Flashcards in Conservation Deck (63)
What is the best way to conserve any living species?
- To keep it in its natural habitat
- Maintaining the natural habitat means that all the 'life support systems' are provide
- We need to protect whole ecosystems threatened by development
What human activities can be limited in areas set aside where wildlife and the environment have some form of protection?
Building, grazing farm animals, hunting and other activities that might adversely affect plants and animals
What are national parks?
- Areas of land controlled by the government of a country and protected by legislation where agriculture, building, mining and other industrial activities are strictly controlled
- They can act as conservation areas where populations of wild animals are maintained
- They have restrictions on human activities
How can tourism benefit the environment?
- Tourism brings in money to pay for the maintenance of the parks and helps to inform people about conservation
- This raises awareness and can elicit support from the public
- Tourism works best if local people are involved e.g. by allowing them to use some areas of the park for herding their animals or growing crops, employing them as wardens or rangers, or using some of the money raised from tourism to improve local health/education facilities
How are the Galapagos islands an example of conservation?
1) authorities have restricted access to the uninhabited islands and limited access to other areas which are sensitive to human interference
2) a marine reserve has been set up to protect the environment from destructive activities of fishing
3) alien animal species are being removed and invasive plants are being dug up and destroyed
4) there are captive breeding and reintroduction programmes, notably for giant tortoises
How do marine parks protect the environment and give an example of one
Marine parks conserve fragile environments and areas at risk of overfishing, dredging and pollution
e.g. the establishment of marine parks around the coast of NZ has increased biodiversity and led to an increase in fish catches
Give an example of conservation areas dedicated by international bodies
- Ramsar sites are wetlands designated under an international treaty, considered important for conserving wildlife
- This gives protection against threats e.g. building development and extraction of minerals
- Wetland habitats e.g. estuaries, salt marshes and mangrove forests are ecosystems with high biodiversity
Why does the standard of management of parks and reserves vary throughout the world?
Some countries have the resources and national will to provide excellent protection and careful management but others do not
What are the 4 roles of zoos?
1) provide protection for endangered and vulnerable species
2) carry out captive breeding programmes, often with the long-term aim of reintroducing animals to their natural habitat
3) provide enjoyment and interest for visitors who can see and study animals that they would otherwise not be able to see
4) carry out research, especially to gain a better understanding of breeding habits, habitat requirements and ways to increase genetic diversity in captive breeding
What is the problem with breeding animals from small populations and why?
Inbreeding bc this decreases genetic diversity
What is a major aim in the conservation of many endangered species?
Maintaining the genetic diversity e.g. with the cheetah
What is the major goal of captive breeding?
To reintroduce animals to their natural habitat (can be very difficult as many factors that affect success)
What are the difficulties in captive breeding?
1) some animals refuse to breed in captivity
2) often, it is not possible to create suitable habitats for animals ∴ they cannot be returned to the wild
3) sometimes, even if a habitat exists, it is very difficult for the animals to adapt to living in it after being cared for in a zoo
4) some captive-bred animals do not have the skills to survive in their natural habitat as they might not know how to avoid predators, find food or rear their own young
What is an example of success of captive breeding?
Herds of breeding oryx have been established in reserves in North Africa
What is an example of difficultly of captive breeding?
The giant panda
What is assisted reproduction the solution to?
The problem of inbreeding and transport of large mammals, which is difficult and expensive and breeding did not always happen
What is the cheaper option to assisted reproduction?
- Collect semen and keep it frozen in a sperm banks
How is semen collected and stored?
1) samples are collected from males, checked for sperm activity and then diluted with a medium containing buffer solution and albumen
2) they are then stored in thin tubes at -196 degrees
What does artificial insemination (AI) solve the problem of?
The problem of males and females who do not show any courtship behaviour and will not mate
How does AI work?
1) a straw (thin tube of sperm) is placed into warm water so that the sperm become active
2) they are then put into a catheter, which is inserted into the vagina, through the cervix and into the uterus - this may happen when the female is naturally 'on heat' or following hormone treatment so she ovulates at the time of artificial insemination
3) the hormone treatment can stimulate the female to 'superovulate' to produce a large number of follicles
What happens following AI?
- The resulting embryos may be 'flushed out' of the uterus and transferred to other females (can be a different, not endangered species) that have had hormonal treatment to prepare them for pregnancy = embryo transfer
- This process protects the endangered animal from the risks of pregnancy and means that she can be a source of many offspring
What is the female receiving the embryo called?
The surrogate mother
How do you carry out IVF?
1) oocytes (eggs) are collected by inserting a needle into the ovaries and withdrawing some mature follicles and kept in a culture medium for a short time
2) the oocytes are mixed with sperm and the resulting zygotes divide to form embryos, which are cultured for several days and then placed into the mother or other females of the same/different species
How can eggs be stored?
They can be fertilised in vitro and then frozen until such time as a surrogate mother becomes available
Why are eggs difficult to freeze?
Because they are more likely to be damaged by the freezing/thawing process
What is a frozen zoo?
- A place that holds genetic resources in the form of sperm, eggs and embryos from many endangered and vulnerable species until they might be needed
- Frozen zoos can hold much more genetic diversity than a normal zoo and the material can be kept for very long periods of time
What is the problem if conservation is too successful?
The organism saved from extinction has increased in numbers beyond the capacity of the ecosystem to sustain such numbers
Describe 3 ways of preventing overpopulation
1) culling - often used to reduce numbers but it is a controversial practice, especially when used to control the number of elephants
2) transferring animals to places where there are small populations (not easy over large distances and expensive)
3) vasectomy (birth control) - sedating male wild mammals and cutting their sperm ducts
4) chemical contraceptives
Describe chemical contraceptives in animals
- Not the same as steroid hormones women may use
- A vaccine is used which targets the region surrounding the layer of glycoproteins around the egg (zone pellucida)
- When the vaccine is injected into a female animal, it stimulates an immune response that produces antibodies against these glycoproteins
- These antibodies attach to the glycoproteins around the female's own eggs ∴ blocking sperm from fertilising the egg
- 90% success rate in mammals