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.
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.
The dominant lizard in the video must be shouting at the other guy, “Leave now! Run away! Show me your tail!”
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.
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.
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.)
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.
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!
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.
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.
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.
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.
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.”
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.
Here’s a live pickerel frog showing off his spots.
The Pickerel Frog shows off its striking pattern. If it’s cover gets blown, plan B is the poison that it packs in it’s skin. Mildly irritating to people, distasteful to predators, they are the only native poisonous frog in the USA. pic.twitter.com/GN2HdltcKc
In September porcelain berry’s (Ampelopsis glandulosa) beautiful porcelain-like fruits show why the plant was imported as an ornamental.
Unfortunately this Asian vine is terribly invasive, engulfing small trees and draping itself over large ones.
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.
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?
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.
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.