An adult female fly is shown below, much larger than real life. She’s slightly bigger than a housefly.
In the spring she uses her sharp ovipositor to insert her eggs into goldenrod stems near the developing buds. When the eggs hatch, each larva chooses a place to rest and eat. Its saliva contains a chemical that induces the plant to grow a gall which becomes the larva’s food and shelter.
In September the larva prepares its exit strategy, even though that won’t happen until next spring. It digs a narrow tunnel to the outside that doesn’t break the surface. Next spring when it becomes an adult, the fly will chew a hole in the outer cover to escape.
Not all of them make it. During the winter downy woodpeckers and chickadees probe the galls to eat the bugs.
For migrating songbirds there are two deadly attractions in this photo.
On the left, Downtown Pittsburgh glows in the distance illuminating the night sky. At center-right, Pitt’s blue Victory Lights beam up from the Cathedral of Learning roof. (The building itself is hidden by the dark spruce.)
Downtown Pittsburgh glows every night. Pitt’s Victory Lights glow on Saturday and Sunday nights after Pitt wins a football game. Photographer Dave DiCello tweeted his photo, below, of the Victory Lights on 15 September after Pitt beat Georgia Tech.
The moon shines beside the Cathedral of Learning tonight, as the Victory Lights and spotlights from the roof illuminate the sky over #Pittsburgh in celebration of Pitt’s first ACC win of the season pic.twitter.com/SuTRzRVpl9
City lights are a fatal attraction for songbirds because they migrate at night using celestial lights for navigation. Lured by artificial lights they become confused and circle them. Some crash into buildings. Others land in the city and try to leave after dawn but mistake glass reflections of trees and sky for the real thing. They fly headfirst into glass buildings and windows. Some are stunned, many die. Warblers and wood thrushes are especially vulnerable. Every year nearly half a billion birds die this way in the U.S.
You can help birds survive Pittsburgh’s bright lights, both now and in the future. Jon Rice at BirdSafe Pittsburgh is mobilizing volunteers to help stunned birds now and to collect data on deaths to mitigate the future.
Here’s what you can do:
Report Dead Birds: If you find a dead bird pause to report it. Enter what, where and when in BirdSafe’s I Found A Bird online tool. Your smartphone automatically knows “where.”
After the Tribute began in 2003, people noticed that thousands of birds were lured to the lights and dying there, so in 2005 New York City Audubon mobilized volunteers to monitor the beams. When volunteers count 1,000 birds circling in the beams or if a bird is found dead, the lights are turned off for 20 minutes. That’s all it takes for the “stuck” birds to resume their migration and not become trapped again. Since 2005 only two birds have died during the Tribute of Light!
The article also describes how we can apply this knowledge across the U.S., including in Pittsburgh.
We also discovered that on average, half of the total passage of autumn bird migration density over the continental United States occurs on fewer than 10 nights. With migration forecasts developed by scientists at the Cornell Lab, the University of Massachusetts at Amherst and Oxford University, these cities and others could determine the optimal nights to dim or extinguish lights so that birds can pass safely.
This easy solution will save migrating birds but we need the data to convince others to make it happen. Please help the birds by helping BirdSafe Pittsburgh.
(photo credits: Downtown Pittsburgh and Pitt Victory Lights by Kate St. John. Cathedral of Learning and Pitt Victory Lights embedded tweet by Dave DiCello. 9/11 Tribute of Light from Wikimedia Commons; click on the caption to see the original)
The ancestors of this saltwater snail changed oceans twice.
California horn snails (Cerithideopsis californica) are native to the Pacific Ocean from the California coast to Baja California Sur in Mexico, but a DNA study published in 2011 found they contain traces of a closely related Atlantic snail, Cerithideopsis pliculosa, and vice versa. The DNA mixing went like this:
3 million years ago North and South America joined at Panama, blocking sea travel between the two oceans.
750,000 years ago, Pacific Ocean snails somehow traveled east to invade the Atlantic.
72,000 years ago, Atlantic Ocean snails came back to invade the Pacific.
How did the snails cross Central America from one ocean to another? Twice?
On Throw Back Thursday, find out in this vintage article: Flying Snails
You would think that all shorebirds live at the shore but not this one. The red-necked phalarope (Phalaropus lobatus) spends most of his life at sea, spinning like a top.
Phalaropes live inland from June through August while they’re breeding in the sub-arctic northern hemisphere but most of the year — November through March — they’re out to sea on the tropical ocean. Their food is on or near the water’s surface.
Phalaropes feed by swimming in tight circles, rapidly picking tiny insect larvae, crustaceans, and mollusks from the water. Their feet are specially equipped for swimming. They have lobed toes like coots. (“Phalarope” is Ancient Greek for “coot toes.”)
In winter red-necked phalaropes don’t have red necks. Right now they’re wearing gray “basic” plumage, shown above, as they migrate to their final destinations in the southern hemisphere. Western birds take an inland route through the western U.S. but you probably won’t see one in the east. Except for a few stopovers at the Great Lakes, the eastern population flies immediately to the Atlantic Ocean.
If you really want to see red-necked phalaropes in beautiful breeding plumage you’ll have to wait for spring. Sparky Stensaas filmed this group feeding at their breeding grounds in Churchill, Manitoba, Canada.
If the spider was there, you’d see that it’s only 9-22 mm (.3 to .8 inches) long. Males are the typical spider shape but the females have large, round, marbled abdomens ranging in color from orange to yellow with purple markings and pale spots.
“Marbled orb weaver” describes them perfectly. They’re also called “pumpkin spiders” for obvious reasons.
I’ve rarely seen the marbled female and here’s why: After she spins her web she attaches a signal thread to the center and retreats to a hiding place where she holds the thread while she waits. The signal lets her know when something hits the web and out she comes.
Where does the spider hide? The Capital Naturalist tells us in this video.
(photos from Wikimedia Commons; click on the captions to see the originals. video by the Capital Naturalist)
In September I often find sprays of oak leaves littering the woodland trails. I used to think they fell in windstorms but I’ve discovered a more common reason. In autumn it’s squirrels at work.
Gray squirrels build leaf nests high in the trees for shelter in winter, nests for their young, and for sleeping at night. The outer layer is composed of leaves and twigs that make a water resistant blob about the size of a beach ball. The inside is lined with moss, grass, shredded bark and other soft vegetation. The entrance faces the trunk.
Squirrel nests can be as much as 70 feet off the ground. Here’s what one looks like.
To gather building materials, the squirrel gnaws near the branch tip — often an oak — until the spray of leaves comes loose. If he isn’t careful to hold the twig, it falls. Oh well. The squirrel gnaws another one.
You can tell when a spray of leaves is a squirrel’s handiwork. The tip of the twig looks chiseled. Teeth made this mark!
Last week I found many leafy twigs on the trails in Pittsburgh. After four days of cold rain the squirrels were making nest repairs.
As winter approaches you’ll find them, too. The squirrels are fortifying their nests and they don’t have much time. The leaves will be gone in November.
(photos by Kate St. John, Marcy Cunkelman and from Wikimedia Commons; caption has a link to the original)
Birds can sense when bad weather is coming. If it’s going to be dangerous and they have some lead time they get out of the way. Hurricane Florence gave them plenty of time to prepare.
Weather radar shows us where it’s raining by detecting objects in the sky. When masses of birds are on the move they show up on radar, though less intense than steady rain. Flocks of birds look green on radar and are only detected when near radar stations. Since most birds migrate at night, that’s when to watch.
This radar image from 5:08am on Saturday September 15 shows the rain bands of Hurricane Florence swirling over the Carolinas. Notice that there’s no rain for miles surrounding the circle of the storm but there are intense green blobs southwest of Florence over the Florida panhandle.
Thousands of birds! They’ve heard the news and they’re leaving the area. Evacuate!