Evidence that raptors spread brushfires to flush out prey

Now the paper at hand is far from conclusive, but it raises questions that really do deserve investigation, for it suggests that at least three species of Australian raptors, jointly called “firehawks,” spread brushfires to flush out prey. If true, that would mean that birds either “use fire” or “weaponize fire”—something known only in our own species.

It’s long been known that predatory birds from many places hang around the edges of spreading fires to snap up prey fleeing incineration or to feast on burnt corpses. But what’s new about this paper by Mark Bonta et al. in the Journal of Ethnobiology (reference below, free text and pdf) is the description of raptors carrying in their beaks or talons burning sticks from places on fire to places yet unburned, igniting new fires (they spread quickly) and flushing out more prey to eat. The study was conducted in Northern Australia, and the behavior hasn’t been described in other areas.

First, here, from Cosmos Magazine, are some pictures of raptors in Australia hanging around the edges of fires. The photos were taken by an author of the paper.

Black kites swooping around a fire that observations suggest they may well have started themselves. Photo: BOB GOSFORD

 

Black kites swooping around a fire that observations suggest they may well have started themselves. Photo: BOB GOSFORD

The species involved in this behavior are mainly Black Kite (Milvus migrans), Brown Falcon (Falco berigora), and Whistling Kite (Haliastur sphenurus). 

There are three ways the authors document this behavior, though none are satisfactory to those who want convincing evidence that raptors start fires. First, they collected twenty cases from twelve aboriginal tribes of “local knowledge” that birds do this. While these shouldn’t be dismissed, there’s always the possibility that these aren’t eyewitness reports but constitute local lore or tradition that may be spread among populations.

Second, the authors compiled six first-hand accounts, some of them published, from people who said they saw birds spreading fires by carrying firebrands from one place to another that was not yet on fire. Here’s an example:

Two eyewitnesses report intentional, cooperative fire-spreading. Bob White (Table 1:Record 16), while fighting a bushfire in the Roper River, NT region, watched a small group of raptors—presumably Black Kites—pick up numerous smouldering sticks and transport them ahead of a fire front, successfully helping the blaze spread up a small valley. ‘‘MJ,’’ a Kimberley, WA cattle station caretaker manager (Table 1:Record 17; Supplementary Report 7), saw kites working together to move a late dry season fire across a river by picking up, transporting, and dropping small, burning sticks in grass, which immediately ignited in several places. The experience resulted in an uncontrollable blaze that destroyed part of the station’s infrastructure. The observer later saw the larger group of hundreds of kites that had gathered for the fire actively pursuing prey in the intentionally burned area.

Finally, two of the authors (Eussen and Ferguson) directly observed “fire spreading,” though sadly didn’t document it with photos or video. That’s understandable, though, for, as the authors note, when one is busy dealing with fire—the men are fire officers—or avoiding it, your mind is on other things! Plus the spreading behavior is not that common. Here are two of the authors’ descriptions:

From Eussen:

Another fire-spreading encounter occurred at the Ranger Uranium Mine near Kakadu, NT, where Eussen was a firefighter (Eussen and Angelo 2003; Martin 2003, 2004; Table 1:Record 15). One afternoon, while he was ensuring that a grass fire did not leap across a highway, he observed fire-foraging activities of both Whistling and Black Kites. Though the fire burned itself out, Eussen was alerted to a new blaze on the unburnt side of the road. He drove over and put it out, noting a Whistling Kite flying about 20 meters in front of him with a smoking stick in its talons. It dropped the stick and smoke began to curl from the dry grass, starting a spot fire that had to be immediately extinguished. In all, he put out seven fires, all caused by the kites. On that occasion, approximately 25 kites were foraging at the edge of the dying fire, but only two were adept at transporting smoking sticks. One repeatedly swooped at a stick, only lifting it a meter or less before dropping it.

From Ferguson:

While Ferguson’s most recent fire-spreading observation in March 2017 (Table 1:Record 18) involved unsuccessful attempts to transport burning sticks, previous observations that stand out most to him, from September 2016 and around 2000-2001 (Table 1:Records 19 and 20), were of a few kites, within gatherings of hundreds during very hot fires, successfully seizing burning sticks in their beaks, sometimes switching them to their talons, transporting them over 50 meters, dropping them, and, thus, igniting unburned grass. Like several other non-Aboriginal observers, and in concordance with Aboriginal IEK, Ferguson is adamant that fire-spreading behavior, whether successful or not in starting new fires, is intentional.

So this is what we have, and it’s pretty much hearsay. Yet given the consilience of all the reports, I tend to believe it. I say “tend”, because I’d be a lot more confident if I saw video or pictures of this behavior occurring. Given its frequency, that should be possible, and there’s clearly work to be done here—especially given the fame that would accrue to anyone who “proved” that animals can use fire in this way.

Now just a picture or video of a raptor carrying a flaming stick isn’t sufficient, for there have to be “controls”: do raptors around fires also pick up nonburning sticks? (I can’t see why they would, but it could happen.) If not, and if there’s, say, a good video showing one (or preferably more) birds carrying and dropping firebrands, I’d start to be convinced.

Further, if fire-spreading is real, is it learned or somehow evolved and coded in the genes? (Or both: a bird could have the propensity to spread fire but do so only when that propensity is triggered by seeing another bird do it.) That would be harder to test, but in principle could be seen as purely hard-wired if a hand-reared bird who had never seen the behavior was seen to perform it.

I really want to believe this is true because it’s so cool, and because it baffles me a bit how a bird could learn to do this, for it would have to connect a lot of dots to take a burning firebrand and start a new fire somewhere else. But raptors aren’t dumb. I hope some Aussie researchers will take up this problem!

 

h/t: Chris

______________

Bonta, M. et al. 2017. Intentional fire-spreading by “firehawk” raptors in northern Australia. Journal of Ethnobiology 37(4):700-718. 2017. https://doi.org/10.2993/0278-0771-37.4.700

47 Comments

  1. mikeyc
    Posted January 11, 2018 at 10:25 am | Permalink

    I don’t know about birds spreading fires but my brother, who fought wild fires in Eastern Washington in the 1990s, remembers seeing birds – he thinks they were hawks of some kind- gathered near the fire lines. They would swoop down and catch small animals fleeing the fires.

  2. ThyroidPlanet
    Posted January 11, 2018 at 10:27 am | Permalink

    Sub

  3. Posted January 11, 2018 at 10:29 am | Permalink

    Raptors snatch up prey and take it to a nest or other secure location to devour it. If fire is recognized as a source of prey, it does not seem to be too far of a stretch to take the one behavior and adapt it. The fire is just one step away from the prey.

    • mikeyc
      Posted January 11, 2018 at 10:48 am | Permalink

      I’ve seen video on the show Nature of birds diving into prairie fires to catch insects fleeing the flames. As noted above, birds station themselves at fire edges to catch fleeing prey. Given all this and what we now know about their keen intelligence (at least in some species), it isn’t implausible that some figured out that picking up a burning twig and dropping it elsewhere can provide food.

      When I was young calling someone a “bird brain” was an insult. I tell my sons now that that it is a compliment to be compared to some of the most intelligent creatures on earth.

      • loren russell
        Posted January 11, 2018 at 12:28 pm | Permalink

        Raptors do seem keen enough — though they are regularly given ‘Kick Me’ signs by corvids. Oddly, owls sppest to br dumb as rocks.

      • Diane G.
        Posted January 11, 2018 at 6:39 pm | Permalink

        IIRC, for years it was assumed that birds could not be very intelligent since they lacked a cerebral cortex. Then researchers discovered that birds had similar functionality in a completely different part of their brain. More recently it’s been learned that their neurons pack more tightly than those of mammals as well. Once we get beyond our parochial assumptions new worlds open up. 😉

  4. Nate Boykin
    Posted January 11, 2018 at 10:37 am | Permalink

    Reminds me of hearing about birds who time their brush dives with passing cars- flushing out prey into oncoming traffic. Also- I’ve heard of birds dropping hard nuts on roadways so that the cars can smash ’em open. Anyway, all incredibly fascinating, and I, too, hope its true because its so damn cool.

    • Dee
      Posted January 11, 2018 at 1:08 pm | Permalink

      I’ve seen film of birds dropping nuts in front of cars. I believe I saw that on PBS, on a Nature program about crows.

  5. Posted January 11, 2018 at 10:48 am | Permalink

    sub

  6. ploubere
    Posted January 11, 2018 at 10:49 am | Permalink

    Given other evidence of the intelligence of many birds, it doesn’t seem too farfetched. Apparently it doesn’t take that large a brain to do creative problem solving.

  7. Ken Kukec
    Posted January 11, 2018 at 10:50 am | Permalink

    Prometheus not merely unbound, but in flight.

  8. Randall Schenck
    Posted January 11, 2018 at 10:51 am | Permalink

    The amazing thing about this, if true, is the bird risking his own harm by handling a burning stick in order to spread fire. What other reason would their be for the bird to take this risk? I don’t think we have any animal examples of arsonist besides humans.

  9. TJR
    Posted January 11, 2018 at 11:05 am | Permalink

    We didn’t burn him!

    Fascinating and a bit scary.

  10. rickflick
    Posted January 11, 2018 at 11:07 am | Permalink

    As long as there are tantalizing questions like this, science will continue expanding knowledge via it’s wonderful way of knowing. Just reading about this fascinating process might encourage a young person to decide to become a researcher…which I think is a hopeful thought.

  11. Michael Fisher
    Posted January 11, 2018 at 11:23 am | Permalink

    Relating to comments #1 & #3 above…

    I can imagine hawks picking up dead smouldering prey from near the windward [upwind] direction of a fire & flying away from the smoke & noise of fire to feast on the ground. Sometimes they will mistake a smouldering stick for dead smouldering prey & thus spread the fire upwind or crosswind [rather than leewards as sparks would do].

    I can’t imagine hawks picking up anything that’s visibly alight no matter how hungry, but we’re talking about crazy Aussies so anything’s possible! 🙂

    • Posted January 11, 2018 at 1:42 pm | Permalink

      This is a well considered counter-proposal, I think. But if they are ever filmed repeatedly picking up smoldering sticks, then that will be somewhat a different matter.

    • Posted January 11, 2018 at 4:30 pm | Permalink

      I was wondering if anyone would pick up on that. The acounts sound like the hawks are presumed to have spread the fire in the direction the fire was taking. That would require picking up a smouldering stick in the burnt ground, flying over the firefront to drop the stick and then identifying a good site to drop the stick. If they were spreading fire I would expect to see spotfires occurring out on the flanks. Incidentally on a fireline I’ve had duff smouldering around me without noticing any hot fly ash,so minute sparks can carry well ahead of a fire to ignite fuel without seeing the cause. I too would like to see a good video to support the anecdotes.

    • Ivan Romic
      Posted January 12, 2018 at 1:21 am | Permalink

      This is a very good point. If the hawks are indeed spreading fire, we can consider them ecosystem engineers. Then we can hypothesize that they are either accidental engineers, spreading fire (accidentally) by mistaking smouldering sticks for prey, or engineers with evolved/learned ecosystem engineering behavior which involves positive feedback effects on the fitness.

      • Gregory Kusnick
        Posted January 12, 2018 at 2:16 pm | Permalink

        I’m skeptical of the idea that the birds are mistaking smoldering sticks for prey. Raptor visual systems are highly optimized for distinguishing prey from their surroundings, and are therefore unlikely to be easily fooled. In the (presumably) rare instance when a bird is fooled, one would expect it to realize its error immediately on grasping the stick. One would not expect it to carry the stick a considerable distance, or to engage in repeated, cooperative stick-carrying with other birds (as per the reports), unless the stick-carrying is an intentional behavior meant to spread fires.

  12. Liz
    Posted January 11, 2018 at 11:33 am | Permalink

    I don’t know why that would seem so eerie. It’s so interesting, though. The first picture is like artwork. It’s engaging and thought-provoking. Couldn’t help but think of the scene from Jurassic Park. “You bred raptors?”

    • Diane G.
      Posted January 11, 2018 at 6:41 pm | Permalink

      I too was struck by that first picture!

  13. Barry Lyons
    Posted January 11, 2018 at 11:37 am | Permalink

    This seems hard to believe because I’d always assume that ALL creatures have a natural disposition/inclination to avoid fire. Fascinating, as Mr. Spock would say.

    I rather side with Michael Fisher’s comment above: it seems more believable that a hawk would pick up something that’s smouldering as opposed to something that’s clearly on fire. But, hey, if the evidence suggests otherwise, well, there you go.

    • darrelle
      Posted January 11, 2018 at 1:13 pm | Permalink

      I don’t know. Just going by the 2nd picture above it doesn’t look like the kites are particularly concerned about being in close proximity to large flames. Though it could just be tricky perspective it really does look like two of the kites are very close to the flames.

    • Diane G.
      Posted January 11, 2018 at 6:43 pm | Permalink

      One of the eyewitnesses did specify a “smoking stick,” which could mean a smoldering one.

  14. Gnu Atheist
    Posted January 11, 2018 at 12:13 pm | Permalink

    Man, nature sucks… imagine expending all that energy fleeing from a wild fire and just escaping being burned alive, only then to be eaten alive for your efforts.

    By the way, did anyone else notice that the name of the first witness mentioned was Bob White? Just saying.

    S,
    Ben Dover

    • Christopher
      Posted January 11, 2018 at 12:35 pm | Permalink

      Yes, that caught my attention as well. Perhaps we ought to dismiss this particular “eyewitness” as it might be a smear campaign against raptors by an aggrieved Colinus virginianus.

    • Posted January 11, 2018 at 1:44 pm | Permalink

      😊

    • Posted January 11, 2018 at 4:43 pm | Permalink

      yeah that is funny, but seriously, highly unlikely that a firefighter in the tropical Northern Territory (or most Australians for that matter) would know what a bobwhite is.

    • Diane G.
      Posted January 11, 2018 at 6:45 pm | Permalink

      Couldn’t help but do so. 😉

  15. Mark R.
    Posted January 11, 2018 at 1:06 pm | Permalink

    (Or both: a bird could have the propensity to spread fire but do so only when that propensity is triggered by seeing another bird do it.)

    I imagine this could also happen with the drumming of the Cape palm cockatoos. The cockatoos in New Guinea who don’t drum might see/hear a Cape cockatoo do it and become triggered. I’m still perplexed by that darn drumming.

    Thanks for all the cool bird posts lately.

  16. Dee
    Posted January 11, 2018 at 1:10 pm | Permalink

    My first reaction to reading what the firefighters had to say was ‘goddam birds’.

  17. Charles Sawicki
    Posted January 11, 2018 at 1:54 pm | Permalink

    Very interesting post!

  18. Posted January 11, 2018 at 2:07 pm | Permalink

    The species involved in this behavior are mainly Black Kite (Milvus migrans), Brown Falcon (Falco berigora), and Whistling Kite (Haliastur sphenurus).

    Sounds like the lineup for the next Avengers movie.

  19. sshort
    Posted January 11, 2018 at 2:23 pm | Permalink

    I just saw a vid (was it on WEiT?) of a parrot-like bird being taught to recognize and select specific shape pieces to push into same shaped holes in a box for a reward. The last part showed the bird flying over to a chair and ripping off a twig-like piece of it, flying back to the box and using that to outsmart the box.

    small jump, i think, to deliberately carrying a flaming twig to another area to flush out more prey. They are fairly adept puzzle solvers.

    • Posted January 11, 2018 at 4:51 pm | Permalink

      In the bird world parrots are smart but applying that to all birds is like applying primate intelligence to all other mammals.
      At this stage there are many birds that use found objects as tools but top marks go to the New Caledonian Crow that makes tools (one too in particular) and that is a learned behaviour.

      • sshort
        Posted January 11, 2018 at 6:43 pm | Permalink

        Yes. A very good point and a valid distinction. Although I did briefly glance at something that said the avian brain was being re-thought (meta enough?) a bit because it was hard to explain its capabilities in such a very tiny package. Wondering if there were some new insights on general principles across all bird brains?

        Thanks much.

        • Diane G.
          Posted January 11, 2018 at 7:05 pm | Permalink

          Not the original paper, but from a Scientific American summary of one:

          Although many in the field expected the bird brain could be densely packed, the extent came as a surprise to the study authors. “My expectation was simply that bird brains should be different from mammals in size and number of neurons,” says neuroscientist Suzana Herculano-Houzel, now at Vanderbilt University, one of the senior authors on the paper. “But we didn’t have any idea that the difference would be so extreme that in a parrot brain you would have as many neurons as in a mid-size primate.”

          https://www.scientificamerican.com/article/bird-brains-have-as-many-neurons-as-some-primates/

          (Not a “general principle across all bird brains,” though, AFAIK.* And in general, social birds are thought to be more intelligent than the rest, IIANM.)

          *I’m feeling lazy tonight; but then, Google is your friend, too. 😀 )

          • sshort
            Posted January 12, 2018 at 9:13 am | Permalink

            Thank you!

          • Posted January 12, 2018 at 1:12 pm | Permalink

            ‘social birds are thought to be more intelligent than the rest’
            Thanks Diane, I understand that all animals which live in structured groups (social systems) tend to be more intelligent than their solitary relatives, and omnivores are also likely to be more intelligent. The latter tend to be adaptive and innovative in the search for food. The same source also said that the ratio of brain matter to body size is an indicator of intelligence, so Suzana’s article is very interesting.

            • Diane G.
              Posted January 13, 2018 at 12:02 am | Permalink

              I hadn’t been aware of the omnivore correlation, though it makes perfect sense when you think about it…thanks.

  20. Gregory Kusnick
    Posted January 11, 2018 at 2:40 pm | Permalink

    I’d make a distinction between spreading fire and starting fire. These birds are (apparently) doing the former but not the latter.

    When they start knocking flints together or piling tinder on hot engines, then we can say they’re starting fires.

  21. Steve Pollard
    Posted January 11, 2018 at 3:25 pm | Permalink

    Thanks for another fascinating natural history post! I have little to contribute to the debate on conjectures such as this; but the remarkable acumen and intelligence shown even by the birds in my back garden suggests that there could well be something in it.

    Maybe the dinosaurs have inherited the earth after all.

  22. Posted January 11, 2018 at 3:27 pm | Permalink

    I believe the “smoldering prey item” theory should be taken seriously. Since these birds are already known to seek prey at the edge of a fire, they are bound to find “cooked” prey and may even prefer it for the same reasons we do. Since birds and fire have been around for millions of years, they may instinctively seek out recently cooked prey. If so, then it is just a small leap of faith to suppose that such prey is sometimes still smoldering.

    • sshort
      Posted January 11, 2018 at 7:04 pm | Permalink

      I think barbecue is a significant first step on the evolutionary ladder. Can napkins be far behind?

  23. Posted January 12, 2018 at 12:20 pm | Permalink

    There’s an Inuit story (see _Tales from the Igloo_ for one version) about Raven picking up a burning log from somewhere. This is a bit of an unusual story since in most of the Inuit range there are no trees.

    It seems plausible enough – though one has to be wary of anthropological evidence like this.

    • Hempenstein
      Posted January 17, 2018 at 7:51 pm | Permalink

      From reading about the Greenland –> Vinland Vikings, here’s apparently a lot of driftwood, tho.

  24. Joseph O'Sullivan
    Posted January 13, 2018 at 5:55 am | Permalink

    I know herons and egrets have watched people feed bread to ducks and see that the bread attracts fish, their natural prey. Individual birds have learned to use bread to attract fish and then catch them. There are lots of internet videos of this. Could the raptors deduce that fire can get them food? fascinating stuff!


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