Hare today, gone tomorrow? Has myxomatosis “jumped” species?
What would the British countryside be like without the sight of boxing hares in Spring? They have become woven into our landscape and folklore. Many of us have seen statues of moon gazing hares, craning their necks to look up into the night sky. These figures represent birth and renewal and are strongly associated with Spring. But, all is not well for our moon gazing friends. Recently, news outlets report that the rabbit disease of myxomatosis has “jumped” species and killed Brown Hares in the UK. Are these claims as mad as a March Hare? Can a virus like myxomatosis really “jump” from rabbits to hares?
Myxomatosis was first found in laboratory rabbits at the Institute of Hygiene, Uruguay, in 1896. The Myxoma virus, which leads to myxomatosis, is very similar to smallpox and like smallpox, is a naturally occurring disease. There is some natural immunity to the virus and two species of rabbits, native to the USA, that have been found to be immune.
Since its discovery, like smallpox, Myxomatosis has been manufactured in laboratories and made into a biological weapon. In the 1950s, Myxomatosis was purposefully released into the wild rabbit populations in Australia (1950), France (1952), UK (1953) and into Ireland (1954) in a war against rabbits. Wild rabbits were breeding, well, like rabbits and this was causing a lot of problems for farmers. The rabbits were eating all the grass needed for livestock. They were eating so much, that they were destroying complete grassland habitats and endangering food production for both animals and humans. They were a natural disaster! The release of myxomatosis in the UK in 1953 saw the rabbit population drop by over 99%. But, this didn’t stop our furry foes. Over the years, British rabbits have developed an immunity to the disease. This has meant that the rabbit population has grown back, and the virus is less effective than before.
The ability for some diseases to jump between species is known as Cross-species Transmission (CST). Most CST examples, such as HIV/AIDs, happen in species that have a lot of close contact with each other. This can be through handling or in the eating of one species by another (bush meat) and in species that are closely related, such as humans and primates. Rabbits and hares are from the same Family (Leporidae), but they are different species. They may look similar, but they rarely come into close contact with each other. Rabbits live underground in large groups, while hares are solitary and live in nests above the ground. In Australia, in the 1930s, investigations were made looking into the possibility that hares could also be affected by myxomatosis. Hares were caught and injected with the myxoma virus, but they did not get the disease. This meant that the hares could be carriers of the myxoma virus but were themselves naturally resistant to the disease.
So, why have there been recent reports of hares dying of myxomatosis? This could be down to large outbreaks in our rabbit populations. If there is a large volume of the myxomatosis virus in the area, the hares are succumbing to the sheer pressure of the disease. A small amount of myxoma virus is easily fought off by the hare’s natural immunity, but large epidemics, could mean they contract the virus and die, just the same as the rabbits.
Does this mean that the European Brown Hare and the Mountain Hare (the one which turns white in winter) going to become extinct in the UK? Both species of hare are not actually native to the UK. They were most likely introduced by the Romans about 2,000 years ago for food. Last officially surveyed in 2008, the IUCN (International Union for the Conservation of Nature) have stated that both the European Brown Hare and the Mountain Hare are both considered of Least Concern. The IUCN do note that both species are currently declining in population levels.
Estimating how many hares there are in the UK is difficult. Unlike rabbits, who are most active at dawn and dusk, hares are mostly nocturnal. Surveys have to be done at night using a torch. The hare’s eyes reflect red at night in torchlight, making them visible for counting, but if they don’t look directly into the torch, then they are almost impossible to find. This means that most are not counted when surveys are being done and estimated population number can very different to actual number.
Even though the hares are classed as least concern by the IUCN, there are still plans in place to help our dwindling UK populations of Brown and Mountain Hares. In 1994, the UK launched a programme of Biodiversity Action Plans (BAP) and the Brown Hare was one of the original species included. The Mountain Hare was added in 2008. The BAP means that farmers and other land owners are encouraged to look after the hares, by being given funding under Environmental Stewardship schemes. These schemes encourage and financially reward farmers to look after their land in an environmentally friendly way. Therefore, both the environment and the welfare of the wildlife improve.
How many Brown and Mountain hare are left in the UK is unclear, but for the time being, it seems that Mad March Hare’s boxing in misty fields will be a sight to be enjoyed for a while yet.
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