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.
Okay, this one is really hard—perhaps the hardest “spot-the” photo we’ve ever had.
Somewhere in the photo below is a salamander. Can you spot it? If you do, just say “found it” or “didn’t find the damn thing” in the comments below. The reveal will be at 1 p.m. Chicago time.
The photo comes from reader Bob Woolley from North Carolina. He sent an “easy” one first, but I thought it was too easy so I’m posting the second one he sent. Here are Bob’s notes:
If you’d like an easy “spot” feature, attached is a picture I took yesterday of a salamander in a stream in Gorges State Park, North Carolina, on the trail to Rainbow Falls. [JAC: this photo isn’t shown.]
On the way back from the waterfall, I looked for the salamander again. This time he was much harder to see. I’ll send those in the next email, in case you want to do what I think would be a very hard version of the same game.
And it’s the “very hard” version you see below.
Click the photo to enlarge it: twice (with a short pause between clicks) to make it big:
Today I’m assembling photos from readers who sent in a small number. Their captions are indented, and you can enlarge the photos by clicking on them. I’m assuming all ducks are mallards (Anas platyrhynchos).
DUCKS from Peter Fisher:
I came across this family of ducks in a rather lovely setting in Rydal Water in the English Lake District. Mum is clearly keeping watch. There were six ducklings, (one must have escaped the frame).
From Christopher Moss:
Some more for your stash. I received the 2x teleconverter today, so these were taken with the full frame equivalent of a 1200mm lens! I need to practice some more with it, as it is prone to camera shake, but there is promise there.
The California Department of Fish and Wildlife writes (click here)
“Adult American bullfrogs have voracious appetites and will eat anything they can fit into their mouths, including invertebrates, birds, bats, rodents, frogs, newts, lizards, snakes, and turtles. Bullfrog tadpoles mainly eat algae, aquatic plant material, and invertebrates, but they will also eat the tadpoles of other frog species. As a result of these feeding behaviors, all life stages of bullfrogs prey upon and are able to out-compete native frogs and other aquatic species. Additionally, bullfrogs are a known carrier of chytrid fungus, which causes the potentially fatal skin disease in frogs called chytridiomycosis. Chytridomycosis is believed to be a leading cause of the decline of native amphibian populations all over the world and responsible for the extinction of over 100 species since the 1970s.”.
Apparently, the American bullfrog will, or will try to, eat anything that won’t eat it first. My extended family member, Eleanor, knew that bullfrogs had exterminated her singing chorus frogs, (genus Pseudacris, multiple species) and was not terribly surprised when she came upon this bullfrog attempting to swallow a pre-deceased adult bird, one that ultimately proved to be too large for consumption – but the frog came very close to swallowing something nearly as large as itself!
From Sharon Diehl:
Bald Eagle (Haliaeetus leucocephalus) pair atop Transform Tower #199, Wally Toevs Pond, Walden Wildlife Habitat, Boulder, Colorado. I have photographed this mated pair for years at Walden Wildlife Habitat, where they hang out atop the transform towers that overlook Wally Toevs Pond. They aren’t always successful breeders, but they keep at it, together year after year.
Red-tailed Hawk (Buteo jamaicensis) hunting at my backyard bird feeders–where, alas, it caught a bird–at least it was a Starling. I know the raptors have to eat, too:
Downy Woodpecker (Dryobates pubescens), on the Hornbeam tree I believe, waiting for the flicker to leave the suet feeder–my backyard, Boulder, Colorado.
Osprey (Pandion haliaetus) in a tree, overlooking a lake in East Boulder Community Park, Boulder Colorado.
. . . and more DUCKS from reader A. C. Harper:
Two ducks making the most of pondweed on water at Fairhaven near the Norfolk Broads. Pictures taken on holiday at South Walsham July 2025.
Aaaaand. . . we have two batches left, so please send in your good wildlife photos.
Today we have another demonstration of the presence of wildlife in urban habitats, this time in temporary ponds. The photographer is Dick Kleinknecht; his captions and IDs are indented, and you can enlarge his photos by clicking on them.
Neighborhood storm-water ponds can become waterfowl habitat
Increasing governmental requirements for storm-water management have led to a sizable growth in the number of small, year-round mini-lakes throughout the region (Western Washington), which mitigate rain runoff problems ,as intended, but also increase available annual habitat for aquatic fauna. This post describes one such storm-water mini-lake. My particular pond, in the middle of a medium to large housing development, has a half-mile long asphalt path around it and provides substantial visual interest while out for a multi-lap walk. Year-round mini-lakes such as this can create a home for year-round aquatic residents. All photos are mine or my daughter’s, and all were taken with a Samsung Galaxy S9 phone/camera.
The next photo shows a pair of Canada Geese (Branta canadensis) and their two new goslings standing in the grass border between the pond and the path. Papa Ganders (male geese) are always on guard duty while Momma Geese and the kids eat. The city mows the grass/reed lake border but has agreed not to do so until after the nesting waterfowl’s eggs have hatched and the newborns can swim.
The following picture shows a basking resident turtle (most likely ID is a non-native Trachemys scripta elegans, AKA Red-eared Slider) and a momma Mallard (Anas platyrhynchos) with her brood:
Our ducks and geese certainly play well together. Here we see a dozen or so ducks on the shore while a small flotilla of geese, all in a row, swim over to join them:
There were several duck families on the pond, and each had their own duckling brood. This family seemed to be trying to swim in a straight line behind Mom, but perhaps they were a bit too undisciplined to pull it off. They gave the appearance of trying, however ineffectual the performance.
A curious observation on this pond: Drakes (male ducks) didn’t stick around very long after the ducklings had progressed to the point where they began to replace fluff with feathers, while the ganders actually guarded and went swimming with the whole family at least until the goslings matured to the point where I had difficulty differentiating them from their parents at a distance.
Our resident Great Blue Heron (Ardea herodias) does more than just pose for pictures. The bird also is a successful hunter, doing its part to keep the bullfrog population under control: Happy heron, sad American bullfrog (Lithobates catesbeianus)!:
Reader Lou Jost, a naturalist and evolutionist who works at the Dracula Reserve of Ecuador’s EcoMinga Foundation, just sent me this Facebook post put out by an Ecuadorian province a few years ago. It features MY frog, Atelopus coynei (it’s got a Wikipedia page, too), so it’s a bit self-aggrandizing of me to post this, but in fact the species is critically endangered and I want it saved. There are surely other undescribed and endangered species on the property (here’s a new tree frog discovered and described by the tem on the reserve.)
The story of the frog, how it got my name, and how it seemed to have gone extinct, but, Lazarus-like, was discovered by Andreas Kay decades later in Chinambi, Carchi, Ecuador, can be seen here.
Isn’t it a beaut? I suspect that its colors indicate that the frog is aposematic, i.e., toxic or dangerous to eat or touch. (The photo is by the late Andreas Kay courtesy of Wikimedia Commons.)
Click photo below go to the FB post:
Lou adds this:
The province is proud to be the only place in the world where your frog survives. It is one of the fruits of our work trying to raise awareness for the rare species of our reserves.
Our president, Noboa, is firing massive numbers of public employees from ministries he doesn’t like, and closing or re-organizing them so he can do what he wants. Last week he placed the ministry of the environment into the ministry of energy and mining, and this is expected to make it harder for us to fight our main threat in the Dracula Reserve, mining.
There is at least one population of A. coynei outside our reserves. It was the first one that Andreas Kay found. We tried to buy it but the property was apparently involved in drug trafficking and arms dealing, and this scared us too much to deal with it. Maybe someday we or others will be able to protect this population too. We also continue to search for more populations using eDNA. Meanwhile we are monitoring our own populations and they are doing well. Each individual can be identified by their back pattern, so we can keep track of many of them.
If you want to donate to the reserve to save not only the frog, but tons of rainforest wildlife, Lou gave me this information:
Thanks Jerry, the Orchid Conservation Alliance is a US charity that can accept donations for us, and give tax credit for the donations. Donors should specify that their support goes to EcoMinga’s Dracula Reserve (which protects your frog)
I hope some readers can cough up a few bucks for the Reserve! Any amount will help.
photo by Juan Pablo Reyes and Jordy Salazar/EcoMinga
Today Mark Sturtevant has returned with pictures of diverse critters, including insects, amphibians, and gastropods. Mark’s IDs, links, and narrative are indented, and you can enlarge the photos by clicking on them.
Here are more pictures of various critters in my area, which is in eastern Michigan.
The first picture is a young treefrog, and it is about as big as your thumbnail. This will be one of two sister species in the area, either Cope’s Gray Treefrog, Dryophytes chrysoscelis, or the Gray Treefrog, D. versicolor. They are commonly green in green surroundings. If it is the latter species, then it is tetraploid and that is why it is a separate species from the former. Polyploidy is one way to quickly form a new species, and this is a classic example.
Next up are a couple of our local snails, the Brown-lipped snails, Cepaea nemoralis. I was not sure what to do with them, and so I did this. These snails were introduced from Europe, and are now widespread in the U.S.
The next several pictures are manual focus stacks that were staged on the ‘ol dining room table. First up is a young Flower Crab Spider. That name applies to many species of crab spiders that often lurk on flowers to capture prey. Based on its eye arrangement and prominent hairs, I am pretty sure this one is Mecaphasa sp.
The jumping spiders that follow are species that I’ve shown here many times. The first is a Dimorphic Jumping Spider, Maevia inclemens. This one was very fidgety and it needed something to eat to help settle down. The lights in the eyes of the first picture came from an LED modeling light to help me to focus. I liked the look and so I did not remove the highlighting in post-processing. In the second picture you can see reflections of my fingertips in the large frontal eyes.
Another common spider is the Bold Jumping Spider, Phidippus audax. This youngster was very easy to work with.
The weird creature shown in the next picture is one of our Harvestmen, I think Phalangium opilio. I don’t see this species very often even though it’s distributed all around me. I like them because males have really long pedipalps and horned chelicerae. In some populations, the chelicerae horns are much longer than what is seen here.
Next is a moth that flew inside the house one evening. I think it’s a new species for me – the Lunate Zale Moth, Zale lunata.
And finally, I spotted this large caterpillar one day when out with the cameras. This is a mature Polyphemus Moth larva, Antheraea polyphemus, and it will become maybe the 2nd or 3rd largest moth in the U.S. For the portrait picture, I was trying to get it to look all haughty and Offended, as caterpillars like this often look very offended when being handled. But instead, this one looked like it was Eevil and plotting something, Mwa ha ha haa.
These are additional photos from reader Loretta Michaels trip to the tropics (part 1 is here). Her IDs and identifications (the binomials are from me) are indented, and you can enlarge the photos by clicking on them. Some of the IDs weren’t supplied, so readers are welcome to try their hand. From Loretta:
These were taken in Oct/Nov 2024 on the Upper Amazon in Peru, as part of a boat trip around the region. If you wanted to add this to my description, I use a Sony DSC-RX10 M4 (a fantastic camera that for some reason Sony has discontinued, much to the disappointment of fans.)
Three more: The first one is a rare hybrid of a white-fronted capuchin and a red uakari (Cacajao sp.); when we visited a village, an old lady was caring for this juvenile, and said it had just shown up one day. Our guide was amazed, he’d never seen one. The other two are poison dart frogs:
Today we have photos of amphibians and other items from Matt Moran, an ecologist at Monteverde in Costa Rica as well as Professor Emeritus in the Department of Biology and Health Sciences at Hendrix College, Conway, Arkansas. Matt’s captions are indented, and you can enlarge his photos by clicking on them.
These are photos from the Children’s Eternal Rainforest in Costa Rica (25,000 hectares), where I work as a field biologist. I am engaged in several projects, but my major one is a study on the status of amphibians in the park. Amphibians around the world have been declining and this area of Costa Rica is one of first places it was documented. While many theories have been developed as to why amphibians are declining, the one with the most support that explains the sometimes sudden collapse of amphibian populations (especially frogs) is the arrival of a pathogenic fungus (Batrachochytrium dendrobatidis), commonly called chytrid. This fungus infects the skin of frogs and often causes high levels of mortality. It has been implicated in the extinction of dozens of species of frogs around the world.
In the Monteverde area where I work, the population collapses occurred in the late 1980s. Initially, 25 of the known 50 species from the area were missing, but over time, most reappeared, apparently surviving in small numbers and then recolonizing larger areas. It appears that this was a major selection event, so that individuals with natural resistance to the fungus survived to reproduce, while most died. It is estimated that in many species, over 99% of individuals died. About 5 species originally found in the area appear to be totally extinct. Others still missing from here exist elsewhere, although often at critically low levels. Many, however, have recovered and probably exist at levels similar to pre-fungus invasion times.
I am attempting to determine the frog community structure 35 years post-chytrid invasion. These data will be valuable in two ways: 1) to determine how the community structure has changed over the last 35 years, and 2) to determine how future community structure is different from today so that we will have long-term population trends (using now as a baseline).
This is an amazing place to work. I retired from academia several years ago and this has become my new passion. It is one of the most biodiverse protected areas on the planet and every minute I spend in the forest is enchanting beyond description.
Emerald Glass Frog (Espadarana prosoplebon). This is the most common glass frog (Family Centrolenidae) found in this area. As their name suggests, they have transparent skin on the ventral side and their internal organs are easily visible. Interestingly, this species, like most glass frogs, does not appear to have declined because of chytrid fungus invasion. Like all glass frogs, this one breeds in streams:
Reticulated Glass Frog (Hyalinobatrachium valerioi). A fairly common species in mid-elevation areas of rainforest. It is easily identified by the large yellow spots on the dorsal side:
Clay-colored Rain Frog (Pristimantis cerasinus). A small frog found perched on leaves in the rainforest. It is identified by its eye color, often called “sunset” eyes, with the contrasting yellow (dorsal) and brown (ventral) parts of the iris. It has direct development where eggs are laid on the forest floor and the tadpole develops inside the egg directly into a miniature version of the adult. This species declined with the arrival of chytrid fungus but now appears to be relatively common again:
Sunset over the Children’s Eternal Rainforest, Costa Rica:
Evergreen toad (Incilius coniferus). A common toad found in mid- and low-elevation rainforest. This species is one of the few true toads (Family: Bufonidae) that can readily climb vegetation, although they are also often found inside the burrows of other animals. They are highly toxic and probably have few predators:
Puma (Puma concolor) track. These big cats are common in rainforests through Costa Rica. We also have jaguars (Panthera onca), but jaguar tracks are the size of your hand, including the fingers!!, while puma tracks are the size of the palm of your hand. Because it had rained very hard the night before, I knew this track was less than 8 hours old!:
Atlantic Forest Toad (Incilius melanochlorus). Another common toad. This one declined dramatically with the arrival of chytrid fungus but now appears to have fully recovered:
A giant Ceiba tree (Ceiba pentandra). This is one of largest trees in Central America, reaching heights of over 70 meters. Because they often grown above the canopy (emergent tree), they are the favorite nesting sites of many raptors (e.g., Harpy Eagle, Harpia harpyja) where the elevated platform provides a good viewing point and relative safety from nest predators. This tree may be over 300 years old:
When I first saw this snake, I thought it was the highly venomous Fer-de-lance (Terciopelo in Costa Rican Spanish, Bothrops asper). However, this is the False Fer-de-lance (Xenodon rabdocephalus), a harmless mimic. I have often wondered if it is true case of mimicry trying to make potential predators think it is the deadly pit-viper or if its patten is actually an example of convergent evolution for camouflage. It might function in both ways in that it does provide great camouflage, but if spotted, it also has the pattern of something very dangerous!?:
JAC: I added a photo of a real fer-de-lance from Wikipedia:
thibaudaronson, CC BY-SA 4.0, via Wikimedia Commons
