Archive for the 'Insects, Fish, Frogs' Category

Sep 22 2016

Catch Them From The Sky

Coast Guard Cutter Rush escorts the suspected high seas drift net fishing vessel Da Cheng in the North Pacific Ocean on August 14, 2012. (photo credit: U.S. Coast Guard)

Coast Guard Cutter Rush escorts suspected high seas drift net fishing vessel Da Cheng in the North Pacific Ocean on August 14, 2012 (photo from U.S. Coast Guard via NOAA)

After two days of sad stories about fish populations in decline here’s some hopeful news.

With sensible catch limits and sanctuaries where fishing is prohibited, we can turn the tide on ocean species decline — but only if we can enforce the laws.  Unfortunately the ocean is a huge place with few “cops on the beat” and a lot of places for illegal, unreported, and unregulated fishermen to hide.

Until now.

Last week Oceana, SkyTruth, and Google launched the public Beta of Global Fishing Watch (GFW), a free online tool that allows anyone in the world to monitor and track the activities of the world’s largest commercial fishing vessels in near real-time.

Here’s how it works:  Every ship over a certain tonnage is required to transmit Automatic Identification System (AIS) data containing its identity, location, course and speed.  The data, received by satellites and accumulated since 2012, is used to plot each ship’s movements.  To determine which boats are fishing vessels, Global Fishing Watch developed an algorithm that identifies fishing by the characteristic patterns it makes on the map.

The map shows no-fish zones and Economic Exclusion Zones where it’s easy to see if illegal fishing is going on.  Vessels that turn off their AIS transmitters or purposely falsify their GPS data are automatically suspect.

Nations at the mercy of illegal fishing are happy to use GFW. In December 2014, when the tool was still in test mode, SkyTruth analyst Bjorn Bergman (from his desk in West Virginia!) saw a Taiwanese boat fishing illegally in Palau’s protected waters. And it turned off its AIS. The boat left Palau and headed for Indonesia.  When it returned in January Bergman remotely helped Palau authorities chase it down. Read the whole story here at the GFW blog.

So if you’re wondering how the U.S. will stop illegal fishing in 582,578 square miles of the newly expanded Papahanaumokuakea Marine National Monument (surrounding the Northwestern Hawaiian Islands) the answer is:

We’ll catch them from the sky.

For more information, watch the video and visit the Global Fishing Watch website.

(video from Global Fishing Watch on YouTube)

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Sep 21 2016

Passenger Pigeon Of The Sea

Published by under Insects, Fish, Frogs

Pacific bluefin tuna, Kaiyukan Aquarium, Osaka, Japan (photo from Wikimedia Commons)

Pacific bluefin tuna, Kaiyukan Aquarium, Osaka, Japan (photo from Wikimedia Commons)

Today, a fish story.

Bluefin tuna are following the same trajectory as the passenger pigeon.  Because they taste good they’re poised to go extinct.

Atlantic (Thunnus thynnus) and Pacific bluefin tuna (Thunnis orientalis) are highly migratory predators that spawn on one side of their respective oceans and travel thousands of miles on migration to their feeding grounds.  When they reach maturity at three to five years old they return to spawn.  Bluefins can live 15 to 50 years and reach up to 990 pounds but because of overfishing very few live to maturity.

Like the passenger pigeon, human hunting pressure is the only reason for the bluefin’s decline.  Technological advances in deep sea fishing have made it easy to catch all of them.  Their meat is so prized in Japan for sushi and sashimi that the Pacific population has declined more than 97%.  Large specimens are so rare that according to the January 11, 2013 issue of TIME magazine, “Just last week, a 489-lb. bluefin was sold at a fish auction in Tokyo for a record $1.76 million—or about $3,600 per pound.”  That was nearly four years ago.  Their status has only gotten worse.

Like the final decades of the passenger pigeon, the bluefin’s plight has been discussed for years.  Catch limits for Atlantic bluefin have been in place since 2007 and it’s been nominated for endangered status.  In 2010 the World Wildlife Fund pointed out there was still so much over-capacity for Atlantic tuna fishing that EU boats reached their catch limit in only one week.  In 2011 Salon magazine asked, “Why are we still eating bluefin tuna?”  In 2014, the Center for Biodiversity called for a Pacific bluefin fishing ban.

This summer the situation became so dire that a dozen environmental groups called for listing the Pacific bluefin tuna as Endangered and the Pew Trusts called for a Pacific bluefin moratorium.

This Pew Trusts video explains how the Pacific moratorium, implemented immediately, would save the species.

 

We still have time to turn it around — but not much.

Will bluefin tuna go the way of the passenger pigeon … from billions to none?

 

(photo from Wikimedia Commons. Click on the image to see the original.)

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Sep 20 2016

The Biggest Die First

Large swordfish on deck during long-lining operations (photo by Derke Snodgrass via NOAA Photo Library)

Large swordfish on deck during long-lining operations (photo by Derke Snodgrass from NOAA Photo Library)

It happened to land animals. Now it’s happening in the ocean.  The biggest die first.

Based on Earth’s current extinction rate of 1,000 times the normal background rate (predicted to become 10 times worse) scientists believe we’re at the start of the sixth mass extinction.

Stanford geoscientist Jonathan Payne wondered if the traits of extinct marine animals could predict the likelihood of extinction in today’s ocean organisms. For mollusks and vertebrates Payne and his colleagues compared ecological traits such as habitat preference and body size in past extinct and present threatened genera (genus: one level above species).  The results were surprising.

In past extinctions habitat preference was a good predictor that an animal would disappear.  That’s not the case now. In this era, the best predictor of future extinction is large body size.

The difference is us.  Human hunting pressure is driving ocean extinction.  Our demand for seafood is high (there are billions of us to feed) and we’ve become very efficient at capturing the largest fish.  Highly migratory predators like the Pacific bluefin tuna have declined precipitously.

We’ve seen this before.  At the end of the Ice Age, as human population expanded across the globe, the megafauna simultaneously went extinct.  It’s now known that sabretooth tigers, giant armadillos and woolly mammoths disappeared due to human hunting.

Woolly mammoth statue in the Royal BC Museum, Victoria, BC, Canada (photo from Wikimedia Commons)

Woolly mammoth statue in the Royal BC Museum, Victoria, BC, Canada (photo from Wikimedia Commons)

We humans are successful because we make tools and hunt cooperatively.  Of course we kill the largest prey first. One large animal feeds more people.

Unfortunately we don’t know when to stop.

 

Read more about Payne’s study here at Science Daily.

(photo of swordfish from NOAA Photo Library. photo of woolly mammoth statue in Royal BC Museum, Victoria, Canada via Wikimedia Commons. Click on the images to see the originals)

p.s. A word about the swordfish pictured above:  Swordfish are highly migratory predators whose population is in danger — or unknown — in many oceans around the world.  In 1998 the North Atlantic population dropped so low that fishing was suspended.  A 2009 international assessment of North Atlantic swordfish showed they had recovered in U.S. fishing areas, so fishing has resumed.  Note: The fishermen who lost their lives aboard the Andrea Gail in The Perfect Storm were longline fishing for swordfish.)

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Sep 17 2016

Honeybee Knickers

Published by under Insects, Fish, Frogs

Honeybee with pollen bags on his legs (photo by Kate St. John)

Honeybee with pollen bags on his legs (photo by Kate St. John)

Honey bees are busy right now collecting nectar and pollen to get them through the winter.  They carry nectar to the hive by swallowing it.  They carry the pollen in sacs on their legs.

According to Wikipedia, the bee’s pollen basket or corbicula is “a polished cavity surrounded by a fringe of hairs.”  Each bee grooms the pollen off her body and stores it in her pollen baskets. Here’s how:

A honey bee moistens its forelegs with its protruding tongue and brushes the pollen that has collected on its head, body and forward appendages to the hind legs. The pollen is transferred to the pollen comb on the hind legs and then combed, pressed, compacted, and transferred to the corbicula on the outside surface of the tibia of the hind legs.

This honeybee’s pollen basket is so big that it looks like she’s wearing orange knickers.

 

(photo by Kate St. John)

p.s. for my British readers:  The word “knickers” in the U.S. is short for “knickerbockers,” the baggy trousers tight at the knee formerly worn by golfers.

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Aug 30 2016

Tiny Emperors

Published by under Insects, Fish, Frogs

Tawny emperor caterpillars (photo by Kate St. John)

Tawny emperor caterpillars (photo by Kate St. John)

Ten days ago Marcy Cunkelman flipped over a leaf and showed us two hundred tiny emperors.

The squiggly green lines are caterpillars of the Tawny Emperor butterfly (Asterocampa clyton) eating the mature leaves on a hackberry tree. They also feed on other trees in the elm family (Celtis).

At this stage the caterpillars huddle and move together for protection but after the third instar they travel alone.

Eventually each caterpillar spins a cocoon and pupates into a butterfly that looks like this:

Tawny emperor butterfly (photo from Wikimedia Commons)

Tawny emperor butterfly (photo from Wikimedia Commons)

The butterflies don’t visit flowers. Instead they feed on rotting fruit, dung, carrion and tree sap … an odd feast for an emperor.

 

(photo of caterpillars by Kate St. John, photo of butterfly from Wikimedia Commons)

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Aug 21 2016

Butterfly With a Birthday Cake

Published by under Insects, Fish, Frogs

Butterfly with a birthday cake (photo by Dana Nesiti)

Butterfly with a birthday cake (photo by Dana Nesiti)

Dana Nesiti (who usually takes photos of bald eagles) has been experimenting with insects.  This one caught my eye.

Is this butterfly celebrating its birthday with 16 candles?

Well, no.  The birthday cake is actually a black-eyed susan with stamens.

And the butterfly is a wild indigo duskywing.

 

Thanks to Dana Nesiti for the cool photo and butterfly identification.

(photo by Dana Nesiti)

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Aug 15 2016

Found A Big Cat

Published by under Insects, Fish, Frogs

Caterpillar of the Promethea moth, twig held by Ramona Sahni (photo by Kate St. John)

Caterpillar of the Promethea moth, twig held by Ramona Sahni (photo by Kate St. John)

On August 6 at Jennings Prairie we found a big green “cat” with a yellow face.  Ramona Sahni held the twig while I took the caterpillar’s picture.

Dianne Machesney later identified it as the larva of a Promethea moth (Callosamia promethea).  He’s named for Prometheus, a Titan in Greek mythology who was a clever trickster and benefactor of mankind.

Nowadays “Promethean” means “boldly creative, defiantly original” — and because he was a Titan, “big.”  The adult male and female moths show off these qualities.

Male Promethea moth (photo from Wikimedia Commons)

Male Promethea moth (photo from Wikimedia Commons)

 

Female Promethea moth (photo from Wikimedia Commons)

Female Promethea moth (photo from Wikimedia Commons)

 

It’s amazing that they look so different.

Big, bold, defiantly original.  No wonder these moths are Promethean.  😉

 

(caterpillar photo by Kate St. John. Moth photos from Wikimedia Commons. Click on the images to see the originals)

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Aug 11 2016

TBT: Watch Out Guys!

Published by under Insects, Fish, Frogs

Praying Mantis (photo by Marcy Cunkelman)

Praying Mantis (photo by Marcy Cunkelman)

On Throw Back Thursday (TBT):

Why is it so dangerous to be a male praying mantis?  Find out in this article from August 2010: “Watch Out Guys!

 

(photo by Marcy Cunkelman)

 

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Aug 10 2016

Tree Crickets Tune Their Ears

Published by under Insects, Fish, Frogs

Bug noise is everywhere on hot summer nights. Some of the singers are tree crickets.

Tree crickets (subfamily Oecanthinae) live on every continent except Antarctica.  Camouflaged to match their habitat, these long, skinny, nocturnal insects live in trees and shrubs where they eat just about anything. They’re especially fond of aphids.

Male tree crickets “sing” to attract a mate by rubbing the ridges of their wings together, shown in the video above.   The females don’t sing but they certainly listen.  Each species has a distinctive range of frequencies.  The ladies ignore the cacophony of other species. They only listen for their own.

Because insects are cold-blooded they move slower in cold and faster in heat, so they trill faster when the weather’s hot.  This means the frequency, and thus pitch, of their songs goes up in higher temperatures.  Here’s the sound of a snowy tree cricket (Oecanthus fultoni) at different temperatures.

So here’s an interesting problem:  Female tree crickets recognize their own species by the frequency of the trill, but the frequency increases as the temperature rises.  How do they recognize the higher-pitched songs?

In a study published last April, researchers at the University of Toronto Scarborough used laser Doppler vibrometry to measure vibrations inside the crickets’ ears.  The instruments were so sensitive that they could see changes at the cellular level.

The study found that “as the temperature changes, tree cricket ears adjust at a cellular and therefore mechanical level to match the changing frequency of the song.”

Read more about it here in Science Daily.

 

(video of a tree cricket “singing” in Alameda County, California from Wikimedia Commons)

7 Oecanthus species in western Pennsylvania as shown at Oecanthinae.com:  Four-spotted (O. quadripuntatus), Snowy (O. fultoni), Black horned (O. nigricornis), Pine (O. pini), Narrow winged (O. niveus), Two spotted (Neoxabea bipunctata), Davis’ (O. exclamationis)

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Aug 06 2016

Big and Beautiful

Published by under Insects, Fish, Frogs

Royal Walnut or Regal Moth (photo by Don Weiss)

Royal Walnut or Regal Moth (photo by Don Weiss)

Beautiful moths come in all sizes.

On Monday I wrote about the pink-and-yellow rosy maple moth whose wingspan is only one to two inches.  Don Weiss supplied Monday’s photo and commented that they found this big and beautiful moth at the same time.

The royal walnut or regal moth (Citheronia regalis) is the largest moth in the western hemisphere north of Mexico.  With a wing span of 3.75 to 6+ inches, it lives in deciduous forests from New Jersey to eastern Kansas and east Texas to Florida.

Citheronia regalis is always big but not always beautiful.  As a caterpillar it’s so scary-looking that it’s called a hickory horned devil.  Click here to see its final instar on someone’s hand.

True to its name the caterpillar feeds on walnuts, hickories and a lot of other trees.  Since their only job is to procreate the adults never eat. They live only a week.

Now’s a good time to find this big and beautiful moth in southwestern Pennsylvania.

 

(photo by Don Weiss)

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