By JANET HAGEN There are many wombat myths, but the biggest one is people thinking there is a population 'explosion' of the species. But in fact, wombats cannot have population explosions. Bare nosed wombats breed every two to three years and have only one joey each time. While it is technically possible for them to breed yearly, this can only happen if a young wombat still suckling on its mother is killed. Therefore, destruction or removal of young wombats leads directly to an increase in young born in a particular period. Like all mammals, wombats have young in a 50:50 sex ratio; hence, of all young born and successfully reared in any period half of them will be male. The young females take two years to reach sexual maturity and are unlikely to breed until they have established a territory; therefore, most females will not breed until their third year. There is some evidence outlined by wombat expert Barbara Triggs that if wombats cannot establish a large enough territory to have access to a range of burrows not being used by other breeding females, then they don’t breed. A pair of bare nosed wombats can only produce the equivalent of one female every four years, so it is not possible to have an explosion in numbers. Why are there so many wombats on our roadsides? • Habitat loss and fragmentation Roads and development reduce and fragment wombat habitat, forcing them to cross roads more frequently to access food and other resources. • Food availability Wombats are herbivores and may be attracted to the edges of roads where there is often a strip of green grass that has not been grazed by other animals. • Nocturnal behavior Wombats are primarily active at night, increasing their risk of being hit by vehicles, particularly during peak traffic hours. • Territoriality and mating Wombats are territorial and may travel significant distances at night, especially during mating season, to find food and mates, leading them to cross roads. • Sarcoptic mange While not directly causing them to be on roadsides, the parasitic skin disease mange can weaken wombats, making them more susceptible to vehicle strikes. • Increased traffic Higher traffic volumes, especially during tourist seasons, increase the likelihood of collisions with wombats. What can we do to keep wombats out of areas? Wombats are known to be discouraged by a hormone found in male urine. Any males in the household should start urinating in and around the perimeter of any area wanted as an exclusion zone. (This might be a business opportunity for someone in Ruffy where human males are scarce.) 'Virtual fencing' for wombats is a technique using light and sound to deter them from crossing roads, reducing roadkill. It involves strategically placed devices that emit audible alarms and flashing lights when activated by vehicle headlights, creating a virtual fence that warns wombats of approaching traffic. This method has shown promise in reducing wombat road fatalities and is being trialed in various locations. Wombat crossing hot spots in any area can be mapped, perhaps by the shire. Joining Land for Wildlife and planting wombat habitat away from roadsides along creek lines and gullies will help, including fencing the areas to exclude stock and encourage undergrowth and grasses to feed wombats. For more information, visit www.wildlife.vic.gov.au/protecting-wildlife/land-for-wildlife
