Though the female lays two to four eggs, when the eggs hatch the parents shower all their food and attention on the first hatchling and neglect the others. The second chick has a 45% chance of survival but the rest starve.
This low reproductive rate is bad for a species threatened by forest fragmentation and the pet trade, so Tambopata has come up with an innovative way to save the abandoned chicks. They've developed a project to rescue the neglected chicks and relocate them to foster parents in wild nests with none or only one chick.
Shannyn Courtenay at the Macaw Project writes, "There is already great interest in this new work from macaw managers and conservation projects in Mexico, Guatemala, and Costa Rica where scarlet macaws are endangered."
In fall and winter you've probably heard large flocks of European starlings (Sturnus vulgaris) having loud conversations in thick trees or bushes. Then suddenly the flock falls silent and takes off.
Here's a good audio example: Listen for 53 seconds to a lot of noisy chatter. Then the birds fall silent and you hear them take off in a whoosh. (If you don't want to wait 53 seconds, click in the middle of the audio bar after it starts rolling.)
What signal do starlings use to trigger their escape? Is it an audio cue? Or is it visual?
Male ducks are easy to identify because of their bright plumage but females are difficult because they're camouflaged for nesting. Female gadwalls are really hard to figure out; they look like female mallards. If only they'd hang out with their mates the problem would be solved.
And by November it is. Unlike most ducks, gadwalls pair up in autumn. By November 97% of the females are swimming close to a male.
The males are much easier to figure out. From a distance they look boring brown with black butts but a closer look reveals their beauty. The male's back has gray and russet tones, his chest is marbled, and his sides sport a tiny zigzag pattern.
Female gadwalls and mallards look alike except for this: The gadwalls have thinner darker bills, a square head shape, and a white speculum on each wing. (Click here to see the iridescent blue speculum on a female mallard.)
If you see a confusing female duck alone it might be a mallard, but not for long. 90% of female mallards have a mate by November.
Both species are paired up already.
(photo credits: gadwalls by Walter Siegmund via Wikimedia Commons. mallard pair by M. O. Stevens via Wikimedia Commons; click on the images to see the originals)
Tuesday evening (October 23) Michelle Kienholz sent me the photo below of a huge flock of crows flying over Schenley Park toward CMU at 6pm. See those specks above the horizon? Hundreds of them!
Yes, it's late October and the crows are back in Pittsburgh for the winter. This is just the beginning of the flock. More will follow.
In the next few weeks the crows will move their roost several times until they settle on a favorite safe place. Meanwhile, you'll see them at dawn and dusk flying down the Allegheny River valley and through Oakland.
Last weekend at Cape Cod I saw a swirling flock of tree swallows at their staging area.
Staging: Designating a stopping-place or assembly-point en route to a destination -- from The New Shorter Oxford English Dictionary.
Tree swallows (Tachycineta bicolor) breed as far north as the tundra/tree line in Canada and Alaska and spend the winter from Florida to Central America. Their departure from western Pennsylvania is barely noticeable but on the East Coast they gather in salt marshes in huge flocks of a hundred thousand birds. Their interim stops on migration are called staging areas.
In the evening tree swallows funnel down to the marsh in a tornado of birds. At dawn they burst up from the roost, as shown in the Central Florida video above.
Last Saturday I saw thousands of tree swallows flying in tight formation at West Dennis Beach. Though sunset was two hours away they flew low across the salt marsh, hovered and touched down on bushes, swirled up and around and away.
At the height of their swirling I took some photos but couldn't capture their magic. However, this picture shows why they flew so fast and so close. There's a falcon in the upper right corner with a swallow in its talons. Perhaps it's a merlin. I would never have noticed without this photo.
This month chimney swifts (Chaetura pelagica) are migrating to South America, leaving before the weather's too cold for the flying insects they eat on the wing.
At dusk the flocks swirl around large chimneys then dive in to roost. This video from New Glasgow, Nova Scotia shows them streaming into an old schoolhouse chimney. Wow!
Don't worry when you see smoke coming out of the chimney at the end of the video. An observer explains: "There are actually two flues in the chimney. The chimney swifts use the larger flue, while the smoke is vented from the smaller flue, so the birds are safe. In fact, they probably benefit from the bit of heat that comes from the smaller flue."
Stake out a chimney in town to enjoy the air show or monitor a wooden chimney swift tower near you.
Where are the birds? What did they do during the storm?
Fortunately birds have strategies for coping with bad weather including:
Shelter in Place
Like us, birds hide out of the wind and rain and wait for the storm to end. They use man-made structures, thickets, and deep valleys where the wind is less intense. Their strategies are described here in Shelter From The Storm.
Birds can sense when a storm is coming and often evacuate before it strikes. A study of golden-winged warblers found that they left Tennessee a day ahead of a tornado: Warblers Fled Tornado One Day Ahead. Land birds in Florida can move northwest as Irma approaches but the birds on Caribbean islands had nowhere to go.
Fly In the Eye of the Storm
Sea birds have a third option. As they fly in search of a calm spot, they end up in the eye of the hurricane where they travel with the storm until the winds die down. This NASA image shows that the eye of Irma on Sept 5 was larger than both Anguilla and St. Martin so it was probably a relatively safe place. However, the hurricane won't lose power until it's over land so the sea birds may be exhausted when they finally stop far inland.
People and birds in the path of Hurricane Irma are all getting ready. I think of my friends and family in Florida.
(photo credits: Hurricane Irma satellite animation from NOAA, photo of pigeons sheltering from Wikimedia Commons, photo of tornado from Wikimedia Commons, Eye of Hurricane Irma from NASA Sport. Click on the images to see the originals.)