Question for birders: Why would there be two dead kestrels in the road?

Factual Questions
1

O.K., I’m walking down the street near where I work in Cambridge MA this week. In the gutter I happen to notice a dead bird. I figure “pigeon”, but I take a closer look, what with being a scientist and a bird freak, and all.
Turns out it’s a kestrel (sparrow hawk) which are found in the general area, but I haven’t seen one myself in years. Then I notice, next to the kestrel is another dead bird. I figure it could be something the kestrel was eating when it got hit by a car or something, but then see that the second bird is also a kestrel! So my General Question, which should have a factual answer, is how the heck do two kestrels die within a foot of each other, in MA, in mid November (they had clearly only been there a day or two)?
Some thoughts:
1. If they died of diesease, they wouldn’t fall within a foot of each other. Same if they were fighting…I can’t imagine two birds would literally expire in each others clutches. Anyway, its nowhere near the breeding season. Would they fight this time of year?

2. At least one of the birds was a male. The other, I'm not sure because it was on its back. It was about the same size though, which makes me think it was also male (females are noticeably larger, I believe).

3. There are no tall glass-fronted buildings in the area they could have flown into accidentally. Its a post-industrial neighborhood, brick former factories a few stories tall at most that now house biotech companies, MIT dorms, and small businesses.

4. I read on a web page that peregrine falcons sometimes hunt cooperatively, with a pair going after the same bird. Also, that they will knock their prey out of the air and kill it and feed off it on the ground. Do kestrels do all this? And then, with their excellent eyesight, they didn't see a big slow truck in time to get out of the way, and they both got killed?

 5. I have seen red-tailed hawks in the neighborhood. Might they attack the smaller birds, and then leave them without eating them?

So, not a world shaking problem, but one of those things that just seemed stranger the more I thought about it. Any ideas?

2

The subject line should have a question mark at the end, of course. A kindly mod could fix, perhaps?

3

Secondary poisoning.

4

By this, I think you mean they ate birds or something that had themselves been poisoned. But would they drop dead next to each other? Do they eat carrion?

5

Sorry, gotta ask.

Do they mate in mid-air? If so, did they bottom out (so to speak) together?

6

Only problem with that theory, Zenster, is that we are nowhere near mating season! Anyway, I believe they “do it” on a perch, or ledge, or whatever. (Some birds have mating rituals where they pass each other items in flight, I think.)
I can’t believe a species would evolve in such a way that would allow the birds to get so engrossed in what they were doing that they crashed and died. Kind of defeats the whole purpose of the excercise, methinks.

7

It might be a good idea to report this to the state health department. American Kestrels have tested positive for West Nile Virus since the disease reached N. America, and WNV has been reported in Cambridge, Mass. I have no idea if this might be WNV, but it’s a thought.

BTW, I fixed the thread title.

8

is it possible one got killed by a truck etc whilst eating something, and the other one flew down to check what happened to his friend, and another vehicle came speeding along and mushed it too?

9

What we need is forensic evidence. Did the birds show signs of blunt trauma, being hit by a car, or did they look ill?

10

Bibliophage: I thought about WNV. Mass. recently had its first human fatality to the disease. I will report the birds, although again I have trouble picturing two sick birds expiring at what seems to be the same instant, right next to each other. I mean, think of all the people on this board who have apparently never seen a dead pigeon. Then consider how few have seen TWO dead pigeons, right next to each other. Then consider kestrels are far less numerous than pigeons! Thanks for fixing the title.

Mirage: While I am generally an enthusiatic fighter of ignorance, I didn’t actually touch either of them. They probably are not going to look too good the next time I am in the area, on Monday. They didn’t just look ill, they looked dead. Really, really dead. They looked like they had been in good health, though, fully feathered and all that. No obvious external injuries, no blood. They are startingly beautiful birds up close.

Niobium: Yes, I suppose thats a possibility. I don’t know how closely pairs stick together outside the breeding season. Again, though, they are quick birds, and being falcons they have excellent eyesight. I would think they could see and get out of the way of cars and trucks pretty easily-the speed limit along there is 30 mph, although it being Mass. most people drive a lot faster. It’s a crowded street, with a lot of parking, driveways, kamikaze pedestrians and construction vehicles.
I guess I was hoping someone would have anecdotal evidence of falcons being hit in the road by cars.

11

How about this: could they have been placed there by someone who held them in captivity for whatever reason and just dumped them there when they unexpectedly expired?

12

Mid-air collision? Maybe they were stooping at the same prey and collided.

13

I see kestrels here in Denver fairly regularly, but never two at the same time. A mid-air collision sounds far-fetched, but outside of poison or disease,I can’t think of anything more likely than that.
I did once see a severely injured starling floundering on a busy city street, and what was either its mate or parent hovering nearby. The first starling was obviously near death, and the second clearly risking its life to stay near.
Perhaps something similar to this happened with the kestrels?

14

Possibility- They are actually a male and female pair and sipped at an anti-freeze puddle (looks litle water to them and tastes sweet) in the street nearby.

15

I am once again impressed by the brain power and original thinking displayed by members of this board. Thanks all!

Astro, your idea is the best so far, I think. Antifreeze is wildly toxic, and it would explain why they would be in the road, and if it killed them quickly they would be close together. I know there was a big problem with released California Condors drinking it and being poisoned. Audrey K’s idea is a possibility as well.

16

Perhaps they were attacking the chicken…

(Sorry, I have nothing to add to the earlier ideas but the thread title sounded like the set up for a joke.)

17

Pairs of eagles (which do mate in mid-air) have been known to “not pull out in time” (as it were).

18

Eagles do NOT mate in mid-air!!!

The actual act of copulation takes place on a tree branch or other solid surface where there birds can balance. The male eagle does not have a penis, per se, but a cloacal opening which must match up exactly to the female’s cloacal opening in order to transfer sperm. This takes an awful lotof balance and precision: two of our permanently crippled birds at the rehab center (he is missing his left wing [electrocuted on a high-voltage wire, wing was amputated], she is missing her right wing [arrow sheared through the wing joint, causing irreversible damage]) have been ‘going at it’ during mating season for the last several years: she will still lay eggs, but they are infertile.

What people actually are seeing with the birds in mid-air is a re-affirmation of the pre-coital ‘pair-bonding’ process: kind of a ‘date with your mate’, re-establishling trust between the two birds. The birds will fly quite high (several hundred feet, IIRC), lock talons, and freefall to earth, tumbling over and over and over, and at the very last second, release talons and fly away, fly upwards, lock talons, and start the whole thing over again. This is only one of several rituals repeated over several days before the pair gets down to the business of raising babies, but it is among the most spectacular (others include nest-building and food sharing - obviously not spectacular).

[Sorry to jump on the first line, Zens-sweetie, but I’ve been answering this question at work a lot lately: the Bald Eagle breeding season is beginning here in Florida, and I get a lot of calls from worried and/or mis-informed people who don’t quite understand what they are seeing. Lucky stiffs - they get to SEE it, and I have to sit in an office…]

And yes, occasionally they do miscalculate and hit the ground.

Whoa, one other thought - what people may also be seeing is an actual life-or-death struggle between one eagle defending an established territory, and an interloper into that territory. Eagles set a certain territory for their hunting and breeding area: it’s not just the nest, but the whole area around the nest which is patrolled by both birds. An immature eagle (under 3 years old) is likely to be ignored, but any eagle over that age (approaching maturity - getting the distinctive white head and tail) is seen as a threat to the pair-bond and the territory - kind of like the 20-y-o moving right next door to the couple that has been married for 10 years and making a move on the spouse. THESE fights can and are often deadly - our rehab center gets dozens of eagles (and other territorial raptors) brought in with anything from superficial lacerations to a case where the birds were brought in still locked together - their talons were embedded so deep in the other’s flesh that they could not remove before hitting the ground. And yes, we do get a lot of losers (dead birds) brought in: we are seeing more and more of these territorial fights since there are more Bald Eagles being born and surviving (Osceola County [my area] has one of the highest eagle counts per acre), but less acreage for these birds to grow up in and establish their own nesting area (more housing developments and shopping malls mean less suitable habitats).

Contact me off board for statistics.

19

Screech-owl, re the O.P.:

  1. Do kestrels do this locked free-fall thing?

and

  1. If yes, would they be doing it this time of year in Mass.? I’ve been told the earliest bird to breed up here is the Great Horned Owl (a distant relative of yours!), in January.
20

Not sure about the free fall thing. I’m off work for a few days (where all my books are), but perhaps Colibri or brachy will be by to answer.

Breeding seasons are going to vary across the country, so it’s possible that GHOs will be breeding soon in your area.