Narrow openings don’t bother cats because their free-floating collarbones are attached to muscle, allowing them to flatten vertically.
Short openings are a problem though. Young cats make mistakes.
Cats: We’d had them less than an hour when Sid went in a hole and couldn’t get out – had to break the grill off to let him out. — caption on the photo below by cormac70
As cats gain body size awareness they become better at judging short openings.
Though this video is not the iScience experiment, it is very similar.
Last Sunday in Frick Park we were privileged to see an 8-point buck hanging out with a doe. They were obviously a couple and merely gazed at us before returning to their interest in each other. The only thing that really got their attention was an off-lease dog on a trail to the right. Fortunately for the dog, he and his owner went the other way.
The paired stayed close together and the buck licked the doe’s face, ears and estrous. Bright light and shadows make it difficult to see them in this photo so I have brightened the remaining pictures.
Over-bright photos allow you to pick out the deer.
Most people never see this because white-tailed deer hide in dense forest during this period but Frick Park has a serious browse line so there is nowhere to hide.
During the 20th century a myth about deer mating practices governed deer management in Pennsylvania. Namely that it was OK to have 1 white-tailed buck for every 7 does because one buck could “service” all of them in the few weeks that all the does were in heat. Surely the males could get it done.
In 2002 the PA Game Commission changed deer management practices with antler restrictions to protect the young males and increased doe harvest to balance the sex ratio. The combination has given Pennsylvania’s deer the time they need to form a temporary pair bond.
Pittsburgh’s winter crow flock is building as more birds from the north join the thousands already here. By the end of December at the Pittsburgh Christmas Bird Count, there will be as many as 20,000 crows on the move at sunset.
This month while the flock is growing, the roosts that were adequate in October are too small, so they move the entire roost or split into several locations. The moving or splitting happens every week, if not more often.
On Halloween they chose a favorite spot in the Hill District overlooking the Allegheny River, but those coming from the southeast had to change course to get to it. Thousands flew over my apartment building just after sunset on 1 November. On 2 November they found a shortcut and took a different route.
Tonight sunset is during rush hour at 5:12pm and for the first time this fall many people will be outdoors while the crows are on the move. Those who hadn’t noticed the flock before will think the crows suddenly showed up. Nope. Crows have been traveling at sunset all their lives. It’s the people who suddenly showed up.
p.s. Thank you to Sue Faust & Betty Rowland for alerting me to the crows’ whereabouts. It’s always a challenge to find the roost, especially in late December.
Last week began with light morning frost but rose to 80°F on Halloween.
The colors were gorgeous at Duck Hollow on Monday …
… while tendrils of fog chased each other across the river.
These wisps were formed at the rivers edge as clear cold air passed over warm water. Sunbeams make this a poor quality video, below, but you can see the wisps starting near shore. (You might also hear a song sparrow chipping in the background.)
Slanting light illuminated the trees at Schenley Park.
A leaf-hidden cocoon reminded me why clearing out leaves is bad for insects. This insect will overwinter on a leaf in Frick Park and emerge as — perhaps — a butterfly or month next spring. Or it may become food for a bird this winter. The insect chain is broken where don’t leave the leaves.
Spring Forward, Fall Back. Daylight Saving Time ends tonight as our clocks turn back an hour. Tomorrow the sun will set an hour earlier. A lot of us will be grumpy. Some will be depressed.
Most Americans agree that changing the clocks is bad.
Numerous polls have found that most Americans believe that a standard time should be fixed and permanent—as many as 75% favor no longer changing clocks twice per year. One of the most common observations among researchers of varying backgrounds is that the change itself causes most of the negative effects, more so than either standard time or daylight saving time. Researchers have observed numerous ill effects of the annual transitions, including reduced worker productivity, increased heart attacks and strokes, increased medical errors, and increased traffic incidents.
There are places that don’t participate in this dreaded exercise: Arizona, Hawaii, Puerto Rico and other U.S. island territories.
But there is an area in northeastern Arizona of self-governed indigenous tribal land where part of it uses Daylight Saving Time (DST) and the center does not. The DST area is the Navajo Nation which spans three states and has chosen to use DST. The donut hole is the Hopi Reservation that uses Standard Time. Here’s a closer look.
If you drive from Tusayan, AZ to Tuba City to Ganado to Window Rock in March through October, you will change time zones seven times between Standard Time and DST. (Did I count correctly?) People who have to make that trip will be relieved that everyone is on Standard Time tomorrow.
Changing your clocks: Everything connected to the Internet — mobile phones, etc. — will change automatically at 2:00am Sunday. The rest of the clocks are up to us.
p.s. I wonder what happens to a cellphone on the trip from Tusayan to Window Rock during DST.
In 1944 the US Army Corp of Engineers completed a flood control dam across the Youghiogheny River that created a lake into Maryland. The project included a new bridge for US Route 40 because the Great Crossings Bridge at Somerfield would be submerged and so would the town’s low lying streets and buildings.
Normally the lake is full and beautiful. You would never know there was a bridge underneath it.
But this year a drought in the Youghiogheny watershed has lowered the lake so far that you can walk out on the old Great Crossings Bridge.
Pittsburgh is not in severe drought so it’s hard to understand how this lake could drop unless you know where the river comes from. The Youghiogheny is a north-flowing river with headwaters in the mountains of West Virginia and Maryland. Notice that the rest of the Monongahela river basin starts in West Virginia as well.
The headwaters of both the Youghiogheny and Monongahela have been in drought since early July. At this point the drought is Extreme to Exceptional in western Maryland and West Virginia.
Water levels have dropped in both rivers but the Monongahela cannot afford to get too low because it carries a lot of barge and boat traffic.
However, there is water upstream to feed the Monongahela. Releases from Youghiogheny River Lake have, in part, kept the Mon navigable.
And so the old bridge emerges from the deep.
p.s. This isn’t the first time the old bridge has been exposed.
On Halloween 2008 I came across a small bat roosting on a tree in Schenley Park, described in A Bat on Halloween. Every time I pass the tree, especially on Halloween, I look for a bat but the chances of finding one are slim to none.
Little brown bats (Myotis lucifugus) used to be one of the most common bats in North America but their population in the Northeast has declined 90% since 2006 because of white nose syndrome (WNS), a disease caused by a European fungus that was accidentally introduced by cave explorers near Albany, NY.
The fungus spreads rapidly. It was confirmed county by county in southwestern PA in 2010, 2011 and 2012 and now it spans the continent. Little brown bats were listed as Endangered by the IUCN in 2021.
There are far fewer bats in Pennsylvania this Halloween than there were 16 years ago. It is unlikely that I will ever see a little brown bat in daylight again.
A long term study of white storks (Ciconia ciconia) in Germany and Austria discovered they improve their migration routes year after year as they gain experience. Older is wiser when it comes to migration.
Back in 2013 researchers fitted more than 250 juvenile white storks with tracking devices that followed each bird as it traveled to its wintering and breeding grounds. As the individuals aged they learned shortcuts, used more direct routes, and moved faster in Spring even though it used more energy.
White storks mate for life and set up housekeeping at age 3 or 4. On the graph we can see that older birds — mated adults — were in a rush to get home but young birds with no nest to reclaim spent time dawdling and exploring.
With age comes experience and changing priorities.
Last spring during the nesting season I was so distracted by peregrines that I neglected to check on a merlins’ nest reported in Highland Park. By the time I got over there the young had fledged, the merlins were gone, and a small group of American crows were inspecting the area and commenting on what they found.
Crows are intensely interested in merlin nests because those nests may have been stolen from crows.
Merlins (Falco columbarius) never build a nest. Instead they search for crow or hawk nests, ideally in conifers, and take them over. If the target nest is unoccupied no problem but merlins are feisty and will try for an active crows’ nest by driving off the incubating female crow. If harassing her doesn’t work, they shout at her all day until another predator shows up and forces her to leave.
This often works because merlins are loud and fearless. They’ll drive away anything that irritates them including this raven (a merlin predator not a competitor).
However, in southwestern Pennsylvania there are now two species of crows — American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus) — and it makes a difference to the merlins’ success.
Not so with fish crows. Merlins and fish crows are new to each other so they haven’t worked out their differences and continue harassing for a much longer period. Few or none on either side have a successful nest. In the study of 25 fish crow nests in upstate New York, 40% failed due to merlin interference. The study tracked 31 merlin nests and found 66% of those made in fish crow nests did not fledge young.
Autumn and winter are good times for seeing merlins and fish crows in Pittsburgh. It would be interesting to find them interacting in spring and watch what happens.
p.s. Thank you to Don Nixon of PA Merlins for alerting me to this fascinating topic. The paper(*) is by Connor O’H. Loomis and Anne B. Clark (Binghamton University), John Confer (Ithaca College), Kevin J. McGowan (Cornell Lab of Ornithology) but it is behind a pay wall. The fish crow and merlin nesting studies continue beyond 2019 in Ithaca, NY at Cornell Lab of Ornithology.
Six of us went birding yesterday at Duck Hollow and we didn’t just stand around. Here we are on the move to look in the thickets.
Before the rest of us arrived, Claire Staples captured this image of sky, sun and fog on the Monongahela River at 7:55am.
As 8:36am the sky cleared a bit. Two contrails make dogleg turns to the north.
Our Best Bird skulked in a thicket, of course, but kept making noise. He soon became the most photographed bird of the day: a winter wren in shadow and then in the open.
Duck Hollow’s northern mockingbird is still present and noisy.
We found a bumper crop of honeysuckle fruit along the Lower Nine Mile Run Trail.
Unfortunately …
Invasive honeysuckle berries aren’t strictly bad for birds. They’re an easy food source when birds are in a pinch, but they’re kind of like junk food: Compared to native berries, they have less fat and nutrients that birds need to fuel their long-distance flights.
Our “rare” bird of the day was a flock of 16 fish crows vocalizing as they flew. eBird didn’t believe we could find that many but eBird’s “rare” filter doesn’t know about, or cannot pointpoint, the fish crow phenomenon in Pittsburgh’s East End.