Pigeons (Columba livia) and the raptors who hunt them have evolved together for millions of years. The raptors’ successful hunts leave only the fastest, most maneuverable pigeons. Speedy, elusive pigeons mean only the most skillful raptors can survive. Most of us never get to see this interaction so this dramatic video from Romania is a real treat.
The pigeons stay in a tight flock because raptors can’t pick out a victim in a moving ball of birds. The raptors try to separate one bird from the group by slicing through the flock. If it works, the raptor pursues the lone bird.
In a study conducted in Italy, researchers released racing pigeons fitted with GPS backpacks from sites 20 to 80km from home (12.5 to 50 miles). In over 200 flights, the data showed that experienced pigeons preferred to follow roads and rail lines in the early and middle parts of their trips. As they got close to home they left the road grid and made a beeline for the loft.
On the first trip from each site pigeons didn’t use the grid, but the more they made the same trip the more they used big roads.
Why do they do this? Scientists suspect that easier navigation above major roads makes up for taking slightly longer routes. The birds don’t have to think about where they’re going and can focus on flying fast and watching for predators.
That’s why I take expressways in my home town, even when they’re clogged at rush hour. I know the back roads but I’d rather not think about navigating.
Despite their size and ungainly appearance, wild turkeys (Meleagris gallopavo) can fly. They have to be airborne twice a day to get to and from their roosts in trees.
Most of us never see them fly but here’s some indirect evidence. The wild turkey below was photographed on Thompson Island in the bay east of Boston, Massachusetts. The photographer’s mobile phone provided GPS.
What is that hooting? Is it an owl calling in the middle of the day?
In the spring, male mourning doves (Zenaida macroura) perch high, puff their throats and make the deepest loudest sound possible for a bird so small. The first rising note is lost in the distance, but the last two or three low notes carry far.
Last week at Moraine State Park I was momentarily transfixed when I heard “Hoooo Hoooo” across the valley. When I paused to listen I realized that the cadence didn’t match any local owl. Not the great horned owl. Not the barred owl. I heard only two notes but they were spaced like the mourning dove’s.
Listen as a mourning dove sings one rising note, then 3 or 2 low notes. Imagine you can hear only the last two notes. (Xeno-canto recording XC153652 by Paul Marvin at Moosehead NWR, Maine)
Now compare it to these two owls:
GREAT HORNED OWL recording by Ted Floyd, Boulder, CO at Xeno-canto XC344952
BARRED OWL recording by Tim Spahr, Ithaca, NY at Xeno-canto XC25239
White-tailed ptarmigans (Lagopus leucura) hide in plain sight by blending into the landscape. They’re speckled brown in summer and white as snow in winter. They virtually disappear when they close their eyes.
In late November Dan Arndt found these birds in the snow at Highwood Pass, Highway 40 in Alberta, Canada.
How many ptarmigans do you see?
Willow ptarmigans hide, too. Practice finding them in this 2010 article: Where’s Willow?
Birds use alarm calls to warn each other of danger but pigeons are generally silent. What sound could a pigeon make to signal danger? The crested pigeon (Ocyphaps lophotes) of Australia uses his 8th feather.
Crested pigeons make a whistling sound when they fly — a high note on the down stroke, a low note going up. Researchers found out that the eighth primary feather is the source of the high note and that the speed of the low-high modulation provides the warning.
When a bird flaps slowly the whistle repeats slowly, so other pigeons decide the bird is not afraid. When the sound repeats rapidly it sounds like the pigeon is fleeing, so the other birds do, too.
The two wild turkeys at top are displaying to females. Which one has the best snood? I can’t tell but the females can. Click here to see how the ladies reacted.
(photo credits: two wild turkeys by Cris Hamilton; women wearing snoods from Wikimedia Commons; man wearing a beard snood from sales page at Creeds UK; wild turkey diagram from Wikimedia Commons. click on the images to see the originals)
If successful, they’ll release the new bird in the wild to repopulate eastern North America.
But a new study published this month in Science may throw a wrench in their plan.
Researchers gathered DNA from the toepads of passenger pigeon museum specimens and sequenced the full genomes of four birds. In doing so they discovered that passenger pigeons were extremely diverse at the ends of their chromosomes but had low diversity in the middle. Most animals, including the band-tailed pigeon, aren’t like that. Most animals are diverse all the way through.
This trait may indicate that the passenger pigeon in its final form had evolved to live in enormous flocks.
So, why did this superspecies die out? Shapiro thinks it’s because the bird specifically evolved to live in mega-flocks, and developed adaptations that became costly when their numbers suddenly shrank at human hands. “Maybe they were simply not adapted to being in a small population, and didn’t have time to recover,” she says. Maybe they hit a tipping point when there were just too few of them to survive, regardless of whether they were being hunted.
Would a small population of passenger pigeons be possible in the wild? And could the birds survive in this century’s altered and deforested landscape? Revive and Restore believes the answer is yes.
Can humans bring back the passenger pigeon? Should we try?