Amazing Cicada Life Cycle, presented (and bewitched) by the amazing Sir David Attenborough in this clip from the BBC’s Life in the Undergrowth.
“Magicicada Brood II will make its 17-year appearance when the ground 8” down is a steady 64°F,” reports Radiolab in this excellent Cicada Tracker DIY project page. And why 17 years underground? From Scientific American:
The curious phenomenon of the cicada’s periodical life cycle is the subject of much debate among scientists, who are limited to no small extent by the infrequency of the insect’s visits to the surface. Most agree, however, that climate shifts — notably the rapid warming following the end of the last ice age — have played a role.
There are seven species of periodical cicadas in North America, four bound to a 13-year cycle, three in a 17-year cycle. All are characterized by black and orange bodies, and males woo their mates with species-specific choruses that can be deafening in large numbers.
The genetic similarity of these seven species suggests a common ancestor in the last 8,000 years. And because emergence seems closely linked to soil temperature and moisture, it is likely that climate has played a role in both regulating their life cycles and cueing their appearance.
Cicadas don’t sting or bite. After a few weeks making noise up in the trees (measured at 94 decibles), eggs will be laid and will hatch. After feeding on sap, these hatchlings will drop down to burrow and live underground, next seen in the year 2030.
Like an elusive, caped creature in the ocean, a female blanket octopus glides through the water. We know this video is of a female of the species because she is around two meters (6.6 feet) long. In contrast, the male blanket octopus is less than 3 centimeters wide. Yes, centimeters!
Differences in males and females of a species is called sexual dimorphism, and can include size, coloring or ornamentation, form or structure, and behavior. A few examples of this include peacocks, peacock spiders, birds of paradise, lions, elk, and even humans. The BBC is a good start for further viewing.
This clip is from Oceans, a French documentary film by Jacques Perrin (released in the US by Disneynature). You can watch another clip from the movie here.
via Scientific American’s Octopus Chronicles.
Professor Brian Cox explains how Monarch Butterflies navigate by “monitoring the position of the sun, and compensating for its location in the sky using their internal timekeeping mechanism… even when it’s cloudy.” This is an episode 5 preview of the BBC’s Wonders of Life. Full screen this.
This short, silent video shares a few behind-the-scenes moments from the ”fish tornado” photograph, titled David and Goliath, taken in Cabo Pulmo, Baja California Sur, Mexico by photographer Octavio Aburto.
“As people have seen this image, I have been getting a lot of messages in my inbox and phone calls asking me “is this photo real?” And “how did you congregate all these fish in one place to take the photo?”
“My response to these questions has been this — of course it is real. Fish, as is the case with many other animals, have certain behaviors that they perform when they reproduce. For example, when monarch butterflies mate they travel hundreds of thousands of kilometers, crossing from Canada down through Mexico to form unbelievable congregations. Sea turtles also have unique reproduction behavior —some travel the entire Pacific just to return to the beaches where they originally hatched. Birds fly hundreds of kilometers to certain areas to nest as well. These behaviors are well known within terrestrial animals and within the scientific community we have also known of these behaviors with fish and other marine creatures for many years. In Cabo Pulmo for example, blacktip reef sharks and mobula rays also congregate in large numbers to mate during the winter season.
“Even after I explain this unique behavior and the spectacular spawning aggregations of fish that occur naturally, some people don’t believe this image is real.
“In some ways I think this photo, and others like it, force people to think about the environment and more specifically in this case the ocean, dwindling fish populations the health of marine ecosystems worldwide and our role in it all.”
via EarthSky.org.
Photographer Steve Simonsen films an epic Caribbean hermit crab mass migration at Nanny Point, St. John, in the U.S. Virgin Islands. This video has gone viral, and it’s pretty clear as to why! How many thousands and thousands and thousands of crabs are on this beach?!
From ABC News:
Hermit crabs, also known as soldier crabs, are found throughout the Caribbean islands and take part in a great migration en masse annually in August to mate. The crustaceans travel to the beach, leave their shells and enter the water to lay eggs, according to Smithosianmag.com. After spending two minutes in the water, Simonsen said the crabs turn around, return to land and make their way home.
People who live on St. John know this happens in August. I’ve never been able to see it or know when it happens,” said Simonsen, who plans to study the creature’s migrations, moon phases, tides and stake out beaches next August to see the phenomenon again.
You can read more about “crazy crab migrations” on SmithsonianMag.com.
Thanks, @ceili.
