All posts by Kate St. John

20 Quadrillion Ants & Why It Matters

A line of ants (photo from Wikimedia Commons)

Last week the Washington Post reported that the number of ants on earth is unimaginably large. Scientists from the University of Hong Kong estimated there are 20 quadrillion total or 2.5 million ants for each human being.

They reached this number by combining studies from thousands of researchers around world whose reports span a century. Dedicated ant researchers count ants by literally trapping them or by sweeping them up in leaf litter and counting what they’ve found. Their counts were combined and extrapolated to reach the 20 quadrillion estimate.

Why count ants? To get a benchmark on their population. Our planet is in the midst of an insect apocalypse in which the number of insects has declined 75% over the past 50 years. Butterflies and beetles are the hardest hit. Has the trend affected ants? Soon we’ll know.

Dead painted jezebel butterfly (photo from Wikimedia Commons)

Some of you are probably thinking: Wouldn’t we be better off without bugs? Actually, no. The insect apocalypse matters because bugs provide so many hidden benefits. They consume decayed matter, plant seeds, aerate the soil, pollinate plants and ultimately feed the larger organisms on earth. Their disappearance is especially dire for anything that directly eats insects and anything that eats the insect-eaters. Especially birds.

The decline of insects is one reason why birds have declined 29% in North America in the past 50 years. Hardest hit have been the insect eaters — swallows, swifts and nighthawks. In fact most songbirds feed insects (protein) to their young even if they eat fruits and seeds at other times of year.

Here are just a few of the birds that eat insects at least part of the time. Some of them may surprise you.

  • American redstart with insect (photo from Wikimedia Commons)

Learn more about ants at “The Washington Post: Scientists have calculated how many ants are on Earth. The number is so big it’s ‘unimaginable.’

Read about the insect apocalypse in The Guardian: The insect apocalypse “Our world will grind to a halt without them”.

p.s. Did you know that northern flickers eat ants?

(photos from Wikimedia Commons including insect-eating American redstart, mountain bluebird, barn swallows, olive-sided flycatcher, American kestrel at these links)

Revisiting a Favorite Place

Brooding sky at Acadia National Park near Thunder Hole, 2009 (photo from Wikimedia Commons)

23 September 2022

Today we’re in Maine for a week-long return to a favorite place.

For 36 years starting in 1983 we visited Acadia National Park every September, only missing two years in all that time. But now it’s 2022 and we haven’t been back since 2018.

The ocean, mountains and lakes will be the same.

Jordan Pond, Acadia National Park, 7 Sep 2016 (photo by Kate St. John)
Jordan Pond, Acadia National Park, 7 Sep 2016 (photo by Kate St. John)

But some things will be different.

Maple leaves turning red, Acadia National Park, Sept 2018 (photo by Kate St. John)

We’ll be surprised by the changes to businesses, buildings and people we haven’t seen for four years though my husband and I have changed, too. We’ll notice our own changes when we pass by difficult trails we won’t climb anymore. Fortunately there are plenty of easy trails we’ve never walked because we thought they were “too easy” 30 years ago.

Tomorrow we’ll re-experience a hurricane passing offshore when Hurricane Fiona generates high surf and high winds on its way to Nova Scotia. Many things are memorable.

(photos from Wikimedia Commons and by Kate St. John)

Intense Migration Forecast for Tonight

Sunset and birds (photo from Wikimedia Commons)

22 September 2022

Tonight’s BirdCast Migration Forecast shows there will be intense migration from Michigan down to Mississippi and Georgia. The flocks will fan out east and west, touching southwestern Pennsylvania.

Birdcast migration forecast for the night of 22 Sept 2022 (map from BirdCast)

If you go birding on Friday 23 September, expect to find warblers and thrushes still passing through and an increasing variety of sparrows. Watch for the skulkers – Connecticut and mourning warblers — in late September. Perhaps you’ll see the last of the flycatchers, some of which are already considered “rare” now in eBird.

Friday’s sun and northwest wing will also encourage broad-winged hawks to migrate during the day. Keep an eye to the sky or visit a hawk watch in your area. Hawk watch locations and data are listed at

Broad-winged hawk on migration (photo from Wikimedia Commons)

Check out the migration forecast and lots of migration tools at BirdCast.

Friday will be great day to go birding.

(photos from Wikimedia Commons, map screenshot from Birdcast; click on the captions to see the originals)

Hot Enough to Sunbathe

Ecco sunbathing at the Pitt peregrine nest, 20 Sep 2022, 1:30pm (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

21 September 2022

Yesterday’s high in Pittsburgh was 77 degrees but the sun probably felt much warmer at the Cathedral of Learning peregrine nest. Ecco took advantage of the sun to heat his feathers and skin.

Though it looks odd when they do it, birds sunbathe primarily for feather maintenance. The sun’s heat kills feather lice, the tiny parasites that nibble on feathers. The bugs that aren’t killed outright move off the bird’s back to locations where it’s easier to preen them away. National Audubon explains how this works at Hot, Bothered, and Parasite-free.

For additional reasons for sunning see The Spruce: Bird Sunbathing – Why Do They Do It?

Photos: Though the nestbox streaming camera is off for the season, you can see live snapshots at Cathedral of Learning Falconcam Snaphots.

(photos from the National Aviary snapshot camera at Univ of Pittsburgh)

More Heat Ahead

Heat at sunset (photo from Wikimedia Commons)

20 September 2022

Now that summer’s heat is over we may be fooled into thinking climate change is no longer affecting us. Unfortunately, above normal temperatures are predicted for most of the U.S. for the next three months. Southeastern Alaska is the only place with any chance of being cooler than normal.

U.S. 3-month temperature outlook, Oct-Dec 2022 (map from NOAA

Heat and drought often go hand in hand.

The seasonal drought outlook through the end of 2022 indicates New England will finally see a break in their drought, perhaps hastened by rain from a downgraded hurricane. But there is no help for the American West where the drought persists and gains new ground (see yellow on the map).

U.S. 3-month drought outlook (map from NOAA)

The drought in California is particularly dire.

California drought (photo from Wikimedia Commons)

Why does this matter to the rest of us? Because the worst drought is in the Central Valley and that’s where more than half of the U.S. fruits, vegetables, and nuts are grown.

(photo credits in each caption; click on the captions to see the originals)

The Most Teeth in North America?

Sperm whale skeleton showing teeth (photo from Wikimedia Commons)

19 September 2022

Adult humans typically have 32 teeth after our wisdom teeth come in at age 12-14, but our count is low compared to other animals.

7-year-old smile with missing tooth (photo from Wikimedia Commons)

Which animal in North America has the most teeth?

The Virginia opossum (Didelphis virginiana) is a contender with 50 teeth in his small mouth. He shows them when he feels threatened.

Opossum showing teeth (photo from Wikimedia Commons)

Some say that sharks have the most teeth but as far as I can tell their tooth count, often lower than 100, is not as remarkable as their tooth replacement. For instance, young lemon sharks replace all their teeth every 7-8 days so that in their lifetimes “the lemon shark Negaprion brevirostris, may produce 20,000 teeth in its first 25 years, and may live as long as 50 years.

The winner of the most-teeth contest are land and sea snails which usually have between 10-15,000 teeth, though some may have up to 25,000. This includes snails in the ocean off the North American coasts.

Studies of the European garden snail (Cornu aspersum), an alien in North America, indicate it has 14,000 teeth. Take a look at his toothy mouth under a microscope and find out why snails have so many teeth at Microscopic look at snail jaws.

European garden snail (photo from Wikimedia Commons)

p.s. Amazingly, the most abundantly land snail found in Pennsylvania, Zonitoides arboreus, has no teeth at all!

Quick gloss snail, Zonitoides arboreus, Edgewater, Maryland (photo from Wikimedia Commons)

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

Bird Calls in the Dark

Swainson’s thrush, May 2019, Toronto, ON (photo from Wikimedia Commons)

18 September 2022

If you’re awake one to two hours before dawn on a calm September night, put your ear to the sky and you may hear birds calling overhead in the dark.

Millions of birds migrate at night and call in flight to maintain contact with their fellow travelers. In the one-to-two hours before dawn they begin their descent and are easier to hear but it takes dedication or insomnia to be awake during those prime sleeping hours.

Fortunately with the advent of microphones, recording devices and sonogram technology, ornithologists and amateurs have recorded nocturnal flight calls (NFC) and can identify who’s calling as they fly by. The sonograms are like fingerprints for each species and can be compared at this quick reference website,, announced this month by Tessa Rhinehart at the University of Pittsburgh’s @KitzesLab.

Many calls, especially those of warblers, are so high-pitched that they are outside my range of hearing so here are three examples of some easily audible nocturnal flight calls.

The Swainson’s thrush (Catharus ustulatus), above, has such a distinctive flight call that you can identify it in the dark by sound. All About Birds describes the call as a hollow peep that resembles the call of a spring peeper frog.

The rose-breasted grosbeak (Pheucticus ludovicianus) repeats a single rough whistle.

Rose-breasted grosbeak (photo by Cris Hamilton)
Rose-breasted grosbeak (photo by Cris Hamilton)

Click here for a clearer version of the rose-breasted grosbeak flight call that was “photo-bombed” by a killdeer.

Though it is extremely unlikely to hear a dickcissel (Spiza americana) fly over Pennsylvania, this sound is so distinct that it’s worth a listen.

Dickcissel singing in western PA, 10 June 2017 (photo by Anthony Bruno)
Dickcissel singing in western PA, 10 June 2017 (photo by Anthony Bruno)

Leanr more about nocturnal flight calls at Nocturnal Flight Call FAQs from David Brown. He recorded dickcissels during the 2017 irruption over Montoursville, PA.

Make your own NFC recorder using a microphone, a dinner plate, a bucket and a computer. Instructions and information at Nemesis Bird’s Night Flight Call primer. (This article may be as old as 2012.)

Know which nights will be good for listening by checking BirdCast’s migration forecast.

(photos from Wikimedia Commons, Cris Hamilton and Anthony Bruno; recordings embedded from Xeno Canto)

Why Is Wingstem Thriving in City Parks?

Honeybee approaches wingstem, Frick Park, 8 Sep 2022 (photo by Kate St. John)

17 September 2022

In Schenley and Frick Parks you can look straight through the forest if you duck your head below four feet high. In Schenley Park the ground is often bare and most plants in that four-foot zone are gone. But one flower, wingstem (Verbesina alternifolia), is doing just fine in the city parks.

Wingstem, Frick Park, 8 Sep 2022

The absence of cover from the ground to 4 – 5 feet is called a browseline (below) and is evidence of an overpopulation of white-tailed deer.

Bare ground and absence of cover below the trees in Schenley Park, September 2022 (photo by Kate St. John)

According to this KDKA report, the deer population in Schenley Park is estimated at 80-150, which roughly equates to 100-200 deer per square mile. A healthy population in a balanced forest would be 20-30 deer per square mile, so any plant that survives in the Pittsburgh’s city parks is something that deer don’t eat.

Doe browsing in Schenley Park, September 2022 (photo by Kate Sr. John)

So why don’t deer eat wingstem?

A thicket of wingstem on the “elbow” trail, Frick Park, 8 Sep 2022 (photo by Kate St. John)

The leaves are bitter!

Find out more about wingstem at Illinois wildflowers.

(photos by Kate St. John)

Not a Leaf

Not a leaf. An orange oakleaf butterfly, ventral view (photo from Wikimedia Commons)

16 September 2022

This Asian butterfly is a camouflage artist. When its wings are open it’s orange and brown and iridescent blue, below.

Orange oakleaf butterfly, dorsal view (photo from Wikimedia Commons)

But when its wings are closed it looks like a leaf, shown at top.

Touch the “leaf” and it comes alive as an orange oakleaf butterfly (Kallima inachus).

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