26 January 2017
On Throw Back Thursday:
Back in January 2010 when I first learned about emerald ash borer, I thought we’d see a slow decline of ash trees in the Pittsburgh area.
Not so! The bugs wiped out the ashes much faster than expected. Within five years Schenley Park’s ash trees were dead except for the few treated with pesticides.
What did things look like as the invasion began? Here’s a look back seven years:
(photo by April Claus)
Here’s something I didn’t expect to find in November, but that’s because I didn’t know much about snakes.
A year ago at Hillman State Park near Florence, PA I found this freshly shed snake skin on a gravel road. I must have just missed the snake.
Snakes shed because their skins don’t grow. The skin stretches a bit but when it gets too tight the snake makes a tear on something sharp and slides out of the outer layer. The new skin underneath is the right size until the snake grows more. This snake chose the warmest place available to shed his skin — a sunny, heat-absorbing gravel road.
Snakes are cold-blooded (ectotherms) and can’t survive freezing so they go into hibernation or brumation in communal dens below the frost line. I thought they’d all be underground by November 1, but no. Even in cold northern Pennsylvania snakes don’t go to their winter dens until late October or early November. In Hillman State Park on 1 November 2015 the temperature ranged from 53oF to 66oF, very respectable snake weather.
This year is even better for snakes. Their favorite temperature is 80o-90oF and we reached that last week — a record-breaking 80oF on 2 November 2016.
It was a good week to leave his skin behind.
(photo by Kate St. John)
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On Throw Back Thursday:
Halloween’s coming so it’s time for witchy things. Here’s one that’s new to me.
The black witch moth (Ascalapha odorata) is a very large owlnet moth that ranges from the southern U.S. to South America. Its common name comes from folklore that considers it a harbinger of death.
No, these moths don’t kill you. However, Wikipedia says there’s a joke in Mexico that if the moth flies over your head you’ll go bald. 😉
What other things in Nature have a Witch in their name? Here’s my list from 2011: Witchy Things
Can you think of more?
(photo from Wikimedia Commons. Click on the image to see the original)
19 October 2016
If you live in a Lyme disease area and feed the birds, you might get Lyme disease in your own backyard. Here’s what makes that possible and how you can make your yard safe.
When you provide food for birds, a lot of other animals eat that food as well. Squirrels and chipmunks eat during the day. The mice come at night, especially white-footed mice pictured above at a peanut feeder.
Animals live close to their food sources so they live in your backyard or even your house. Here’s a favorite mouse and chipmunk home — the nooks and crannies of stone walls.
The abundance of birds and rodents in your yard attracts predators: hawks, owls, cats and even ticks. You’ll see the big predators but you might not notice the tiny ones. Adult black-footed ticks are very hungry in October and November so watch out.
Birdseed –> mice –> ticks –> Lyme disease. White-footed mice are reservoirs for Lyme disease so the black-footed ticks that feed on your backyard mice may be infected.
What to do?
It’s impossible to get rid of all the mice — even if you stop feeding the birds — but you can get rid of ticks, and that’s what counts in the battle against Lyme disease.
The mice will help you do it. Mice like soft fluffy bedding in their nests and will carry it into their secret hiding places. If you give them anti-tick bedding it kills the ticks on them and in their nests.
This ingenious defense can be bought at TickTubes: The Safe and Effective Solution for Tick Control. In TickEncounter’s photo below, a mouse is gathering anti-tick bedding — permethrin-sprayed cottonballs — from the blue-green tick tube.
Don’t make your own tick tubes. (You’ll not get the dosage right and Permethrin can poison cats!) Instead buy EPA certified tick tubes at ticktubes.com. And then …
No more ticks!
p.s. You’ll see at Tick Encounter that July and August are the optimal time for setting out Tick Tubes. Sorry my timing is off.
p.s. Be careful with Permethrin. READ AND FOLLOW ALL LABEL DIRECTIONS. It is very bad for pets!
(photo credits: Click on the images to see the originals in context
White-footed mouse at night by Rob Ireton, Creative Commons license on Flickr,
Stone wall photo from Wikimedia Commons,
Chart of black-legged tick life stages from Wikimedia Commons,
White-footed mouse with anti-tick tube and cottonball bedding from tickencounter.org)
18 October 2016
It’s warm today but as soon as it turns cold brown marmorated stink bugs (Halyomorpha halys) will try to squeeze into every crack in our buildings. They’re everywhere. What can we do?
Ever since these Asian bugs first appeared in North America (in Allentown, PA in 1998) we’ve wondered how to control them. They destroy crops, especially fruits and tomatoes, so USDA has been studying them for a while. Do our native species eat them or must we import a stink bug predator from Asia?
To tease out the answer, researchers at USDA-ARS Appalachian Fruit Research Station in West Virginia placed stink bug egg masses near potential predators and documented what happened.
Some of the egg masses disappeared. It turns out that katydids eat the eggs completely, shell and all!
Other egg predators include crickets, ground beetles, earwigs and jumping spiders.
Jumping spiders pick up the entire egg mass, flip it over and suck out the eggs’ contents from the underside. (This is a “daring jumping spider” … cool name, eh?)
Moral of the story: If you don’t use pesticides, native insects and spiders will do the work for you. Goodbye, stink bugs!
Read more about the study and watch the videos here in Entomology Today.
p.s. In 2018 an alien stinkbug predator showed up on its own!
(photo credits:
Stink bug on leaf by Kate St. John
Stink bug eggs by David R. Lance, USDA APHIS PPQ, Bugwood.org
Katydid, Microcentrum species from Wikimedia Commons; click on the image to see the original
Daring jumping spider photo by Joseph Berger, Bugwood.org)
After two days of sad stories about fish populations in decline here’s some hopeful news.
With sensible catch limits and sanctuaries where fishing is prohibited, we can turn the tide on ocean species decline — but only if we can enforce the laws. Unfortunately the ocean is a huge place with few “cops on the beat” and a lot of places for illegal, unreported, and unregulated fishermen to hide.
Until now.
Last week Oceana, SkyTruth, and Google launched the public Beta of Global Fishing Watch (GFW), a free online tool that allows anyone in the world to monitor and track the activities of the world’s largest commercial fishing vessels in near real-time.
Here’s how it works: Every ship over a certain tonnage is required to transmit Automatic Identification System (AIS) data containing its identity, location, course and speed. The data, received by satellites and accumulated since 2012, is used to plot each ship’s movements. To determine which boats are fishing vessels, Global Fishing Watch developed an algorithm that identifies fishing by the characteristic patterns it makes on the map.
The map shows no-fish zones and Economic Exclusion Zones where it’s easy to see if illegal fishing is going on. Vessels that turn off their AIS transmitters or purposely falsify their GPS data are automatically suspect.
Nations at the mercy of illegal fishing are happy to use GFW. In December 2014, when the tool was still in test mode, SkyTruth analyst Bjorn Bergman (from his desk in West Virginia!) saw a Taiwanese boat fishing illegally in Palau’s protected waters. And it turned off its AIS. The boat left Palau and headed for Indonesia. When it returned in January Bergman remotely helped Palau authorities chase it down. Read the whole story here at the GFW blog.
So if you’re wondering how the U.S. will stop illegal fishing in 582,578 square miles of the newly expanded Papahanaumokuakea Marine National Monument (surrounding the Northwestern Hawaiian Islands) the answer is:
We’ll catch them from the sky.
For more information, watch the video and visit the Global Fishing Watch website.
(video from Global Fishing Watch on YouTube)
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Today, a fish story.
Bluefin tuna are following the same trajectory as the passenger pigeon. Because they taste good they’re poised to go extinct.
Atlantic (Thunnus thynnus) and Pacific bluefin tuna (Thunnis orientalis) are highly migratory predators that spawn on one side of their respective oceans and travel thousands of miles on migration to their feeding grounds. When they reach maturity at three to five years old they return to spawn. Bluefins can live 15 to 50 years and reach up to 990 pounds but because of overfishing very few live to maturity.
Like the passenger pigeon, human hunting pressure is the only reason for the bluefin’s decline. Technological advances in deep sea fishing have made it easy to catch all of them. Their meat is so prized in Japan for sushi and sashimi that the Pacific population has declined more than 97%. Large specimens are so rare that according to the January 11, 2013 issue of TIME magazine, “Just last week, a 489-lb. bluefin was sold at a fish auction in Tokyo for a record $1.76 million—or about $3,600 per pound.” That was nearly four years ago. Their status has only gotten worse.
Like the final decades of the passenger pigeon, the bluefin’s plight has been discussed for years. Catch limits for Atlantic bluefin have been in place since 2007 and it’s been nominated for endangered status. In 2010 the World Wildlife Fund pointed out there was still so much over-capacity for Atlantic tuna fishing that EU boats reached their catch limit in only one week. In 2011 Salon magazine asked, “Why are we still eating bluefin tuna?” In 2014, the Center for Biodiversity called for a Pacific bluefin fishing ban.
This summer the situation became so dire that a dozen environmental groups called for listing the Pacific bluefin tuna as Endangered and the Pew Trusts called for a Pacific bluefin moratorium.
This Pew Trusts video explains how the Pacific moratorium, implemented immediately, would save the species.
We still have time to turn it around — but not much.
Will bluefin tuna go the way of the passenger pigeon … from billions to none?
(photo from Wikimedia Commons. Click on the image to see the original.)
It happened to land animals. Now it’s happening in the ocean. The biggest die first.
Based on Earth’s current extinction rate of 1,000 times the normal background rate (predicted to become 10 times worse) scientists believe we’re at the start of the sixth mass extinction.
Stanford geoscientist Jonathan Payne wondered if the traits of extinct marine animals could predict the likelihood of extinction in today’s ocean organisms. For mollusks and vertebrates Payne and his colleagues compared ecological traits such as habitat preference and body size in past extinct and present threatened genera (genus: one level above species). The results were surprising.
In past extinctions habitat preference was a good predictor that an animal would disappear. That’s not the case now. In this era, the best predictor of future extinction is large body size.
The difference is us. Human hunting pressure is driving ocean extinction. Our demand for seafood is high (there are billions of us to feed) and we’ve become very efficient at capturing the largest fish. Highly migratory predators like the Pacific bluefin tuna have declined precipitously.
We’ve seen this before. At the end of the Ice Age, as human population expanded across the globe, the megafauna simultaneously went extinct. It’s now known that sabretooth tigers, giant armadillos and woolly mammoths disappeared due to human hunting.
We humans are successful because we make tools and hunt cooperatively. Of course we kill the largest prey first. One large animal feeds more people.
Unfortunately we don’t know when to stop.
Read more about Payne’s study here at Science Daily.
(photo of swordfish from NOAA Photo Library. photo of woolly mammoth statue in Royal BC Museum, Victoria, Canada via Wikimedia Commons. Click on the images to see the originals)
p.s. A word about the swordfish pictured above: Swordfish are highly migratory predators whose population is in danger in many oceans around the world. In 1998 the North Atlantic population dropped so low that fishing was suspended. A 2009 international assessment of North Atlantic swordfish showed they had recovered in U.S. fishing areas, so fishing resumed. Note: The fishermen who lost their lives aboard the Andrea Gail in The Perfect Storm were longline fishing for swordfish.
Honey bees are busy right now collecting nectar and pollen to get them through the winter. They carry nectar to the hive by swallowing it. They carry the pollen in sacs on their legs.
According to Wikipedia, the bee’s pollen basket or corbicula is “a polished cavity surrounded by a fringe of hairs.” Each bee grooms the pollen off her body and stores it in her pollen baskets. Here’s how:
A honey bee moistens its forelegs with its protruding tongue and brushes the pollen that has collected on its head, body and forward appendages to the hind legs. The pollen is transferred to the pollen comb on the hind legs and then combed, pressed, compacted, and transferred to the corbicula on the outside surface of the tibia of the hind legs.
This honeybee’s pollen basket is so big that it looks like she’s wearing orange knickers.
(photo by Kate St. John)
p.s. for my British readers: The word “knickers” in the U.S. is short for “knickerbockers,” the baggy trousers tight at the knee formerly worn by golfers.
Ten days ago Marcy Cunkelman flipped over a leaf and showed us two hundred tiny emperors.
The squiggly green lines are caterpillars of the Tawny Emperor butterfly (Asterocampa clyton) eating the mature leaves on a hackberry tree. They also feed on other trees in the elm family (Celtis).
At this stage the caterpillars huddle and move together for protection but after the third instar they travel alone.
Eventually each caterpillar spins a cocoon and pupates into a butterfly that looks like this:
The butterflies don’t visit flowers. Instead they feed on rotting fruit, dung, carrion and tree sap … an odd feast for an emperor.
(photo of caterpillars by Kate St. John, photo of butterfly from Wikimedia Commons)