Autumn is a good time to look for unusual leaves. They used to be boring until something happened to them. Like this.
There's an elaborate squiggle on this coltsfoot leaf (Tussilago farfara) made by a leaf miner, an insect larva that makes a path as it eats within the leaf tissue. Eventually the larva settles down to pupate and the path comes to an end. When the adult insect hatches it leaves a hole.
What makes these lines? I had no idea until I googled "leaf mine on coltsfoot"and found the answer. A blogger at Nature Post collected similar coltsfoot leaves, put them in jars, and waited for the adult insects to appear. It turns out his leaf mines were made by tiny moths called Phyllocnistis insignis.
Travel puts nutrition demands on birds in migration. What's on the menu for birds that eat fruit? Here's what they've been eating lately in Pittsburgh's Schenley and Frick Parks.
Number One on the menu is devil's walkingstick (Aralia spinosa). The picture above shows a beautiful full fruit cluster but you can't find these anymore. The tops of the plants are now empty pink stems with a few berries hanging on. Here's one in Schenley Park, looking up from below.
Another favorite are these tiny black cherries (Prunus serotina). Many black cherry trees have already been stripped of their fruit by large flocks of American robins and cedar waxwings.
At this time of year an eerie sound echoes through the north woods of Pennsylvania, the mating song of the elk.
In September and October Pennsylvania's elk herd (Cervus canadensis) has an annual period of sexual activity called the rut. The bulls gather harems, pursue the females, spar with other males, and "sing" a bugling love song.
Based on the size and posture of a bugling elk you'd think his voice is low -- but not at all. The bugle call is bell-like and echoing even when the animal is close by. His song carries far in the woods and fields.
Listen and watch the video below to hear the elks' eerie mating song.
News from the Caribbean, especially Puerto Rico, is horrific now that two Category 5 hurricanes have passed through the islands in just two weeks. Homes, infrastructure and habitat are all destroyed. Our hearts and help go out to everyone affected by these storms.
Images of the widespread damage also have made me wonder: Did birds survive these hurricanes?
North American whimbrels (Numenius phaeopus) that breed in the tundra of northwest Canada make long migrations to their wintering grounds in the Caribbean and South America. To understand their migration The Center for Conservation Biology fitted a few of them with satellite transmitters when the birds made migration stopovers on Virginia's eastern shore. One bird, nicknamed Hope, was tracked for three years beginning in 2009. Her transmitter was removed after it broke in 2012 but she still wears two colorful leg tags. Every year she returns in late August to St. Croix.
St. Thomas and St.John (purple pin markers) took a direct hit from Irma. Hope spends the fall and winter on St. Croix (blue pin) at Great Pond (yellow star). She was fortunate that Irma passed more than 45 miles north of her location. St. Thomas and St. John were so devastated by Irma that survivors were evacuated to Puerto Rico and St. Croix. (Click here to see a video of Hurricane Irma damage on the U.S. Virgin Islands, posted by the U.S. Navy.)
In July and August I noticed something I'd never seen before along the trails of western Pennsylvania -- scattered instances of leaves turning white.
The leaves had been green but now their tips or even whole branches were white. The plant below had advanced to the stage where some of the stems were completely white.
The condition is called chlorosis and it means the plant is not producing enough chlorophyll to look green. Since chlorophyll uses sunlight to make food for the plant, it's a sign the plant is in distress. But why?
Any trip outdoors this month will find a lot of goldenrods in North America. Here are just a few of the species I've photographed over the years. All of them are different.
Can I tell you their names? No. Goldenrods are notoriously hard to identify.
Above, a beautiful bushy goldenrod at Acadia National Park in Maine.
Below, the classic goldenrod shape in Pittsburgh: a tall plant with narrow alternate leaves and a tassel of yellow flowers on top. To identify it I'd need more information than the photo provides. For instance: Do the leaves have two or three prominent veins? Are they toothed or entire? Is the main stem smooth or downy or both?
In the photo below: An unusual goldenrod shape photographed in Pittsburgh. The plant reaches out horizontally with flowers perched in clusters on top of the stem. The leaves are long and narrow. Perhaps it's blue-stemmed or wreath goldenrod.
This one is a stand-up spike of yellow flowers with egg-shaped alternate leaves, found in Pittsburgh.
Is this goldenrod the same species as the tall tassel above? I don't know.
I've never seen white goldenrods in Pittsburgh. This spike of white flowers was photographed at Acadia National Park in Maine.
And finally, a ball-shaped flower cluster with long leaves, growing in a granite crack at Acadia National Park.
So much variety. So many goldenrods. And often so hard to identify.