Mammals Flashcards
(21 cards)
Describe the diversity of mammals and the 3 main types of mammals
Live in every environment
Extremely diverse in form and lifestyle
Monotremes - 5 species, egg laying, platypus and echidnas
Marsupials - 334 species, young are born early and carried in a pouch, ~70% of species live in Australia
Placental - Most diverse ~5000 species, young are born well developed, colonised all environments on Earth
Why are certain mammals so well funded in regards to conservation?
Animals such as monkeys, rhinos, pandas and whales get a lot of funding as they are “emotive” creatures. Conservation is led by emotion rather than science - This is important though in that it raises the profile of conservation
Describe the primates
Largely diverse group ~300 species
Forward facing eyes on skull (distance perception)
Colour vision
Opposable thumbs
Advanced cognitive abilities - enlarged neocortex
- make and use tools
- complex social groups
- hunting strategies involving co-operation, influence and rank
- manipulative and capable of deception
- can learn to use symbols
- can understand aspects of human language
What are the main threats to primates?
Primary cause is deforestation - logging, agriculture, oil palm plantations, mining
Pet trade - middle East and Africa are major exporters
Hunting - bush meat
Main points on captive breeding in primates
Number of animals released will be directly correlated to their success in establishing new colonies
Appropriate stock - genetic compatibility to avoid outbreeding depression
Risk of introduction of diseases
Original cause of decline must be addressed before re-introduction
Must be sufficient good quality habitat which is linked to current surviving populations
Cost is estimated to be around $22,000 per individual golden lion tamarin
Describe Cetacea diversity
Whales, porpoises and dolphins More than 80 species Many are highly endangered - Blue whale 10,000-25,000 indv. - fin whale 30,000 indv. - Maui's dolphin 111 indv. - river dolphin
Why are whales so important?
Ecosystem services - “whale pump” - upward biological pump from the depths to the surface
- whale faeces are liquid and stay on the surface, food for phytoplankton and fisheries
- whale carcasses fall to the ocean floor, providing a habitat for marine life
Cultural
Political - huge importance to the environmental movement for galvanising support for environmental issues
What threats to Cetacea face?
Whaling
Fishing activities - entanglment, decreased fish stock, bycatch, ship strikes, sonar
Habitat loss - fish farms, harbours, shipping channels
Pollution - old nets, POPs, EDCs, concentration of pollutants
Oil industry
Climate change
Entertainment - overexploitation
Weapons testing
Why are rodentia a cause for concern in conservation despite being so highly successful?
~50% of all mammal extinctions are rodents
Important in seed dispersal and habitat alteration (eg. beavers and prairie dogs)
Habitat destruction is the biggest threat to rodents
Golden rumped sengi, Okinawa spiny rat and Red crested tree rat are all at risk of extinction
What are the causes of red squirrel decline in the UK?
Food source - Grey squirrels are better at digesting acorns than red squirrels
Disease - Parapoxvirus is carried by grey squirrels but does not affect them, passed to red squirrels it can cause mortality
Reproduction - red squirrels are more sensitive to stress and reproduce less
Describe the chiroptera’s main features and their diversity
Body plan - forelimbs form webbed wings, only mammals capable of true flight
Second largest order of mammals ~1240 species
- Flying fox/fruit bats ~60 spp. (feed on nectar, fruit etc, limited to tropical regions, smell and eyesight well developed)
- Echolocating bats ~1200 spp. (feed on insects, blood, fish lizards etc, widely distributed, small eyes, rely on echolocating)
Communicate using a variety of calls, pheromones and scent marks
Why are chiroptera important?
Indicator species
Transmission of rabies
Guano
Fruit bats - pollination and seed disperasal, prey for snakes
Echolocating bats - prey and predators, pest control (midges)
What are the main threats to chiroptera?
Habitat loss - clearing of vegetation, inappropriate fire regimes, invasion of weeds
Disturbance of roost sites - tourism, mining activities, recreational caving, land clearing
Hunting
Windfarms
Often portrayed negatively
Describe the diversity of the Carnivora
Range across a number of orders and occupy every type of terrestrial habitat and many aquatic habitats
281 spp.
- ~122 are on IUCN redlist
- 5 spp. have recently gone extinct - giant fosa, Falklands wolf, Carribean monk seal, sea mink, Japanese sea lion
Includes canidae, felidae, mustelidae, ursidae and pinnipeds
Why are carnivora so important?
Top predators Mesopredators Pest control Indicator species Protecting carnivores allows protection for entire ecosystems Clothing - fur trade Political - flagship species
What are the main threats to carnivora?
Habitat destruction Hunting for fur Hunting for fun - ~600 lions killed per year, 30,000 left in Africa Hunting to protect livestock Hunting for food Hunting for Chinese medicine Pet trade Climate change - snow leopards - prey reduction Inbreeding
Describe rhino diversity
Odd toes ungulates such as horses, donkeys, zebras and tapirs 5 species of rhino Africa - White Rhino ~20,000 indv. - Black Rhino ~5000 indv. Asia - Sumatran rhino
What threats do rhinos face?
Habitat loss - agriculture, development
Hunting
Inbreeding
Why should focus be put on conservation of flagship species?
Future generations have a right to experience the same species we have
Every species has the right to exist
Result in the protection of entire ecosystems
Platform to raise the agenda for other environmental issues
Why shouldn’t focus be put on the conservation of flagship species?
Individual species may not be essential to the functioning of the entire ecosystem
Small number of individuals lead to inbreeding
More important to focus on saving habitats that contain the highest biodiversity
Vast sums of money that is spent on these species could be diverted to more important issues such as climate change
Species that are the focus of conservation should be chosen on there importance to an ecosystem rather than how they look
What are the main features of mammals?
Endotherms
Amniotes
Physiology: hair, three middle ear bones, mammary glands, neocortex
Include the largest animals on the planet
Smallest mammals are the bumblebee bat and the estrucan shrew
Contain the most intelligent animals such as elephants, primates and cetaceans
Show all three major kinds of reproduction found in amniote vertebrates: Oviparity (egg laying), Ovoviparity (embryo retained internally with little maternal support), euviviparity (embryo retained internally with much maternal support)
