Wednesday, 18 April 2012

Orca Communication

Orca Communication

            Many of us wonder what our pets are saying. Over time we learn what they want by their actions, but we never understand fully what they are saying. It’s the same for spectators and wild animals. Each species has its own language, almost like different cultures and back grounds of humans, but unlike animals we have a common language; English.

            Orcas are remarkable creatures and communication lies at the core of orca social awareness. Family members are seldom out of ear shot of other family members. Orca calls can be as loud as jet plane engines and they echo over miles and miles in the ocean. In a pod, every orca knows where he or she is, and where the others are. Each orca in a pod shares a high attachment to one another, and given this strength of attachment, communicating to each other and knowing where everyone is must be quite calming to them. Communication is essential glue to maintaining harmony in an orca community.
            Orcas make three different types of vocalization: clicks, whistles, and pulsed calls. The clicks are part of the orcas sonar and are used for echolocation; for finding and locating food sources, for defining other objects in the ocean, and for locating where the orca is in its environment. An orca echo locates by producing clicks and then receiving and interpreting the resulting echo. The click trains pass through the melon (the rounded region of an orcas forehead), which consists of fats.  Echo locating orcas can determine the shape, distance, size, direction, speed, and even some of the internal structure of objects around them in the water. Whistles are typically continuous tone emissions that can last for many seconds. The melon acts as an acoustical lens to focus these sounds into a beam, which is projected forward into the water ahead of the orca.  Resident orcas use whistles as private signals during close-range communication. Pulsed calls are the most common vocalization of orcas. Other experts think pulsed calls are used in group recognition and coordination of behavior.  Calls that sound the same time after time are known as stereotyped calls.
            Calls, simply put, are pulsed signals that have discreet patterns that can be recognized by ear and spectrogram. They are the main component of the orca communication repertoire. Each pod has its own select dialect which differentiates one pod from another. After recognizing that each pod has its own “dialect,” john ford was able to group pods with similar dialects into larger groups, which he referred to as ‘clans’. The sound of the calls is created by moving air between their nasal sacs in the blowhole region. Humans make sound by forcing air through the larynx, and the vocal cords in the larynx vibrate as air flows across them, therefore producing sound. During some vocalizations an orca will release air through the blowhole creating bubbles, but this is most likely just a visual display. Creating bubbles during communication is not actually needed.  An orca can produce sound form at least two separate sources in its complex of nasal sacs.
            A calf learns a repertoire of calls selectively from its mother and can vocalize within days of its birth, but vocalization matures with age. The first calls of a calf are known as screams, they are high pitched and unlike any calls of adult orcas. In about two months a calf can produce their first pulsed calls that sound similar to the calls of an adult orca. From about two to six months of age, a calf’s repertoire increases, and the calf will continue to learn calls until puberty.
            An orca, Luna, was separated from his pod as a young calf. He appeared on the coast of Vancouver Island by himself, and he kept coming up to humans and playing with their boats. It’s believed that he wanted to make friends, that he craved attention. He did amazing things trying to create a bond with the humans. Because humans and orcas don’t share the same way of communicating, Luna attempted other forms of communicating. Luna would imitate the sounds of a motor boat in an attempt to talk to the people in the boat. Luna captured the hearts of many humans, by playing tug and rolling on to his side and looking people in the eye. Luna learnt different forms to communicate with the people near him, he would imitate sounds he heard or he would bang the hulls of boats to get your attention, he would imitate motors, or chainsaws, Luna would even slap the water. A young First Nations boy, Jaime, would whistle to Luna and Luna would whistle back. There is a documentary all about Luna called Saving Luna. There are videos all about him on YouTube, the following is just one:  This story tells us that orcas are very intelligent; if they run into a road block they find ways to overcome it.

The following are links to websites containing sounds of different orca dialects and websites in which I found information:
-         Images from Google

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