There’s a tiny bat in the eastern U.S. that’s even smaller than the little brown bat. The tricolored bat (Perimyotis subflavus), formerly called the eastern pipistrelle, weighs only 0.16 to 0.23 ounces making it 30% smaller. Tricolored bats, like so many U.S. bats, are declining rapidly due to the fungal disease white nose syndrome and are Endangered in Pennsylvania. It’s pretty amazing that two of these tiny bats showed up in Downtown Pittsburgh in the past two years. We know this because both were rescued and rehabilitated at Humane Animal Rescue of Pittsburgh’s Wildlife Center in Verona (HARP).
To give you an idea of the tricolored’s size, here’s one roosting in a bat cave in North Carolina.
Before the two bats were found in Pittsburgh, there was no known record of their occurrence here. A female and a male came separately to HARP many months apart so there are probably more of them but who knows where?
Almost a year ago the male arrived at the Wildlife Center.
On August 22nd [2023] we received a male Tricolored Bat…a bat we never would have thought to ever come through our door! Tricolored Bats are an Endangered Species here in PA. Aside from being moderately emaciated and dehydrated, he sustained no other serious injuries. Weight gain was our main goal, he was 5.2grams at intake and the goal was to get him to at least 7.0grams before release.
He was fed the tiniest mealworms, gained weight, and was soon ready for release. HARP points out that bats cannot take off from the ground. “In order for a bat to fly, first it must climb to a high place and then it launches itself by intentionally falling into the air!” Here he walks out of the sheltering blanket, up the tree, and he’s off!
(*) p.s. The bat is called tricolored because each hair on its back has three color bands, like a tabby cat hair. The bat is not striped. All the tips are reddish brown.
Leaves turned white, Three Rivers Heritage Trail near Herrs Island, 3 Aug 2024 (photo by Kate St. John)
5 August 2024
Last weekend I noticed something I hadn’t seen for a while. Among a sea of green leaves a single plant had turned white. One was at the Herrs Island back channel, the other at Duck Hollow.
My two specimens are not the same species and they haven’t turned white in the same way. The plant above seems to have whitened from its tips inward. The plant below is turning white from the stem outward.
Leaves turning white, Duck Hollow, 2 Aug 2024 (photo by Kate St. John)
The difference in their response may indicate different reasons why they are experiencing chlorosis, or it might be specific to species.
Seven years ago I ran into a similar puzzle and described possible causes in this vintage article.
Pokeweed flowers at the tip and fruit forming at the bottom, Duck Hollow, 2 August 2023 (photo by Kate St. John)Small teasel completely in bloom, Herrs Island backchannel, 3 Aug 2024 (photo by Kate St. John)
Insects are busy in the heat. On 28 July sycamore tussock moths (Halysidota harrisii) dangled by silk threads as they lowered themselves from the sycamore trees. The only way to photograph one was to wait until he landed.
Sycamore tussock moth at Frick, 28 July 2024 (photo by Kate St. John)
Zabulon skippers (Lon zabulon) have been easy to find. Some of them look ragged.
Zabulon skipper, Frick Park, 31 July 2024 (photo by Kate St. John)
We found a pair of greenhouse millipedes (Oxidus gracilis) who kept walking as they mated. Two million legs in one photo?
Greenhouse millipedes mating, 31 July 2024 (photo by Kate St. John)
And on 29 July I was surprised to see seven common mergansers (Mergus merganser) at Duck Hollow. They made arrow shapes on the river’s reflection as they swam. (The seventh one is underwater.) All but one of them looked female — in eclipse or molting.
Common mergansers make arrowheads on the surface of the Monongahela River, 29 July 2024 (photo by Kate St. John)
This week Donna Foyle and Betty Rowland both found black swallowtail caterpillars (Papilio polyxenes) on host plants in their gardens. Donna Foyle’s are on parsley. Betty Rowland’s are on fennel.
Two black swallowtail caterpillars on fennel, 1 August 2024 (photo by Betty Rowland)
This success prompted a lively discussion of next steps.
#1. Birds, insects and spiders prey on black swallowtail caterpillars so the first step is to protect them. Birds are easy to exclude. Betty Rowland put a butterfly shelter over her fennel.
Shelter to protect the caterpillars from predation, 2 August 2024 (photo by Betty Rowland)
#2 What if the caterpillers eat all your host plants? Where can you get more? Well, don’t buy greens for your caterpillars! You can’t be sure they haven’t been treated with chemicals. Donna Foyle will look for Queen Anne’s (not near a road) if it she runs out of home-grown parsley.
Black swallowtail caterpillar on home-grown parsley, 2 August 2024 (photo by Donna Foyle)
When the caterpillar is ready to pupate it develops a somewhat camouflaged chrysalis, two examples shown below. (The brown one was photographed in Pittsburgh by Scott Detwiler.)
Variability of black swallowtail chrysalis color: brown and green-gold (photos from Wikimedia Commons)
As adults, black swallowtails are sexually dimorphic …
The Papilio polyxenes demonstrates polyandry and a lek mating system, showing no male parental care and display sites. Females are therefore able to choose males based on these sites and males are the only resource the females find at these sites.
Ecco and Carla bow at the nest, 1 Aug 2024, 6:23pm (photo from National Aviary snapshot cam at Univ of Pittsburgh)
2 August 2024
Yesterday it was at or near 90°F for most of the day. No peregrines were visible when I walked around the Cathedral of Learning at 11am but by 5:45pm the nestbox area had been in the shade for several hours and had cooled off enough to attract Ecco and Carla.
Peregrines are not courting at this time of year but when a pair stays on territory year round they develop and maintain their pair bond through bowing at the nest. Yesterday they bowed for eight minutes at 5:45pm, then joined each other for 16 minutes at 6:20pm.
On Tuesday 30 July after a period of abnormally dry weather Pittsburgh had a series of gully washers that scoured the creeks and greened up the grass. The downpours were sudden and stupendous. In just three brief episodes — fortunately spaced seven hours apart — we received 0.85″ of rain.
Ten years ago we were amazed by these episodes because they were so different from our usual slow, soaking rains. Back then the only place I’d experienced this weather prompted me to call it “Texas rain.” In 2014 climate.gov predicted an increase in heavy rain episodes on this map. Pittsburgh registered an uptick but not the worst.
OLD PREDICTION IN 2014. Heavy Rain Days in 2041-2070
Predicted Change in days of extreme rainfall in 2041-2070 compared to 1971-2000, Greenhouse gas higher emissions (map from climate.gov)
Five years later climate.gov revised their prediction and it was worse.
REVISED! PREDICTION IN 2019. Heavy Rain Days in Late 21st Century
The two maps are not “apples to apples.” On the 2019 map the prediction time frame is longer and change is expressed as a percentage rather than an absolute number of days.
Monarch butterfly on swamp milkweed, 27 July 2014 (photo by Steve Gosser)
31 July 2024
Have you seen any monarch butterflies this summer?
Twenty years ago this question would have been absurd in late July, but this year nature observers are worried that they have seen only one monarch butterfly so far … or none at all. There are two reasons why monarchs are scarce. One is the symptom, the other is the cause.
The Symptom:According to World Wildlife Fund, last winter’s annual survey of monarch butterflies on their wintering grounds in Mexico found that “the species occupied only 2.2 acres during the 2023-2024 winter season — 59% less than the previous year when scientists observed 5.5 acres.” There are 59% fewer monarchs this year compared to last. UPDATE: See Christine Rickabaugh’s comment below with the backstory on what’s happening in Mexico.
The Cause: Since the 2010’s biologists have warned that we are experiencing an Insect Apocalpyse. They have declined an alarming 75% in the past 50 years. The reasons for decline have been hard to tease out because there are so many factors at work.
Fortunately scientists at Michigan State University conducted a comprehensive study on the effect of herbicides and insecticides on insects, and especially on monarch butterflies (Danaus plexippus), in the Midwest. Published last month in PLOS One the study collected recent and historical data from Wisconsin, Michigan, Iowa, Illinois, Indiana and Ohio. MSU Today describes the findings.
While habitat loss, climate change and pesticides have all been implicated as potential causes for the declining insect abundances being observed globally, this work was the first comprehensive long-term study to evaluate their relative effects. Using 17 years of land use, climate, multiple classes of pesticides and butterfly survey data across 81 counties in five states, the researchers found that shifts in insecticide use toward neonicotinoid-treated seeds are associated with an 8% decline in butterfly species diversity across the American Midwest.
These findings include the decline of the migratory monarch butterfly, which has been a prominent concern. Specifically, it is noted that insecticides rather than herbicides are the strongest pesticide factor associated with monarch declines.
Neonicotinoids are so deadly to insects because they are so pervasive. Applied to the soil or as a seed coating, they migrate into the soil, the plant, its pollen, the water table and the air. This diagram shows the transport of neonics as red dots. They are everywhere.
The biggest danger comes from agricultural use. In 2017 the percentage of soy and corn planted with neonic seed coatings (colors below) was high. Now it’s even more.
Neonicotinoids are so effective that they create places without insects. These biological wastelands are missing everything that depends on insects, all the way up the food chain. This cornfield is a wasteland. There are no bugs and no birds here.
And the sneaky part is that you may be putting neonics on your grass or in your garden without realizing it. If you (or your lawn care company) sprays your grass it may well contain neonics. The potting soil and plants you buy at the store are probably treated with neonics before you buy them. Suddenly your lawn and garden are deadly to the butterflies and bees you’re trying to attract. Read more about it in the PDF linked below (or here).
It is going to take a concerted effort from all of us to remove neonicotinoids from our environment and stop the decline of insects. The best time to begin is right now.
Today in Pittsburgh we’re looking forward to a week of heavy downpours.
HAZARDOUS WEATHER OUTLOOK, Pittsburgh, PA, 30 July 2024 Scattered showers and thunderstorms could produce heavy rainfall that creates localized flooding concerns, favoring low lying or urbanized areas.
This is bad news for trees that are on the southern edge of their range. Not only do they live a long time but they cannot adapt as fast as our climate is changing. For example, quaking aspens, which prefer cooler weather, will disappear from Pittsburgh by the end of this century. Meanwhile eastern cottonwoods will do just fine.
Chickory opening slowly as the sun gets higher, Frick, 28 July 2024 (photo by Kate St. John)
29 July 2024
Yesterday there were just four of us on the walk at Lower Frick Park. Charity Kheshgi took the picture so she’s not in it.
Small group at the Frick Park outing at Commercial Street, 28 July 2024 (photo by Charity Kheshgi)
Of all the things we saw, a surprising number of them were blue. Chickory was just opening in the morning sun. We saw and heard two indigo buntings.
Indigo bunting still singing at Frick Park, 28 July 2024 (photo by Charity Kheshgi)
Ebony jewelwing damselflies were courting above the creek. The female jewelwings looked blueish.
Ebony jewelwing, female, Frick Park, 28 July 2024 (photo by Charity Kheshgi)
The males glowed iridescent emerald green.
Male ebony jewelwing, Frick, 28 July 2024 (photo by John Dzikiy)
Best Insect Experiment:
On the way upstream I found two funnel spider webs hiding behind the boardwalk railing. Not a great picture but it shows the hole where the spider is hiding. I have never been able to fool a spider by touching its web so I didn’t even try.
Funnel spider lair. It’s hiding in that hole, Frick Park, 28 July 2024 (photo by Kate St. John)
On the way back we saw red nymph spotted lanternflies. Of course this invasive insect is expendable so … Would the spider come out if we dropped one on his web? Indeed he did and he was fast! He zipped out, stung(?) the nymph, hid for a moment and then raced out and carried the nymph back to his lair.
Do you have a “problem” raccoon that’s getting into your trash no matter what you do? Do you need ideas on how to outsmart it? A study published last week in the Proceedings of the Royal Society B: Biological Sciences can help set your expectations.
From 2016 to 2017, Lauren Stanton and colleagues [at the University of Wyoming] placed six puzzle boxes in areas that locals in Laramie reported as having a lot of raccoons—a residential backyard, behind a food store, and near an abandoned barn. …
Night vision cameras captured raccoons at their most active and revealed some immediate surprises. In one instance, a raccoon shoves a skunk out of the way to fiddle with a difficult latch, then easily opens it. In another, some raccoons wait near the puzzle box until another raccoon solves it, shoving the competitor aside and reaping the reward of kibble and sardines without any of the work.
In all, about 25% of the raccoons were able to open at least three doors over the 3-month study period. That’s not as good as the 65% observed in the lab, but Stanton says animals in captivity studies have more energy, free time, and attention.
