If you’re like me, you’re in the midst of a low spot in the birding year. There are lots of birds in Pennsylvania right now but they’re secretive because they’re nesting, and they’re going to stop singing in July. Sigh. (Check out this graph of the birders’ emotional year to see what I mean.)
However, it’s Bug Season! Beautiful bugs are here to fill our need for color on the wing.
In June Charlie Hickey and his wife watch for the dragonflies to emerge from the lake at their backyard in Berks County. Charlie posted this Calico Pennant (Celithemis elisa) on his Flickr page on June 5, the day they first appeared.
Because I live in the city, I have to leave home to hear frogs calling. Though there are streams and a wetland in Schenley Park, the wetland is too recently restored and probably too isolated to have spring peepers. The park is surrounded by dense city neighborhoods and all of its water flows into a mile-long culvert that takes it to the Monongahela River. Where would frogs and fish come from? Not from downstream.
So I was delighted to hear spring peepers (Pseudacris crucifer) by the Sunken Garden Trail at Moraine State Park last Sunday. I made a point of sitting near the wetland, surrounded by their sound. Hundreds of them called in front of me but I couldn’t see even one because they’re so small and good at hiding. The video above (from Wisconsin) shows how tiny they are.
As a group the peepers were almost deafening but I heard two wood frogs and a single creaking sound among them. It sounded like a western chorus frog but it was probably an angry spring peeper. Wikipedia says, “As in other frogs, an aggressive call is made [by spring peepers] when densities are high. This call is a rising trill closely resembling the breeding call of the southern chorus frog.”
The video below gives you an idea of what I heard. Listen for the quacking of wood frogs at the beginning.
Jeepers creepers, do you hear the peepers?
Update: Check the comments for places where readers have heard peepers in the City!
Wood frogs are often the first frogs to appear in the spring in eastern North America, quickly followed by spring peepers. As the video indicates temperatures have to be in the 40s for the wood frogs to “wake up,” but western Pennsylvania hasn’t had a lot of warm weather yet.
The cold winter has made a difference. Two years ago we had an exceptionally warm spring and the frogs came out in early March. This year we’ve had a few blips of warm weather surrounded by temperatures in the teens, a discouraging combination for cold-blooded frogs.
Today we’re headed for a spate for warm weather that may signal the end of winter’s grip. We’ll know it’s really spring when we hear frogs calling.
In fact, there were never any snakes in Ireland since the last glacial maximum. St. Patrick’s legend may actually refer to the rise of Christianity and the end of Druid snake symbols.
In recent years biologists in Guam are trying to accomplish St. Patrick’s legendary feat. Invasive brown tree snakes are devastating the island’s native birds. The snakes must go. So far the most ingenious plan has been to air drop 2,000 mice wearing tiny parachutes. The mice were dead bait laced with a very small dose of acetaminophen that kills the brown tree snake but nothing else.
There was no need for St. Patrick to eradicate this grass snake from Ireland. Photographed in Europe, it cannot cross the sea.
Happy St. Patrick’s Day!
(photo from Wikimedia Commons, Creative Commons license. Click on the image to see the original)
Last spring the hemlock woolly adelgid (HWA) reached Cooks Forest, scary news for the old-growth eastern hemlocks there.
The pest is easy to recognize by its white egg sacs that cling to the underside of the branches. They kill hemlocks by sucking the juice out of the needles. Infected trees look gray-green instead of deep green and, under a heavy infestation like the one shown above, can die in only four years. This is sad anywhere but especially unfortunate in Cooks Forest where the old growth hemlocks are over 300 years old.
It has taken a long time for the bug to reach Cooks Forest. HWA arrived from Asia in 1924 but moved very slowly across the eastern U.S. By 2007 it was present in 50% of the eastern hemlock’s range, unable to spread far northward because of harsh winters. Unfortunately our climate is warming so new adelgid territory opens up every year. (Notice on this NOAA plant hardiness map that the location of Cooks Forest warmed enough to change growing zones.)
HWA was first spotted in eastern Pennsylvania in 1967 but took about four decades to cross the Allegheny Front into western PA. Slowly, slowly it crept toward Cooks Forest. By 2010 it was in the vicinity. This year it was there.
Knowing the imminent danger DCNR has treated the area and the old growth trees. They use biological controls — Asian beetles that eat adelgids, though not enough of them — and soil or bole-injected insecticides on specific trees. The poisons are systemic, similar in concept to the insecticide treatments for emerald ash borer that kill or repel all insects. The treated trees will have fewer insects living on them. Will this make them less useful to birds?
The question hardly matters. Nature can’t produce a 300 year old hemlock as fast as the adelgids can destroy one. In the case of our oldest treasures our task is clear. Save these trees if we can.
For more information on the hemlock woolly adelgid, click here for DCNR’s report.
(photo via Wikimedia Commons by Nicholas A. Tonelli at Jacobsburg, Northampton County, PA. Click on the image to see the original)
p.s. Thanks to Kim Getz for alerting me to this news. Because of the adelgids activity cycle, DCNR treated the old-growth trees in May and again in October.
This blog is made possible by caffeine… administered every morning in a 16 oz mug of coffee at 5:00am. Boing! I’m awake! It works. And it makes me happy.
Apparently it is not good for everyone.
According to Wikipedia, Swiss pharmacologist Peter Witt began testing different drugs on European garden spiders in 1948 because a zoologist friend of his, H. M. Peters, was annoyed that the spiders always wove their webs between 2:00am and 5:00am. Dr. Peters wanted to study web building when he was awake, not when the spiders were.
Naturally it made sense to try caffeine. Perhaps it would keep the spiders awake longer so that they’d “sleep in” and start weaving after dawn.
Not so! Instead of time-shifting their web construction, caffeine made the spiders build whacky dysfunctional webs.
In 1995 NASA conducted a similar study and took photographs of the spider webs both before and after caffeine (above).
So much for Dr. Peters’ brilliant idea. He was forced to study his subjects in the dark. I’m sure he had to be on caffeine to do it.
(photos from Wikipedia. Click on the image to see the original)
A week ago I saw my first and only monarch butterfly of 2013. Their sudden disappearance is both troubling and saddening. It’s now possible to imagine a world without monarch butterflies. We are nearly there.
Last winter’s monarch survey in Mexico showed their population was down 59%, a record low. There have always been population fluctuations but the trend has been running low and lower since 2004. Scientists believe that agricultural pesticides and herbicides have reduced available poison-free habitat for butterflies (similar to the bees’ problem), so this spring monarch enthusiasts encouraged people to grow safe-haven milkweed for the butterflies. It wasn’t enough.
Each species has an intrinsic value. If, or when, the eastern monarch butterfly goes extinct we will lose its pollination contribution, milkweed symbiosis, beauty, and the amazing adaptations that allow multiple generations to migrate from Mexico to Canada and back.
One of the adaptations that will disappear is this: Monarch butterflies have a sun compass in their antennae.
Their antennae have light sensors that track the amount of light each day. According to a study in 2009 by Merlin, Gegear and Reppert, this circadian clock “provides the internal timing device that allows the butterflies to correct their flight orientation, relative to skylight parameters, and maintain a southerly flight bearing, as the sun moves across the sky during the day.” Migratory monarchs without antennae fly in aimless directions. Monarchs with antennae always orient southwest.
The monarch’s sun compass was discovered only a few years ago. Now there are almost no monarch butterflies to study. The world will be a poorer place without them.
Click here for more information on the monarch’s amazing sun compass.
The weather was sunny and cold a week ago when I visited Flagstaff Hill so I was surprised to see over a hundred Green Darner dragonflies patrolling in the chilly breeze. They were having a picnic.
Each dragonfly faced the wind and hovered, then wheeled away to a new spot and hovered again. With binoculars I could see thousands of small insects being blown uphill in the wind. The dragonflies reached out and grabbed them. Their wings glinted orange in the sun.
Green darners migrate south in the fall so I was witnessing a “flock” that happened to stop there for an easy meal.
I don’t have a video of their amazing maneuvers but this one shows how they do it.