by Greg Mayer
Ground nesting birds are more vulnerable to predation of both themselves and their eggs because the ground is accessible to a larger variety of predators than are nests built in trees. There are a number of ways of dealing with this. One is for the bird, its eggs, or both, to have concealing coloration. This is very common, and such cases constitute a large class of examples in the classic work establishing the principles of adaptive coloration.
I saw this myself recently during a stop in New Madrid, Missouri, where I heard a bird yelling in my ear. But it took some time to find the bird.
Eventually I did spot it (I had binoculars), sitting on the ground. A second killdeer was running about on the grass not far away.
As I approached, it did not attempt to lead me away in a distraction display (which killdeer will do), but once I was close enough it stood up and displayed its more strikingly marked tail feathers, although not as vigorously as did one photographed by a WEIT reader earlier this summer.
According to the Cornell Laboratory of Ornithology, which of the two possible displays is used—distraction (which leads the interloper away from the nest), or tail (which alerts the interloper to the location of the nest)—depends on the nature of the interloper. If perceived as a predator, the distraction display is used to lead the predator away; but if perceived as a blundering ungulate (bison in the old days), the tail display is used to make an annoying spot on the ground that the ungulate will walk around (rather than on top of). So, she perceived me as a lumbering, dumb, brute, rather than an egg predator; clever girl!
There were two eggs, both camouflaged with dapples and spots, and no apparent nesting materials, but I didn’t want to bother her enough to move her off the nest to get pictures of the eggs.
Another common way of dealing with the problems of a ground nest is to use a less accessible piece of ground, such as an island or a cliff, as the nesting site. Seabirds frequently do one or both of these. In my part of Wisconsin, Canada geese have become cliff nesters over the past twenty years, building their nests on ledges and roofs of buildings, a behavioral change that has resulted in a huge increase in nesting success and nest abundance. It would be interesting to determine how much of this new nesting behavior is an evolved adaptation or part of a learned repertoire.
________________________________________________________________
Cott, H.B. 1940. Adaptive Coloration in Animals. Methuen, London.
Where are these cliff-dwelling Wisconsin geese? Along the bluff of Lake Michigan somewhere?
The poo danger from above would be horrifying! There are geese all over our campus at work and it is like a small dog has pooped everywhere!
There are bluffs on the Mississippi, on the Western edge. The Raptor Resource Project maintains some nestboxes there
For geese?
I’ll be out on the Missippi, in Winona, at the end of the month. I’d assume raptor project boxes would be for eagles there.
The geese nest on buildings, not naturally occurring rock formations. At the University of Wisconsin-Parkside in Kenosha, in 1993, Canada geese nested on the ground, and there were relatively few nests, and they suffered fairly high mortality. Over the past 20 years, the geese moved from nesting on the ground to nesting on the buildings. Nests on the buildings are safe from raccoons and other abundant predators (although not from buildings and grounds keepers). Nests, young geese, and adult geese have become much more common (continental trend here) since this change in nesting habits, and they have also become year round residents (formerly, there was a period in mid-winter when geese were absent). It’s not clear to me which of these things are causes and which effects, but there has been a striking change in goose behavior and abundance. All of this occurred during a time when geese have been thought of as a nuisance; earlier, in the mid 20th century, there were many conservation efforts aimed at increasing geese in the midwest.
As noted by a reader below rock doves moved from natural cliffs to buildings, but the movement of geese from ground to buildings is a much bigger change, at least by my lights. I don’t know if there is an evolutionary component to this change.
GCM
We have had a year-round goose population up here in Milwaukee for many years now, perhaps a few decades. I don’t remember exactly when it started but I don’t recall them from my younger years.
Is she in the upper left in the first photo? Almost at the top, about 1/3 of the way from the left?
b&
Yes. I found her by clicking and enlarging the image.
Me too, it was much more fun than finding Waldo.
At Chicago State University (95th and King Dr) a Killdeer built it’s nest an inch off of the sidewalk on the busiest parking lot closest to the buildings. I staked off a 3′ square area around it with yellow “Caution” tape and added a sign. This, on a 162 acre, beautifully landscaped campus, with *all sorts* of suitable areas. So I’m thinking that this bird was not particularly bright.
They always do annoying things like that. When I worked in a park in my youth, I was forever putting picnic tables over kildeer nests & warning campers not to drive/walk/disturb the eggs.
During the Evolution meetings in Norman, OK a killdeer had a nest at the edge of the parking lot seen by many at the conference. Also a hen wild turkey was seen several times crossing the parking area.
Once when I was driving to work a couple years ago, a flock (I’m tempted to say herd) of turkeys (I think all hens – can’t remember if there was a tom in the mix), crossed in front of my car on a country road. I stopped and let them cross and they walked in front of me as if it was just a normal thing, “yeah lady we’re wild turkeys, it’s okay”.
It was a very unusual experience.
Also, at the evolution meeting there were two nests of scissor-tailed flycatchers in the small trees in the parking area, greatly appreciated by the avid bird watchers that had never seen this state bird of Oklahoma.
That, by the way, would have been a ‘rafter’ of turkeys. ‘Gang’ is also listed, but is not as impressive, I think.
Collective nouns for kildeer (plovers) are ‘congregation’, ‘stand’ or ‘wing’.
I kind of like “gang” because it’s mildly threatening. Like the turkeys might make you bite the curb if you look at them the wrong way. Wild turkeys do have a peculiar look about them.
I take your point. The reporter used the word ‘gang’ several times without ever seeming to know that it was the collective term.
Turkeys are quite common here in the country, now. (I’m in SW Michigan.) We get quite a few on our property. They’ve even established a dust bath out in the field.
A few weeks ago, though, I was driving on the freeway when one flew in front of my car, about hood level. Now that was exciting! And a little scary.
I had one fly out in front of my car, it was probably the tastiest turkey I’ve ever had.
At least you knew it was fresh roadkill. 😀
I missed mine (or it missed me)–I don’t know how, considering I was doing 70 mph at the time!
And was I ever glad–I don’t think the car would have gotten through unscathed.
Damn they’re big in flight.
We have one as our Governor.
Ha, ha!
Sad thing is, it’s not immediately obvious just which state you mean.
I’ve had gangs of wild turkeys walk right out in front of my car many times, fortunately on curvy country roads that kept my speed down so I could stop quickly. But they definitely have a “why yes, we do own the whole damn road” attitude.
They do that here in Western Pennsylvania, too (where I once counted 43 on the hillside behind the local bank one March morning). As my cousin would say, you’ll have that with turkeys. Strange thing is, in something close to 20yrs of coexistence with them here, I’ve only seen one roadkill turkey.
Well, they are very easy for motorists to see, and they don’t usually dart in front of your car like deer do.
“In my part of Wisconsin, Canada geese have become cliff nesters over the past twenty years, building their nests on ledges and roofs of buildings, a behavioral change that has resulted in a huge increase in nesting success and nest abundance. It would be interesting to determine how much of this new nesting behavior is an evolved adaptation or part of a learned repertoire”
I read somewhere that the pigeon evolved from a cliff-dwelling species of dove during the 12th-13th centuries when the great cathedrals of Europe were built. I haven’t been able to verify it though
The pigeon (rock dove)came from Europe. Historical reports described them as nesting on rocky ledges (thus the proper name ‘rock dove’). One description is here:
http://www.pigeoncontrolresourcecentre.org/html/the-pigeon-in-history.html
Earlier this summer I had a Killdeer start with the tail display and then switch to the broken wing distraction display. I didn’t let the bird get to far into the distraction display though. I didn’t want to force it to leave the nest so I turned around and it cut the distraction display short after only moving away briefly. So my point is that they can also choose to combine the behaviors.
A new Killdeer fact for me! Ain’t evolution wonderful?
Hey Greg, do you know interesting books, articles or documentaries where on can see the evolution of these features from birds not possessing them?
I’ve now idea how many years it would take for evolution to achieve this, it would be fascinating to see the intermediary steps.
Lothars Sohn – Lothar’s son
http://lotharlorraine.wordpress.com
I’m not a bird guy– I’ll ask an ornithological colleague. I don’t know whether there is any evolutionary component to the goose’s change in behavior. I would have thought that such changes would take longer than 20 years, which is why I suspect some kind of learned basis for the new behavior.
GCM
So fast? Wow, that’s kind of impressive for a layman like myself.
I’d have thought at least 1000 years.
As you can see, biology is really not my specialty, my research area being technologies used promoting the safeguard of the environment.
Lothars Sohn – Lothar’s son
http://lotharlorraine.wordpress.com
There is a great deal more plasticity in the genome than any Idiot Designist is wont to admit.
That is, it is not necessary for adaptations to evolve into the genome. Modern organisms have already evolved the ability to adapt themselves to wide varieties of environments. For example, a crow that’s already adapted to ripping open the skin of an animal killed by a wolf to get to the carrion’s flesh doesn’t need to evolve anything new to rip open a bag of dog food to get to its contents.
b&
So here are some suggestions on changes/evolution of bird behavior, especially in response to urbanization:
1) The PBS Nature video “A Murder of Crows”;
2) David Lahti has studied weaver birds in the West Indies adapting to the absence of parasitic cuckoos (eggs get darker, more uniform; probably genetic and since ca. 1700);
3) Changing nesting/migration behavior of barn swallows in Argentina; paper here.
Hope this gives you a start.
GCM
Many thanks!
If I’m correct, David Lahti is a Christian. This might be an indication that not all Christians are similar 😉
Lovely greetings from Germany.
Liebe Grüsse aus Deutschland.
Lothars Sohn – Lothar’s son
http://lotharlorraine.wordpress.com
Thanks for the Barn Swallow article!
The most annoyingly awesome bird
I hear them more easily than see them. We often have one nesting in the grass near the edge of our driveway, despite the presence of vehicles and the neighbors’ marauding cat. Which may be why I hear them so often…they seem to “cry” when doing the distraction behavior.
Species do what they can, when they can, where they can.
Which is to say Life will move into any and all available niches.
Any time a species becomes highly successful itself, it presents rewarding opportunities for predators and parasites. Humanity’s monoculture crops and domesticated animals are especially at risk. Likewise us, given there are now 7 billion potential hosts and constant travel across the globe.