If you’ve only seen Jack O’Lantern mushrooms (Omphalotus olearius) during the day you may have thought they were named for their orange pumpkin-like color.
Jack O’Lantern mushrooms, Schenley Park, 30 Sept 2018 (photo by Kate St. John)
Instead they are aptly named because they glow green in the dark, as shown in the top photo.
Perhaps, like Armillaria mushrooms, Omphalotus olearius is bioluminescent because of the chemical reaction they use to consume decaying wood. Armillaria‘s chemical reaction glow is described in this vintage article on foxfire.
Though 70% of the songbirds in our field guides have sexes that look the same to us, this isn’t true from the birds’ point of view. Birds can see ultraviolet light (we cannot) and often have plumage differences in the ultraviolet range. With the invention of inexpensive UV viewing equipment, scientists looked at birds and were amazed at what they found. 90% of the species tested had differences between males and females under UV light. We humans just can’t see it.
Eurasian blue tits (Cyanistes caeruleus), shown at top, were one of the first wild birds examined in the ultraviolet range. Both sexes look alike … or do they?
Using a spectrophotometry probe to scan the feathers of wild-caught birds, Andersson and his colleagues discovered that blue tits themselves have no problem telling males from females: Males have a patch of feathers on the crown of the head that strongly reflects UV light; females do not.
Both sexes of yellow-breasted chats (Icteria virens) look the same from afar, though in the hand the sexes can be distinguished (interior mouth color for instance). A 2004 study, Sexual dichromatism in the yellow-breasted chat, detected that the male’s throat has ultraviolet colors that make it much brighter than the female’s.
Apparently most birds are sexually dimorphic in ultraviolet including cedar waxwings, barn swallows, mockingbirds and western meadowlarks. According to True Colors: How Birds See The World, biologist Muir Eaton scanned the plumage of museum study skins of 139 songbird species in which males and females appear alike — but they aren’t alike under UV. He concluded, “To the birds themselves, males and females look quite different from one another.”
For more information see:
Photos of birds showing ultraviolet features at uvbirds.com. (Check out the flamingo!)
Beautiful autumn in the woods, 26 Oct 2023 (photo by Kate St. John)
28 October 2023
The last full week of October brought beautiful weather and fall foliage to Southwestern Pennsylvania. Early mornings were chilly but warmed up quickly. Here are a few scenes from the week.
Frick Park is beautiful in early morning sunlight on 26 October. With Charity Kheshgi.
American beech leaves in Schenley Park show three color stages: green, yellow, brown.
Sugar maple leaf is red at SGL 203, Marshall Twp
The arching trunks of a mature Norway maple in Shadyside, City of Pittsburgh.
Fall colors reflecting on Lake Arthur at Moraine State Park.
Beautiful sunrise on 26 October. Three crows pass by on their way from the roost.
American beech changing color, Schenley Park, 21 Oct 2023 (photo by Kate St. John)Sugar maple leaf, SGL 203, 22 Oct 2023 (photo by Kate St. John)Norway maple in yellow, Shadyside, Pittsburgh, 23 Oct 2023 (photo by Kate St. John)Fall foliage reflection at Moraine State Park, 24 Oct 2023 (photo by Kate St. John)
Golden yellow is a them from leaves to sky.
Sunrise with three crows, 26 Oct 2023 (photo by Kate St. John)
The Mercator projection that transforms our 3-dimensional Earth into 2-dimensions was invented in 1569 for use in navigation, which is why Google uses it. Unfortunately it totally distorts the size of land closer to the poles. It makes Greenland look big, maybe bigger than Africa. New Zealand is often cropped off this map.
The animation at top alternates between the Mercator projection and each country’s actual relative size. Hello, Northern Hemisphere, you aren’t as big as you think you are!
If we correct for size, as in the Gall-Peters projection, we mess up shapes and navigation.
Making a flat map of the Earth is like trying to cut an orange peel to make it lay flat on the table. Good luck!
p.s. Here’s a screenshot from the thetruesize.com mapping tool that Johnny Harris mentions at the end of the video. Its initial screen demonstrates that the contiguous U.S. + China + India can easily fit into Africa with room to spare. Try it at thetruesize.com
Pittsburgh’s spotted lanternfly plague (Lycorma delicatula) is mostly over after recent cold weather knocked out lots of adults. It’s not a bad year for brown marmorated stink bugs, so are the insect plagues over? Not quite. Yesterday I happened into a swarm of Asian ladybeetles.
Asian ladybeetles (Harmonia axyridis) were imported to the U.S. 35 years ago as predators for aphids, adelgids, psyllids and scales. They do a good job and they caused no trouble until they were able to overwinter starting in 1993.
It is not uncommon for tens of thousands of beetles to congregate in attics, ceilings and wall voids, and due to the warmth of the walls, will move around inside these voids and exit into the living areas of the home.
In addition to beetles biting (which they do), they exude a foul-smelling, yellow defensive chemical which will sometimes cause spotting on walls and other surfaces. Most people are only annoyed by the odor of these chemicals. However, some individuals have reported experiencing an allergic reaction to the defensive excretions.
Red oak acorns on the branch, August 2023 (photo by Kate St. John)
25 October 2023
By late October leaves and nuts are underfoot and still falling. Red oak acorns that were green on the branch in August litter the footpaths and sidewalks now.
Red oak acorns on the ground, Sept 2020 (photo by Kate St. John)
Underneath black walnut trees it’s hard not to misstep on the yellow husked nuts. You may even be hit by a black walnut detached and dropped by a squirrel gathering nuts above you. Squirrels save time by crawling all over the tree and detaching lots of nuts. Then they scurry down to collect them. Ouch!
Keep looking down and you may find unusual nuts and seeds like these.
Magnolia cucumber tree lea and seeds, Sept 2011 (photo by Kate St. John)
Even without leaves, you can identify the trees above you by knowing the nuts at your feet. This fall I’ll run a series on identifying nuts found in western Pennsylvania.
Meanwhile to kick it off …
Adam Haritan explains a few trees you can identify without even looking up in this 15-minute Learn Your Land video.
On 18 October while Jim McCollum was taking photos of the Hays bald eagles a raven showed up and began to harass the new male eagle, nicknamed “V.”
10/18 – The new fella went for a fly about and got jumped by a Raven. The Raven chased him all over the sky. This guy needs to work on his fighting skills.
A little tidbit I read recently. Crows will lite on eagles backs and peck at their necks. The eagles don’t fight back just soar higher and higher until for lack of oxygen the crow passes out and falls off the eagles back. I’m not sure about the validity but it’s a good story!
At what altitude does lack of oxygen affect birds?
Birds are the champions of high altitude and can breed and exercise (fly) at altitudes that kill humans. Some species are so well adapted to high altitude that they fly as high as a jet, over the Himalayas where humans die without supplemental oxygen. Even our North American songbirds fly high …
Migrating birds in the Caribbean(*) are mostly observed around 10,000 feet, although some are found half and some twice that high. Generally long-distance migrants seem to start out at about 5,000 feet and then progressively climb to around 20,000 feet.
Join me on Sunday 12 November 2023, 8:30am to 10:30am, for a bird and nature walk.
Meet at the Duck Hollow parking lot at the end of Old Browns Hill Road. Dress for the weather and wear comfortable walking shoes. Bring binoculars, field guides and a birding scope if you have them. (Always remember to visit the Events page before you come in case of changes or cancellations.)
We’ll walk the nearby paths seeking birds, interesting plants, and lingering insects. Migrating ducks may be resting on the river. Mallards will attract attention because they’re courting.
Occasionally a rare bird shows up, so keep your fingers crossed. I can tell you we will not see is this American avocet that stopped by Duck Hollow on 3 October but it was sure fun while it lasted.
American avocet at Duck Hollow, 3 Oct 2023 (video by Charity Kheshgi)
The great-tailed grackle (Quiscalus mexicanus), a close relative of our common grackle, is so numerous and annoying in Austin, Texas in the winter that there are always news stories about them. This interview with a grackle researcher revealed a very cool fact about great-tailed grackles that probably applies to our grackles as well.
Great-tailed grackles can move their eyes independently to keep watch in two different directions at the same time! Check out the video below.
