Mark Grossman: Meet the “Air Shark” – Tigerfish Catch Birds in Flight

24 January 2014

African Tigerfish jump out of the water . . . into the air . . . and catch birds in flight.  Tigerfish, in a storage lake for the Schroda Dam in South Africa, were caught, on video, grabbing barn swallows out of the air.


Sometimes called the “African piranha,” the tigerfish is a scary looking fish.  [image]  However, the tigerfish and piranha are two different species with the tigerfish winning contest as the bigger and meaner of the two.   Like piranhas, tigerfish have “interlocking, razor-sharp teeth”, “are … extremely aggressive … predators”, and “often hunt in groups.”  Both species have been known to attack humans.  But unlike the relatively small piranha, an individual tigerfish weighs about 110 pounds.


The story of the tigerfish jumping out the water and grabbing birds, in flight, has been around since the 1940’s.  But, for the first time, an “air-feeding” tigerfish has been caught on video.

Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa, was part of the team that caught the tigerfish feeding on birds.  He said that the whole “event” happens so fast that it took a while before the researchers were sure what they were seeing.

It didn’t just happen fast.  It happened often.  They saw 20 “catches” the first day and about 300 during the next two weeks.  The “event” was caught on video for the first time by team member Francois Jacobs.  The team’s findings were published in the Journal of Fish Biology and

Tigerfish catches bird video shocks scientists worldwide

The tigerfish favors the twilight as the time of day for hunting birds in flight.  This fish has two varied approaches to the hunt.  Sometimes, the tiger will swim near the surface of the water following the birds, in flight, before jumping up into the air to make a catch.  Other times, the fish will lurk in the deeper water tracking the birds.  Then, it will leap out of the water and ambush a bird as it flies by.

Smit is amazed at the skill displayed by the fish in spotting and pacing the birds from the water.  Not only does the fish have to estimate and exceed the birds’ speed, but the tiger has to compensate for the light refraction in water.  This is quite a trick. The angle of the light changes when it passes from the air into the water.  This makes estimating the location and speed of objects in the air a lot tougher.

This has been quite a year for videos catching aquatic animals feeding out of the water.  First, Julien Cucherousset of Paul Sabatier University caught catfish on video in France’s River Tarn as they practiced their recently acquired skill of jumping out of the water to grab and eat pigeons wandering on shore.  Then, an octopus was caught on video leaving the ocean for a stroll on a California beach in search of meal.  And, now, a fish leaps into the air to catch birds — in flight!

Catfish hunt pigeons in France

Octopus Walks on Land at Fitzgerald Marine Reserve

Where will it end?

Maybe it hasn’t.

In another recent “photo first,” Jun Yamamoto of Hokkaido University and his team recorded squid leaping out of the ocean just off the coast of Japan.  These “flying” squid travel almost 100 feet before reentering their water.  Not only do these flyers extend their legs and gills, like wings, to stay airborne, but they actually flap their fins for some added “bird-like” lift.

Flying Squid [image] [video]

Squids ‘can fly 100 feet through the air’

You have to wonder (or worry) what’s going to be walking or flying out of the water next.



Mark Grossman: Bees – Little Robots or Thinking Beings?

16 January 2014

Could bees be more intelligent than we think?  We’ve been hearing about a lot discoveries in the area of animal intelligence.  It’s one thing to speculate about the intelligence of birds and even octopuses, but insects?

Well, at least one group of scientists has tried to “look into” the question.  I say “look into” because, with insects, it’s difficult to come up with anything even remotely resembling a standardized test.  So, the researchers began by biting off a piece that scientific testing “could chew”: Do bees have individual personalities?

A research team at the Queen Mary University of London designed an experiment in which they observed the foraging preferences of bumblebees.  However, the experiment was not designed to test the general foraging preferences of the bees, as a group, but the individual preferences of the individual bees.   In other words, let’s look past the swarm and ask: what’s on the mind of the lone bee in the crowd?

The team of researchers, Helene Muller, Heiko Grossmann, and Lars Chittka, released bumblebees into an enclosed space with artificial flowers of different colors.  The idea was to see if individual bees had their own individual favorite colors.  Do some bees prefer one color while some of their peers prefer other colors?   The researchers measured how quickly individual bees approached flowers of a certain color, and how long individual bees stayed at flowers of a certain color.

In a paper published in Animal Behavior, the team reported finding no difference among the individual bees’ observed “preferences.”  The result suggests that bumblebees do not have individual personalities.   Of course, this doesn’t end the investigation.  There may be future studies with other tests based on other criteria.  But, for now, if you’re in advertising and bumblebees compose your target market, it makes no difference what colors your product comes in.

One interesting aspect of the experiment or, perhaps, interesting aspect of bee species, themselves, is the difference between the hive-less loner — the bumblebee – and its more social cousin — the honeybee.  All bees are social, but bumblebees live in relatively small groups in nests that are abandoned and rebuilt on a yearly basis.  These bees tend to forage for food alone.  In contrast, honeybees live in densely populated hives, which will remain their home from birth to death.  Honeybees travel and forage for food in swarms.

What difference does sociability make?  Well, maybe none.  However, the development of human intelligence has long been attributed to the necessity for social interaction.  In other words, because humans developed social groups in order to survive, they were compelled to develop intelligence in order to interact with other members of the group.

If the relationship between intelligence and social interaction were the rule, the bumblebee subjects of this latest study would be the “less intelligent” species when compared to their more social cousins, the honeybees.  So, maybe the colored flower test should be performed on the honeybees because these bees are more social.  That means they must be more intelligent.  Right?  Well, maybe it’s not that simple.

Perhaps, human intelligence did develop in response to social interaction with the result that human researchers assume that this is the only way intelligence could develop.  The social interaction “rule” has been seriously challenged by the high levels of intelligence displayed by one of the most unsocial animals on earth: the octopus.

Octopuses have virtually no social interactions with members of their own species.  These creatures, literally, meet their peers only briefly to eat them or mate with them.  Both process result in the death of either one or both of the guests at the party.  (With octopuses, mating is followed by the swift death of both participants.)  That’s the social life of the octopus.  Period.

Perhaps, just because human intelligence developed out of the necessity for social interaction, human researchers have a built-in prejudice in favor of social intelligence.  And, perhaps, it was just this prejudice that blinded human researchers to the clear displays of octopus intelligence – at least until relatively recently.  What got the unsocial octopus noticed?  Its use of tools.  The octopus displays an amazing repertoire of tool selection, retention, and use and, also, displays a remarkable ingenuity in its interactions with its inanimate environment.  So, social intelligence certainly isn’t the only type of intelligence.

See: “THURSDAY: A Different Flavor – Just How Smart Are Octopuses?

Given the amazing intelligence of the loner octopus, perhaps, the more intelligent bee species would be the (relatively) lone bumblebee.  Forced to develop its individual initiative through ages of lone foraging, perhaps, the bumblebee has developed a resourceful intelligence.   But is intelligence the same as personality?

While no one knows the answer to these interesting questions, the “The Best Bees Company” added some interesting suggestions based on their own interactions with bees and bee keepers.

In their experience, different hives seemed to have different “personalities.”  The honeybees of one hive “hoarded” pollen – gathering and storing it in large quantities.  But the bees of another hive seemed to prefer gathering and storing more honey in preference to pollen.  While noting that these and other differences could be attributable to different environments, or even genetics, the authors make an interesting suggestion with a question.

Could individual hives, rather than individual bees, develop personalities?  As the authors put it, could there be a “personality” distinct to each hive’s “social super organism?”  From yet another angle, could the “whole” be more than the sum of the “parts.”  That is, could the “whole,” hives and swarms, consistently develop and display particular behavior patterns distinct from other hives and swarms.  In contrast, the “parts” alone, the individual bees, display no apparent individual behaviors?

See: “Individual personality in bees? Animal consciousness? Cool research.

Well, all of these are interesting questions.   Experienced observation together with the earliest research predictably seems to provide many more questions than answers.  At this point, the puzzle boils down to whether or not bees (and all insects) are, intellectually, “little robots” or “thinking beings.”