Sunday, November 7, 2010

What is a Swift Fox? + their Niche


Swift Foxes are part of the Canidae, or "Dog", family - scientifically called vulpes or velox species. The average Swift Fox can grow up to 80cm (31.2 in.) in length, including their tail, and 2.25 - 2.45kg (5 - 5.4 lb.) in weight.

 The Swift Fox lives in pairs on open, sparsely vegatated prairies in dens that are located in well-drained slopes and hilltops near permanent bodies of water - like a river or a pond/lake. They live between 30 to 45 degrees in latitude and are found in Alberta, Saskatchewan, Montana, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, New Mexico, and Texas.

Their diet consists of mice, conttontail rabbits and carrion, small mammals, birds, insects, reptiles, and amphibians. So their interactions with other organisms is "to kill or be killed". They usually laze about while the pups play with each other and explore. When they are ready to find some prey for food, the mated pair shows great cooperation and skill in finding and swiftly killing the prey.

It has a broad niche and is a generalist, which means that it can adapt easily to dramatic changes in weather, such as summer and winter in Canada, as well as their food source - if their main food source is gone then they can adapt to find and survive on a new one.

Definitions Used + Conservation Efforts

Endangered - in imminent (about to happen/occur) danger of extinction

Extirpated - when a species are extinct in one area but are still alive in other areas

Threatened - likely to become endangered near the future if they are not protected

Special Concerns - a species that is uncommon or has an unique requirement for them to survive; they are not exactly endangered or threatened

The Swift Foxes are now endangered because of strychnine-poisoning, intensive trapping (in the past), and destruction of habitat - or so it is thought to be the primary causes of why the Swift Fox is endangered.

There are many conservation efforts to re-increase the population of the Swift Fox. These efforts have started shortly after the rapid decrease of the Swift Foxes from the Canadian prairies in 1938. One example of a conservation strategy that has began to increase the population of the Swift Foxes is a captive breeding program.

In 1973, a captive breeding program for the Swift Foxes began in Cochrane, Alberta. This program was meant to capture the remaining numbers of Swift Foxes left and breed them to increase the population of the species. The program, supported by Wildlife Preservation Trust of Canada (WPTC), has proved to be very successful in increasing the numbers of the Swift Fox.

With the number of Swift Foxes increasing, the organization started to release the Swift Foxes back into their natural habitats in the Canadian prairies in 1983. The program decided to start releasing the Swift Foxes in southern Alberta and Saskatchewan. Over 800 Swift Foxes have been reintroduced to the wild since 1983 but only about 250 Swift Foxes that have been released survived by 1991.

After keeping an eye on the Swift Foxes for two harsh winters, there were only around 120 - 150 Swift Foxes left from the 800 Swift Foxes that have been released. The result of this outcome could have had an relation with the doubling in population of the coyotes during the two harsh winters.

Researchers are still observing the Swift Foxes to find more information on why the Swift Foxes are becoming endangered and to find a more effective way to protect these animals.

Another conservation strategy that is being used is the protection of prairies where the Swift Foxes live. With the protection of their habitat, the Swift Fox will find all that it needs - ex) food, shelter, etc. - and will surely prosper. As a result, hopefully their population will increase. There has also been laws that ban the hunting/poisoning/killing of the Swift Fox. These laws prevent meaningless killing of the Swift Fox so that they will be safer from "unnatural" harm.

Structural Adaptations

One of the structural adaptations that the Swift Fox has is that it has two coats of fur - a brown one for the summer and a white one for the winter. The Swift Fox has two coats of fur to camouflage with its surroundings. Because Canada has basically two seasons, summer and winter, the Swift Fox needs to camouflage well for each of the season so that their prey or their preditors do not spot them. If the Swift Fox was, say... white, all year round then come summer, it would be very easy to spot them. The same situation would occur if the Swift Fox was brown all year round. This adaptation increases their survival and well-being in the wild.

Another structural adaptation that the Swift Fox has is that it has strong, sharp teeth to chew and eat their food. All carnivores - for example... a Swift Fox! - have sharp teeth to rip apart the flesh of their, now dead, prey. If the Swift Fox had flat teeth, like a herbivore, their teeth would be useless because they wouldn't be able to kill their prey or rip them apart. They would more or less be the prey themselves! Also, their teeth act like a defence mechanism. They show their teeth when they feel dangered - the bigger and sharper their teeth, the better.

Behavioural Adaptation

A behavioural adaptation that the Swift Fox have adapted into is that the different groups of Swift Foxes consists of a mated pair and their pups. Occasionally, the group has two or three female foxes with one male fox.  One of the female foxes is a "breeding" female while the other one or two is a "non-breeding helper". There is never two fully grown male foxes in a group. It is basically every family for themselves.

This behavioural adaptation increases their survival because it is a smaller group of mouths to feed - just their mate, themselves, and their pups. Also, there isn't a "fight" about the leader of the group, like some species (for example, wolves), because there is never more than one fully grown male in the group.

Physical Variations between the Swift Foxes

Physical differences, or variations, that I saw between the Swift Foxes are:

1. Height/Size - how tall or big each Swift Fox are; this is a continuous variation because there are many possible outcomes of the height and size of the fox; there are a range of possibilities
2. Weight - how fat or skinny they are; this is also a continuous variation because there are many possible outcomes of their weight; there are a range of possibilities
3. Coloring - what shade of fur they have; this is also a continuous variation because the shades could range from very light to very dark; this usually depends on their environment
4. Gender - if they are female or male; this is a discrete variation because there is only a limited possible outcome, in this case, it is if you are a male or a female, one or the other
5. Shape of their Eyes - this is a discrete variation because there is only two possibilites, big or small eye shape; I noticed that it is the females that have the larger eyes and the males that have the smaller eyes
6. Shape of their Ears - this is a discrete variation because there is only two possibilities of the shape of the ears, pointed or curved
7. Length of their Tails - how long their tails are; this is a continuous variation because there is a range of possibilities and it is usually "decided" with how big or small they are
8. Shape of their Snouts - this is a discrete variation because there are only two "options" or "choices", pointed or curved
9. Length of their Snouts - this is a continuous variation because there is a range of possible lengths for their snouts; this usually depends on how big or small the fox is
10. Size of their paws - this is a continuous variation because there is a range of possible sizes for their paws; it is usually the male foxes that have the bigger paws and the female foxes that have the smaller paws

How Humans have Impacted the Swift Foxes

Zoologists have found that Swift Foxes are threatened by hunting, trapping, poisoning, and expansion of agriculture into their native praire grassland habitat, causing their whole species to become classified as "endangered". So who are the cause of the decrease in the population of the Swift Foxes?
...

Us! Humans are the main cause of the decreasing rate of Swift Foxes! We destroy their habitat to provide land to grow our food to feed the growing human population and hunt, trap, and poison Swift Foxes to get their fur. Did you know that we also hunt/trap/poison Swift Foxes for fun and as a sport?

Swift Foxes have disappeared from Canadian prairies in 1938 as a result from the factors listed above. Today, only a small population of Swift Foxes remain in the Canadian prairies. Their survival mainly depends on the protection of their habitat, which we, humans, could provide for them.

Who is helping the Swift Foxes now?

One of the "organizations" that helps protect these furry little creatures is the Calgary Zoo. They help both national and international recovery teams aiming to ensure the future of Swift Foxes in the Canadian prairies.

An example of a conservation strategy that the Calgary Zoo uses to ensure the future of not just the Swift Fox but all endangered animals is an "endangered species breeding facility". In this facility, endangered species are brought in, taken care of, and breeded to make sure that their species will recover their numbers and drop their "status" as endangered. This conservation strategy was recently used to breed the Asian Wild Horse to increase their numbers from 8 to 11. This is the first time, since 1994, that three Asian Wild Horse foals have been born at the Calgary Zoo's endangered species breeding facility.

Another conservation strategy used by the Calgary Zoo is the Species Survival Program that are managed by the Association of Zoos and Aquariums. The Species Survival Program focus on animals that are threatened or endangered to the point where they believe that captive breeding programs are their only chance for survival. This program engages in cooperative population management, research of these animals, public education about the animals, reintroduction, and in situ or field conservation projects. An example of an animal that is a part of this program is the Western Lowland and Mountain Gorillas. They have become endangered because of habitat loss, poaching, and disease.

A conservation strategy that is also used by the Calgary Zoo is a "program" called Conservation Training. The Centre for Conservation Research (CCR) is dedicated in helping scholars from around the world become future conservation leaders. The Centre provides hands-on training in conservation research and endangered species management to undergraduate and graduate students in both Canada and abroad so that these students can make a difference in the survival of endangered animals in the future. This "program" doesn't really focus on the endangered species itself but trains young people to learn about these animals' circumstances and what they could do to help them. So hopefully in the future, these people will take part of programs mentioned above to ensure the future of these animals that are currently known as "endangered".

Even with all of these conservation strategies that the Calgary Zoo uses to try and ensure the future of these animals, there is still the possibility that the zoo could decrease biodiversity of the endangered animals. At the Calgary Zoo, there are a couple of each species, usually only one male and female. When these two produce offspring(s), it is very likely that the offspring will interbreed with each other unless a new animal of the same species with different genes from the offspring comes to the zoo and mates with one of the offspring. If this species keep interbreeding with each other with no new genes from another animal of the same species, then it is quite possible that that species will eventually become too sickly and die out anyway.