Heat Changes Their Tune And Their Ears

Insects
Snowy tree cricket (photo by Andrey Zharkikh via Flickr Creative Commons license)

18 August 2023

On summer nights male crickets chirp to attract a mate. Each species has a distinctive call meant to lure the proper females. If you know bug sounds you can identify the chirping species.

One of the most common is the snowy tree cricket (Oecanthus fultoni) which occurs in most of the U.S. Unless you live outside their range you’ve probably heard this nighttime sound.

video embedded from Laura Symes on YouTube

Because they are ectotherms, crickets chirp faster in heat and slower in cool weather. You can even use Dolbear’s law(*) to calculate the ambient temperature based on the snowy tree crickets’ chirp rate.

So the sound changes. But does this heat-related change in tune mean the females no longer recognize the males? Nope. The heat changes the sound and it changes the crickets’ ears so that they hear the same old tune. Read more in this vintage article:

Tree Crickets Tune Their Ears

(*) p.s. The name of Dolbear’s law has an interesting backstory.
Amos Dolbear published The Cricket as a Thermometer in 1897 in which he described how to calculate the temperature based on the snowy tree crickets’ chirp rate. However, according to Wikipedia, Margarette W Brooks had already published the formula in 1881. She did not get the fame and it took some sleuthing to discover her. He got the fame and the name because, at the time, Science listened only to men. 140 years later women have a greater voice but the playing field is still uneven.

(photo and video credits are in the captions)

A Limpkin Irruption?

Migration, Water and Shore
Limpkin at Moraine State Park, 16 July 2023 (photo by Steve Gosser)

17 August 2023

After a limpkin was discovered yesterday afternoon in a small cove at Moraine State Park (first ever in Butler County!) western PA’s birding world spun on its axis and quickly went to find it. Many saw the bird yesterday including Steve Gosser who shared his photo above.

Limpkins (Aramus guarauna) are very, very rare this far north. Primarily from South America, these mussel and snail-eating wading birds have extended their range only to Florida where they live year round.

Limpkin range map from Wikimedia Commons

So what is a limpkin doing here? And not just “here.” A limpkin showed up at Middle Creek Wildlife Management Area last month and was still there last weekend. Two limpkins were in opposite corners of Ohio.

In fact, limpkins have been doing this crazy Northern Summer Visit thing for a long time but it appears they’ve ramped up since 2016. On 8 July 2023 Tim Healy posted a map of Limpkin Firsts in North America at the ABA Rare Bird Alert on Facebook. (The color descriptors are for the map.)
“Hot Limpkin Summer forever! Keep it going! Who’s next?
Green: home base
Blue: historical first records
Orange: 2016-2022 first records
Red: 2023 first records”

ABA Rare Bird Alert on Facebook: 8 July 2023, Tim Healy

This eBird map shows where they’ve been in 2023 up until 16 August. (I’ve marked the Butler County sighting as a red asterisk.)

eBird map of limpkin sightings in 2023 up until 16 August 2023

Is this an irruption of limpkins similar to the winter irruption of snowy owls? Maybe…

Young night-herons often do an out-of-range dispersal at the end of the breeding season when first-year birds explore to the north, then head home or die during their adventure. Perhaps limpkins are doing it, too. Perhaps they’ve had so much breeding success that there are extra limpkins to try it. (This family of 5 was photographed in Florida in 2014.)

Adult limpkin with 4 young, Winter Haven, Florida, 2014 (photo from Wikimedia Commons)

It will take some research to know the answer. The limpkins aren’t saying.

(photos by Steve Gosser and from Wikimedia Commons, maps from Wikimedia and eBird)

Where Is This Mosaic?

Musings & News, Trees
Beautiful mosaic. Where is it? (photo from Wikimedia Commons)

16 August 2023

Beautifully colored tiles. An intricate pattern. What floor, wall or ceiling holds this mosaic? Click here to see a closeup.

The photo caption at Wikimedia Commons has the answer:

Woody Dicot Stem Vascular Cylinder in One Year Liriodendron, photo from Berkshire Community College Bioscience Image Library, Pittsfield, Massachusetts.

The mosaic is made of cells in the woody stem of a one year old tuliptree (Liriodendron tulipifera), sliced thin and magnified 100 times. The colors and shapes are specific to the species and its age. The description indicates that things change at lot in a one year old tulip tree.

The mosaic slice was photographed in 2014 at Berkshire Community College in Pittsfield, MA from a sapling that probably grew in Western Massachusetts.

When a tulip tree grows up it has leaves and flowers like this.

Tulip tree leafout, Schenley Park, 28 April 2014 (photo by Kate St. John)
Tulip tree flower, 4 May 2017 (photo by Kate St. John)

Still beautiful and intricate even when not magnified.

For more information on the mosaic image see the description of the image here. It is so technical that I need a glossary to figure out what it means.

(photos from Wikimedia Commons and Kate St. John)

Baby Doves Get Taken For A Ride

Doves & Chickens, Nesting & Courtship
Juvenile mourning dove on a fence, 2008 (photo from Wikimedia Commons)

15 August 2023

Last Sunday while Bob Donnan was at the Pirates’ game, two young birds nestled in the windshield wiper well of his car.

Yesterday [13 August] when our Chevy Bolt was parked at the South Hills Village – Public Rapid Transit garage, two young [Mourning] Doves nestled into the lower windshield area. We didn’t even notice them until exiting the garage into brighter light! 

The car is so quiet that their short ride didn’t alarm them. After I stopped the car and waited for all traffic to pass, I waved my hand toward them and they flew off, back toward the parking garage.

— email from Bob Donnan, 14 August 2023
Immature mourning doves are surprised to take a ride (video by Bob Donnan)

I could tell by the birds’ appearance that they are juvenile mourning doves because they look spotty rather than smooth. Juvenile body feathers are so new that each one has a pale tip, giving the bird a scalloped look. Compare the top photo of a juvenile with this one of an adult.

Mourning dove adult (photo from Wikimedia Commons)

Why did the two birds hang out together?

Mourning doves (Zenaida macroura) nest multiple times per season and at each nesting the female lays two eggs that hatch in 14 days and fledge 12-15 days later. Just before they fledge the father completely takes over feeding duty so his mate can cycle and lay a new clutch.

The siblings are dependent on their father for 12-15 days after they fledge (26-30 days old). During this period they stay together in the same area during the day, never straying far, waiting for dad to show up. In the nest they learned to associate his voice with a feeding so if he calls they come.

Interestingly they have good homing skills even at this young age. If juveniles are forced from their “reference area” before they are 21 days old — i.e. while still dependent on their father — they always return within 24 hours.

Why at the parking garage?

Mourning doves nest in trees, shrubs and even on the ground but they have no problem nesting near humans and, according to Birds of the World, “may use unusual human-made substrates for nest sites, e.g. rain spouts, mops hanging on walls, immobile car accessories.”

Hmmm. “Immobile car accessories.” These two are probably not the only baby doves who’ve been taken for a ride.

(photos from Wikimedia Commons, video by Bob Donnan)

Migration! Arrivals & Departures This Week

Migration
Ruby-throated hummingbird, Annandale, NJ, 5 Sept 2012 (photo by Ellen & Tony via Flickr Creative Commons license)

14 August 2023

A lot of us think that fall migration doesn’t start until the end of August, but guess what? BirdCast resumed migration predictions on 1 August and their regional lists of Species On The Move show an influx of 10 noticeable species this week while five have already left, or are about to. Don’t wait to go birding. Check BirdCast tools to find out why.

Species On The Move uses two decades of eBird data to calculate movement from start to finish within four regions: Upper Midwest & Northeast, Gulf Coast & Southeast, Great Plains, and West. Of course they list First Arrival, Peak, and Last Departure but my favorite markers are:

  • Noticeability: *** Three asterisks mean we’re really likely to notice this species.
  • Rapid Migrant Influx: A few may be here already but numbers increase rapidly on this date.
  • Rapid Departure: Numbers drop quickly on this date though a few will linger.

The tables are grouped by region with Pittsburgh in the heart of BirdCast’s Upper Midwest & Northeast region. These dates are estimates but they’re good ones. Let’s take a look at who left and who’s coming soon.

Noticable Departures: Who Just Left?

Orchard oriole singing at Frick Park, 26 April 2023 (photo by Charity Kheshgi)

Have you noticed that orchard orioles, northern rough-winged swallows and willow flycatchers are basically gone? They started leaving in July, then rapidly departed in the first week of August. Yellow warblers and purple martins are not far behind. They’ll leave this week.

The screenshot below is a quick summary of rapid departures as of 13 August 2023. It shows:

  • Upper Midwest and Northeast region
  • Pared down to Noticeable birds (*** or **)
  • Sorted by Rapid Migrant Departure date
  • Not including some goodies such as Louisiana waterthrush, alder flycatcher and least bittern. (They’re on the website but not “Noticeable” for my pared-down screenshot.)
pared-down screenshot of BirdCast Species On The Move, noticeable Last Departures, Upper Midwest & Northeast

Noticeable Arrivals: What Rapid Influx will we see this week?

Immature ruby-throated hummingbird (photo from Wikimedia Commons)

If you haven’t seen them already ruby-throated hummingbirds will make a rapid influx today, 14 August.

The larger region will see increased numbers of common nighthawks and Canada Warblers but in Pittsburgh it’s usually the last week of August.

Common nighthawk photo by Chuck Tague; Canada warbler photo by Kuldeep Singh

Here’s a quick summary of Beginning Arrivals as of 13 August 2023 — same parameters as the departures above.

pared-down screenshot of BirdCast Species On The Move, noticeable Beginning Arrivals, Upper Midwest & Northeast

The tables change every day, dropping past dates and picking up new species in the future, so check out BirdCast’s Species on the Move to find out what’s happening near you.

p.s. How will you know if it’s worth going birding? Check BirdCast Migration Tools for forecast maps, live maps and alerts.

(photos from Wikimedia Commons, Charity Kheshgi, Chuck Tague, Kuldeep Singh. Tables are modified screenshots from BirdCast’s Species On The Move for the Upper Midwest and Northeast. Be sure to check BirdCast for the latest data)

The Calm Before The Rut: Deer in August

Deer, Schenley Park
6-point buck in Schenley Park, 4 August 2023 (photo by Kate St. John)

13 August 2023

In the city of Pittsburgh there are so many white-tailed deer that it’s easy to see them in August. The bucks are eating, eating, eating to bulk up. The does are hanging out with their adolescent fawns in this brief period between birthing and mating. It’s the calm before the rut.

Last Friday morning I found eight deer resting in dappled shade in Schenley Park. My cellphone photos don’t do them justice except for this: The photos show how hard it is to notice deer that are lying down and not moving.

Four bucks resting in Schenley Park, 11 August 2023 (photo by Kate St. John)

A few of them moved, however, grooming to shed their chestnut brown summer coats for gray-brown winter pelage. The photo above shows four bucks with antlers in velvet, each with a different point count: 4-point, 6-point, 7-point and 8-point.

Two does and two fawns rested a short distance from the males. The fawns gave the group away. They did not hold still for long. (The second doe is not in the photo.)

Doe and two fawns resting in Schenley Park, 11 Aug 2023 (photo by Kate St. John)

One week earlier it was impossible not to see this six-point buck browsing the hillside right next to the Lower Trail.

Deer eating in Schenley Park, 4 August 2023 (photo by Kate St. John)

He’s leaving a lot of greenery behind but the leaves he’s not eating are unpalatable invasive aliens called goutweed. The buck is nosing through them to re-browse the deer-food plants hidden below the goutweed. Those food plants won’t recover this late in the season. All the food will be gone and he won’t be back to this spot.

Buck browsing in Schenley Park, 4 August 2023 (photo by Kate St. John)

In August the days are still longer than the nights and deer hormones are not surging yet but it’s only a matter of time and the Equinox before their sedate demeanor ends. According to the PA Game Commission, after 12 weeks of rut excitement from mid October through early January:

  • 98% of the mature does will have bred
  • 40% of the fawns will have bred at only 6-7 months old (city/suburb phenomenon)
  • 85% of the pregnancies will result in twins or triplets, some with different fathers.

It’s calm now before the storm.

Schenley Park suffers from its overabundant deer population. See this article for more information: The Forest Lives in Mortal Fear of Its Deer.

A NOTE TO COMMENTERS: Some interesting threads have developed in the comments with new readers weighing. Please note that comments on this blog are moderated and may be edited for clarity. Comments that could inflame others will be edited or deleted.

(photos by Kate St. John)

The Bugs Are Busy

Insects, Phenology, Spotted Lanternflies
Butterfly weed, Schenley, 9 August 2023 (photo by Kate St. John)

13 August 2023

The birds are quiet now but the bugs are busy.

After I photographed this butterfly weed (Asclepias tuberosa) I zoomed in to look at the yellow spec on the back edge of the flower cluster and found a tiny yellow crab spider clinging to the flowers. My guess is that he’s a member of the Thomisidae family, lying in wait for something. But what?

Tiny yellow crab spider on butterfly weed, Schenley, 9 August 2023 (photo by Kate St. John)

On Monday, while walking the Three Rivers Heritage Trail River opposite Herrs Island, I noticed a caterpillar on the wide aluminum railing. It reminded me of the hickory tussock moth except that this one was blonde.

Sycamore tussock moth caterpillar near Herrs Island, 7 Aug 2023 (photo by Kate St. John)

iNaturalist identified it as a sycamore tussock moth (Halysidota harrisii). The railing was directly beneath his host plant, a sycamore tree (Platanus occidentalis).

Sycamore leaves and stems, Aug 2023 (photo by Kate St. John)

The caterpillar walked rapidly down the railing in a straight line until Whoa! a spotted lanternfly red nymph walked rapidly toward him. The caterpillar made a detour.

Sycamore tussock moth detours to avoid a spotted lanternfly, 7 Aug 2023 (photo by Kate St. John)

At Frick Park on 6 August we found a lot of millipedes on the paved Nine Mile Run Trail. iNaturalist says they are greenhouse millipedes (Oxidus gracilis), thought to be native to Japan but introduced around the world. They get their name from being a pest in greenhouses.

Greenhouse millipede, Frick Park, 6 Aug 2023 (photo by Kate St. John)

And finally I was fooled yesterday by these mating orange and black bugs, as fooled as they intended me to be. They looked like milkweed bugs, but why were they on a false sunflower?

False milkweed bugs mating on a false sunflower, 11 Aug 2023 (photo by Kate St. John)

I should have known! These are false milkweed bugs (Lygaeus turcicus) who masquerade as a poisonous species and whose host plant is the false sunflower. Read more about them and the bugs they imitate here.

(photos by Kate St. John)

Formal in Black and White

Water and Shore
Black-necked stilt reflections (photo by Susan T Cook from Wikimedia Commons)

11 August 2023

As if they are wearing white tie and tails, black-necked stilts look formal in black and white. Their beauty is enhanced by reflections in their watery habitat.

Black-necked stilt. Reflecting. (photo by Susan T Cook via Wikimedia Commons)
Three black-necked stilts. Not six. (photo from Wikimedia Commons)

The mothers look more casual when protecting their chicks. As you can tell by the sound track on this video, the chicks are adorable.

narrated video from Wild Wonders with Sushanta

Black-necked stilts (Himantopus mexicanus) are native only to the Americas, mostly South America. Check the map for their breeding zones to see their tiny chicks.

Black-necked stilt range map from Wikimedia Commons

(photos and map from Wikimedia Commons; click on the captions to see the originals)

Is This Stink Bug Early?

Insects
Brown marmorated stink bug, 8 August 2023, Pittsburgh (photo by Kate St. John)

10 August 2023

Not to be outdone by spotted lanternflies, this year’s first brown marmorated stink bug (Halyomorpha halys) showed up outside my window on Tuesday 8 August. His nymphs have been around since June, maybe earlier, but as an adult I think he’s early. Usually we don’t notice the adults until October.

Seven years ago I wrote about the animals that eat brown marmorated stink bugs. Now that the bugs are already here, their predators had better get on the job quickly. Or are they all worn out by spotted lanternflies?

What Eats Stink Bugs?

p.s. Speaking of predators, on 8 August I mentioned that researchers are working on importing a natural predator for spotted lanternflies but that it will take years to make sure it’s safe. Well, in 2018 scientists discovered that a natural predator of stink bugs had showed up on its own, accidentally imported the same way as the stink bug. Maybe this will happen for spotted lanternflies. It would save everyone a lot of trouble!

(photo by Kate St. John)

Hummingbird Day on August 19

Books & Events, Migration, Songbirds
Ruby-throated hummingbird, July 2014 (photo by Steve Gosser)

9 August 2023

Have you noticed a lot of ruby-throated hummingbirds at your feeders lately? Their fall migration is already underway so this month is the perfect time to see them up close at Powdermill.

Powdermill Nature Reserve, operated by the Carnegie Museum of Natural History, has one of the longest continually-running bird banding stations in the U.S. Throughout the year they see species abundance ebb and flow based on weather and migration timing.

Ruby-throated hummingbirds (Archilochus colubris) start their fall migration earlier than many other species so they’re more abundant than usual now. Come to Westmoreland County for a family friendly hummingbird event on:

Hummingbird Day, Saturday 19 August 2023, 9:00am-noon at
Powdermill Nature Reserve
1795 Route 381
Rector, PA 15677

Powdermill Nature Center (photo embedded from CMNH Powdermill website)

Learn about hummingbirds, the plants that attract them, and how to care for your feeders so the birds stay healthy. There will also tips on taking great bird photos. And if the weather is good and the birds cooperate we(*) will get to see hummingbirds up close like this one in the bander’s hand. This bird was banded by Bob Mulvihill in Marcy Cunkelman’s garden in July 2015.

(*) I say “we” because I’ll be there, too, to teach you about hummingbirds. I’m looking forward to it!

Ruby-throated hummingbird in bander’s hand, July 2015 (photo by Kate St.John)

This event is free but do register here in advance so Powdermill knows to expect you. As the registration page says:

Events fill up fast! Registration is recommended to guarantee your spot and help us plan timing, seating, and/or trail routes. If there are spots available at the time of the program, non-registered individuals can join on a first-come, first-served basis.

— CMNH: Hummingbird Day Event

Click here for more information. Hope to see you there.

(hummingbird photos by Steve Gosser and Kate St. John, Powdermill photo embedded from carnegie.org)