Peregrines: a truly fantastic photo (and a discussion)

This is one of the best reader photos I’ve ever posted, and it comes from photographer John Chardine.  He described the scene in his first email (all posted with permission):

I’ve been photographing a pair of Peregrine Falcons at a nest not far from home.

Right now there is a single chick in the nest. The (much smaller) male is hunting for birds—mainly American Robins—and is bringing them back plucked and usually without the head (which he eats). The interesting part of the story is that rather than bring them back to the nest, the male transfers the prey to the female in mid-air, and the female then takes the prey item back to the nest and feeds the chick. All this happens in 5 seconds ± so you have to be quick on the the camera trigger!
In the image the smaller male is above with the food item in its beak. The female is reaching up with her talons to grab the food item.
Peregrein
The natural questions are these: is it normal in peregrines for females to do the feeding, even when males do the hunting? And, if so, why? Here’s John’s responses, which show that which sex does the hunting (they differ in size) depends on how old the chicks are.
There is pronounced (reverse) sexual dimorphism in the Peregrine with the male much smaller than the female. When the chicks are young the parents only need to bring in small prey like robins and the male is supremely built to kill small birds. Peregrines capture their prey by diving on them at incredible speeds—the fastest in the bird world. Later on when the chicks get older, they need more food delivered per unit time and sometimes the larger female will step in taking larger prey like for example ducks and gulls. A big problem for flying predators like Peregrines is “payload mass”. They have to be able to carry back the prey (payload) and if it’s too heavy they can’t do it. Larger females can fly with bigger prey than the smaller males.
I then asked John this:
But why doesn’t the male just feed the small birds he catches directly to the chicks? Why does he hand them over to the female?
And he replied:
That’s a good question and I don’t know the answer. There are many options for what the male could do. The simplest might be to do what you suggest- bring back the prey and feed the chick. The next obvious option might be for the male to deliver the prey to the female at the nest and then she feeds the chick. This is known to occur in some pairs. What I can say is that immediately after the food exchange in mid-air we see the male fly away and we assume he is traveling to his “kill” location. There is no lost time in doing this, which may explain why he does not stick around and feed the chick. If he stayed, the most efficient system would be for the female to fly out to hunt, and that is indeed an option that probably occurs when the chick is old and requires bigger meals. To have both birds attending the nest- one feeding and one hanging around- is inefficient and indeed may not allow sufficient power delivery (energy per unit time) to the nest. It should be mentioned that feeding takes time as the parent has to tear apart the prey in appropriately small morsels for the chick. Currently, with a chick about 12 days old, a complete feeding may take 20-30 minutes.
Reader speculation (or knowledge) is welcome.
John’s photography website is here; a visit will reveal many splendid images.

 

40 Comments

  1. JBlilie
    Posted June 21, 2013 at 4:54 am | Permalink

    Awesome photo John! What lens are you using?

    • Posted June 21, 2013 at 5:17 am | Permalink

      Thanks! That was with the Canon 400mm f4 DO lens.

      • JBlilie
        Posted June 21, 2013 at 5:45 am | Permalink

        Do you have APS-C sensor or “full-frame”?

        One of the things I love about the APS-C is that extra 50% reach with a telephoto lens.

        • Diana MacPherson
          Posted June 21, 2013 at 5:47 am | Permalink

          This is why in the end I ordered the Canon 7D instead of the MKIII. It is a toss up between being able to shoot with higher ISO and getting nice results plus getting less noise in dark areas vs. the reach of the crop.

          I went for the extended reach but the 7D is going to be a step up from my 40D anyway!

  2. bonetired
    Posted June 21, 2013 at 5:00 am | Permalink

    I have forwarded the post to our local peregrine expert and see what he has to say …

    https://www.facebook.com/worcesterperegrines?fref=ts

    • Posted June 21, 2013 at 5:18 am | Permalink

      Falconers are generally very knowledgeable about “their” group of birds. Look forward to hearing the response!

      • bonetired
        Posted June 22, 2013 at 1:23 am | Permalink

        And an answer…

        “Peregrine Falcons in Worcester Interesting xxxxx, very similar current behaviour with our kestrels – the male does most of the hunting & deposits prey cashes close to the nest site for the female to collect. With peregrines the male will feed the chicks as they mature as we witnessed 2009 in our last breeding season. Pigeons were the main prey even when the chicks were small, food passes we witnessed were pre- nesting though.”

  3. gbjames
    Posted June 21, 2013 at 5:05 am | Permalink

    Much of this behavior is quite similar to how Coopers Hawks behave. Coopers males are also smaller. They do the hunting and turn over the prey to the females, although what I’ve seen is that the male will land on a tree branch in the vicinity of the nest (not the actual tree nest, in my observations), and call the female over to the food. This pattern starts early in the spring well before the eggs are laid and is part of the courtship. I don’t think the females do any of the hunting.

    I’m not an ornithologist but I did spend a couple of years watching them when they were nesting outside our house in Milwaukee. What I learned was from talking to the real specialist who would come back every year to band the chicks. It was a marvelous thing to watch although there was a grizzly side to it. Our morning stroll to the coffee shop was a bit like a walk through a charnel house… legs, decapitated heads, and other juicy body parts fall to the sidewalk. Still, I miss them now that they moved off to some other part of the territory.

    • gbjames
      Posted June 21, 2013 at 5:06 am | Permalink

      I got some fun pictures, but nothing as great as John’s!

      • Dominic
        Posted June 21, 2013 at 5:10 am | Permalink

        How the heck do you get that close without camera shake on a zoom? How do you keep the bird in the camera’s viewfinder when on a close zoom?!

        • gbjames
          Posted June 21, 2013 at 5:14 am | Permalink

          Well, John’s a pro and I’d wager he’s using pretty high quality equipment, tripods, etc.

          In my case, my best shots were of the birds after they were captured and brought to the ground for weighing, banding, and getting blood samples. (They were running a study about the progress of some sort of parasite. So they also captured the parents one year.)

        • Posted June 21, 2013 at 5:31 am | Permalink

          It’s not easy! The lens was 400mm in focal length and has image stabilization. You have to use a fast shutter speed and set your autofocus to track the bird as it flies. Birds in Flight photography takes a lot of practise!

          • JBlilie
            Posted June 21, 2013 at 5:40 am | Permalink

            And, I’m sure, many attempts for each satisfying photo!

    • JBlilie
      Posted June 21, 2013 at 5:43 am | Permalink

      We have Cooper’s Hawks near us every year. I’ll seen them strike mourning doves and American robins many times — right over my back yard: Fantastic. (Never with a camera in hand though!)

      I’ve also seen an osprey take a fish from the pond 50-feet (15m) behind my house. And we get otters feeding on the winter-killed fish every year at ice-out.

      It’s a wonderful spot.

  4. Dominic
    Posted June 21, 2013 at 5:08 am | Permalink

    Do we know what weight of food each chick needs per day to grow normally, from hatchlings to fledglings?

    Do we know, quantitatively, how successful breeding compares with prey availability – what bird ‘biomass’ of prey is required to sustain a breeing pair of falcons?

    Do they usually take birds as opposed to groung hunters like (most?) owls?

    • Posted June 21, 2013 at 5:39 am | Permalink

      I only know the answer to the last question. Peregrine Falcons take birds almost exclusively. They do so in open habitats by diving on their prey at high speed. Contrast this with how an accipiter (e.g., Cooper’s Hawk) hunts- flying fast through tangled woodland at more or less the same height as the prey, dodging the trees as they go.

      The old North American name for the Peregrine was “Duck Hawk”. I’ve only managed to ID two feedings from the pair I’ve been watching and they were both American Robins.

      I’m sure answers to the first two questions are known but I’m not near my reference material at the moment.

  5. Diana MacPherson
    Posted June 21, 2013 at 5:09 am | Permalink

    Wow a gorgeous picture and not the easiest to capture either!

    • Dominic
      Posted June 21, 2013 at 5:12 am | Permalink

      Bet he has a super-dooper camera & lens!

      • Posted June 21, 2013 at 5:37 am | Permalink

        That’s not enough!!! Skill and practice and dedication and immense patience are just as important as the mechanical stuff (which is also important, of course). This photographer has all those qualities, for sure.

        • Posted June 21, 2013 at 5:44 am | Permalink

          Thank you…. and practise, practise, practise!

          • JBlilie
            Posted June 21, 2013 at 5:48 am | Permalink

            Almost anything worthwhile must be practised diligently to be done well.

  6. Geoff Boulton
    Posted June 21, 2013 at 5:13 am | Permalink

    A few years ago I had the opportunity to work as a volunteer for the RSPB at Symond’s Yat in the Forest of Dean. Two weeks showing visitors the nesting Peregrines on the cliffs opposite the viewpoint. It was a great opportunity to watch the behaviour of these fantastic birds. The hunts were spectacular but here they fed almost exclusively on the flocks of pigeons which regularly passed through. I’d recommend it for anyone and I hope you don’t mind the plug for a very worthwhile charity.

    http://www.rspb.org.uk/volunteering/

  7. Sarah
    Posted June 21, 2013 at 5:20 am | Permalink

    It’s like a bucket brigade! One is the “hunter” and the other is the “feeder”. Presumably the male goes back to find more prey? What an astonishing picture!

  8. Alexandra M
    Posted June 21, 2013 at 5:30 am | Permalink

    “Do we know what weight of food each chick needs per day to grow normally, from hatchlings to fledglings?”

    Whatever it is, it’s an astonishing amount. Doug Tallamy, an entomologist at the University of Delaware, has done some studies of chickadees and concluded that a pair of chickadees needs to collect between 6,000 and 9,000 caterpillars to fledge one brood. Considering that an adult chickadee weighs only 9 to 14 grams, that’s a lot of food!

  9. Andrew
    Posted June 21, 2013 at 5:57 am | Permalink

    This strikes me as being about efficiency. If food throughput is so high then it makes sense for the male to hunt for as much time as he’s capable. Spending time flying all the way back and feeding the chicks is time he could be spending hunting. The female allocates her time shuttling back and forth and feeding the chicks.

    This would only work if the male is capable of hunting all the time. Can they do that for all waking hours?

    When the female starts hunting for larger animals, do they reverse roles? Or does the male hunt for supplemental food? Both would still work.

    • Posted June 21, 2013 at 6:17 am | Permalink

      Agree. There is strong selection for parental efficiency. However, not all pairs are equally efficient. Young, inexperienced parents will tend to be less efficient and there are probably inherent differences in quality between individuals. Male-female compatibility is also a factor.

      Peregrines are diurnal hunters and I assume they can hunt from dawn to dusk. As the chicks get older they are left alone at the nest and both parents can feed.

      • Andrew Stringer
        Posted June 21, 2013 at 7:46 am | Permalink

        Also during the night which has been observed by numerous webcams set up to watch the birds in UK cities.

    • Marvol
      Posted June 22, 2013 at 4:49 am | Permalink

      Yes, this struck me as being an almost trivially correct answer/solution.

      Male is better at hunting => male maximises hunting time to generate as much food as possible.

      Then when bigger food is required, the female steps in and the process of ‘taking turns’ becomes more efficient.

      Isn’t this comparable to like, human bucket chains?

  10. nickswearsky
    Posted June 21, 2013 at 6:20 am | Permalink

    Alas, I found a dead juvenile peregrine outside my Condo (NW Side of Chicago) just this week. I reported the find, but the bird had not band on legs. I guess it is that time when juveniles are striking out on their own, and unfortunately they suffer a fairly high mortality.

    • nickswearsky
      Posted June 21, 2013 at 6:39 am | Permalink

      I just found out it may have been a Cooper’s Hawk, which are very similar to Peregrines in size and appearance.

  11. Andrew Stringer
    Posted June 21, 2013 at 6:35 am | Permalink

    The experience from studying our local pair of breeding Peregrines in Sheffield has shown that both parents catch prey and both feed the chick. This could be because there are three chicks, which have all successfully fledged, and there is a plethora of food available. At the end of the day survival depends on adaptablilty which means that behaviour will be varied depending on the local environment the birds find themselves in.

    http://sheffieldperegrines.wordpress.com/

  12. Notagod
    Posted June 21, 2013 at 7:01 am | Permalink

    Fantastic picture, thanks for sharing.

    Coincidentally, I was out painting this morning and heard some unusual flapping above my head. I couldn’t look immediately but when I did there was a mass of around 80 smallish feathers floating down. Maybe dove feathers judging by color and the abundance of them in the area. Interestingly, there was a dove sitting on a wire nearby that didn’t seem the least bit distressed, maybe it was as surprised and confused as I was. I’m wondering if it is the case that when a falcon hits a bird is there likely to be a plume of feathers pulled out upon inpact? Also, I found it interesting that there wasn’t any squawking, no sound except wing flapping.

  13. marksolock
    Posted June 21, 2013 at 7:16 am | Permalink

    Reblogged this on Mark Solock Blog.

  14. darrelle
    Posted June 21, 2013 at 10:09 am | Permalink

    I like fast, and I find all kinds of extreme capabilities in nature fascinating, so it is only natural that I really like Peregrines.

    Fantastic picture!

    One of my bikes was partially inspired by the Peregrine falcon. It was designed back when the best recorded speed for a stooping Peregrine was around 186 mph. Another more recent attempt at measuring a Peregrine’s speed recorded something like 248 mph (going by memory, but should be close). Of course that has not been duplicated and there is some controversy over it.

    Alas, the bike in question will do the 186 mph no sweat, 200 in perfect conditions, but 248 mph? To reach the 248 range would take a huge hardware investment to boost the motor up into the 550 to 600 hp range. And a bout of testosterone therapy.

  15. Aaron Siek
    Posted June 21, 2013 at 10:50 am | Permalink

    I know that part of peregrine falcon courtship includes the male bringing food to the female, and transferring it to her in this same manner. (I’ve been lucky enough to watch that amazing scene a couple of times; it’s pretty astounding how aerobatically skilled these birds are!) Could retaining this kind of transfer while raising a brood be a kind of continuing bonding behavior between the adults?

    (Or am I just a hopeless romantic?)

    • Posted June 21, 2013 at 12:35 pm | Permalink

      I think you are right on the money Aaron.

  16. mud man
    Posted June 21, 2013 at 4:56 pm | Permalink

    Guessing that the female won’t tolerate the male close to the nest, perhaps because of an unfortunate tendency of daddy to eat the kids? (This explanation relies on the reverse dimorphism)

    • Posted June 23, 2013 at 8:43 am | Permalink

      There’s one paper published in 2011 reporting infanticide for the first time in Peregrine Falcons and it was the female who killed and partially ate the chick. Apparently, the two chicks were left alone during a rain storm and by the time the female returned to the nest, one of the chicks was almost dead. This is the one that was killed.

  17. Diane G.
    Posted June 22, 2013 at 9:59 am | Permalink

    Stunning shot!


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