Hypnotic Hydrothermal Vents

One of the most fascinating features found in the ocean are hydrothermal vents.  (Hydrothermal vents occur on land as well in the form of hot springs and geysers; the most famous is Old Faithful in Yellowstone Park.)  Vents are found along the mid-ocean ridge system, an underwater mountain range where there are active volcanoes and the tectonic plates are gradually moving away from each other.

The existence of these vents was discovered fairly recently in 1977 by scientists aboard a submersible, and were found at a depth of nearly 8,000 feet below the surface.  Ocean water seeps into small cracks in the ocean floor, is heated by volcanic rock, rises and then spews back into the ocean.  As the hot water meets the cold ocean water, minerals that have been collected on its journey form particles and can gather and develop into 'chimneys'.

Source: NOAA

These chimneys are known as 'smokers'.  The type of minerals that form the chimneys determine whether it's a white smoker (barium, calcium, silicon) or a black smoker (sulfide, iron).  Chimneys can grow to be more than 30 feet tall.

The average depth for vents is around 7,000 feet, where sunlight can't reach.  Plus the water that spews from these vents can be up to 700 degrees Fahrenheit, which makes it even more astonishing that the surrounding areas are teeming with life.  That's because the minerals support chemosynthetic bacteria which is eaten by plankton.  Both the bacteria and plankton is food for the rest of the vent community filter feeders which include giant tube worms, shrimp, limpets, mussels and clams.  Eels, fish, crabs and octopus can also be found.  Because the type and mix of minerals can vary, each community is unique.

Giant tube worms  Source: Fisheries and Oceans Canada

Deep sea clams and crabs  Source: Sea and Sky

Limpets  Source: Fisheries and Oceans Canada

 Source:  Fisheries and Oceans Canada

Over 300 new species have been found in these vent communities and more are being discovered on a regular basis.  It has been theorized that life on earth originated at a hydrothermal vent.  There is much more to learn about these unique ecosystems.

Merry Meerkats

I love meerkats!  Anyone who has watched the show 'Meerkat Manor' can't help but admire them.  How could you not love something that looks like this.

Source:  Pensacola Junior College

Okay, so I cheated.  All baby animals are cute!  But as cute as these guys are, meerkats also have their no-nonsense side.  Living in the Kalahari Desert is serious business, and, as Cesar Millan would say, there need to be 'rules, boundaries and limitations' if a meerkat family is to survive.

Source: University of Wisconsin

Meerkats live in family groups called 'mobs' or 'clans' and there can be 20 to 50 or more member, but only the alpha pair is allowed to have babies.  If another female has a litter of pups, it can be deadly for both the mother and the pups.  The alpha female will likely kill the pups in order to ensure the survival of her own babies. The offending female is usually evicted from the group, and a lone meerkat is easy pickings for predators.

Source: safaris in namibia

Meerkats are members of the mongoose family and eat mostly insects, including beetles, millipedes and centipedes, and spiders, along with the occasional lizard, snake, or small mammal.  They also eat scorpions and are immune to their venom.  As they forage, there is always one individual that keeps a look out for predators.  If one is spotted, the alarm call goes out.  Like some other animals, meerkats have different vocalizations that help the group know where the threat is coming from - on the ground or from the air.  Depending on which alarm is given decides the group's strategy for escape - simply take cover or go for one of the many bolt holes they have dug throughout their territory.

Meerkats are very territorial and will avidly defend it from other clans.  They also patrol their territories to make sure another group is not depleting their food resources.  Meerkats have a complicated system of burrows and dens and will occasional share their home with ground squirrels or mongooses.  However, they will move the main living area if food is scarce in their current location.

Source:  It's Nature

All adult meerkats are responsible for the care and protection of the babies.  Once they are old enough to forage with the rest of the clan, each youngster has an adult 'mentor' in charge of its care and feeding.  The youngsters learn what food to eat by watching the adult, and the adult helps with catching dinner.

Meerkats are cute, funny, but tough little critters.  They have to be.  To see a video of a gang of meerkats against a puff adder, go here.

Crazy for Corn

Whenever my mother would ask me what vegetable I wanted for a birthday dinner, Thanksgiving, Christmas, or any other special occasion, she would know my answer before she even asked - CORN!  Growing up in Iowa I was in heaven because corn - and I mean FRESH corn - was always available six months out of the year.  You could buy it at the grocery store, on roadside stands, or even go out in the country and sneak an ear right off the stalk!  Of course, I never did that, but it was possible.  Iowa is in the middle of the corn belt, and the corn grown in Iowa, Illinois, Minnesota and Nebraska account for over 50 percent of the 332 metric tons grown in the United States annually, the world's top producer.

Source: sogoodblog.com

Corn, or maize, was cultivated and developed from a wild grass called teosinte over 7,000 years ago in Central Mexico and spread north into the southwestern U.S. and south into Peru.  It became a staple food for the Aztec, Mayan, and Native American people and most certainly was present at the 'first' Thanksgiving in 1621.  When the very first Thanksgiving happened is contested since there was reportedly a similar event that occurred in St. Augustine, Florida as early as 1565.  Canadians also celebrate Thanksgiving, and THEIR first Thanksgiving was celebrated in current Newfoundland and Labrador in 1578 when explorer Martin Frobisher gave thanks for surviving a long journey looking for a northern route to the Pacific Ocean.

Source: Wikipedia

There are now over 100 different types of corn.  My favorite is Green Giant's White Shoepeg corn!  At least my favorite kind now.  I haven't tried all 100 - so little time, so much corn.  I hope you enjoy your favorite kind today and have a happy Thanksgiving!

Echoes of Elephants

I recently watched a great segment of Wild Kingdom about Borneo's pygmy elephants.  Of course, I know there are elephants in Asia, but didn't realize there were elephants in Borneo.  Asian elephants in general are smaller than African elephants. And pygmy elephants, which live in both Africa and Asia, are even smaller because of the habitat they live in - the forest as a opposed to savanna.  Smaller bodies make navigating around dense trees easier.  Pygmy elephants also have narrower, longer heads, straighter tusks, and some are darker in color - all adaptations to their forest habitat.

Source: World Wildlife Fund

The Borneo pygmies are a genetically distinct subspecies of the Asian elephant, having longer tails, bigger ears, and a very gentle nature.  They also tend to live in smaller family groups.  They are endangered with the population estimated at only about 1,000 individuals.

Source:  World Wildlife Fund

Not nearly as much is known about pygmy elephants as we know about their savanna cousins, mainly because they are harder to track.  But World Wildlife officials are trying to remedy that, particularly with the Borneo pygmy elephants. A few years ago they were fitted with radio collars with GPS units in them so their movement could be documented.  Like so many other species whose habitat is being fragmented by human development, the Borneo forests are slowly disappearing as they are being logged or cleared and converted to palm oil plantations.

Source: World Wildlife Fund

One of the most interesting thing about elephants is how they communicate.  Elephants have more than 70 vocalizations used to warn of predators, find other group members, coordinate travel, and care for their young.  Elephants use infrasound - rumbles or grunts in frequencies lower than the human ear can hear - and can contact elephants many miles away.  They also communicate with over 150 gestures or visual signals, as well as touch and smell, in order to get their point across and maintain social networks.  Individuals will often touch each other when two herds meet, and seem to pay their respects when they come across an elephant that has died.

(African elephant photo)  Source: wildlife-pictures-online.com

It would truly be a tragedy if we lost these Borneo treasures.  To me there is nothing as cute as a baby elephant and nothing as stately and majestic as the matriarch of the herd.

Zany Zion

I took a trip to Utah a couple of years ago and part of that trip included a drive through Zion National Park.  Zion is an amazing place and a geological wonder.  It is part of the Colorado Plateau, a 180,000 square mile area known as the Grand Staircase.  It begins with Bryce Canyon to the North, and ends with the Grand Canyon to the south.  Zion was carved by rain and the waters of the Virgin River which joins up with the Colorado River at Lake Mead.  The layers of Zion Canyon were formed by 150 million years of mud, lime, sand and ash deposits, which were then uplifted more than 10,000 feet by tectonic activity.  This process of river deposits, earthquakes and erosion is still being played out.  The varying environments that once occurred in this area included shallow seas, steams and ponds, and desert are represented by layers of marine fossils, shale, mudstone and sandstone.  Here are a few of the pictures I took while I was there.  Enjoy!

Scary Scorpions

And speaking of spiders (see previous post), I'll never forget one day at my apartment in Georgia, I came out of the bedroom into the living room and saw all the cats gathered around something on the living room floor.  I went to investigate and couldn't believe what I saw - it was a little scorpion.  I had no idea there were scorpions in Georgia.  How it got inside I'll never know, but I totally freaked.  I had heard about how bad scorpion stings can be and had no idea whether any of the cats had been stung or not.  I quickly got something to pick it up with, got it contained, and, I confess, flushed it down the toilet!  Then I frantically called Poison Control.  As it turned out, the scorpions in Georgia aren't very lethal at all, although their sting can be painful.  I still watched the cats closely until I was sure everybody was okay.  I think it might have been one of these guys because it did have a pinkish hue, although these are supposed to be dark brown.  It was really small so I don't know if it was a baby or not.

Hentz Striped Scorpion (Centruroides hentzi) Source: floridiannature.com

You think of scorpions as desert dwellers, but scorpions can be found in places where there are no deserts that I know of - like Kentucky!  And I don't recall there being any deserts in Georgia either.  These guys live under leaf litter, bark, stones, or along dirt roads.  They can live three to five years. Some scorpions live up to 25 years or more.

There are over 1300 species of scorpions and are found on every continent except Antarctica.  Wikipedia claims that only 25 of those are venomous enough to kill a human.  How reassuring!  They are found in nearly every type of habitat except the coldest climates and they glow under a black light. They are also known to be nocturnal, but as I recall my scorpion showed up during the day.  Curious. 

Source: fireflyforest.net

One source says they love to eat cockroaches.  Everybody in New York City needs one of these.  Instead of flushing it down the toilet maybe I should have sent it to one of my friends in the City!

Woolly Wolf Spiders

I guess I've got Georgia on the brain this week because I have been thinking about the big wolf spiders that hung around the lab where I worked.  We kept the doors to the outside cage area open for the bonobos, so we had a lot of 'visitors', including wolf spiders.  Whenever one got inside, I'd get a big glass, capture them and then take them back outside. Our receptionist, Charlene, hated the things and she would yell, 'Carolyn, come get this spider.' whenever one would get in her area.  So I would oblige.

Source: spiderzrule.com

Wolf spiders are hairy like tarantulas and catch their prey by hunting rather than by a web.  They have 8 eyes, and got the name wolf spider because it was originally believed they actually hunted in packs like wolves.

Source: spiderzrule.com

The momma spider carries both her eggs and her kids on her back, and I was always afraid there would be little spiders everywhere if they scattered while I was trying to catch momma.  But that never happened.  Plus I don't know that I ever noticed babies on the back of any of the spiders I caught.

A lot of people hate spiders, but I don't mind them so much.  Even though there was a wooded area just outside my front door in the apartment complex where I lived, I never saw any wolf spiders there.  I might have felt differently about them if I'd ever found one in my bed!

Pensive Panbanisha

Today is Panbanisha's birthday.  Panbanisha is another bonobo I took care of in Georgia.  While I was doing my post on Kanzi (see Keeping Kanzi), I realized all my favorite bonobo stories were about Panbanisha.  They definitely have different personalities.  Kanzi is the gregarious one and always up for meeting new people, while Panbanisha is the introspective one.  As a youngster, Panbanisha was part of a study comparing the language learning capabilities of a bonobo and a chimpanzee, Panzee.  Panbanisha's language abilities are actually better than Kanzi's, but Kanzi is the one who gets the limelight probably because he was the first bonobo to use lexigrams and he totally enjoys the attention.  I don't think Panbanisha is as comfortable in the spotlight.

When I first started taking care of Panbanisha in the main building, she was a bit distrustful. She would work with the researchers during most of the day, and then I would feed her dinner and 'put her to bed' in the late afternoon. In the beginning, I would sit until she came through the tunnel from the tool room into the sleeping area and down the ladder.  Then I would ask her if it was okay to close the door that allowed access to the tool room.  When you ask Kanzi or Panbanisha a yes or no question and there's no keyboard available, if you get silence, that means no.  If they reply with a vocalization, that means yes.  So I would wait until Panbanisha would vocalize and then shut the door.  As time went on and Panbanisha and I got to know each other better, I could simply tell her I was closing the door, but I would still wait until she got all the way down the ladder.

There was only one exception to the routine and that was when Panbanisha was very, very pregnant with her second son Nathan.  At that time, her first son, Nyota was a few years old.  One night about a week before Nathan was born, Panbanisha was obviously exhausted and didn't even want to go down the ladder.  I closed the door while she was still in the tunnel and then hand fed her dinner - the first and only time I did that.  I got a big spoon and stood on a footstool to reach where she was.  A couple of times I also tried to give a little food to Nyota, but each time Panbanisha would take hold of the spoon and pull it toward herself.  In that instance she wanted all of the attention on her.  I know she really appreciated the special treatment.

One of the graduate students that also worked with the bonobos was a woman named Severine.  Severine was blind.  One day we were interacting with Liz who was in with Panbanisha, and Severine and I were in a room with a big window where we could watch.  We didn't have the light on because it was easier for me to see Liz and Panbanisha without a lot of reflection and, of course, Severine didn't need a light.  We were talking to Panbanisha and she was answering on the keyboard.  I forget now what question Severine asked her, but Panbanisha pointed to a lexigram on the keyboard.  Then Liz tried to explain that Severine couldn't see her answer.  Panbanisha then pointed to the 'light' lexigram.  We thought she was telling us to turn on the light so Severine could see.  Liz then had to explain to her that even the light wasn't going to help.

One day there were several of us back in the sleeping area with Panbanisha and Nyota.  Nyota had a habit of reaching out and pulling people's hair.  Even though he was small, he would really give it a yank, so it hurt as well as being really annoying.  This day I'd finally had enough, and without thinking I just blurted out, 'Nyota, if you don't stop pulling my hair, I'm going to bite your little fingers."  (Grabbing a hand and biting fingers is bonobo punishment and a way of saying, 'don't do that'!)  Of course, I had no intention of actually biting Nyota, especially with Panbanisha right there.  And I certainly wouldn't have hurt him; I was just threatening him.  I don't know if Nyota understood what I said, but Panbanisha certainly did.  She suddenly got a very worried look on her face.  And after that any time Panbanisha saw Nyota pull my hair, she would grab his hand and bite his fingers for me!  I guess she thought she'd do it before I had the chance.

The other incredible thing about Panbanisha is that she started drawing the lexigrams on the floor with chalk.  The drawings weren't Van Gogh's, but you could tell what she was trying to draw.  And I believe she did this all on her own without any prompting from caretakers.

Just like children, the bonobos always said exactly what was on their minds.  I was making DVD copies of some research tapes of the bonobos.  I was in a room where there was a window into the area where Panbanisha was.  She came over to the window and started watching the tape I was copying.  The bonobos love watching TV or movies, and especially tapes of themselves.  I said hello and tried to engage her in some conversation.  There was a transparent copy of the keyboard taped to the window. She looked at me and then pointed to the 'quiet' lexigram, reminding me of proper movie theater etiquette!

Source:  Great Ape Trust

Working with the bonobos in Georgia was truly an incredible and humbling experience.

Update:  Unfortunately, Panbanisha passed away November 6, 2012. You can read the story here.

For more on bonobos, check out 'Bonobo: The Forgotten Ape' on my Book Recommendations page.

Wily Wolverines

I watched a great show on wolverines last night on Nature.  Funniest thing - my sister called and she happened to be watching the same show.

Wolverines are the largest members of the weasel family and have a reputation of being pretty fierce and aggressive, like badgers. They also are known for being loners.  Because of where they live in remote northern forest areas, they have not been widely studied, but this program showed that they are much more family oriented than originally believed, and have a definite playful side.

Source: irreplaceablewild.org

A lot of the program showed filmmaker Steve Kroschel raising a couple of wolverine kits after their mother died.  They were so cute.  But as they got older they needed a lot of room to roam and play.  They definitely had a huge amount of energy like so many youngsters.

It was mentioned that the territory of adult wolverines can be up to 500 square miles.  This is one reason why they may be in trouble if habitats are fragmented.  That said, wolverines have been seen recently in areas where they haven't lived in a hundred years or more, like Michigan, Colorado, and the Sierra Nevada.  They are also found in Glacier National Park, but the largest populations are found in remote areas of Alaska and Canada, and northern regions of Asia and Europe.

Source: tigertailfoods.com

Wolverines eat small rodents and rabbits, will eat carrion, and try to take down much larger prey such as caribou if it is sick or injured or steal a meal from almost any other animal.  Their scientific name, Gulo gulo, literally means glutton. They also have thick, beautiful fur that is impervious to frost and they were once trapped and hunted for its luxurious coat.

I was so glad I caught that show.  It gave me a whole new perspective about wolverines.

Tolerant Tippi

In the continuing saga about my seven cats, the first feral/stray cat I took in when I was living in Georgia was Tippi.  I had had another cat named Tippy, but it was a male cat.  And when I saw that Tippi had just a speck of white at the tip of her tail, I thought I would name her Tippi II, only since she was female I spelled her name like Tippi Hedren, of course! 

I started noticing Tippi when she would continually sit on my window sill and peek in.  I started to get to know her by sticking a finger out the door and wiggling it around to see if she was interested in playing.  She was, and eventually she started coming in the door.  I still had the two cats I had brought with me from Colorado to Massachusetts to Georgia, and I was not going to bring in another cat unless the three of them could get along, so when I first brought Tippi in it was for a 'trial period'.  One of my cats Misty wasn't quite as comfortable, but Cookie and Tippi got along well.  (Cookie was a totally mellow cat I had gotten from a shelter in Colorado.)  So Tippi stayed.  Cookie and Misty are now in kitty heaven, but these three get along fine.

Tippi, Tanya and Yoda

When I first saw Tippi I thought she was a kitten because she was on the small side, but I now know that she's just a small cat - the smallest of all my 'kids'.  Small, but mighty, because she has no trouble at all standing up to Pugsley, the biggest and only male cat in the group.

Pugsley and Tippi sunning themselves

I call Tippi my 'anger management' cat.  It seems like whenever I get upset and frustrated she's there meowing at me as if to say, 'Calm down.  Everything's going to be okay.'  And how can I stay angry with her sweet little face looking up at me?

Wondrous Whale Sharks

The biggest fish in the ocean is the whale shark.  They can be more than 40 feet in length and weigh more than 20 tons, although this may be a very conservative estimate.  The biggest fish in the ocean eats some of the smallest creatures in the sea.  Unlike most sharks, the whale shark is a filter feeder and swims with its huge mouth open (it can be up to 5 feet wide) as it scoops up plankton, krill, and sometimes small fish.  And the whale shark's mouth can contain upwards of 3000 small teeth.

Source: www.aboututila.com

Whale sharks live in warm temperate waters and can often be found around coral reefs.  Each whale shark has a unique pattern of spots by which individuals can be identified and they have the thickest skin of any animal on the planet.

Source: bluepeacemaldives.org

Whale sharks are wanderers and can travel thousands of miles going from feeding site to feeding site.  In the spring they are regular visitors to the Ningaloo Marine Park in Australia.  Whale sharks don't reach maturity until 25 to 30 years of age, and it is believed that they can live up to 100 years.  The biggest threat to humans from this shark is accidentally getting slapped by its large tail.  The biggest threat to the whale shark is us.  This behemoth is truly a gentle giant.  To see an amazing video and learn more, click here.

Survival Superstars

Looking at this beetle

Upis beetle  Source: asknature.org

you probably wouldn't think there is anything too remarkable about it.  Or this one?

Red flat bark beetle  Source: bugguide.net

I have to admit the second one is a gorgeous color.  But the most amazing thing about both of these beetles is that they live in Alaska and are able to withstand temperatures of MINUS 100 degrees Fahrenheit and survive!  And what's even more interesting is that they use two different methods to do it.

In fact the red flat bark beetle can withstand a temperature of MINUS 238 degrees F (lab tested, not actual earth temperature!) and not freeze.  Around August they begin to produce antifreeze proteins that attach to areas of the body where ice could form.  Later they produce glycerol which lowers the temperature at which they could freeze.  And finally they start to lose water in their bodies.  So basically a natural process starts that replaces the water in their bodies with antifreeze just like you winterize your car.

The Upis beetle's strategy is to tolerate freezing rather than avoid it, but has a complex sugar antifreeze that reduces the temperature at which ice forms to about 19 degrees.  It is also capable of forcing the water outside of its cells so that when it does freeze there is no damage to the cell membrane.  When it thaws out, it's just fine.

Other insects and some fish also are capable of producing antifreeze so that they can survive temperatures colder than freezing.   But the Upis beetle and the red flat bark beetle are the real superstars of surviving frigid temperatures.

Bodacious Black Bears

I mentioned in a recent post (see The Historic Hudson) one of the reasons I enjoyed visiting my friends in New Jersey.  A second reason I enjoy my visits to New Jersey is the possibility of seeing bears!  You probably don't associate New Jersey with bears, but my friends live right on the New Jersey/New York state line in a wooded area and they occasionally see bears right in their front yard.  Okay, sometimes in the back yard too, but see them they do.  The adult bears are very impressive and the little cubs so cute!  Here is a photo of a bear walking up Lynne and Rick's driveway; Lynne calls her Fertile Myrtle - I think you'll understand why!

Photo by Lynne Robinson

You may be wondering whether a mom with five cubs is a bit unusual.  I don't think Lynne had ever seen that many cubs before, but in fact, a black bear can have up to 6 cubs.  However, two cubs are the most common.  Some scientists believe the number of cubs depends on the availability of food.  There must be really good food in Lynne's neighborhood.

I've only seen bears from a distance a couple of times, but the most memorable viewing was maybe a little too close for comfort.  One evening right at dusk, we were all sitting in Lynne and Rick's living room watching TV when all of a sudden Lynne whispered loudly, 'There's a bear on the deck!"  Rick and I both turned to look and sure enough, there was a young bear climbing up on an urn attempting to get seeds out of the bird feeder.  The sofas where we were sitting were right next to the sliding glass doors that go out to the deck, so this little bear was literally just feet away from us.  Where there's a young bear, there's a pretty good chance momma's not too far behind.  Momma bear was on her way up the steps from a lower level.  My friends have three Bernese Mountain dogs, and after watching a few minutes we were all astounded that the dogs hadn't barked with the bears so close.  About the time we were wondering that one of the dogs must have heard or smelled something because the barking started.  The bears lost no time in deciding maybe they'd better hit the road, and both youngster and momma started back down the stairs.  But not before we had gotten a wonderful up close and personal few minutes with them, and certainly something to talk about for the rest of the evening.

Black bears' diets are 85% vegetation and the balance is mostly insects, although they will occasionally eat small animals and salmon if they can find them.  They are not considered endangered because of their wide North American distribution, although the majority are found in Canada.  They are also good opportunists and do well in fragmented habitat and, obviously, near human communities.  Black bears are not true hibernators, but are much less active in the winter.  You can go here for more information about black bears.

Here are a few more pictures of the New Jersey bears.  If you'd like to hear more about my friends' bear encounters, you can go to Lynne's blog.  On the right hand side, there is a category list.  You can click on Bears for recent posts and also Bear Diary for her older entries.  Enjoy and thanks, Lynne, for letting me share your great photos and thanks for the great title for the post!

Photo by Lynne Robinson

Photo by Lynne Robinson

Leapin' Lizards!

I mentioned in my previous post on colugos that the program I watched focused on gliding reptiles.  Two of the reptiles mentioned in the show are the Draco lizard and the Paradise tree snake.

While the show focused on animals in the Malaysian rain forest, there are about 30 different species of draco lizards that live in various parts of southeast Asia.  Like the colugos they too have membranes attached to their bodies supported by 5 to 7 'ribs' that allow them to glide through the trees for up to 25 feet.  (A fossil found in 2007 shows that these 'flying lizards' have been around for over 100 million years.)  One species is known as the flying dragon.

Source: indonesiatraveling.com

It eats ants and termites it finds in the trees and the only time it's found on the ground is during mating season when the female lays its eggs.

Draco lizard, Photo by: Premaphotos, Alamy  Source: nationalgeographic.com

The paradise tree snake is one of several species of tree snake that can leap from tree to tree or from tree to ground by gliding through the air.  After it launches itself into the air, it spreads its ribs and flattens its body actually making it concave to 'catch more air'.  Right before landing on the ground, it lowers its tail to help break the fall and raises its head to make sure it doesn't take the brunt of the landing.  Isn't this an absolutely gorgeous snake?

Source: naturemalaysia.com

It has weak venom, strong enough to paralyze the smaller animals it preys on, but harmless to humans.  Its main prey is tree dwelling lizards.  Hmm.  Like draco lizards for example?  Since the lizard has to ability to glide through trees to escape predators, perhaps that's why the snake has also developed a way to 'chase' after them.

Source: livescience.com