The Social Behaviors of Fresh and Sea Water Dolphins - Essay Example

The Social Behaviors of Fresh and Sea Water Dolphins s Contents The Social Behaviors of Fresh and Sea Water Dolphins 3 Habitat 3 Mating of Dolphins 4 The Art of Group Hunting 5 Dolphins and Play 5 Defense and Vigils 6 Conclusion 6 Bibliography 8 The Social Behaviors of Fresh and Sea Water Dolphins Documentaries and studies reveal that dolphins are the most social creatures in the seas of the present day world (Iriarte & Marmontel, 2013). They are cetacean mammals that are closely related to the whales and the porpoises. Often, they live and thrive in groups especially when they are involved in the wild. In almost all cases, dolphins are engrossed in group activities. Research studies from various scientists have revealed that the social behavior of dolphins in fresh water medium and salty water medium share not many distinctions (May-Collado & Wartzok, 2007). Even so, there are occasions whereby there are notable differences in their social behaviors. These reactions are studied based on their habitats, mating, hunting, playing, defense and cognitive behavior. Habitat There are about forty species of dolphins that are found in seventeen genera. They vary in sizes and are found worldwide, often, in shallower seas along the continental shelves (Gomez-Salazar, 2011). Dolphins are carnivores that feed predominantly on fish and the sea squid. They belong to the family Delphinidae, which scientists claim to have evolved about ten million years ago in the era of Miocene. It is vital to note that the species of dolphins in fresh aquatic medium and saline medium are different. Analysis will be based on the Pink-river dolphin, which lives fresh waters and is scientifically referred to as Inia geoffrensis, and the Dusky dolphin (Lagenorhynchus obscures) that lives in saline waters. Dusky dolphins are vastly distributed in pods (Gomez-Salazar, 2011). They are predominantly situated in areas of South America and the New Zealand. They are renowned to exhibit and demonstrate greater acrobatic skills than the other species. According to researches and observations from several scholars, the dusky dolphins are capable of adapting to several ecological niches than others species of dolphins. The female dusky dolphin can make a turn of up to 180 degrees during movement that makes them exceptional. The Pink-river dolphins, just as their name suggests, live along the river estuaries especially in Caribbean and the South American rivers (Gomez-Salazar, 2011). They have also been identified to live in flood plains out of the rivers. Occasionally, the Pink-river dolphin exposes aggressions that are not easily explained towards other animals. They can quickly to grow and adapt to the environment. These adaptations are learned from the surroundings and are passed to the next generations through observation. Mating of Dolphins The Pink-river dolphins engage in group mating (Wurtz & Repetto, 2010). They do this by constant rubbing of their bellies on one another. They usually engage in sex for fun. For example, they can be seen rubbing their reproductive organs or parts using their fins. Mating is highly competitive and is a matter of Charles Darwin’s Survival of the Fittest (Gomez-Salazar, 2011). The males become aggressive towards one another, and this is in a bid of winning a female partner. They also engage in supremacy mating battles. This is demonstrated by the carrying of the sticks using the mouth. Dusky dolphins also interact socially when mating as a group (Wurtz & Repetto, 2010). During mating, the adults, who are eligible to mate, will be commonly seen to move along the shores since they are looking for small pods that are the ideal mating sites. One female can mate with several males (Gomez-Salazar, 2011). This is a clear indication that the dusky dolphins have multiple mating partners. There is a likelihood of the males to fight over female mating partners and scientists refer to this as a sperm competition. The female exhibit mixed reactions during mating (Gomez-Salazar, 2011). They can be warmly receptive to the males, or they can be downright hostile to them. It is important to note that Lagenorhynchus obscurus also engage in mating for other reasons other than reproduction like fun. This is closer to being human. The Art of Group Hunting Inia geoffrensis dolphins hunt for food in a group (Orbach, Kirchner & Wursig, 2014). It is of great importance to note that the aggression that they portray during mating is absent during food hunting. Their primary sources of food are crustaceans, crabs, and the shrimps. In case the rivers flood, they extend their ecological niche to the flooded plains as a single hunting group. In other cases, Inia geoffrensis steals fish from the nets and lines of the fishermen and feed on them. Consequently, there often exists a conflict between the Pink-river dolphin and the fishermen. They holistically rely on echolocation as the medium to acquire food and after that utilize their teeth to prey. Lagenorhynchus obscurus always forage for their food individually though they may end up in groups hunting (Whitehead & Rendel, 2014). They are renowned to look for food in the deeper waters during night hours. They predominantly feed in a variety of fish species like the mackerel and the lantern fish (Wurtz & Repetto, 2010). The dusky dolphins have been observed to work in unison as schools of fish where they alternate turns to enter in the rings they form while feeding. When foraging food at hunts, they protect their mouths from being hurt using sponges. Dolphins and Play The Pink-river dolphins are known to engage in group play mainly as a social behavior. Upon being rendered in captivity, Inia geoffrensis portray social relationships with people. Some of these social bonds that are seen to be demonstrated to human beings can be observed from the following of human boats. The Pink-river dolphins also travel together while playing. The Dusky dolphins demonstrate play as elements of social behavior through aerial stunts that are carried out in groups (May-Collado & Wartzok, 2007). They are involved in many acrobatic jumps in the air as they leap back in the water with the head going first into the water. The female Dusky dolphins can be seen to swim in the company of their playful calves. Other males form friendship bonds that glue them together and are precisely aimed at hunting of females since they exhibit a polygamous sexual relationship Defense and Vigils The Inia geoffrensis (Pink-river dolphins) can sleep while one hemisphere of their brain is very conscious for security purposes (Iriarte & Marmontel, 2013). This enables them to detect predators and seek a defensive plan. They also defend themselves in groups by utilizing high pitch sounds (White, (2007). Other species of the dolphins for keep vigils in turns whereby one group is awake as the other sleeps for security (White, (2007). The Lagenorhynchus obscurus often maintain their pods just to ensure that they are safe and favorable for habitation. Encephalization Quotients in Dolphins Studies show that the brain capacity of the Pink-river dolphin is about 40% greater than that of human beings. Encephalization quotient is viewed to be responsible for the dolphins’ cognitive roles. For example, the dolphins use it in identification of schools of fish. The Dusky dolphins have a larger encephalization quotient (Samuels, 2014). This is evidently portrayed in the manner in which they round up and stay closely adjacent to each other as they squeeze to form tight rings and turns when feeding. Conclusion Dolphins are indeed social animals (Wurtz & Repetto, 2010). They acknowledge the importance of living in groups is social. The Pink-river and the Dusky dolphin demonstrate a lot of social behaviors. The behaviors show a wide range of similarity and a few differences. The most notable converging social practices are found in the group hunting of food and the games. Their social differences can be easily seen in their manner of coupling and the way they look for mating partners. The larger encephalization quotient is believed to be the instigating factor of the social nature of dolphins (Lundquist, 2011). They have well-developed brains like that of human beings that make them appreciate the need of thriving in group and carrying out their daily routines together. It is for these behaviors that dolphins are very closer to human beings and even go extra miles to engage in plays with them. Bibliography *Gomez-Salazar, C. (2012). Ecological factors influencing group sizes of river dolphins ?(Inia geoffrensis and Sotalia fluviatilis). Marine Mammal Science 2011. The writer states that ecological factors influence the social nature of dolphins. The writer also argues that social behavior of dolphins is portrayed in relationship to those of humans. *Iriarte, V., and Marmontel, M. (2013). River Dolphin (Inia geoffrensis, Sotalia fluviatilis) ?Mortality Events Attributed to Artisanal Fisheries in the Western Brazilian ?Amazon. Aquatic Mammals, 39(2), 116-124 The authors argue that the social behaviors of dolphins are related to the ecology. The paper also explores the marine medium and gives guideline of human interaction with dolphins without conflicts. *Lundquist, D.J. (2011). Behaviour and movement patterns of dusky dolphins ?(Lagenorhynchus obscurus) off Kaikoura, New Zealand: Effects of tourism. A thesis ?submitted for the degree of Doctor of Philosophy at the University of Otago, ?Dunedin, New Zealand. The work gives the specific information on the behavior of dolphins according to their species. The study is guided by the behavior that occurs at the species level. *Martin, A.R., da Silva, V.M.F., and Rothery, P. (2008). Object carrying as socio-sexual ?display in an aquatic mammal. Biology Letter, 4(3), 243-245 The authors are categorical in portraying the social behaviors of the dolphins. They compare the behaviors with those of other animals like human beings. *May-Collado, L.J., and Wartzok, D. (2007). The freshwater dolphin Inia geoffrensis ?geoffrensis produces high frequency whistles. Journal of Acoust. Soc. Am., Vol. 121, ?No. 2. The authors demonstrate that greater part of the social behaviors of dolphins entails the echolocation mechanism as a group location. The work reveals how whistling helps in identification of mates *Orbach, D.N., Kirchner, T., and Wursig, B. (2014). Measuring the Mating Behaviors of ?Free- ?Ranging Dusky Dolphins (Lagenorhynchus obscurus). Proceedings of ?Measuring Behavior 2014, (Wageningen, The Netherlands, August 27-29, 2014) Dolphin’s social behavior at some time surpasses the species level to the adaptation mechanisms according to the study. Samuels, J.B. (2014). Dolphins: Ecology, Behavior and Conservation Strategies. New ?York: ?Nova Science Pub Inc. This study explains how the knowledge of ecology can be used by dolphins for conservation. The work also highlights social behaviors and the ecological adaptations that are helpful in marine management. White, T. (2007). In Defense of Dolphins: The New Moral Frontier. New Jersey: Wiley- ?Blackwell White’s work is about the social behaviors of dolphins. Although dolphins are capable of complementing the economic activity of humans, the interaction must be guided. Whitehead, H., and Rendel, L. (2014). The Cultural Lives of Whales and Dolphins. Chicago: ?University Of Chicago Press The two scholars demonstrate that dolphins have the ability to learn new behaviors that are correlated to their social culture. They explain how the carrying of sticks is social in the world of dolphins. Wurtz, M., and Repetto, N. (2010). Dolphins and Whales: Biological Guide to the Life of ?the Cetaceans. Davis, CA: White Star Publishers The works show the comparisons that are exhibited in the mating behavior of dolphins and help us understand the aggression depicted by dolphins. Read More