Category Archives: Insects, Fish, Frogs

Like a Furry Robot

Jumping spider on a human finger (photo from Wikimedia Commons)

If you have ever approached a tiny spider that jumped suddenly far and fast you’ve probably seen a jumping spider (Salticidae), one of 6000 species on Earth.

Jumping spiders are harmless to humans and can be identified by the position of their eyes. They have four pairs(!) with the largest front and center. As for jumping, they use their back legs.

Jumping spiders’ well-developed internal hydraulic system extends their limbs by altering the pressure of their body fluid (hemolymph) within them. This enables the spiders to jump without having large muscular legs like a grasshopper. Most jumping spiders can jump several times the length of their bodies.

Wikipedia: Jumping Spider

When not jumping I’ve seen them move in a jerky fashion.

Like a furry robot.

(photo from Wikimedia Commons; click on the caption to see the original)

Show Me Your Tail

Male zebra-tailed lizard, Tucson, AZ (photo from Wikimedia Commons)

11 December 2020

One thing we don’t see in Pittsburgh are the antics of lizards. Only two lizard species occur in southwestern Pennsylvania but are rarely found, so when I saw Russ McSpadden’s tweet of two zebra-tailed lizards in the Sonoran Desert I was fascinated.

Their territorial sparring looks like cartoon dinosaurs.

So who are these guys?

Zebra-tailed lizards (Callisaurus draconoides) are 2.5 to 4 inches long, not including their tails, and are endemic to the open desert of the southwestern U.S. and northern Mexico.

During the breeding season, May to August, males are particularly colorful with iridescent blue and sometimes orange on their bellies. Each male defends a territory and works to attract multiple females. The more females he has the greater his social status and the more aggressively he defends his territory. Hence the threatening dance.

You can’t see much of the zebra tail in the video but these lizards use it as a social signal and predator deterrent. According to Wikipedia, “When threatened zebra-tailed lizards run quickly with their toes curled up and tails raised over their backs, exposing the stripes” as shown in the photo below.

Zebra-tailed lizard, Death Valley (photo from Wikimedia Commons)

The dominant lizard in the video must be shouting at the other guy, “Leave now! Run away! Show me your tail!”

(*) The two lizard species that occur in southwestern PA are the northern fence lizard and five-lined skink. I’ve never seen a five-line skink and have only seen a fence lizard once — in Virginia Beach.

(photos from Wikimedia Commons; click on the captions to see the originals. embedded tweet from Russ McSpadden @PeccaryNotPig)

The Virus That Kills Birds

  • Ruffed grouse (photo from Wikimedia Commons)

As we struggle with a nearly out-of-control coronavirus pandemic I was stunned to learn there’s an equally deadly virus among birds. The discovery came when I found the answer to Craig’s question: “Kate, why is the ruffed grouse population in decline in Pennsylvania? Habitat destruction?” No, West Nile Virus is killing them off.

West Nile Virus arrived in North America more than 20 years ago and spread across the continent in just five years, killing native raptors and songbirds in its wake. When it struck Pittsburgh’s bird community in 2002 it was fairly common to find dead crows. That was a long time ago and I don’t see dead crows anymore so I thought birds were now able to survive the virus. Instead a 2015 study found that West Nile Virus is still wiping out birds in North America. It affects each species differently.

Some such as wild turkeys, chickens and house sparrows had a die-off when the virus arrived and then recovered with apparent immunity. Others never developed that resilience. The virus ravages their bodies so quickly that they die without reproducing.

The birds in the slideshow above are some of WNV’s most devastated victims. Every year their populations decline in a downward spiral. Greater sage-grouse and yellow-billed magpies have such restricted ranges that WNV may push them to extinction. This explains why I haven’t seen so many warbling vireos, purple finches and American goldfinches as I did a decade ago.

In 2016 the PA Game Commission studied the plight of the ruffed grouse and found that birds never exposed to WNV had only a 10% survival rate. This 9-minute video tells the whole story.

It’s ironic that we worried so much about West Nile virus when it’s actually a bird disease. Read more about West Nile Virus In Birds at kenyon.edu.

(photos from Wikimedia Commons, J. Maughn, Steve Gosser and Chuck Tague,)

Make Every Day Count

In November, when the rains begin in southwest Madagascar, all the Labord’s chameleons (Furcifer labordi) hatch from eggs and begin their growth spurt to adulthood. They will live a glorious four to five months.

Labord’s chameleon, Madagascar (photo from Wikimedia Commons)

By January they are sexually mature, the males fight for dominance, they breed and the females lay eggs. (Male shown above. Females lack the snout “horn” and bony head casque.)

Labord’s chameleon, Madagascar (photo from Wikimedia Commons)

By the end of March, all of them die. Every one of them. All that’s left of Labord’s chameleons are their eggs, waiting eight months for the next rainy season.

There is no other terrestrial vertebrate with a shorter known active life-span.

from Labord’s chameleon description at Wikimedia Commons

Our own lives are short, too, compared to Galapagos tortoises (190 years), Greenland sharks (300-500 years) and giant bristlecone pines (5,000 years).

Make every day count.

Thanks to Jason Bittel (@bittelmethis) for his tweet that brought Labord’s chameleon to my attention.

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

Ticks Are Still Active!

Yesterday damp weeds brushed our clothing as two friends and I walked a creek side trail in the drizzle. When we got back to our cars we checked for black-legged ticks (Ixodes scapularis) and found many on our clothing. I also found one on the car seat where I’d dropped off my backpack and gloves. Yikes!

Relative size of black-legged ticks (image from CDC.gov)
Relative size of black-legged ticks (image from CDC.gov)

Black-legged ticks transmit Lyme disease and other bacteria that can ruin your life for a very long time so it’s important to be vigilant about them.

You don’t have to go far to find them. Of course they are in the woods but they’re also found in backyards in Allegheny County. Damp weeds are a favorite habitat. Click on this photo of Japanese barberry to read why.

Needless to say I felt itchy all over after finding the ticks. When I got home I took a careful shower and put all my clothes in a hot dryer for 10+ minutes. Really. Dryers desiccate ticks. In 10 minutes they’re all dead.

Keep yourself safe by following these guidelines –> Forewarned is Forearmed.

Don’t be fooled. Black-legged ticks are still quite active in western Pennsylvania.

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

Tracker Eggs May Save Endangered Turtles

Green sea turtle (photo from Wikimedia Commons)

Green sea turtles (Chelonia mydas, above) are endangered and olive ridley sea turtles (Lepidochelys olivacea, below) are vulnerable even though both have a wide distribution in the tropical oceans. The threats they face are caused by humans including boat strikes, nets, poaching of the adults and collecting their eggs.

Olive ridley sea turtles nesting in Mexico (photo from Wikimedia Commons)

Back in 2015 conservation scientist Kim Williams-Guillén came up with a way to protect turtle eggs by using GPS-equipped decoys. Her award-winning idea was tried recently in Costa Rica with the results published this month in Current Biology.

Green sea turtle laying eggs (photo from Wikimedia Commons)

A team of scientists led by Helen Pheasey placed a decoy egg in each of 101 clutches of green sea and olive ridley turtles. 25 of the clutches were stolen by poachers. Five of the GPS eggs were taken for a ride. One traveled 85 miles. This diagram from Current Biology shows the decoys and the routes they traveled.

Decoy eggs, data, and estimated routes used by turtle egg traffickers (illustration from Current Biology PDF. Click this caption for the full description)

Revealing the trade routes is a step toward saving the turtles though not the silver bullet. Conservation laws and their enforcement can be ambiguous from country to country. As Science Magazine explains:

Ultimately, though, scientists and nonprofits are going to need to engage communities with local outreach and education programs to save sea turtles, Williams-Guillén says. “The real meat and potatoes of conservation isn’t going to come from deploying eggs.”

Science Magazine — Endangered baby sea turtles may have new savior: GPS eggs

Every little bit helps. Fake eggs will allow more baby turtles to hatch and walk to the sea.

Baby green sea turtle (photo from Wikimedia Commons)

Read more in Current Biology Magazine: Using GPS-enabled decoy turtle eggs to track illegal trade.

(photos from Wikimedia Commons, diagram from Current Biology Magazine: Using GPS-enabled decoy turtle eggs to track illegal trade; click on the captions to see the originals)

Spiders On Caffeine

European garden spider on web (photo from Wikimedia Commons)

6 October 2020

Since I began blogging 13 years ago my morning life has settled into a predictable pattern: I get up very early (4:00 am), make coffee, settle at my computer and start writing. Coffee is essential.

What’s essential to me doesn’t work well for spiders. On caffeine they make wonky webs.

Effect of caffeine on spider web construction (images from Wikimedia Commons)

Why did a scientist bother to find this out? His friend wanted to sleep late.

Read the details in this vintage article, On Caffeine, written years ago when I got up later myself.

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

Which One Is Mildly Poisonous?

Leopard frog and pickerel frog (photos from Wikimedia Commons)

22 September 2020

Pretty soon it’ll be too cold for frogs but right now we still have a chance to see these two in Pennsylvania. Though similar it’s useful to know the difference because one is mildly poisonous.

Northern leopard frogs (Lithobates pipiens), at left above, are harmless and sometimes green. Don’t rely on their green color for identification though because some are plain brown. All four below are northern leopard frogs from the same place in Minnesota. Notice that the spots on their backs are irregular circles and somewhat scattered even on the brown one.

Green morph (left) and brown morph (right) northern leopard frogs (photo from Wikimedia Commons)

Pickerel frogs (Lithobates palustris) are mildly poisonous. When frightened they excrete a poison from their skin that’s toxic to predators and mildly irritating to human skin. To identify them, notice the chocolate brown blob-like rectangles arranged in two rows between the two folds on their backs (dorsolateral folds).

Pickerel frog, Souderton, PA (photo from Wikimedia Commons)

The Pickerel frogs can also be distinguished by the bright yellow or yellow-orange color on the inside concealed surface of the thigh. Leopard frogs are white in the same area. 

BioKids article at Univ of Michigan

Here’s a live pickerel frog showing off his spots.

He’s the one that’s poisonous.

p.s. A note on Poisonous versus Venomous:

  • Poison is passive, just used as a defense. You have to ingest or touch a poisonous substance to be harmed by it.
  • Venom is active, injected into you by the animal that carries it. It’s used as both offense to capture prey and defense.

(photos from Wikimedia Commons, click on the images to see the originals)

Porcelain and Primrose

Porcelain berry, Three Rivers Heritage Trail, 7 Sep 2020 (photo by Kate St. John)

In September porcelain berry’s (Ampelopsis glandulosa) beautiful porcelain-like fruits show why the plant was imported as an ornamental.

Porcelainberry, 3 Rivers Heritage Trail in Pittsburgh, 7 Sep 2020 (photo by Kate St. John)

Unfortunately this Asian vine is terribly invasive, engulfing small trees and draping itself over large ones.

Porcelain berry drapes a hillside in Schenley Park (photo by Kate St. John)

Some people call it “wild grape” but you’ll never see grapes on it. Just porcelain berries.

This month you’ll find common evening primrose (Oenothera biennis) blooming in meadows, along roads and bike trails. The name implies that it opens only in the evening but I photographed these at midday. The flowers are 1-2 inches wide. The plants are hard to miss at six feet tall.

Common evening primrose, Eliza Furnace Trail, 7 Sept 2020 (photo by Kate St. John)
Common evening primrose buds, Eliza Furnace Trail, 7 Sept 2020 (photo by Kate St. John)

Meanwhile, bug love continues. This pair of goldenrod soldier beetles (also called Pennsylvania leatherwing (Chauliognathus pensylvanicus)) are perched on a flower in the Aster family while working to continue their species.

Spend time outdoors this week while the weather is good. Autumn is beautiful and all too short.

p.s. Thank you to Monica Miller and John English for correcting my bug identification mistake!

p.p.s. Did you notice that Pennsylvania is misspelled in the bug’s scientific name (only 1 ‘n’). This is not the only species with this misspelling. Can you name another?

(photos by Kate St. John)

Monarchs Are Using Their Sun Compasses

Monarch butterfly on swamp milkweed, Aug 2014 (photo by Steve Gosser)

10 September 2020

Though 2020 has been an awful year it has a silver lining: Monarch butterflies are relatively plentiful. I saw my first monarch in late July. Now that they’re migrating to Mexico I see several every day.

How are they navigating to Mexico?

During their fall migration, Eastern North American monarch butterflies (Danaus plexippus) use a time-compensated sun compass to aid navigation to their overwintering grounds in central Mexico.

Antennal circadian clocks in migratory monarch butterflies

The compasses are in their antennae! Combined with a circadian clock that figures out where the sun ought be at any time of day, the compass compensates for the sun’s position and keeps the monarch heading in a southwesterly direction.

Monarchs can navigate better than some of us!

On Throw Back Thursday, read more in this vintage article: The Sun Compass.

(photo by Steve Gosser)

p.s. The article was written seven years ago when the monarch population hit a dangerous record low. The population rebounded in 2018-2019 but it’s hard to know if they’re safe yet. This population graph from Journey North was not updated in spring 2020. I’ll bet COVID-19 interfered.