In a few weeks this plant will be very aggravating. Those tiny green balls are solidly attached to the stems right now but soon they’ll dry out and grab onto your clothes and your dog if you brush past the plant. They’re the fruits of Virginia stickseed (Hackelia virginiana).
Virginia stickseed is so inconspicuous in bloom that we barely notice it at this stage.
Virginia stickseed flower (photo by Kate St. John)
When fertilized they become small burs made of four nutlets facing each other. The outer surface is like velcro.
Fruits of Virginia stickseed, early August 2019 (photo by Kate St. John)
To give you an idea of their size, I pulled some fruits off the stem. It was hard to detach them because they haven’t dried out yet in early August.
Just wait until they turn brown!
p.s. There’s another less common native plant called small flowered agrimony with a similar fruit. Read more about it in this vintage blog: Slightly Aggravating.
(flowering plant photo from Wikimedia Commons; click on the caption to see the original. All other photos by Kate St. John)
Perhaps you already know this but it was news to me: Cinnamon repels ants.
Cinnamon comes from the dried inner bark of a tropical evergreen, the cinnamon tree (Cinnamomumsp.). Ants would eat these trees alive if they could but the cinnamon genus evolved a very effective defense: two chemicals, Cinnamaldehyde and Cinnamyl alcohol, that are toxic to ants. Ants stay away from cinnamon.
In this 9-minute video, the guy from You Can Science It shows that even swarming, warring ants will drop what they’re doing when confronted with cinnamon. He theorizes that it changes their messaging from “Kill the other colony” to “Oh no! It’s cinnamon!” (video begins where he starts discussing cinnamon. Click here for the full video.)
Yes, cinnamon repels ants but it has to be fresh and you have to use a lot of it.
There are many cool things about Atlantic puffins (Fratercula arctica). Here are two things that might come as a surprise.
(1) When Atlantic puffins fly back to their nests to feed their hungry chicks they need to carry as many fish as possible. How do they clamp them in their beaks? They press their spiny tongues on the fish to hold them against the roof of the mouth.
(B) We think puffins’ beaks are beautiful but we’re seeing only half of it. Where we see yellowish stripes the puffins see glowing ultraviolet. Read more about their colorful beaks in this article from Audubon.org.
Late last month observers discovered a small green pond at the bottom of Halema’uma’u Crater at Kilauea volcano. Water inside the crater is rather amazing since Kilauea is the active volcano on the Big Island of Hawai’i that erupted violently in 2018, destroying parts of Leilani Estates, Highway 132, Vacationland and Kapoho.
Geologists wondered if the green spot was a rock or algae so they flew over the crater several times looking for a telltale reflection to indicate it was water. Yes, it’s wet.
A week’s worth of photos also showed that pond had grown since it’s original “size of a pickup truck.”
Geologists don’t know how the pond got there but it’s worth watching to find out more. Fortunately by August 2 they’d found a safe place to view it from the crater’s edge.
Deer near Schenley Park swimming pool, 29 July 2019 (photo by Kate St. John)
4 August 2019
White-tailed deer are numerous and very tame in Schenley Park. Last week I encountered a doe with twin fawns near the swimming pool.
The family became alert while I was staring at them, but the mother has learned that we humans aren’t dangerous and is teaching it to her kids. How many generations does it take for the herd to become this tame?
Doe in Schenley Park, 29 July 2019 (photo by Kate St. John)Her twin fawns, 29 July 2019 (photo by Kate St. John)Twin fawns, 29 July 2019 (photo by Kate St. John)Twin fawns, 29 July 2019 (photo by Kate St. John)
In the past ten years I’ve seen the landscape change in Schenley Park while the deer population has grown exponentially. Where there used to be thick slopes of false Solomon’s seal and yellow jewelweed there is nothing green now, just carpets of fallen leaves. Having eaten the good stuff they are working on less tasty food, avoiding the poisonous plants such as white snakeroot at their feet in these photos. Some day their range will fail them.
I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer. And perhaps with better cause, for while a buck pulled down by wolves can be replaced in two or three years, a range pulled down by too many deer may fail of replacement in as many decades.
Blonde-colored groundhog near The Waterfront (photo by Bob Holder)
If you bike the Great Allegheny Passage at the eastern end of The Waterfront near Bristol Metals you may see this blonde-colored groundhog. His color has earned him the nickname “Lou.”
Lou isn’t the normal color for a groundhog. They’re usually brown like this one.
Groundhog in a tree at Flag Plaza, 31 May 2014 (photo by Kate St.John)
Lou is leucistic, a condition that has a partial loss of pigment in his skin or fur but not in his eyes. Pigment loss in the eyes — making them red (or green or blue) — indicates albinism.
But 14,000 years ago most of them were under ice and the lakes that existed weren’t in the same place. The western part of Lake Erie was under Lake Maumee. The toe of Lake Michigan was covered by Lake Chicago. As the ice receded the Great lakes took on their present shape.
A lot has changed in the last 14,000 years. Browse the maps below to find your beach at the ancient Great Lakes.
We all know it’s unsafe outdoors in a thunderstorm but did you know that lightning can be dangerous indoors, too? It depends on what you’re doing.
When lightning strikes a building it follows the quickest path to the ground. If the building has ample lightning rods it follows their lead. Otherwise it travels through the plumbing, wiring, metal door jambs, even the metal rebar inside concrete. If a building doesn’t have plumbing or electricity it’s not safe during lightning.
Don’t touch any electrical equipment unless it’s completely cordless. Anything that’s plugged in is bad.
A cellphone or cordless phone is OK, but not a landline that’s got a cord.
A laptop is OK if it’s not plugged into any wires, not even the charger.
Don’t run around unplugging everything while the storm’s in progress. Lightning could strike while your hand is on the cord.
Avoid the plumbing. Lightning can travel in water. Don’t take a shower, wash your hands, etc.
Stay away from the windows, not because lightning will come through the window (it won’t), but because it will explode the glass if it hits, creating lots of flying glass.
This one is the hardest: Avoid metal structural components including metal window frames, door jambs, and concrete rebar. If you’re in a concrete building good luck!
Of course it goes without saying that carports, porches and balconies are not safe because they’re outdoors. Cars are safe, but only if the windows are closed.
After heavy rains or a spring thaw in Pittsburgh we inevitably see devastating landslides on the news. Why does Pittsburgh have so many landslides and why are they associated with rain or moisture?
The problem is a combination of a particular bedrock and our steep hillsides. Where both are present the location is landslide prone, as shown on the City of Pittsburgh map below. You can see for yourself at the Allegheny County interactive landslide map.
The house in the video above was inside a landslide zone on Semicir Street overlooking Riverview Park. Add water and the house fell down the hill!
The bedrock at fault is Pittsburgh redbed, a claystone that disintegrates into smaller and smaller pieces if exposed to pressure when it’s wet. Redbed is usually under pressure because it’s underneath solid rock and overlying soil. Add water to a steep slope and you have a landslide.
This sandstone boulder on the Bridle Trail in Schenley Park was part of the escarpment above it until the redbed layer beneath it gave way.
An old landslide in Schenley Park on the Bridle Trail, July 2019 (photo by Kate St. John)
Here’s a future landslide on the Lower Panther Hollow Trail. This sandstone boulder, high above my head, will fall some day because the slow drip of water over the boulder has disintegrated the underlying redbed. Notice the reddish crumbled stones.
Sandstone boulder is undercut, a landslide waiting to happen at Lower Panther Hollow Trail, Schenley Park, July 2019 (photo by Kate St. John)
I had read that Pittsburgh redbed disintegrates when wet but I wanted to see for myself so I gathered some redbed rocks and ran an experiment.
Thousands of years ago these small crumbles were a much bigger solid rock but water had already acted on them. Will the crumbles disintegrate in the presence of water and pressure? I kept some rocks dry and soaked others for a day. Here’s my experiment.
Add water and pressure to Pittsburgh redbed claystone and … Watch Out Below!
Near infrared is long-wavelength light beyond the red end of the visible spectrum. Though we can’t see this wavelength we can feel its heat. In fact more than half the sunlight that reaches Earth is in the infrared spectrum, as shown in the graph below.
Australia is a good place to study cooling techniques in birds because 70% of the continent is hot, dry and very sunny. The Australian study examined museum specimens of 90 species, classifying them by habitat and testing them for their NIR reflectant properties. Two species stood out.
The nankeen kestrel and azure kingfisher are at the top of the NIR reflective scale but low reflectors of visible and UV light. The reverse is true of the blueish bird, a male superb fairywren (Malurus cyaneus). He’s great at reflecting UV and visible light, probably because he lives where it’s moist and shady. The great cormorant (Phalacrocorax carbo) doesn’t reflect much light at all.
Interestingly, near infrared reflectivity is more prevalent in small birds because they benefit more for their size. You can’t tell it from the photo but the azure kingfisher is only as big as a sparrow.
Too hot? Reflect near infrared light to stay cool.
(image credits: nankeen kestrel, sunlight graph and azure kingfisher from Wikimedia Commons. Graph from “Reflection of near-infrared light confers thermal protection in birds” at Nature.com, Creative Commons license. Click on the captions to see the originals)
