St. Patrick’s Day, 17 March 2021

Today we celebrate someone who banished snakes from an island.

Legend has it that St. Patrick, patron saint of Ireland, chased all the snakes into the sea after they attacked him during a 40-day fast.

The island of Guam, a U.S. territory in the western Pacific, is plagued by brown tree snakes (Boiga irregularis) accidentally introduced after World War II. In 70 years the snake population exploded to 2 million, more than 100 snakes per hectare, or more 110 snakes per football field. It’s the highest concentration of snakes anywhere in the world.

Brown tree snakes have caused the extinction of most of Guam’s native wildlife, thousands of power outages, widespread loss of domestic birds and pets, and considerable emotional trauma to residents and visitors. Guam’s plant life has diminished, too, because the snakes have eaten the pollinators.

People working to eradicate Guam’s brown tree snakes have learned a lot about the animal. For instance, the snake dies when it eats acetaminophen so they’ve air-dropped acetaminophen-laced mice to tempt the snakes.

A study this year showed that fat slippery poles do not protect nest boxes so that method will have to change. The snakes make themselves into lassos to climb up! Click on the picture below or its caption to see a video of the snake in motion.

Everyone hopes that eradication efforts succeed and that Guam will celebrate No Snakes Day some time in the future. They could certainly use the help of St. Patrick and the luck of the Irish.

(photos from Wikimedia Commons an a screenshot from the lasso video; click on the captions to see the originals)

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.

Two adorable male zebra-tailed lizards engage in territorial street fighting deep in the Sonoran Desert.

?Organ Pipe Cactus National Monument pic.twitter.com/X16Z86QdOf

— Russ McSpadden (@PeccaryNotPig) December 4, 2020

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.

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)

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.

— 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)