Behavioral Episodes in Relation to Leopard Seals Essay
- Length: 5 pages
- Sources: 5
- Subject: Animals
- Type: Essay
- Paper: #38843229
Excerpt from Essay :
Behavioral Episodes in Relation to Leopard Seals
Leopard seals are widely known for their ferocity and have been acknowledged as top predators for a long time now. These are large but slender mammals, with females usually exceeding males in size and weight. The spotty coats, distributed along their bodies, define the leopard appearance and allure to the hunting abilities they possess. With powerful jaws and canine teeth, leopard seals can prey on creatures of whatever size. Their agility and reputation have long formed individuals' negative perception upon the former. This document is to try to dismantle the negative image leopard seals have been inoculated with for such a long time. This proposal looks at some of the facts that have led people forming drastic opinions as well as some episodes that appear to indicate how little we may in fact know in relation to leopard seals.
Statement of Problem
Explorers in the Antarctic have often expressed their opinions as to the dangerous nature of leopard seals (De Laca et. al, 1975, p. 85). Threat displays, unexpected attacks, these have all been familiar to researchers since the first Antarctic expeditions. In 2003 however, when a leopard seal attacked and furthermore, drowned a marine biologist, all expeditions were delayed temporarily. Never before had a leopard seal killed a human being. This was concerning for all explorers since it became obvious that precaution measures needed to be evaluated and updated.
I propose to review some relevant information in relation to the unpredictability of the leopard seals. Hence, the following leads will be considered:
1. provide general information in regard to leopard seals that will relate to the mammals' hunting abilities.
2. indicate that it was unusual that a leopard seal killed a human being and that this is not a specific behavioral pattern.
3. present a relevant case that leopard seals can indeed be opened to interactions with human beings.
Use of sources
The two main sources that provided the information necessary to conduct this inquiry come from the Antarctic Journal of the United States and Antarctic Science. Both are articles, the former by De Laca, T.E., Lipps J.H., and Zumwalt G.S., and the latter by Muir, S.F., Barnes, A., and Reid, K., focusing on various incidents in regards to human beings' interactions with leopard seals. Other subsequent sources included ? Leopard seal predation rates at penguin colonies of different size, ? An article by Ainley, D.G., Ballard, G., Karl, B.J., and Dugger K.M., which was useful to include information on leopard seals' diet, another article by Hiruki, L.M., Schwartz, M.K., and Boveng, P.L., entitled ? Hunting and social behavior of leopard seals (Hydrurga leptonyx) at Sea Island, South Shetland Island, Antarctica? was relevant to understand some behavioral characteristics of the mammals; finally, ?Quantifying the sensitivity of Arctic marine mammals to climate-induced habitat-chance? By Laidre, K.L., Stirling, I., Lowry, L.F., Wiig, O., Heide-Jorgensen, M.P., and Fergunson, S.H. related to our intention of emphasizing the threat that leopard seals are exposed to due to man made induced environmental factors.
In the Antarctic, between the coastal and marginal ice zones, pieces of consolidated ice, rougher, thicker, and stronger than in the other two areas, are referred to as pack ice. This is the predominant space where the leopard seals would be resting, hunting, birthing, or escaping other predators. It was not until recent years that these mammals received genuine interest. And the facts and assumptions seemed to revolve around one idea alone: exclusively and undoubtedly, the former were top ferocious predators in the Antarctic biomass. Expeditions conducted within the past few decades however have revealed that there is also something delicate about leopard seals that seems to counterbalance the negative image so very often and regularly perpetuated. It is the purpose of this essay to extract and indeed emphasize on some of the general conditions and the particularities that define leopard seals.
The scientific name of Hydrurga leptonyx reveals the most common and specific features of these mammals: 'slender -- clawed water -- workers.' Having an average body length of between 2.5 and 3.2 m and an average weight of 200 to 455 Kgs, these marine mammals are similar in regards to their predator skills to the polar bears in the Arctic. Females usually exceed males in size and weight. Nevertheless, these are slender creatures, with an evenly distributed weight, but which do posses most of the wideness at the shoulders area. The front flippers that are also used for swimming have clawed extensions. Although the hint and fore flippers are what permit the swimming process, the leopard seals move graciously and indeed possess an outstanding maneuverability that leave the impression of snake -- like movements. Their common name is given by the spotty coats. Leopard seals are grey along the back, with a lighter grey in the proximity of the flanks, and even lighter at the undersides and have dark spots, which can be distributed differently from one animal to another, and which preserve the leopard appearance. No doubt, the name alludes as well to the mammals' hunting abilities.
In 1975, De Laca et al. acknowledged that the leopard seal ?has a rather sinister reputation among some Antarctic explorers. (p. 85) In 2003, this became particularly evident and concerning when a marine biologist died after being attacked and drowned by a leopard seal. Following the inquest by the coroner, the incident was registered as accidental death and ?a reminder of the dangers encountered when conducting research in the Antarctic. (Muir et al., 2006, p. 62) This unfortunate event however served for the gathering of more detailed information in regards to interactions among leopard seals and humans. Leopard seals' social behavior had been studied previously in some occasions and Hiruki et al. (1999), following their study of hunting and social behavior of the mammals, concluded these are indeed solitary creatures (p. 106). However, their investigation revealed that ?interactions between leopard seals, though not common, have been observed, mostly in situations assumed to be mating or playing contexts. (Hiruki et al., 1999, p. 106) While understanding how leopard seals interact among themselves would not necessarily provide accuracies as to their behavior toward humans, it is nevertheless important to consider these interactions or for that matter, the lack of them, to at least make assumptions. Later considerations regarding the death of the marine biologist assumed the leopard seal had been drifted on pack ice and thus separated from its food sources. As a consequence, and being subjected to starvation, it launched its attack. Leopard seals are carnivore and have a diet consisting of mostly warm blooded prey. They would hunt penguins, with the Adelie penguin being ?the primary prey of leopard seals, (Ainley et al., 2005, p. 335), fish, krill, smaller seals, cephalopods, and crustaceans (as cited in Muir et al., 2006, p. 62). Hiruki et al. identified some of the hunting methods of leopard seals as stalking, rapid approach with wave, or open hunting (1999, p. 100). Moreover, Hocking et al. (2013) concluded that leopard seals have ?the ability to feed on both large and extremely small prey [is] thought to be dependent upon their use of specialized dental morphology. (p. 212). Further, ?besides hunting both large and small prey, leopard seals seem capable of changing feeding modes when feeding on these two disparate size classes of prey, allowing them to take advantage of whichever prey is locally available. (Hocking et al., 2013, p. 212) This would substantiate the idea that food is an influential factor regarding leopard seals and human interactions especially when the former have been deprived of any opportunity to hunt for extended periods of time. Indeed, it was concluded that ?the seal that attacked Kirsty Brown [the marine biologist] displayed hunting behavior? (Muir et al., 2006, p. 72) and that the seal was ?atypical. (Muir et al., 2006, p. 73) This is not to say that hunting prospects solely influence leopard seals' behavior. Indeed, De Laca et al. acknowledged that ?leopard seals occasionally have confronted humans, ? (1975, p. 86) but that these ?seem unaggressive when surprised on ice. This could be related to the fact that their hunting abilities are less vigilant outside water. Countless interactions between humans and leopard seals have been registered throughout the years, both underwater and on ice, and it is understood that ?their behavior undoubtedly is highly complicated? (De Laca et al., 1975, p. 90) and that ?they obviously pose a potential danger to humans. (De Laca et al., 1975, p. 90) This is indeed true but some of the explorations have also served to reveal intriguing behavioral characteristics of leopard seals in regards to their interactions with humans.
As an explorer in the Antarctic, specifically interested in studying leopard seals, one would be all too aware of the unpredictable behavior these reveal. At a distance or perhaps gazing at mere images, one might be led into thinking this impressive mammal with cute face features would unlikely have killer instincts that resemble those…