Dung Beetles Navigate By Looking at the Sky

Insects
Sacred scarab beetle rolling a dung ball with its hind legs, Ukraine, 2015 (photo from Wikimedia Commons)

4 September 2022

Dung beetles coexist with large animals because their entire life cycle depends on the droppings of cattle, elephants and other mammals. When Scarabaeus beetles find a dung pile each one makes a ball and uses its hind legs to roll the ball away from competitors, then buries it in a private location for later consumption. Here a sacred scarab beetle (Scarabaeus sacer) rolls and digs.

To move a dung ball the Scarabaeus beetle travels backwards in a straight line against all obstacles. When the ball rolls off course, the beetle climbs to the top, reorients itself and resumes pushing in the correct direction. This so impressed the Ancient Egyptians that they venerated the sacred dung beetle (Scarabaeus sacer) and carved amulets in its image(*).

How do these beetles navigate?

A 2015 study of South African Scarabaeus lamarcki found that the beetles use the sun’s direction and the variation in the sky’s green and ultraviolet colors like a compass. For example, this S. lamarcki beetle travels in the exact opposite direction when researchers use a mirror to show the bug reflected sunlight.

And a 2019 study found that they also pay attention to the wind when the sun is too high to help. See “(Not only) the wind shows the way.”

Traveling upside down and backwards requires lots of navigational tools.

(*)p.s. Did you know that the sacred dung beetle, Scarabaeus sacer, is the origin of scarab jewelry?

The scarab (kheper) beetle was one of the most popular amulets in ancient Egypt because the insect was a symbol of the sun god Re. … The scarab forms food balls out of fresh dung using its back legs to push the oversized spheres along the ground toward its burrow. The Egyptians equated this process with the sun’s daily cycle across the sky, believing that a giant scarab moved the sun from the eastern horizon to the west each day, making the amulet a potent symbol of rebirth.

— MeTropolitan Museum of Art: Egyptian Art, Scarabs
Ancient Egyptian scarab amulets from Middle Kingdom, Metropolitan Museum of Art (photo from Wikimedia Commons)

Millennia later, a scarab jewelry pin from the late 1960’s.

Scarab jewelry pin, late 1960s U.S. (photo by Kate St. John)

(photos from Wikimedia Commons and Kate St. John; click on the captions to see the originals)

Late August Colors

Phenology, Plants & Fungi
Squash blooming at the maintenance heap in Frick Park, 27 August 2022 (photo by Kate St. John)

3 September 2022

Late August colors came in orange, yellow, purple, gray and green in Frick Park and Moraine State Park.

Above, squash(*) blooms on a fence in Frick.

Yellow daisies without petals are actually tansy (Tanacetum vulgare), native to Eurasia.

Tansy blooming at Frick Park, 25 August 2022 (photo by Kate St. John)

The deep purple of New York ironweed (Vernonia noveboracensis) is never true to color in my cellphone photos. Instead it looks redder than expected because the Pixel 5 Photo app apparently overcompensates for the camera’s blue bias. All cameras have problems with purple, described in this vintage article: Not Truly Blue.

Ironweed blooming at Moraine State Park, 26 August 2022 (photo by Kate St. John)

This velvety bright orange mushroom in Frick deserved a photo on 25 August. Jim Chapman re-found it the next day and identified it as northern cinnabar polypore (Trametes cinnabarina, a.k.a. Pycnoporus cinnabarinus). By then it was already darker orange than this.

Cinnabar polypore, Frick Park, 25 August 2022 (photo by Kate St. John)

Insects specialize on their own host plants. False sunflowers have red aphids. Wingstem (Verbesina alternifolia) has gray ones.

Wingstem with gray aphids, Frick Park, 25 August 2022 (photo by Kate St. John)

And everywhere in late August there is green.

(*) Did you know that zucchini, pumpkin, summer squash and pattypan squash are all cultivars of Curcubita pepo? The plant pictured at top seems to be producing pattypan squash.

(photos by Kate St. John)

One Flap, 15 Moths

Insects
Polyphemus moth mug shot (photo from Wikimedia Commons)

2 September 2022

When we say that a bird has “moth-like flight” do we mean that its wings move like this? Check out Dr. Adrian Smith’s fifteen moths in slow motion flight.

p.s. Polyphemus moth species is shown above. Can you find it in the video?

(photo from Wikimedia Commons, tweet embedded from @DrAdrianSmith)

Scarabs

Insects
Glorious scarab beetle (photo from Wikimedia Commons)

1 September 2022

There are more than 30,000 beetles in the Scarab family (Scarabaeidae), most of them active only at night.

Screenshot of Scarab beetles at bugguide.net

The Glorious Scarab Beetle (Chrysina gloriosa) pictured at top was hiding underground when gardening unearthed it in its native US range of Arizona, New Mexico, Texas.

Hidden gems include Beyer’s scarab which I saw in southeastern Arizona in 2015, described in this vintage article: Like a Jewel.

Beyer’s Scarab Beetle (Chrysina beyeri) at Carr Canyon, Arizona, 30 July 2015 (photo by Kate St. John)

In the eastern US we have beautiful scarab beetles in our own backyards.

Which scarab beetle is this? (photo from Wikimedia Commons)

But we don’t think they’re beautiful because they eat our roses.

Japanese beetle (photo from Wikimedia Commons)

Japanese beetles (Popillia japonica) are scarabs.

(photos from Wikimedia Commons, bugguide.net and Kate St. John, click on the captions to see the originals)

Songbirds Came From Australia

Musings & News
Northern cardinal, singing (photo from Wikimedia Commons)

31 August 2022

Songbirds (Oscines) are the majority of the world’s birds as you can see circled on the supertree below. In August 2016 we found out that all of them originated in Australia. Here’s how it happened.

Phylogenomic supertree of birds, a clockwise spiral from oldest to newest, marked with Australian origins (image from MDPI, July 2019)

The world was a very different place during the Oligocene 35 million years ago. For one thing there was a big gap between Australia and Asia and songbirds’ ancestors could not leave Australia.

Geography of the Oligocene from Wikimedia Commons

Then about 25 million years ago a land bridge formed when tectonic activity forced a patch of islands called Wallacea to the ocean’s surface. Wallacea, now part of Indonesia, bridged the gap and was the first step on the songbirds’ journey. (Ancient Wallacea in yellow below.)

Map of ancient Wallacea from Wikimedia Commons

They made the journey in flying steps, reaching the Western Hemisphere before Eurasia:

  1. Australia (label C below)
  2. Wallacea, an island group in Indonesia (label D)
  3. Southeast Asia and India (label E)
  4. Sub-Saharan Africa (label F)
  5. The Americas (label G)
Steps of songbird radiation from Australasia (map from “Tectonic collision and uplift of Wallacea triggered the global songbird radiation, Nature Communications, 30 Aug 2016) annotation: Wallacea “D” is circled in white

Like this…

Some songbirds were so successful that their DNA is found at each stop in living species across the world. Corvids are one such group.

Common raven, Yosemite (photo from Wikimedia Commons)

Others, like waxwings (Bombycillidae), have few DNA traces to show the path they took. Waxwings’ living DNA relatives are found only in Wallacea, North America and northern Eurasia.

Cedar waxwing (photo by Cris Hamilton)

Learn more about songbirds’ amazing journey in these articles:

(blank world map from Wikimedia Commons. photo and remaining maps are credited in the captions, click on the links to see the originals)

Female Mockingbirds Sing in the Fall

Bird Behavior, Songbirds, Vocalizations
Northern mockingbird (photo by Cris Hamilton)

30 August 2022

Northern mockingbirds (Mimus polyglottos) are special because they challenge our assumptions.

It was a wonder in 2014 when, after centuries of ornithologists saying that only male birds sing, Karan Odom at University of Maryland documented singing females. Most of the species live in the tropics but even back then 150 female-singing species were documented in North America.

After this breakthrough female singing became a hot study topic and more species were added to the list. Recent studies delve deeper. Do northern mockingbird females mimic like males? A study published this April found that they do.

Mockingbirds are also unusual because they sing in autumn when other birds are silent. They do it because they change location. Those that nest in the northern end of their range migrate south while others move locally (see animated eBird map). When mockingbirds “reappear” in September they are singing again to claim new territory.

Northern mockingbird, Nov 2015 (photo from Wikimedia Commons)

Males and females look alike and they aren’t paired up in winter so we cannot tell which sex is singing. Nevertheless we can hear them. Here are some examples.

28 Sep 2021 in Cincinnati, Ohio:

7 Nov 2019 in Harlingen, TX:

I see mockingbirds in Pittsburgh in the winter. Are they local transplants or from further north? Are they male or female? I dunno.

Northern mockingbird wing flash (photo from Wikimedia Commons)

(photos by Cris Hamilton and from Wikimedia Commons; click on the caption to see the original)

Insects, Deer, a few Birds Yesterday at Schenley

Deer, Insects, Mammals, Schenley Park, Songbirds
7-point buck in Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

29 August 2022

A year ago in Schenley Park we had such a slow birding day that I wrote, “We worked for every bird.” A year later, nine of us were there yesterday and the birding was even slower! (14 species instead of 19.) However we found lots of insects and two white-tailed bucks in velvet. Here’s the story in pictures, thanks to Connie Gallagher.

Connie saw the very Best Bird, a blue-gray gnatcatcher.

Blue-gray gnatcatcher, Schenley Park, 28 August 2022 (photo by Connie Gallagher)

We pondered the identity of these wasps and then remembered, all at once, that they are bald-faced hornets (Dolichovespula maculata), a type of yellowjacket wasp.

Bald-faced hornets at their paper nest in a pignut hickory, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

There was still dew on the wild senna as this bumblebee gathered nectar.

Bumblebee on wild senna, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

The browseline is so severe in Schenley Park that there’s no cover for the deer who sleep there during the day. Looking down from the Falloon Trail we saw two bucks, a 7-point buck (at top) and a 10-point below.

10-point buck in Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

Fortunately some of us heard these birds flying overhead. I can tell their identity by shape and the yellow tips of their tails. Cedar waxwings.

Cedar waxwings fly over, Schenley Park, 28 Aug 2022 (photo by Connie Gallagher)

Here’s the group that worked for every bird on Sunday. Thank you all for coming!

Schenley Park outing, 28 August 2022 (photo by Kate St. John)

See our checklist at https://ebird.org/checklist/S117700393 and printed below.

Schenley Park–Panther Hollow, Allegheny, Pennsylvania, US
Aug 28, 2022 8:30 AM – 10:30 AM, 1.5 mile(s), 14 species

Mourning Dove (Zenaida macroura) 5
Chimney Swift (Chaetura pelagica) 4
Red-tailed Hawk (Buteo jamaicensis) 1
Red-bellied Woodpecker (Melanerpes carolinus) 2
Downy Woodpecker (Dryobates pubescens) 1
Northern Flicker (Colaptes auratus) 1
Eastern Wood-Pewee (Contopus virens) 1
Blue Jay (Cyanocitta cristata) 7
Blue-gray Gnatcatcher (Polioptila caerulea) 1 Seen by Connie
American Robin (Turdus migratorius) 1
Cedar Waxwing (Bombycilla cedrorum) 5
American Goldfinch (Spinus tristis) 3
Common Grackle (Quiscalus quiscula) 1
Northern Cardinal (Cardinalis cardinalis) 3 Including a bald female Cardinal

(photos by Connie Gallagher (group photo by Kate St. John))

Meet the Familiar: Synanthrope

Bird Behavior, Deer, Mammals, Plants & Fungi
Pigeons on a traffic light (photo from Wikimedia Commons)

28 August 2022

I had never seen the word “synanthrope” until I found it attached to this photo.

Passer domesticus as synanthrope (photo from Wikimedia Commons)

House sparrows are synanthropes. So are pigeons.

A synanthrope (syn-anthrope) [from Greek: syn-anthrope: syn=”together with” + anthropos=”man”] is a wild animal or plant that lives near, and benefits from, an association with humans and the somewhat artificial habitats that people create around themselves.

— Wikipedia: Synanthrope

We can be forgiven for not knowing this little-used word since its present meaning is only 74 years old(*).

Synanthropes live with us but we often disparage them. They are wild but too familiar, too “tame,” too weedy. Here are some more examples.

The house mouse (Mus musculus)

House mouse (photo from Wikimedia Commons)

Dandelions (Taraxacum sp.)

Dandelions in the grass (photo by Kate St. John)

Horseweed (Erigeron canadensis) and pilewort (Erechtites hieraciifolius) are native North American plants that like disturbed soil. We notice them in August when they start to look ugly.

Horseweed (photo from Wikimedia Commons)
Closeup of pilewort flowers (photo by Kate St. John)

Two local mammals may be recent synanthropes, formerly shunning humans but now benefiting from our habitat.

Squirrels love our birdseed and shelter (attics).

Squirrel on the bird feeder (photo from Wikimedia Commons)

White-tailed deer (Odocoileus virginianus) prefer forest edges next to open areas, a landscape often created by humans. Have deer become synanthropes?

Buck in velvet at Allegheny Cemetery, Pittsburgh (photo from Wikimedia Commons)

p.s. (*) Merriam-Webster explains that the word was introduced by botanist Theodor von Heldreich at a botanical conference in Paris, 16-24 August 1878, making its first-ever use almost exactly 144 years ago.

(photos from Wikimedia Commons and Kate St. John)

Sky Show

Weather & Sky
Sunrise in Pittsburgh, 19 August 2022 (photo by Kate St. John)

27 August 2022

This week’s weather put on a sky show.

Clouds…

Cloud stacks, 22 August 2022 (photo by Kate St. John)

Lightning and lots of it! Dave Dicello captured a split lightning bolt simultaneously hitting BNY Mellon and the east end of Duquesne University (more than 1/2 mile away) on Sunday morning 21 August. Click here for his latest sky/panorama photos or here for his website.

Anticrepuscular rays… are relatively rare and appear opposite the sun at sunrise or sunset. Caused by the backscattering of atmospheric light, the rays we saw on 23 August spanned the sky. I took a photo from my window but it pales in comparison to Dave DiCello’s (@DaveDiCello) from a different vantage point. His tweet and video are shared below my photo.

A cloud shadow across the sky, an anticrepuscular ray, 23 August 2022 (photo by Kate St. John)

The Moon and Venus rise together… my unprofessional cellphone photo on 25 August. Through a window but you get the idea.

Moon and Venus before sunrise, 25 August 2022 (photo taken through a window by Kate St. John)

(photos by Kate St. John, shared tweets by Dave DiCello)