Category: animal behavior

Readers’ wildlife photos

March 30, 2026 • 8:15 am

I’m pretty much out of photos, so please send some in. Thanks!

Today’s photos comr from Jan Malik and were taken in New Jersey. Jan’s captions and IDs are indented, and you can enlarge the photos by clicking on them.

Here are a few pictures from my walk on the first day of spring in the New Jersey Botanical Garden in Ringwood, NJ. The quality isn’t the best (long distance, heavy cropping, fast‑moving subjects, and, let’s be honest, a mediocre photographer), but the series gives a sense of what early spring feels like for the birds.

Tree Swallows (Tachycineta bicolor) have arrived in the Northeast from their wintering grounds in the Caribbean. The first task for the males is to secure a nesting site. A natural tree cavity will do well, but those are scarce, so human‑made nest boxes are highly prized:

There are no property rights in the swallow world. A box is yours only if you can defend it, and a challenger usually appears sooner rather than later:

Both birds are males, judging by their metallic blue sheen and their persistence in aerial combat;

Outside the breeding season, Tree Swallows can be quite social, but securing a nesting site takes precedence over chivalry. No swallow lady is going to elope with a nestless beau:

Nest boxes are fitted with metal predator guards meant to deter squirrels and rat snakes. This one, however, wouldn’t slow down a determined squirrel for long:

Sometimes these fights end badly. Not because one bird actually kills the other, but because a damaged wing is effectively a death sentence:

The combat pauses briefly when a Red‑shouldered Hawk (Buteo lineatus) appears, circling in the thermals to gain altitude on its northward migration. Both swallows take shelter in a nearby tree until the danger passes:

Once the hawk moves on, the duel resumes, with both birds circling around the prize they’re fighting for:

Their Latin name suits them well — they are indeed “fast‑moving, two‑colored” birds. Their high airspeed is a challenge for inexperienced photographers. It doesn’t help that they’re smaller than an average sparrow and weigh only about 20 grams. No way they could tow a coconut, even in tandem:

I’ve had better luck photographing them during nesting season, when they fly more predictably while hunting insects on the wing. In this aerial melee, though, their flight is wildly erratic:

Eventually, the winner of this round inspects his real estate. The duel lasted a little under an hour, with both birds spending most of that time in the air and burning a lot of energy:

Kākāpō cam!

March 18, 2026 • 8:15 am

Today I’m putting up an animal cam in lieu of Readers’ Wildlife Photos because I need to conserve the latter: I have only about two batches left. If you have some, send them in!

But this is one of the best animal cams I have seen, for it shows in real time a very rare animal: a brooding female kākāpō and her chick (Strigops habroptilus). This is the world’s only flightless parrot, and is found in New Zealand, where it evolved in the absence of mammalian predators. Now it’s highly endangered, with only a few hundred individuals left, but an intensive conservation effort by New Zealand is bringing them back. This effort includes putting all kākāpōs onto islands where potential predators birds have been removed. As Wikipedia notes,

The kākāpō is critically endangered; the total known population of living individuals is 236 (as of 2026). Known individuals are named, tagged and confined to four small New Zealand islands, all of which are clear of predators; however, in 2023, a reintroduction to mainland New Zealand (Sanctuary Mountain Maungatautari) was accomplished.  Introduced mammalian predators, such as cats, rats, ferrets, and stoats almost wiped out the kākāpō. All conservation efforts were unsuccessful until the Kākāpō Recovery Programme began in 1995.

Newsweek, via reader Ginger K, offers us a link to a live kakapo cam. This is the only such bird ever to be livestreamed with a cam, and here’s some information about the video below from Newsweek. I find the feed mesmerizing, and watched the female sleep for a while last night (it was day in New Zealand), sitting on her fluffy white chick and occasionally grooming herself and the chick.

Newsweek:

A quiet underground nest on a remote island off New Zealand’s coast is captivating viewers around the globe as the world’s largest parrot species is livestreamed.

The YouTube livestream, Kākāpō Cam, offers a continuous view inside the nest of Rakiura, a 24-year-old female kākāpō—one of just 236 left worldwide. Rakiura has been living beneath a rātā tree on Codfish Island, also known as Whenua Hou, off the country’s southern coast, where she hatched two chicks this breeding season.

Since January, the footage has offered unpolished, intimate glimpses of the nocturnal, flightless parrot. Rakiura shuffles in the nest, preens her green feathers, settles her body protectively over her chick, and occasionally leaves under the cover of darkness to forage before returning to feed. At times, the screen shows little movement at all—just the soft rise and fall of a bird resting, giving viewers a rare, real‑time look at a species most will never see in person.

“This is the only camera in a kākāpō nest this season, and the only nest we’ve ever streamed live,” Deidre Vercoe, operations manager for Kākāpō at New Zealand’s Department of Conservation (DOC), told Newsweek. “Kākāpō Cam provides insights that help guide us to support their recovery, while also giving people around the world a chance to connect with this incredible species.”

. . .While most female kākāpō choose new nesting spots each breeding cycle, Vercoe said Rakiura has returned to the same site every season—allowing conservationists to reinforce the nest and carefully plan a reliable camera setup months in advance through the DOC’s Kākāpō Recovery team.

Hands‑on fieldwork began in October 2025 and will continue for most of the year, involving around 30 DOC staff, specialist support teams and 105 volunteers, each donating two weeks of their time.

The team also added drainage and a small access hatch to protect eggs and chicks without disturbing her natural behavior.

The camera was first trialed during the 2022 breeding season, but this year’s stream went live in time to capture egg‑laying and hatching for the first time.

Rakiura successfully hatched two genetically important chicks on February 24 and March 2, though the older one was later transferred to a foster mother so she could focus on raising the remaining chick, Nora‑A2‑2026, now the star of the livestream. The team will check on the chick every three days until it is one month old.

Okay, enough information. Watch below live NOW. If mother Rakiura is out, you’ll still see the chick. When I put this up at 8:15 a.m. Chicago time, it will be 2:15 a.m. in New Zealand, and it looks like mom is still sleeping.  Watch from time to time so you can see the chick. She’s very solicitous of it and grooms it often.

Lagniappe: a tweet on this season, a great one for baby parrots, from New Zealand Conservation

And one of the best animal videos ever: a male kākāpō, Sirocco, shagging biologist Mark Carwardine while Stephen Fry looks on and narrates. This was from the BBC show “Last Chance to See,” about endangered species:

When I went to New Zealand a while back, I really wanted to see these birds, but you really can’t: you need a good reason to get to the islands where kākāpō are kept. To do that, you have to be somehow involved in their conservation. You can volunteer to live on the island for several months and help monitor the birds, but that’s a big commitment just to see them. However, if you want to help save them, you can donate here.

A muddled argument: Shermer argues for the reality of free will

February 22, 2026 • 10:00 am

Michael Shermer has a new book out called Truth: What it is, How to Find it, and Why it Still Matters, and I’ve mentioned it before. I’m reading it now, and there’s a lot of good stuff in it. But one of the twelve chapters—the one on free will—is, I think, misguided and confusing. In the preceding link you’ll find a video he made about free will, as well as my critique of it. You may not want to read this post if you’ve read the previous one, but the video differs slightly from the article I discuss below.

So here’s my take 2 on Shermer’s views, recently expressed in a longish article in Quillette. (Michael was kind enough to send me a pdf, so I presume he wants my take.) Read it by clicking on the screenshot below, or find it archived for free here.

In short, Shermer is somewhat of a compatibilist—or so I think, for though doesn’t seem to fully on board with libertarian “you-could-have-done-otherwise” free will, but neither does he accept physical determinism.  Further, he doesn’t seem to think that “you could have done otherwise” is even testable, as we’re never in the same situation twice.

He’s right about the untestability criterion. But that doesn’t matter, for even if we were in the identical situation, with every molecule in the universe exactly as it was the first time, there are fundamentally unpredictable events of the quantum kind that might lead to slightly different outcomes. And the more distant in the future we look, the more divergent the outcomes will be. I’ve already noted that the future is probably not completely determined because quantum events could be cumulative.  In evolution, for instance, natural selection depends on the existence of different forms of genes that arise by mutation. If quantum effects on DNA molecules can lead to different mutations, then the raw material of evolution could differ if the tape of life is rewound, and different things could evolve.

Further, if quantum phenomena affect neurons and behavior, it’s possible—barely, possible, I’d say—that in two identical situations you could behave differently. I don’t believe that, and neither does neuroscientist Robert Sapolsky, but quantum phenomena that affect molecular movement or positions do not give us free will, as our “will”, whatever that is, doesn’t affect the physical behavior of matter. And so, if we use Anthony Cashmore’s definition of “free will” as given in his 2010 paper in PNAS (the paper that made me a determinist), fundamentally unpredictable quantum effects do not efface free will. Cashmore:

I believe that free will is better defined as a belief that there is a component to biological behavior that is something more than the unavoidable consequences of the genetic and environmental history of the individual and the possible stochastic laws of nature. 

Cashmore takes care of quantum effects by lumping them as the “possible stochastic laws of nature.” (Some physicists think that quantum mechanics is really deterministic though it seems otherwise.)

But Shermer doesn’t talk much about quantum physics—in fact, he doesn’t mention it at all.  He simply argues by assertion, saying that yes, we could have done otherwise, and we could have done so on the rather nebulous bases of “self-organization” and “emergence”.  Let’s take the assertions first. I’ll have to quote at greater length than usual:

Since philosophers love to employ thought experiments to test ideas, here’s one for you to consider (feel free to plug yourself and your spouse or significant other into the situation): John Doe is an exceptionally moral person who is happily married to Jane. The chances of John ever cheating on Jane is close to zero. But the odds are not zero because John is human, so let’s say—for the sake of argument—that John has a one-night stand while on the road and Jane finds out. How does John account for his actions? Does he, pace the standard deterministic explanation for human behaviour (as in Harris’s and Sapolsky’s definitions above), say something like this to Jane?

Honey, my will is simply not of my own making. My thoughts and intentions emerge from background causes of which I am unaware and over which I exert no conscious control. I do not have the freedom you think I have. I could not have done otherwise because I am nothing more or less than the cumulative biological and environmental luck, over which I had no control, that brought me to the moment of infidelity…

Could John even finish the thought before the stinging slap of Jane’s hand across his face terminated the rationalisation? If free will is the power to do otherwise, as it is typically defined by philosophers, both John and Jane know that, of course, he could have done otherwise, and she reminds him that should such similar circumstances arise again he damn well better make the right choice… or else.

This is argument against free will by assertion alone.  What his wife is evincing here is her illusion of free will. Nobody denies the fact that we feel that we could make real choices. But that doesn’t mean that we do.

But where’s the evidence that John Doe could have refrained from his one-night stand?  He is correct in thinking that he could have not done otherwise (how could he unless some undefinable, nonphysical “will” affected his libido?), but his wife, subject to the universal illusion that our behavior is more than “the unavoidable consequences of the genetic and environmental history of the individual and the possible stochastic laws of nature”, believes in some undefinable property called “will” that could change the outcomes of a given situation. She thinks that John could have chosen not to fall prey to the allure of that other woman.

So Jane gives John a slap (that slap, too, was determined). And the slap could change John’s future behavior so that he refrains from other affairs, for, like all vertebrates, we learn from experience. That’s the result of evolution. (Keep kicking a friendly dog and see how long it remains friendly!).  He concludes what’s below (bolding is mine): But nobody with any neurons to rub together argues that changing behavior via learning somehow violates determinism.

More from Shermer:

But this is not the universe we live in. In our universe (unlike the one in which thought experiments are run), the Second Law of Thermodynamics and entropy means that time flows forward and no future scenario can ever perfectly match one from the past. As Heraclitus’ idiom informs us, “you can’t step into the same river twice,” because you are different and the river is different. What you did in the past influences what you choose to do next in future circumstances (the technical name for this is “learning”), which are always different from the past. So, while the world is determined, we are active agents in determining our decisions going forward in a self-determined way, in the context of what already happened and what might happen. Our universe is not pre-determined but rather post-determined, and we are part of the causal net of the myriad determining factors to create that post-determined world. Far from self-determinism being a downer, it’s the ultimate upper because it means we can do something about the future, namely, we can change it!

I don’t really understand this paragraph, nor the part in bold. In what sense are we active agents in determining our decisions in the future? Shermer doesn’t tell us, but he seems to be thinking of some nonphysical power of “will” to change the physics that governs our brains and behaviors. In fact, there is redundancy here: we determine our decision because our behavior is self-determined!

Apparently Shermer rejects physical determinism because, given the present, more than one future is possible. The laws of physics are likely to be, at bottom, unpredictable, though their effects on “macro” phenomena are probably minimal, and their effects on the behavior of human and other creatures is unknown. Shermer is even somewhat rude to determinists like Sam Harris and Robert Sapolsky (and, implicitly, me, as I’m with them): we are hidebound reductionists plagued by “physics envy” (bolding is mine):

Do determinists really fall into the trap of pure reductionism? They do. Here is the determinist Robert Sapolsky defending his belief that free will does not exist because single neurons don’t have it: “Individual neurons don’t become causeless causes that defy gravity and help generate free will just because they’re interacting with lots of other neurons.” In fact, billions of interacting neurons is exactly where self-determinism arises. But Sapolsky is having none of that: “A lot of people have linked emergence and free will; I will not consider most of them because, to be frank, I can’t understand what they’re suggesting, and to be franker, I don’t think the lack of comprehension is entirely my fault.”

Determinists like Harris and Sapolsky have physics envy. The history of science is littered with the failed pipe dreams of ever-alluring reductionist schemes to explain the inner workings of the mind—schemes increasingly set forth in the ambitious wake of Descartes’ own famous attempt, some four centuries ago, to reduce all mental functioning to the actions of swirling vortices of atoms, supposedly dancing their way to consciousness. Such Cartesian dreams provide a sense of certainty, but they quickly fade in the face of the complexities of biology. We should be exploring consciousness and choice at the neural level and higher, where the arrow of causal analysis points up toward such principles as emergence and self-organisation.

So what is there to behavior beyond atoms moving around according to physical principles? Shermer doesn’t tell us, but he seems determined (excuse the pun) to convince us that we do have free will, and it seems to be of the libertarian sort! He even evokes the mysteries of consciousness, which many people, including Francis Crick, think is best studied not from a “top down” approach, but from a reductionist “bottom up” approach.  And we know from various experiments and observations that we can affect our notion of “will”, making us seem like we have it when we don’t (people who suddenly confabulate a purpose when they behave according to stimulation of the brain), or making us seem like we lack it when we are actually acting deterministically (e.g., ouija boards). We can take away consciousness with anesthesia, restore it again, or alter it with psychedelic drugs.  All this implies that yes, consciousness and “will” are both phenomena stemming from physics.

Shermer rejects bottom-up approaches, raising the spectres of “self-organization and emergence” as arguments against Cashmore’s form of free will:

This we have through the sciences of complexity, in which we recognise the properties of self-organisation and emergence that arise out of complex adaptive systems, which grow and learn as they change, and they are autocatalytic—containing self-driving feedback loops. For example:

Water is a self-organised emergent property of a particular arrangement of hydrogen and oxygen molecules.

Complex life is a self-organised emergent property of simple life, where simple prokaryote cells self-organised to become more complex eukaryote cells (the little organelles inside cells were once self-contained independent cells).

Consciousness is a self-organised emergent property of billions of neurons firing in patterns in the brain.

Language is a self-organised emergent property of thousands of words spoken in communication between language users.

That list goes on, but it’s muddled. First, what do we mean by “self-organized” properties?  Is water “self organized” beyond behaving in a glass in ways that are consistent with, but not necessarily predictable from, the behavior of a single water molecule?  Ditto for complex life.  In what sense are life and water “self-organized” rather than “organized by physics”? Yes, there are emergent properties, like the Eroica emerging from the pen of Beethoven, himself an admirable collection of organic molecules with the emergent property of writing great music.

Let’s dismiss “self-organization,” which seems like a buzzword that doesn’t advance Shermer’s argument, and concentrate instead on “emergence.”  Yes, water is wet. “Wetness” is a quale evinced in our consciousness, yet the properties of water that make it feel wet are surely consistent with, and result form, the laws of physics, just as the “pressure” of gas in a container is an emergent property of a bunch of gas molecules acting as a group. But nobody says that gas molecules have free will, even though some of their properties are “emergent.”

The issue here is not whether emergence is something predictable from a reductionist analysis, but whether it is something physically consistent with its reductionist constituents. If the laws of physics be true, then that consistency does nothing to efface determinism. Shermer’s failure is that he neglects to tell us the nature of something called a “will” that interposes itself between molecule and behavior.  And often, with greater knowledge of physics we can predict emergent properties from a reductionist analysis. (The gas laws are one such thing.)

I’ll draw this to a close now, adding one more note. Shermer’s failure is twofold. He fails to suggest how an undefined “will” can affect the behavior of matter, and he mistakes determinism for predictability, a rookie error. If quantum mechanics is a good explanation of physics, then the future is not 100% predictable, even if we had perfect knowledge of everything, which of course we don’t. And physicists tell me that quantum effects were important at the Big Bang, so at that moment the future of the entire universe was unpredictable. That says nothing about free will.

Shermer closes with another paragraph that I don’t understand; it sounds in some ways (this may anger him, but I apologize) like Deepak Chopra:

It may seem odd to think of yourself as a past-self, present-self, and future self, but as suggested in this language, your “self” is not fixed from birth, destined to a future over which you have no control. We live not only in space, but in time, and as such no matter the pre-conditioning factors nudging you along a given pathway—your genes, upbringing, culture, luck and contingent history—there is always wiggle room to alter future conditions. The river of time flows ever onward and you are part of its future.

Act accordingly.

This is more argument by assertion alone. I’m not sure what he means by “act accordingly”, much less “wiggle room.”  Of course we can be influenced by what we read, but we don’t have a “will” that could alter what we do at any given moment. As Cashmore said in his article:

Here I argue that the way we use the concept of free will is nonsensical. The beauty of the mind of man has nothing to do with free will or any unique hold that biology has on select laws of physics or chemistry. This beauty lies in the complexity of the chemistry and cell biology of the brain, which enables a select few of us to compose like Mozart and Verdi, and the rest of us to appreciate listening to these compositions. The reality is, not only do we have no more free will than a fly or a bacterium, in actuality we have no more free will than a bowl of sugar.

I don’t mind being like a bowl of sugar, or, rather, a complex piece of animated meat.  I admire Shermer for all he’s done to further skepticism and attack quackery, but I think that on the issue of free will he’s gone awry.

From AI:

Chimps engage with pretend objects, suggesting they have imagination and can engage in pretense

February 6, 2026 • 10:30 am

Humans have the ability to do “secondary representations”: that is, to pretend that one object or action is actually different from a real one. This can also be called “pretense”. Examples are children’s “tea parties” in which they use empty pots and toy cups, pretending to drink from the empty cups while knowing they are empty. Then they can pour pretend tea into one of two cups, and when asked to drink will drink from the “pretend full” cup. Or they can have sword fights with sticks, pretending that the sticks are real weapons while knowing they are not.

Secondary representations of states that are only imagined start early (some experiments suggest at 15 months), and the ability to imagine things that haven’t happened, or aren’t real, surely underlie much of human behavior involving planning for the future or imagining what someone might be thinking.  The authors of a new paper in Science (see below) argue that no such abilities to “pretend” or have secondary representations are known from any species save humans. (I am not sure about this. As I recall some birds caching food are known to unhide it and re-cache it elsewhere if they see other birds looking on: something that seems like an ability represent another bird’s state of mind.)

And there is anecdotal evidence that chimps can do this.  For example, female chimps have been seen to hold and carry sticks as if they were their babies; this involves imagining that the stick is a real baby (that only females do this suggests sexually differentiated behavior).  Or if chimps have played with blocks, sometimes they’ve been observed to drag around imaginary strings of blocks.  This and other data suggest that some primates can have imaginative representations, but the existing data, say Bastos et al., don’t rule out other explanations.

They thus did three experiments on a single, human-acclimated male bonobo at a facility in Iowa. The bonobo, named Kanzi, was 43 years old and died the year after the experiment (no, he didn’t pretend to be dead!). Kanzi has his own Wikipedia page, which notes his abilities:

Kanzi is well known for his noteworthy cognitive abilities. He had a very well-documented linguistic understanding of the human language. He is believed to be the first non-human great ape to understand and comprehend spoken English. In addition, he was also heavily documented for his understanding and usage of symbols to communicate, usually through lexigrams and partial ASL. The vast amount of information that researchers gathered from Kanzi created a significant impact for the fields of linguistics and cognitive science. Kanzi’s behavior and abilities have been the topic of research published in scientific journals, as well as reports in popular media. He died in 2025, in Atlanta, Georgia.

Click below to go to the paper (pdf here), or you can read a summary of the study in the NYT, written by Alexa Robles-Gil, here (archived here)

Three experiments were involved, but the second was really a control for the first.

First, Kanzi was prepared for the pretense test by letting him learn about a real object: fruit juice that could be poured into glasses from a pitcher. In 18 trials, real juice was poured into one of two cups from a pitcher. Kanzi, who had been trained to point at what he wanted to have, was then asked, “Where’s  the juice?” He was successful in all trials.

Then the pretense experiment began. The same pouring was done, but from an empty pitcher into both of two empty cups.  Then one of the pretend-filled cups was poured back into the pitcher, so it would be pretend-empty while the other was pretend-full. Again, Kanzi was asked “Where’s the juice?”  In 50 trials, involving no reinforcement of any kind for making the correct choice, Kanzi chose the pretend-full cup 34 times and the pretend-empty cup 16 times, a highly significant deviation from an expectation of 50:50 under the null hypothesis. This showed that Kanzi could track where pretend juice was.

The second experiment used a cup of real juice next to an empty cup, and the empty cup was pretend-filled from an empty pitcher. Then Kanzi was asked, “Which one do you want?” Kanzi wanted the real juice in 14 out of 18 trials, again, a significant deviation from 50:50 under the null hypothesis. This showed that Kanzi didn’t simply believe that there was real juice in the empty cups in the first experiment, for he was able to distinguish real juice from pretend-poured juice.

The third experiment was like the second, except involving grapes. First, Kanzi was “trained to indicate the location of a real grape in one of two transparent jars after observing the experimenter sample a grape from a plastic container and place it into one of the jars and perform a control action on the other jar.” When asked to choose one jar to get the grape, he was successful in every one of 18 trials.

Then Kanzi was given pretend grapes to choose. From the paper;

In probe trials, the experimenter pretended to sample a grape from an empty container, then placed it inside one of the two jars, before repeating the same action on the other side. Then, one of the jars was pretend-emptied, and Kanzi was asked, “where’s the grape?” Kanzi succeeded at this conceptual replication even more quickly than in the first experiment. He correctly indicated the location of the remaining pretend grape above chance, in 31 out of 45 unreinforced probe trials

Again, Kanzi was highly successful at the juice and grape trials, able to recognize a pretend action of pouring and emptying juice, and determining which of two jars containing pretend-grapes had had the grape removed. In other words, he was playing tea party, and highly successfully.

This one chimp, then, was able to conceptualize pretend actions as real ones.

There are a number of possibilities not involving secondary representation that the authors say could be happening here. For example, apes like Kanzi who have been trained to recognize symbols to represent objects (as he was), might be better at communicating their wishes than are wild apes. Or symbol training could actually create the ability to do secondary representation. It’s hard to rule out these possibilities since to do such experiments an ape has to be “enculturated” by interaction with humans, and Kanzi was surely highly enculturated.

But if the authors are right that these experiments show that apes can have secondary representation, playing along with “pretense”, that opens up a world of possibilities of thinking about the cognitive abilities of apes (and other animals). The authors dwell on this at the end:

Secondary representations underlie many other complex cognitive capacities, such as imagining future possibilities (20) and mental state attribution (13). Our results may therefore help to interpret other bodies of data that have been hampered by an apparent logical problem (32). Finding that a bonobo can generate secondary representations in pretense contexts increases the likelihood that these representations are available for other cognitive functions. This finding reinforces growing evidence that apes track decoupled mental states, such as beliefs, rather than simply reading behavior (25, 28, 31). It also increases the likelihood that secondary representations could subserve future-oriented behavior (24, 35, 50–53), whose underlying representations have not yet been established.

In conclusion, our findings suggest that some nonhuman animals can generate secondary representations that are decoupled from reality, and that this capacity was likely within the cognitive potential of our last common ancestor with other apes, which lived 6 to 9 million years ago.

It is no surprise that our closest relative (along with chimps) could do this. As Darwin posited in 1871, our own behaviors and mental states evolved from those present in our common ancestors.

Kanzi died suddenly the year after the experiment, simply collapsing. He apparently suffered a heart attack, as he had a history of heart issues and had previously been obese. You can read about his other training in representing objects with keyboard symbols at the Wikipedia site.

From Wikipedia, here’s Kanzi in 2006 (he died in 2025):

William H. Calvin, PhD, CC BY-SA 4.0, via Wikimedia Commons

Readers’ wildlife photos

January 19, 2026 • 8:15 am

Today we have a photo-and-text submission from Athayde Tonhasca Júnior on fly migration. It’s a subject dear to my heart as I used to work on it, publishing three papers on migration in Drosophila.  Athayde’s subject, though, is hoverflies, not fruit flies. His captions are indented, and you can enlarge his photos by clicking on them. Note: I changed Athayde’s words “hover flies” to the more common usage “hoverflies,” but Athayde notes that most entomologists use the two-word rather than one-word description.

On the road again, goin’ places that I’ve never been

Sometime between 1400 and 1200 BC, Yahweh (aka God) decided it was time to nudge the Egyptians to let their captive Israelites go. Yahweh could have tried diplomacy, but in his infinite wisdom he concluded that “The Egyptians shall know that I am the LORD”. And there was no better way to let the Pharaoh and his people know who the bigwig was around there than by punishing them with a series of plagues. Of the ten celestial disasters inflicted upon the Egyptians, two involved mosquitoes (or midges) and flies, which probably were also the agents behind another two plagues manifested as infectious diseases of people and livestock. Yahweh understood very well the efficacy of some flies (order Diptera) and pathogens to wreck revenge – after all, he created them.

Fig 1. The Third Plague of Egypt, by William de Brailes, circa 1250. Aaron strikes his rod on the ground, transforming dust into gnats (kinnim in Hebrew). In the King James version of the Bible, lice are the culprits, but today most scholars accept that kinnim should be translated as ‘gnats’ or ‘mosquitoes’ © Jan Luyken, 1712, Wikimedia Commons:

The tales of pestilent flies depicted in the book of Exodus could have been inspired by real events, as pest infestations and epidemics were recurrent in the ancient world. Fly outbreaks are facilitated by these insects’ capability to disperse for long distances and arrive at new locations suddenly and in massive numbers. There are no better examples of these efficient colonisers than hoverflies or syrphid flies (family Syrphidae) such as the marmalade (Episyrphus balteatus) and the migrant (Eupeodes corollae) hoverflies. Each autumn, they leave Britain and head south to spend the winter in southern Europe and the Mediterranean. Their offspring move northwards in the spring, lay eggs, and the new generation sets out on the cycle again. Researchers have estimated that up to four billion marmalade and migrant hoverflies cross the English Channel to and from Great Britain every year. This represents 80 tons of biomass. If you are impressed by these figures, you should know that hoverflies account for a fraction of insects’ latitudinal migrations known as ‘bioflows’: about 3.5 trillion insects, or 3200 tons of biomass, migrate into southern Britain annually (Wotton et al., 2019). Insect bioflows pour vast amounts of nutrients (particularly nitrogen and phosphorus) and countless prey, predators, parasites and herbivores into ecosystems, but we have only a vague understanding of their impact on food webs and local species.

Fig 2. A female marmalade hoverfly, a long distance frequent flier © Guido Gerding, Wikimedia Commons:

These hardy wanderers have another particularity of significant ecological importance: they transport pollen grains.

Most flies have no pollen-collecting structures and have few ‘hairs’ (setae), which are important pollen gatherers. These are negative marks for candidates to the pollinators’ club, but some flies compensate their shortcomings by their massive numbers. Each marmalade and migrant hoverfly carries an average of 10 pollen grains from up to three plant species on their journey into Britain. That’s paltry compared to a bee, but altogether, those flies bring in 3 to 8 billion pollen grains on each inward journey.

Pollen importation via flies is a recurrent phenomenon. In Cyprus, warm temperatures and favourable winds bring millions of insect migrants from the Middle East region, more than 100 km to the east. Flies make up nearly 90% of these bioflows, and many of them are loaded with pollen (Hawkes et al., 2022).

Fig 3. A common drone fly (Eristalis tenax) (A) and a blowfly (Calliphora sp.) (B) with orchid pollinia attached to their heads after a > 100-km sea crossing to Cyprus © Hawkes et al., 2022:

Pollen-loaded flies can turn up anywhere the wind takes them, even to specks of dry ground in the middle of nowhere. Over a two-month period, 121 marmaladehover flies reached a North Sea oil rig approximately 200 km from Aberdeen, UK. Over 90% of these flies had pollen attached to them, sometimes from eight plant species. Based on pollen barcoding and wind trajectory modelling, it was estimated that these flies traversed from 265 to 500 km of open water in a single journey, probably from the Netherlands, Germany and Denmark (Doyle et al., 2025).

Fig 4. (a) Location of an oil rig visited by hoverflies (b), and its aerial view © Doyle et al., 2025:

Flies’ long-distance pollen transfers may help connect isolated plant populations, such as in fragmented habitats, but we don’t know much about the ecological implications. However we do know that their contribution can be important. In continental Europe, wild carrot (Daucus carota) depends on a range of insects for pollinators, especially bees. But bees are absent from La Foradada, a 1,6 ha Mediterranean islet about 50 km off the Spanish coast. In this solitary spot of land, D. carota subsp. commutatus relies on the accidental arrival of common drone flies for its pollination (Pérez-Bañón et al., 2007).

Fi 5. La Foradada, devoid of bees and humans, is visited by pollinating drone flies © JavierValencia2005  Wikimedia Commons:

Butterflies, bumble bees, moths and dragonflies are known travellers, but we know much less about migrant flies, which may have significant roles in pollination ecology. We just have to pay more attention to these unpretentious pilgrims.

References

Doyle, T.D. et al. 2025. Long-range pollen transport across the North Sea: Insights from migratory hoverflies landing on a remote oil rig. Journal of Animal Ecology 94: 2267–2281.
Hawkes, W.S.L. et al. 2022. Huge spring migrations of insects from the Middle East to Europe: quantifying the migratory assemblage and ecosystem services. Ecography e06288.
Pérez-Bañón, C. et al., 2007. Pollination in small islands by occasional visitors: The case of Daucus carota subsp. commutatus (Apiaceae) in the Columbretes archipelago, Spain. Plant Ecology 192: 133-151.
Wotton, K.R. et al. 2019. Mass seasonal migrations of hoverflies provide extensive pollination and crop protection services. Current Biology 29: 2167–2173.

Readers’ wildlife video

January 4, 2026 • 8:15 am

Except for a few singletons and small contributions, this is the last readers’ animal contribution I have. Do you want to start the first work week in 2026 without animal photos? I hope not, so please send in your GOOD animal/wildlife photos.  Contributions seem to have slowed to a trickle: a bad portent for 2026.

BUT, Athayde Tonhasca Júnior sent in a YouTube video taken by his wife (Fiona Thackeray), and he adds some text (mostly not his) below.

We have met the enemy and he is us (Pogo the possum) 

A pied wagtail (Motacilla alba) confronts its doppelganger in Perth, UK. Footage by Fiona Thackeray:

For residents of Withycombe (an English village in Somerset), mirror-pecking can be a nuisance:

Love-sick birds have been plaguing a village by pecking and cracking car wing mirrors in the mistaken belief that their reflection is a potential mate. The situation has become so bad that motorists in Withycombe’s main street have taken to making special mittens to protect their mirrors from the onslaughts.

The culprits have been identified as a flock of grey wagtails that live beside the local stream in the West Somerset village. “It all started about two years ago,” said villager Marion Badcock. “We’ve all had to make the special covers in this part of the village near the ford.“If there’s two they don’t seem to bother but the single birds go mad pecking at themselves in the mirror.” She said the wagtails are obsessed by their self-image all year round, but it is “particularly bad now”. “It’s actually very funny to watch them,” she said. “They’ll look at themselves in your wing mirror, then do their business all over it, then fly on to the window ledge of the house to have a go at the glass. It’s as if they are saying ‘look what we’ve done’.”

Peter Exley, of the RSPB in the South West, explained: “Birds in general will do this at this time of year. “It’s all down to hormones. They get very territorial – if they see a reflection in a mirror they see it as an adversary. “The bird says ‘I’m going to see off that intruder in my area’ and then they get very agitated – so much so they can make an unfortunate mess.” He added that mirror attacks are not good for the birds’ stress levels: “Most of these birds don’t pair for life and there’s a whole load of strategies for finding a mate. “And if you’ve got cars parked near a river where grey wagtails are nesting – there’s only going to be one result.” National Biodiversity Network, March 2009.

Readers’ wildlife posts

December 23, 2025 • 8:30 am

Today we have some lovely bird photos from Scott Ritchie of Cairns, Australia. Scott’s captions are indented and you can enlarge the photos by clicking on them. Scott’s Facebook page, full of great photos, is here. (Photos used with permission.)

Social media, including Facebook, gets quite a bit of negative press these days. I get that. But one of the great values of social media is that it can put you in contact with people who can really help you out. In Sept. 2025, I started posting bird photos from my Western Australia trip. I was contacted by John Edmond, who lives in Perth. Last year, I met John in Cairns on our regular Tuesday AM bird walk, and then showed him some local birds along the Cairns Esplanade. John loves a twitch, and was especially happy to see Nordy, Nordmann’s Greenshank.

So John reached out on FB and offered to take me for a day’s birding in Perth. We had a great time and I particularly liked touring around Herdsman Lake. Here are some of my favourite images from that day’s birding.

The Pink-eared Duck [Malacorhynchus membranaceus] is one of my favourite birds. I was lucky to get nice close images of this bird. If you’re wondering about the name, look carefully at the head. You can just see a little bit of pink behind his eye. Personally, I’d name it the Zebra-breasted Duck.

And another. The flaps along the bill are used to help funnel microbe-rich water into their mouth.

The Great Crested Grebe [Podiceps cristatus] is another amazing bird. I just love the hairdo and the neck feathers during breeding season. Interestingly, this bird is found in wetlands from Asia Europe, Africa, and Australia. This is one of the grebes that does a upright mating dance that you may have seen on TV:

So am I gonna get lucky tonight? Let me think about it:

JAC: Here’s a YouTube video I found of the mating dance of this species. Don’t miss any of it!

I love the raking light on this stunning bird:

The Australian Shelduck [Tadorna tadornoides] during breeding season. The female is the one with the spectacles. It’s obvious she’s the only one with a good sense to wear glasses:

I like these this couple out for an evening promenade in the quiet water:

Herdman Lake like has more than water birds. This pair of Tawny Frogmouths [Podargus strigoides] are a bit of an institution there. People come around looking for these interesting, well camouflaged birds. See me if you can:

Australian Reed Warbler [Acrocephalus australis] was regularly heard singing in the rushes. Lovely calls—the sound of the Aussie wetlands:

At an earlier stop, I was happy to see the Western Spinebill [Acanthorhynchus superciliosus]. It’s not the world’s best shot, but it’s still beautiful bird and I hope to get better views of it in the future:

And finally, I’ll leave off this WA tour with a robin, a male Scarlet Robin [Petroica boodang]. Robins are so cute and they sit nicely for the camera, not jumping around like some crazy caffeinated gym rat like so many birds do. Speaking which I’m off for a coffee and a workout to work off some of the pounds I put on this trip: