Cetology
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Branches of Zoology |
Cetology |
History |
post-Darwin |
Cetology is the branch of marine mammal science that studies the approximately eighty species of whales, dolphins, and porpoise in the scientific order Cetacea. The term was coined in the mid-19th century from the Greek cetus ("whale") and -ology ("study").
Cetologists, or those who practice cetology, seek to understand and explain cetacean evolution, distribution, morphology, behavior, community dynamics, and other topics.
Contents |
[edit] History
Observations about Cetacea have been recorded since at least classical times. Ancient Greek fisherpeople created an artificial notch on the dorsal fin of dolphins entangled in nets so that they could tell them apart years later.
Approximately 2,300 years ago, Aristotle carefully took notes on cetaceans while traveling on boats with fisherpeople in the Aegean Sea. In his book Historia animalium (History of animals), Aristotle was careful enough to distinguish between the baleen whales and toothed whales, a taxonomical separation still used today. He also described the Sperm Whale and the common dolphin, stating that they can live for at least twenty-five or thirty years. His achievement was remarkable for its time, because even today it is very difficult to estimate the life-span of advanced marine animals.
After Aristotle's death, much of the knowledge he had gained about cetaceans was lost, only to be re-discovered during the Renaissance.
Many of the Medieval texts on cetaceans comes mainly from Scandinavia and Iceland, most come about around the mid 13 century.
One of the more well known one is Speculum Regale. In this text is described various species that lived around the Island of Iceland. It mentions "orcs" that had dog like teeth and would demonstrate the same kind of aggression towards other cetaceans as wild dogs would do to other terrestrial animals. The text even illustrated the hunting technique of Orcs, which are now called Orcas.
The Speculum Regale describes other cetaceans, including the Sperm Whale, and Narwhale. Many times they were seen as terrible monsters, such as killers of men, and destroyers of ships. They even bore them odd names such as "Pig Whale", "Horse Whale", and "Red Whale."
But not all creatures described were said to be fierce. Some were seen to be good. Such as the whale that would drive shoals of herring towards the shore. This was seen as very helpful to fisherman.
Much of the early studies of Cetology was based off dead specimens and myth. The little information that was gathered was usually length, and a rough outer body anatomy. Because these animals live in water their entire lives, early scientists did not have the technology to go study these animals further. It wasn't until the 1500's that things would begin to change. That cetaceans would be proved to be mammals rather than fish.
Aristotle, as said above, argued they were mammals. But Pliny the Eldar stated that they were fish, and it was followed by many naturalists. It wasn't until Pierre Belon (1517-1575) and G. Rondelet (1507-1566) came along and persisted on convincing they were mammals. They argued that the animals had lungs and a Uterus. Just like Mammals do. It would not be until 1758 when Swedish botanist Carolus Linnaeus (1707-1778) published the tenth edition of [[Systema naturae]]. It was then that they were seen as mammals.
Only decades later, French zoologist and paleontologist, Baron Georges Cuvier (1769-1832) described the animals as mammals without any hind legs. Skeletons were put together and displayed in the first Natural History Museums, and on a closer look and comparisons with other extinct animal fossils led zoologists to conclude that cetaceans came from a family of ancient land mammals.
Between the 9th-20th century, much of our information on cetaceans came from Whalers. Whalers were by far the people who knew most about the animals. But this information only went from Migration routes to an outer anatomy, and only little information of behavior.
When the 1960's came around, it was then that people started studying the animals intentabily. This came from both concern about wild populations and also the capture of larger animals such as the Orca, and gaining popularity of dolphin shows in Marine Parks.
Now even today, the study of cetaceans is hard to get into. Very little colleges. And the ones that do, are not that in depth or only go for half the year. Most studies of cetology are privately owned and underfunded.
[edit] Studying a Cetacean
Scientists have a hard time studying an animal that can only be seen every so often, and it becomes harder when that animal is so adapted to life in a world that humans are not.
Cetaceans only spend 10% of their time on the surface, and all they do at the surface is breath. There is very little behavior seen at the surface.
Another thing it is impossible to find any signs that an animal has been in an area. Cetaceans do not leave tracks that can be followed, nor do they leave dung that can tell important information about their diet. Many times Cetology is sitting, waiting and paying close attention.
Cetologists use equipment that includes hydrophones, to listen to calls, of communicating animals. Binoculars, and other optical devices for scanning the horizon, cameras, notes and a few other devices and tools.
[edit] Identifying Individuals
When scientists needed to know about an exact population number it was then obvious they needed to find a fool proof, yet easy way to find individuals.
One system that has worked rather well, is Photography. This system is highly popularized by Mike Bigg, who was a pioneer in modern Killer Whale research. During the mid 1970's Mike Bigg, and Graeme Ellis, photographed local Orcas in the British Columbian seas. After looking at the photo's they relised they could recognise certain individuals by looking at the shape and condition of the Dorsal fin, and also the shape of the Saddle Patch. These are the same as human fingerprints, for not one animal looks exactly like another. After they could recognise the certain individuals they then found that the animals travel in stable groups of pods.
The system has worked well, in Humpback whale studies as well. Colors of the Pectoral fins, and color of the fluke are what researchers use to find individuals. Even scars from orca attacks are found on the flukes of Humpback Whales, and are crucial to identifying an animal.
It still stands that most of the time researchers use photo identification to find individuals and, if necessary, a group. Much of the time in includes pictures of the Dorsal Fin, Saddle Patch, Flukes, Pectoral fins, and other noticeable features.
No branch of zoology is so much involved as that which is entitled Cetology
– William Scoresby (as qtd in Moby Dick)
[edit] Sources
- Whales: Giants of the Sea, 2000
- Transients: Mammal-Hunting Killer Whales, by John K.B. Ford $ Graeme M. Ellis, 1999