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.
We have a couple of contributors today, and once again I urge you to get those good wildlife photos in.
First up are DUCK photos by a reader who introduces himself (yes, I drew a picture of a cat of his choosing—a lynx—in his copy of WEIT). All readers’ comments are indented:
I am John Rayner of Carleton Place, Ontario, Canada. But if you want to note place, just say Ottawa; it’s easier for all concerned. 🙂 BTW I attended your lecture in Ottawa several ago and had my WEIT book signed and lynxed.
There is a Mississippi River in Eastern Ontario. It flows into the Ottawa River which in turn flows into the St Lawrence and then the Atlantic. I was sitting on the riverbank hoping for seagull photos when a mallard [Anas platyrhynchos] came and sat on a log and preened to her heart’s content. I say her, but could it have been a juvenile male? I don’t know these things.
A bedraggled but tenacious cardinal from Christopher Moss:
Remember I mentioned that the two male Northern Cardinals (Cardinalis cardinalis) that spent the winter here in Nova Scotia, where no cardinals are supposed to be, left just before this female turned up? She has spent a lonely, virtuous and celibate summer here on her own. It rained hard overnight so she looks particularly bedraggled and sad today.
A praying mantis from reader Amy:
I no longer have a back yard as I’ve moved to an apartment with a balcony. This balcony has evergreens at arm’s length, though, so I have some wildlife. This morning I discovered this little dude on my majesty palm. After several tries, I managed to get him/her into focus. Not colorful or beautiful in the least, which is why I almost didn’t see it at first!
And we have two videos by reader Darren Garrison, sent in August 28:
I thought this was worthy of sharing. Making this video last night of a pair of snails I discovered under a mushroom involved two 10-minute sessions of lying on my side on the ground holding my phone just in case anything interesting happened. It paid off with probably the best nature video that I have ever made. Main video is sped to 8x realtime, zoomed clip at the end 4x.
(Earlier in the day I had found a bunch of *really* small snails, all inside around 2 square feet in my yard.) Video at 4X:
Today’s batch of lovely photos comes from our old friend Tony Eales in Brisbane. His notes and IDs are indented.
I went for a weekend up to the Bunya Mountains, a high elevation subtropical rainforest area near my home town of Brisbane QLD. The Bunya Mountains is named after the gigantic Bunya Pine (Araucaria bidwillii). This pine fruits heavily every two to four years with massive cannonball-sized pinecones containing large edible pine nuts. These years of heavy fruiting were a focus for aboriginal groups of the region with people traveling from hundreds of kilometres to take part in the Bunya Festival. The combination of forest type and high elevation is unique in the region and is home to a lot of endemic diversity. It’s winter at the moment, so the wildlife wasn’t as abundant as in the warmer months but I still found a number of interesting photographic subjects.
The first is a dealate queen (a queen that has shed its wings in preparation for forming a new colony) of the species Amblyopone australis. These are part of the Dracula Ant sub-family, so called because the workers pierce the skin of larvae and drink their haemolymph for sustenance. Normally ant workers collect sugary foods like nectar to sustain themselves, but these ants live underground and hunt termites so never get the opportunity to forage for nectar and drink protein only from prey or their own larvae.
Araneus circulissparsus is one of the most beautiful orb-weaving spiders, in my opinion, that I regularly encounter. It’s believed that they are a species complex rather than a single species. Certainly there’s a huge range of colours and abdomen patterns in these spiders. This one is rather simple compared to many but I still find the translucent green very appealing.
Cephalodesmius sp. is one of our native dung beetles. Only small as dung beetles go, these little beetles are endemic to Australia and live only in rain forests. Because of the scarcity of dung in these environments, they also include rotting leaf litter in their balls, which the pair-bonded males and females work on together. The male collects leaves and plant matter and the females shred it to help form it into a ball for the larvae.
This Armadillid [pillbug; a crustacean] was tentatively identified on iNaturalist as Cubaris sp. I can’t find any good resources on Australian Armadillids so I have no idea if this is correct. These were the second most common creature I saw on my night walk in the rainforest after another isopod in the Trichoniscidae family. Every plant and tree trunk was covered with them, and as you shone your torch-light on them they would drop off into the leaf litter below to escape.
The Gympie Gympie or Giant Stinging Tree (Dendrocnide moroides) has a fearsome and well-earned reputation as a bringer of extraordinary pain. I have personally experienced it myself and can confirm that in 52 years of life I have never had a greater pain inflicted on me—and I only brushed a knuckle against a leaf. The pain felt like I had rusty serrated knife drawn across my finger to the bone and the pain flared anew with slowly diminishing intensity, whenever there was a sudden temperature change, for months. Even so the flowers are fascinating and apparently the berries after flowering re sweet if you’re willing to brave it. There’s a YouTube video of a National Geographic host brushing his knuckle against one in almost exactly the same place I did that is very instructive.
This member of the superfamily Eupodoidea is probably Eriorhynchus sp. but really, it’s the same story as with the isopods. It’s very hard to find any good, amateur-friendly resources on mites aside from those that cause human problems. These little guys never stop and wander about waving their front legs like antennae, seemingly oblivious to my presence, making them fairly easy to photograph. They were common under every log and within the leaf litter.
I ended up with a few of these venomous little buggers on me after crawling around in the forest photographing bugs. The Australian Paralysis Tick (Ixodes holocyclus) was something my mother was always warning us about whenever we went walking in wet sclerophyll bush or rainforest. Children can be particularly susceptible as they can often leave a tick on for days getting a large dose of the saliva protiens which can case partial paralysis, flu-like symptoms and even anaphylactic shock as well as being carriers of typhus. I’ve had so many by now that I no longer freak out but they’re still creepy.
Smaller than a tick is this little Goblin Spider, Opopaea sp. They are an important part of the leaf litter fauna and are often overlooked due to their small size. Goblin spiders are notable for the hardened scute on the dorsal surface of the abdomen which can cover the whole dorsal are like with these Opopaea or just be a small oval as in Ischnothyreus sp. I’m a little bit obsessed with photographing this family of tiny cuties.
This ant had me confused for a time. It looked really familiar but I couldn’t place it. That was because it was only a millimetre or two long and most Podomyrma species are large, 10-12mm and very robust. A friend of mine pointed me in the right direction, apparently this is an undescribed species that has been found in other similar environments as shown here on AntWeb.
Terrycarlessia bullaceais one of only two species in this genus of carnivorous snails. They hunt the rainforest for soft-bodied prey including other snails, including other smaller T. bullacea.
And after many decades of not seeing one, I found a Red-triangle Slug (Triboniophorus graeffei) on my night walk. I’ve found a few juveniles over the years but this was a full sized adult. Red-triangle Slugs will appear in the day, infrequently, when conditions are right (ie raining for weeks on end), even in urban settings, startling people who didn’t know they shared the world with such crawling horrors. They are a striking animal, some being 150mmm [about 6 inches] long and often bright white with a blood-coloured non-symmetrical triangle on their dorsal surface, one vertice at their air-hole. They come in many colour forms, including a hot-pink form found only on a single mountain in New South Wales. While not so garish as that, the one I found was still an impressive specimen about 140mm in length. Normally all we ever see are the radula marks on the side of gum-trees, letting us know that they’re around.
Tony Eales, a Research Officer from Queensland, writes in with some lovely arthropod photos. His notes are indented.
So it’s winter in the southern hemisphere, and insects and other arthropods are more difficult to find. However when that happens I turn to the leaf litter. I collect a bag of litter from a likely looking spot and then sort through handful by handful on a white bucket lid, looking for movement. The bucket lid helps me see the tiny things crawling around but also has another effect. With a little manipulation of black/white levels on photoshop and some erasing I can isolate the subject in the photo against a white background. This effect can really help bring out the details of these tiny ground-dwelling creatures. Here’s a sample of some of the things that I’ve pulled out of the litter.
Having said all that the first subject is one from the trees rather than the ground. It’s a small male orb-weaving spider Araneus arenaceus the Sandy Orb-weaver. When disturbed, it heads to a twig and hunches up into this shape and becomes basically invisible, looking like any other small protrusion.
Commonly in the rainforest leaf litter I find harvestmen, arachnids in the Order Opiliones. The commonest are these peculiar creatures in the genus Bogania. I can’t find much information about them but I find the huge articulated spiked jaws fascinating. I’d love to observe them catching prey.
The thing about looking at the small stuff is that you’re going to be finding the unstudied stuff fairly regularly. This photo is of a spider in the cobweb spider family Theridiidae. Consulting with the experts on the spiders of my state, we can get it down to the subfamily Hadrotarsinae, but that’s as far as anyone can get. Despite many surveys of the leaf litter in my part of the world, some groups are just not known. I love the long setae on the back.
Next is an insect I’ve shown before. It’s a Trilobite Roach genus Laxta. This one is a nymph although females remain wingless like this but are much darker with thicker exoskeletons.
This is a tiny ant from a genus restricted to the Indo-Australian region. There are only nine described species and they live in small colonies of around 100 ants, foraging in the leaf litter. I think I’ve keyed this one out to Mayriella abstinens, but it’s definitely Mayriella sp. as identified by the deep antennal scrobes (grooves) in the head.
The rainforest leaf litter contains many tiny land snails, most often in the Family Charopidae. There are numerous species with very similar form and thus it is difficult to even get to genus with most that I find. This one, Nautiliropa omicron, however, is quite distinctive with a bi-concave nautiloid shell, delicate ridges and zig-zag patterning.
I’m not sure why this tortoise leaf-beetle was in the leaf litter, as I normally find them in the bushes on live leaves. It’s definitely in the genus Paropsisterna related to P. decolorata, but there’s a problem for researchers describing these beetles, as they have distinctive colours and golden iridescences until they’re dead, and then they lose their colour. It makes it very difficult to compare with the holotypes, many of which were sent to Europe and researchers here aren’t sure if a particular beetle already has a name or not.
Last, some more from my favourite order, spiders. This hairy one is a crab spider. An undescribed member of genus Sidymella. They appear to be fairly common in the leaf litter which is quite unusual for crab spiders. I can’t think of another one that lives on the ground.
Next, I am told by someone more capable in spider ID than I, is genus Spermophora…maybe. It’s a cute little jack-o-lantern-faced cellar spider, Family Pholcidae. I was trying to get to the bottom of what species it is and the key paper on Australian Pholcids has this to say “Spermophora is probably the most chaotic genus within pholcids”, plus it lists only two species in that genus—both far in the tropical north. So who knows. Cute, though.
Last is a jumping spider in the small genus Tara. It’s one of two types I always find in the rainforest leaf litter. Not very colourful for a jumping spider but with those big forward facing eyes they are the most appealing of all spiders.
Today we have a potpourri of photos from readers who sent in just one or two. All readers’ comments are indented, and the first is from Barbara Wilson:
For years, native Western Gray Squirrels (Sciurus griseus) was the only squirrel in my neighborhood in Corvallis, Oregon. Two or three years ago, they were replaced by Eastern Gray Squirrels (Sciurus carolinensis). On June 12, a Western visited my yard. Soon after it left, an Eastern appeared. I hope the Westerns wipe out the Easterns, but they’ve been losing ground here.
The Eastern has brown in the fur and is facing right. The Western is all gray and white and is facing left.
From Christopher Moss, a buck in velvet and an eagle:
There’s a pair of white-tailed deer bucks (Odocoileus virginianus) coming through the garden quite regularly, and I’m surprised at how quickly they are growing antlers. Two weeks ago this lad had a pair of little nubs. If they decide to continue life in the village they may have the chance to grow a decent rack as they will be safe during deer hunting season here!
Not especially stunning photo of a bald eagle, Haliaeetus leucocephalus, but remarkable for this – they were taken while I stood in the middle of my living room floor! This chap was interested in the remains of a raccoon carcass that the foxes who live under that tree had left outside their den. Actually managed to fly off with a good sized chunk of it, too!
From Alexandra Moffat in New Hampshire:
This picture was taken on Vinalhaven Island, Penobscot Bay, Maine, June 2020 by Banner Moffat. I looked it up in Maine spiders and could not find it -unless it is perhaps some life stage of Yellow Garden Spiders. The latter appear quite different in the guide where I searched. [JAC: To me it looks like some sort of crab spider, but what do I know?]
From Andrée Reno Sanborn. Help provide and ID for these. I’m not sure if it’s a mimic, but the coloration does look aposematic (“warning coloration”):
The first pic was from far away and I knew it was a creature and then thought “must be a bee/wasp/hornet.” Took the long shot, and crept closer and closer till I got the 2nd pic and said,”whoa! I never get a face-on shot.”
Do the colors and wing position say mimicry to you? Or am I reading too much into this? I see it everywhere: moths that look like bark or autumn leaves . . .and this.
From Mark McCauley:
I saw the octopus video on your site. This is a photo of me with an octopus on a night-dive off Cozumel. It was white because it was previously resting on the sand.
Is it my imagination, or is ZeFrank getting more biology into his posts than before? This is a good one, with a lot of good biology but also with the usual humor. It’s also scary! Look at that radula!
This is incredibly cute: the combination of the kind divers helping a vulnerable little octopus, the way the creature explores the proffered shells with its tiny tentacle, and its final acceptance of a new home. Lovely!
Today’s photos comprise an underwater montage from reader Peter Klaver. Peter’s notes are indented.
Here are some diving pictures of ‘(mostly) static’ underwater wildlife, shot on diving trips in Mozambique, Malaysian Borneo, and Australia. The first four are hard corals in the genus Acropora. The one on the first photo may be Acropora digitifera.
The two below are brain corals, the first one possibly being Diploria strigosa, but it could be something else too.
Here is a photo from a dive in very clear water, with the bottom looking like an underwater garden.
And I have no idea of the Latin names of these last two.
Although Jerry has been receiving fresh wildlife photos from readers, I thought I’d chip in with a few of mine and my correspondents from San Diego. We begin with a wild inhabitant of the San Diego Zoo, the introduced green anole, Anolis carolinensis. Native to the southeastern United States, they became established at the Zoo many years ago, probably by escapees.
Anolis carolinensis, female, in West Indian rock iguana exhibit at San Diego Zoo, September 1, 2018.
They are now scattered through several southern California counties, although it’s not clear if they are established and reproducing in all locations from which they have been reported. Another anole, the brown anole, Anolis sagrei, is also in southern California. Greg Pauly, of the LA County Museum, is studying these very interesting introductions. Much can be learned about ecological and evolutionary processes from study of populations confronted by, and confronting, new biotic and physical environments for the first time.
Next we have a western fence lizard, Sceloporus occidentalis, a native species, from Point Loma, San Diego.
Sceloporus occidentalis, Point Loma, San Diego, California, March 22, 2019.
Old Point Loma Lighthouse, San Diego, March 22, 2019.
We’ll finish off with two inhabitants of Murphy Canyon, a suburban neighborhood within the city of San Diego. First a snail on the sidewalk– I’ve no clue on the ID.
Snail, Murphy Canyon, San Diego, March 22, 2019.
And last, but certainly not least– in fact I think it’s the best in this set– a southern alligator lizard, Elgaria multicarinata. It was just strolling along through a lawn.
Southern alligator lizard (Elgaria multicarinata), Murphy Canyon, San Diego, California, March 15, 2019.
Several species of animals, including damselflies, are known to remove sperm—presumably from previously-mating males—before they ejaculate their own sperm into a female. (Damselfly males have a “penis scoop” for this purpose; see photo at bottom.) This removal is a prime example of male-male competition, which is a form of sexual selection that doesn’t involve female preference.
It’s been known for a while that some species of nudibranchs, gorgeous marine molluscs that lack shells, also remove sperm with spiny penises during copulation. These species, also known as “sea slugs”, are simultaneous hermaphrodites, so when they copulate, each individual both donates sperm to its partner and receives sperm in its own female bits. (They do not fertilize themselves).
In a new paper in the Journal of Ethology (click on screenshot below to see the free paper, and get the pdf here), Ayami Skiezawa et al. did something new: they did DNA analysis on the removed sperm to see if it actually did come from males who mated previously. After all, it could be a male’s own sperm instead of sperm from a competitor.
But first, the system. The species studied was Chromodoris reticulata, a lovely nudibranch found in tropical and subtropical waters of the western Pacific Ocean. It’s shown in the first photo below, which also shows how nudibranchs, which means “naked gills” get their name. (All photos and their captions are from a 2013 article by Ed Yong in National Geographic.)
Credit: Stephen Childs
Here’s copulation between two individuals; you can see that each one insinuates a thin penis into the female organs of the other:
Two mating Chromodoris reticulata. From Sekizawa et al., Biology Letters [JAC: reference and link to this paper at the bottom]The penis is covered with backwards-pointing spines that are covered with entangled sperm after copulation. The odd bit about this species is that the penis is self-amputated (“autotomized”) about twenty minutes after mating, and it simply grows a new willy, ready for copulation within a day.
Left: Spines on a nudibranch’s penis. Right: Sperm entangled in the spines. From Sekizawa et al., Biology Letters
The new paper, below, went a step forward from the morphological observations in damselflies and in the earlier paper cited above: it did genetic analysis of the removed sperm.
It turns out that while earlier work showed clearly that penises like this one removed sperm after copulation, it wasn’t absolutely clear that this sperm was that of males who had mated previously. While such removal would clearly be advantageous, leading the remover to have more offspring than he (I’m referring to the male bits) would have had otherwise, the notion that this was what was happening was based on looking at the amount of sperm in the female parts before copulation versus after removal (presumably in these cases ejaculation was prevented). It would be better to actually look at the genes in the sperm itself to see if the nudibranch was removing sperm from other males.
And that’s what Sekizawa did, and that’s what they found. They put nudibranchs, captured off Okinawa, in tanks and then gave them each three successive mating partners over a series of days. Each partner’s genetic constitution was determined using six microsatellite markers (bits of DNA). And after each copulation, they removed the sperm mass adhering to the spiny penis and looked at the genes in that sperm. This is a simple idea, but it’s important to do this kind of analysis so you can see what’s really happening.
The results were crystal clear: in 36 sperm clumps taken from postcopulatory penises, 28 had genes from nudibranchs who had deposited sperm in the mating partner in an earlier mating. Indeed, in some individuals they found sperm that didn’t match any of the nudibranchs who had mated with the partner; this might have been from individuals who mated with the focal nudibranchs before they were taken from the wild. They also found some genes from the mating partner itself, probably from bits of tissue adhering to the spiny penis. And in some cases sperm from at least two previous mating partners was found.
This pretty much finalizes our understanding of this phenomenon, at least in this species of nudibranch. There’s little doubt of the selective advantage that accrues to an individual who removes sperm from a previous mating partner: you get more offspring than you would have had otherwise.
One question remains, though: why do these things self-amputate their penises after each mating? The authors suggest an answer (my emphasis):
C. reticulata autotomizes its penis after every copulation (Sekizawa et al. 2013) and it is thought that the autotomy of the penis evolved to remove allo-sperm from the mating partner efficiently. We clarified in this study that sperm donors removed allo-sperm already stored in the copulatory pouch(es) of sperm recipients with backward-pointing spines on the penis as the final process of their copulation. Though a long and thorny penis is advantageous in scraping out allo-sperm at copulation, such a penis is difficult to pull back into the body again after copulation. And the backward-pointing spines on the penis covered with sperm at copulation will not remove allo-sperm efficiently at the next copulation, like a VelcroTM tape. Such morphological and functional inconveniency may have made C. reticulata develop a cheap and fragile penis and dispose of it, rather than a robust but expensive one and reuse it.
Just for fun, here’s how damselflies do it. This figure, showing the damselfly penis with a glop of sperm, presumably from a male who mated to the female previously, is from a paper by Jon Waage. “sm” refers to the sperm mass adhering to the penis, also bearing backward-pointing spines. This spiny morphology and its function are remarkable examples of convergent evolution in two distantly related groups, insects and molluscs. This photo comes from Jon Waage’s Researchgate page; Waage, now a professor emeritus at Brown University, is the one who made this remarkable finding 35 years ago.
We have some photos from New Zealand sent by reader Keith Cook, whose comments and IDs are indented.
These attachments are a collection of pics from around my home and the local beach. I include some landscapes a la Stephen Bernard, seeing and raising his with a South Pacific sunrise or two… and a moon rise to finish it off. I like how the praying mantis, kereru, poaka, seem to be checking me out and the honey bee’s world of colour.
For animals, the common name is given first, followed by the Maori name.
Asiatic Honey Bee/Pi (Apis cerana probably). While New Zealand already had native species of bees, they were not suitable for producing honey, as their role was as pollinators.
Giant Centipede/Hura (Cormocephalus rubriceps). I think this little creature got a little stressed before i returned it to the bush; it was interrupted while clearing scrub.
The Rata tree unfortunately succumbed to a violent storm which knocked over its support as they are usually epiphytes (or plant perched on a host tree). It was a sad day. It was close to our home and it probably could not have stayed there if it had not been taken out by the storm. I was trying to think of ways to relocate it and where. I see now we may have the possibility of a few more Rata establishing themselves, they can be and are valuable source of food for the locals, a future resource.
This photo is a closeup of the same Nikau palm the Kereru is feeding on: a pair of Kereru, probably generational offspring that come duringspring/summer on their feeding runs (we have lived here for decades). The nikau seeds go shades of red when ripe.
The fronds are pushed aside at the base by a pod containing the seeds which you see here fully developed but not ripe. They are rather delicate and flower when they first burst out. The frond eventually severs its connection to the trunk as all this pod action happens. They are long, usually 2 to 3 meters plus in length and heavy at the base. They are no problem. . . until they start sailing down on you, and THUMP!
