Since we don’t have hedgehogs in the U.S. you might not realize what a loss this is.
Only half the size of house cats, European hedgehogs (Erinaceus europaeus) have soft spines that are prickly but not dangerous. Unlike porcupine quills the spines have no hooks. Here’s a young one held in the hand.
Though they are nearsighted, nocturnal and solitary, hedgehogs are blessed with a keen sense of smell that helps them find beetles, slugs, insects and grubs. In summer they are lightweights (1.8 pounds) but in autumn they double their weight to get ready to hibernate.
There are perhaps just a million left, representing a 97% fall from the 30 million estimated to have roamed in the 1950s.
No one’s sure why hedgehogs have declined so precipitously but theories include a lack of habitat, a lower insect population, pesticides, road kills, and an increase in predators and competition, especially from badgers.
Though elk (wapiti) resemble white-tailed deer they are much larger and have huge antlers. A bull elk’s rack can reach 3.9 feet across and weigh 40 pounds! That’s twice as wide and five times the weight of the largest antlers on white-tailed deer.
Like all Cervids elk rub their antlers on trees to remove the velvet that coated the bone while it was growing. The velvet had nerves in it so the bull learned the dimensions of his antlers as they grew. When the rack is complete he remembers how big it is. This usually keeps him out of trouble when he rubs on trees or spars with another bull .
This month Paul Staniszewski captured photos of a bull elk rubbing his antlers and grooming in Benezette, PA. It’s amazing how the bull maneuvers in the tight space among the trees. What a massive rack!
This morning I went out the back door at 6am — in the dark — with a bag of garbage. I do this every Friday to outsmart the raccoons.
Raccoons are thriving in my neighborhood though we rarely see them. Last night, for the first time in many months, I saw a hunched shadow cross the street on a nocturnal ramble. They’re still here.
Mostly we see their evidence so we try to outsmart them.
The garbage truck arrives in our back alley as early as 6am but we’ve learned from experience that if we put the garbage out the night before the raccoons rip it open and scatter the contents. Nowadays I take out the garbage as close as possible to the garbage truck’s arrival. One morning I missed the truck. Dang!
Seven years ago PBS NATURE premiered a program called Raccoon Nation that showed how creative urban raccoons can be. One of the scientists remarked:
The more obstacles you throw in their way become more challenges, so it’s quite possible that by providing more and more obstacles we are in fact selecting for smarter raccoons.
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?
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.
In the wild and in our yards Thuja trees are a favorite food of white-tailed deer. They browse it from the ground up to the height of their outstretched necks.
When the number of deer is in balance with the landscape, arborvitae have a normal tapered shape. You’d never notice that the deer are eating them.
When there are more deer than the landscape can handle, their browsing is intense. The trees are cropped close to the trunk — even down to the bark — because the plants can’t replace their branches fast enough.
I photographed that row of damaged trees just six blocks from my house. Yes, my city neighborhood has too many deer now. We could protect our trees with netting as described in this video. Or we could give up and never plant arborvitae again.
p.s. There are too many deer everywhere in the eastern U.S., even in the forest. Read more here.
What size of a hole can a mouse get through? If you have ingenuity, time, and tools you can find out.
Matthias Wandel of woodgears.ca takes an engineering approach to woodworking. When a mouse got into his woodshed he made a wooden gauge to find the smallest hole the mouse could squeeze through. His seven-minute video, above, became an Internet sensation.
The mouse tried many holes but gave up quickly if they were too small. What limits the mouse from squeezing through? It’s the size of his skull, not the size of his belly that stands in the way.
Near the end of the video a shrew appears. What limits the shrew?
A flower that’s poisonous to one particular mammal …
If you have a cat, keep this plant far away from him. Easter lilies are extremely poisonous to cats.
Native to Taiwan and the Ryukyu Islands of Japan, Easter lilies (Lilium longiflorum) are popular flowers at this time of year. Unfortunately every part of the plant is poisonous to cats: the flowers, the leaves, the stem, even the pollen.
Did you know that meerkats have complex alarm calls?
Related to mongooses, meerkats (Suricata suricatta) live in colonies in southern Africa where their biggest enemies are jackals and eagles. Because they’re highly social they warn each other when danger is near. They even have special sounds to describe the source and threat level for each danger — combinations of “danger from the ground” or “danger in the air” with low, medium and high threat levels.
In this BBC Earth video, scientist Marta Manser tests the meerkats under various threat conditions. Everything goes as planned until she tests for “danger from the air!” by presenting them with a taxidermy jackal arriving by balloon.
“The results of that experiment were inconclusive.”
The meerkats looked up, confused. There is no alarm call for “flying jackal.”