Dolphin Culture

There has been an ongoing debate in science as to whether or not animals have culture for well over a century. Now when I say culture here, I am not talking of sophisticated manners. Instead, I am speaking of unique behaviors taught or learned within specific groups. Intelligence in nature it would seem, is a subject that many are a bit uncomfortable with. If we have always defined what makes us human as our intelligence and our culture, than what does it mean if we recognize that other animals have not only extraordinary problem solving capabilities, but culture as well? Such a question is probably better left for another blog on the web of course. But this is very relevant when we are learning and teaching about Tursiops truncatas, or the bottlenose dolphin.

In the wild, there is a constantly evolving dance between predator and prey – each in evolutionary motion trying to stay one step ahead of the other. As a predator adapts in ways to advantage itself, those prey, if they are to survive, adapt in turn either physically or behaviorally in new ways to elude the would be predators.

The Currituck Shooting Clubs – article for NCBeaches by OB Expeditions’ own Jared Lloyd

Have you ever sat quietly in a marsh before sunrise? Have you watched as the Homeric rosy finger tips of dawn stretched out across the sky before you and a hidden world where land and water combine comes to life? This is a world unknown by most. It is an experience lived by only a few, these days – the story of Earth awakening.

An arctic mass of air pushed down over top of the Outer Banks a couple days ago and the mercury subsequently plunged into the twenties. The sun has not yet risen, stars continue to illuminate the world, and I find myself laboring my way through knee deep water this January morning. Behind me, attached to a thin strand of rope, I float the tools of my profession in a black plastic tub. Tripod, chair blind, binoculars, water proof bags containing an assortment of camera gear, and most importantly of all, coffee. When you plan to sit waist deep in water that you must break ice to move through, coffee is crucial.

Bottlenose Dolphins and Biosonar

Dolphins have a pretty amazing way of handling the problem of finding food and finding their way around in the oftentimes murky lightless depths of the world’s oceans – sonar. A lot of folks like to refer to this as echo location, which is really more of a description. Either way though, this is some pretty cool technology that dolphins have been wielding and working out the kinks on for some twenty million years!

Basically, dolphins send out a series of sounds – often heard by us as clicks and squeaks. Sound moves 4 times faster in water than it does in air, so navigating by sound makes for a pretty effecient way of doing things. Once the sound hits an object, the sound waves then bounce back. This is why people call it echo location. Humans can hear echos of course, but we sure can’t navigate by it. Dolphins on the other hand are able to Pick out an object the size of an orange from nearly 80 meters away. For those that don’t live in metric world – that is a whopping 262 feet! At shorter distance they are able to differentiate between a BB and a kernel of corn!

Dolphins therefore have a highly adapted way of perceiving sound. To give you an idea of this, humans can hear sounds as high as 20Khz. Dogs on the other hand can hear up to 45 Khz. This is why a dog whistle is completely silent to humans as the sound is to high of a frequency for use to pick up on, but dogs love it. Now a dolphin on the other hand can hear up to an amazing 120 khz with echo location! That’s 6 times what a human can hear. In order to accomplish this feat however, dolphins are not using ears like dogs and humans. Instead, dolphins, like all members of the family of toothed whales (known as odontocetes), have developed a highly specialized type of blubber known as acoustic fat. This fat is what makes up the big giant forehead on dolphins for which the clicks and pops are coming from. Along their lower jaw, they have another strip of this acoustic fat for which is designed to receive the echo coming back at the dolphin. Now just how dolphins are able to interpret what they hear with this biosonar, we have pretty much no clue. This is one of the great mysteries of marine biology which is one of the reasons that dolphins are so fascinating to us.

Just one of the many things that you will learn on one of Outer Banks Expedition’s Dolphin Watch Adventures

 

The image above gives you something of a diagram of how the dolphin is able to use echo location. Below is a really neat video on the subject as well that we highly recommend checking out.

 

Shifting Sands – article in Wildlife in North Carlina by OB Expeditons founder, Jared Lloyd

In 1585, when Sir Richard Greenville first stepped foot upon the barrier islands of North Carolina, he walked into a world wholly different from the lavish resort communities that we now know as the Outer Banks. Aside from the glitz and trappings of a vacation destination, the barrier islands of the days of English exploration were far more numerous and restless than the seemingly subdued versions we sunburn on today. As mere ribbons of sand, the age old axiom of “change is the only constant” is not simply a cliché on these beaches but a law of physics.

With each passing storm, the emerald green waves of the Atlantic that rush upon our beaches turn back another page of history that the sands have hidden beneath their all encompassing embrace. The beaches of our islands are littered with the results: tree stumps protruding from the edge of the surf, clay, pebbles, rocks, coquina boulders, shelves of ink black peat moss, and chunks of coal. Even the shells have their story to tell if only one would listen.

The eyes have it

The avian world is a kaleidoscope of colors. Every possible hue of color imaginable is found upon birds, and the study of this color and its evolutionary functionality is at the heart of one of the larger branches of ornithology. What makes birds colorful, why display such colors especially when they make you an obvious target for predators? These are the questions that researches such as Geoffry E. Hill of Auburn University have devoted their life’s work toward trying to understand.

One of the most puzzling aspects of bird coloration however is eye color. Like the plumage of the birds, eye color seems to come in nearly every possible color as well. Canary Yellow, Mandarin orange, scarlet red, coal black, you name it and you will find it as prominantly displayed in birds as the showy feathers they use to attract mates.

Carolina Tea

Animals have developed an ingenious way of handling problems like competition or attack. We simply move away from the offense. Such a simple act of course, walking or flying away in order to free ourselves from intolerable pressures. We really do take this for granted. Yet what of plants? Some such as Russian tumbleweed exercise the freedom of mobility, but most others are bound to one spot. Inevitably other plants move in around them. Competition becomes intense for those necessities of life such as water, sunlight, and nutrients. Animals come and graze upon the leaves. Insects infest. Plants are therefore bombarded by a litany of attacks from both kingdoms of life. Through it all, most stoically they sit and endure it would seem.

This is an illusion of course. Plants are not adopting Christian teachings of turning the other cheeks. Plants are fighting back. They are constantly at war. Chemical warfare is being waged all you as you read this. In the Darwinian battle for survival, pacifism is extinction.

Autumn Color

October for much of North America is a time of great change. It is a time of casting off the oppressive heat of summer and preparing for the inevitable return of old man winter. October is also a time when the dramatic color of fall begins to sweep across the landscape, inching its way down from the far North. Fingers of scarlet and gold stretch down the spine of the Appalachian Mountains slowly embracing the East in a kaleidoscope of vivid colors, as if nature in all its beauty and grandeur demands to go out with a bang, before succumbing to the dreary bleakness that befalls the eastern deciduous forests in the winter.

Salt

Salt on a barrier island is the grand orchestrator of all life. If you cannot adapt to it, you cannot live here. This goes for plants, animals, and even people. Salt encases everything. Its the reason your car begins to rust as soon as you bring it to the Banks, its the reason we are constantly refilling our windshield wiper fluid out here. Sometimes I think I should own stock in the wiper fluid industry considering the hundreds of dollars I spend on the stuff.

For animals though, the problem of salt is not a simple matter. The problem with salt is that we need salt to survive but like anything else, too much of a good thing can often kill you. Therefore one of the greatest adaptations that any animal must make in a salty environment is the ability to overcome the issue of salinity. And with some 75% of the Earth covered in salt water, this is a major hurtle for many species. Birds, reptiles, and mammals all have different and fascinating ways of handling this problem – and each one is an extraordinary testament to the adaptability of life on Earth.

Animal Magnetism

Migration is about two things: filling bellies and having babies. Imagine that, migratory species are driven by the same two basic things that motivate guys. What else would be pressing enough to convince anyone to risk life and limb each year to undertake an epic journey that statistically speaking you may not  survive? With October now right around the corner, the fall migrations are fully upon us. Birds, fish, whales, sea turtles, monarch butterflies, and everything else that needs more than the landscape has to offer come this time of year is on the move.

Migration in species is one of the most baffling and least understood behaviors in science. Even though migration this time of year is just simply moving from one food source to another, why do animals make the monumental treks that they do when food is available elsewhere? Why and how do they take the same route each year. There are birds that leave Alaska, fly over to the Atlantic coast, then south, and back west again into Mexico. Why not just fly south? How do these species manage to navigate?

Hurricane Earl

Hurricanes are a fact of life in the Southeast. Category 5 storms are the most powerful and destructive weather events on Earth with the ability to completely erase human existence from the coast. As I write this, Hurricane Earl is some 300 miles south of the Outer Banks and is churning our way. With maximum sustained winds of 145 mph at the moment, this storm is a category 4 storm. If we see a 10 mph increase in winds, Earl will become a 5. The roads are clogged with visitors frantically trying to leave under the mandatory evacuations for all of the Outer Banks. The skies have become overcast, the winds are beginning to pick up, and the inevitable barrage of news vans and storm chasers have once again descended upon our islands.

These storms have always been one of the driving forces behind the geology, ecology, and even the history of these barrier islands, the sounds behind them, and the mainland beyond those. Flood plain swamps have evolved along the mainland side of the sounds to handle the extraordinary amounts of water that suddenly race inland with the powerful northeast winds of the leading edge of these storms. The geological study of these barrier islands is called coastal geomorphology due to the never ending change that occurs when these islands migrate westward with every major storm that washes over. As these storms move up the coast, the trailing edge of the low pressure system switches back around to the southwest and all of that water that has been building along the mainland suddenly comes barreling back towards the barrier islands. This backwash effect is what causes inlets to form on these islands when the sound overwashes to the ocean, stripping the islands of sand.