SOCIAL SYSTEM
ANIMAL DESCRIPTION
Photo Courtesy of www.ew.govt.nz/.../rpms2002/operative6.3.7.htm
Animal Description
European rabbits are usually grey-brown colored with pale bellies. They can also been seen in the wild as black/ginger or white, although this is extremely rare. In Western Australia, they weigh about 1200-2250 grams, or 3-5 pounds. They breed from May until November depending on the food resources available. Pregnant females are most often observed during the months of July and August, or during peak breeding season. A single doe has the potential to produce 30 kittens in 6 to 7 litters per year. The gestation period lasts for about 30 days (NA, 2003).
Social System
European rabbits experience cool, moist winters and hot dry summers making the conditions for survival difficult. The rabbits' social group size changes depending on the season. In the winter, they live in small social groups that disperse during the breeding season, or summer months. In warmer months, European rabbits have a large warren with several groups that defend their own territory. Since they are very territorial, they mark their territory through faeces, urine, gland secretions from under their chins onto other objects within their environment. Rabbits tend to graze near their burrows and have been known to overgraze an area to the point that the perennial grasses are unable to regrow(NA, 2003). The European rabbit interacts the most among its species when underground and they tend to avoid one another when feeding above ground (Roberts, 1987) .
Social Organization:
European rabbits are placed into their social group at birth, which has repercussions on the genetic structure of the rabbit population. In the field, rabbits have not been reported to have a high rate of inbreeding. Offspring disband at the end of breeding season possibly due to the dry pastures found within enclosed populations. The offspring are not able to survive under such harsh conditions and move to different warren groups. Such actions as these might help explain the gene flow in the rabbit population. Social organizations affect the gene flow within rabbit populations. Also, the study from Daly with the enclosed Urana population of rabbits observed the range at which rabbits can be separated across. Outside of the area, it was important that subordinate adults venture into different warrens, ensuring gene flow. The Urana experiment showed that, “animals which did disperse are unlikely to be recruited into a strange group if all or most of the original residents still remain in that group.” (Daly, 1981). Of course, observing rabbits in the field is a better solution than enclosed populations due to subordinate animals not wanting to breed and gene flow occurring between different social groups.
The productivity of a rabbit also plays a role in their gene flow because those living within a successful habitat are more likely to have a greater reproduction rate and pass their gene on to the next generation. If rabbits’ are in habitats that possess harsh environmental conditions, their population has a greater chance of plummeting. Rabbits’ have two mechanisms for enhancing the gene flow of their population through an expanding subpopulation or having adults take over recently vacated warrens from rabbits who did not survive the harsh environmental condition. In order for gene flow to not persist within a population of rabbits, there must be a small number of rabbits mating between breeding groups, too selective parental groups or members of the same social group choosing the same male to mate with (Daly, 1981).