An overview of the marine mammal biology
Characteristics of marine mammals
The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Total species range is highly variable for marine mammal species. The occurrence of these two apparently independent elements of social learning suggest that this species can maintain more than one independently evolving culture Allen et al. Both pinnipeds and cetaceans have large and complex blood vessel systems which serve to store oxygen to support deep diving. Whether this reduced fertility rate was the result of female mate choice or other selection pressures is unknown. Many universities require graduate school applicants to take the Graduate Record Examination GRE and include the test scores with their applications. Because the field of marine mammal science is so diverse, students who train in specialized areas have practical tools that may help them gain employment. Fragmentation of social groups may be caused by other anthropogenic effects, such as hunting, bycatch, or harassment. As far as the authors are aware, there are no conservation schemes to alter the migration routes of marine mammals, or reserves set up with the sole intention of attracting marine mammals to a formerly uninhabited area. This may be the result of changes in operational sex ratio as the population declines, which may be related to population density and changes in habitat, but other sexual selection pressures, such as the specifics of mate choice, may also have an influence on population growth rates, making smaller populations more prone to extinction. While research on killer whale Orcinus orca response to an acoustic harassment device, to prevent long-line depredation, indicated habituation to the device Tixier et al. In other words, if your B.
Reproductive behavior in marine mammals includes polygyny and promiscuity and pinnipeds species that breed on land compete for reproductively active females by defending breeding territories. In sperm whales it is not known whether copulation is forced by males, chosen by females or determined by other processes Whitehead, In such cases, maintaining fish stocks for exploitation is, strictly speaking, not a conservation goal but rather an industry goal, which often neglects the importance of diversity within food webs and ecosystems, or the implications of the impact of commercial fisheries on marine mammal populations DeMaster et al.
To become a marine mammal veterinarian, follow the basic curriculum and schooling of other veterinarians, but try to gain practical experience with marine mammals by volunteering at an oceanarium or zoo.
Marine mammal mass
Whilst, Wade et al. For example, when Steller sea lions Eumetopias jubatus were less abundant in the Aleutian Islands s and in Southeast Alaska s predation by killer whales was thought to influence population projections. Requests often take about two weeks to receive a detailed reply. Right whales are now almost entirely absent in the waters of Labrador Katona and Kraus, For more information about each group and special characteristics of certain marine mammals, see our Marine Mammal Classification page. Marine mammal trainers often start by volunteering at an oceanarium or zoo. In the Chukchi and Beaufort seas, polar bears retreat each summer to the ice further north that remains frozen year-round. In addition, critical habitat may also include areas beyond the species range at the time of listing, but which are considered essential to their conservation. Sutherland contends that it is precisely this effect that led to the confidence of the fishing community which brought about the collapse of the Atlantic cod Gadus morhua fishery off the eastern-coast of Canada. Habitat Requirements of Species of Conservation Concern In order to determine habitat requirements for any marine mammal of conservation concern, it is essential to have information on the diversity of prey, home range, sensitivities to specific anthropogenic threats such as noise from vessel traffic, entanglement etc. Key causes of population fragmentation in marine mammals are displacement, through noise, fishing, harassment, or some other environmental stressor, or change in prey abundance or dispersal.
For example, understanding sperm whale Physeter microcephalus depredation of sablefish from demersal longlines across the Alaskan fishery has only been possible with emerging knowledge about the scale and spread of this behavior and whether noise from fishing vessels may be providing an acoustic cue for these whales Thode et al.
Sutherlandp. In contrast, baleen whales have evolved baleen plates to filter feed plankton and small fish from the water.
However, in most instances the best university is determined by selecting a graduate advisor specializing in a particular field. Because the field of marine mammal science is so diverse, students who train in specialized areas have practical tools that may help them gain employment.
Working with marine mammals is appealing because of strong public interest in these animals and because the work is personally rewarding. Research on the social structure of migrating beluga whales D.
For example, if dramatic shifts in behavior as a result of rapid social learning occur that have implications for conservation, plans can be adapted.
Often developing a specialized scientific skill or technique, such as acoustics analysis, biostatistics, genetic analysis, or biomolecuIar analyses, provides a competitive edge.
To understand the role of behavior in some density dependent processes it is necessary to have data on the type of breeding systems, social structure and the transmission of social information within and between populations, as well as an understanding of individual decision making.
For example, chances of obtaining a career designing educational exhibits on marine mammals are greatly enhanced if a candidate has a M. However, the effects of inbreeding are controversial and not always easily predicted Huisman et al. Whilst some cultures may be very stable and may last many generations, some cultures may evolve more rapidly in response to changes in the environment. Behavioral Manipulations Many terrestrial conservation projects involve manipulating behavior Sutherland, Sutherland contends that it is precisely this effect that led to the confidence of the fishing community which brought about the collapse of the Atlantic cod Gadus morhua fishery off the eastern-coast of Canada. In highly social species, behavior may play a particularly important role in differentiation between units to conserve and in understanding the mechanisms of population persistence or decline. The Marine Mammal Center website is a great resource for marine mammal information, learning more about conservation and exploring current scientific research. It is important to understand the relationship between different breeding systems and inbreeding depression Sutherland,
Successful mitigation of environmental threats and identification of critical habitat requires a good understanding of the behavioral ecology of the species and population specific behavior.
based on 15 review