa, Costa Rica
Savage, J.M. 2002. The Amphibians and Reptiles of Costa Rica: A Herpetofauna between Two Continents, between Two Seas. University of Chicago Press, Chicago
Scott, N.J. 1983. in D.H. Janzen, ed. Costa Rican Natural History. University of Chicago Press, Chicago
Villa, J. 1969. Comportamiento defensivo de la “Rana Ternero”, Leptodactylus pentadactylus. Revista de Biología Tropical 15:323-329. pdf
