7/30/2023 0 Comments Rabbit predators![]() ![]() “Reddiex (2004) replicated the experiment at two other South Island sites in Central Otago, where conditions for rabbit survival and growth are more favourable. Thus predation seemed to magnify the impact of the newly introduced disease. Mortality rates of juvenile rabbits were also higher where predators remained.” Rabbit numbers declined on all sites during the RHD outbreak, but the declines were only moderate where predators were removed and quite dramatic where predators were present. Rabbit abundance was measured there and at two other sites where predators were not removed. (2002) removed predators (cats, ferrets and stoats) from two sites in North Canterbury at the same time as Rabbit haemorrhagic disease (RHD) arrived. So what can the latest research tell us about rabbit population dynamics and predator/prey relationships? Research in New Zealand Their paper was recently published in the international scientific journal ‘Mammal Review’ (LINK to original article). In an effort to answer these questions, Landcare Research scientists, Grant Norbury and Chris Jones, supported by the Cape to City Project, reviewed current knowledge on rabbit population dynamics from research carried out in New Zealand, Australia and Europe. So how important, within that network of factors, is the predator/prey relationship? If cats, ferrets and other predators are removed, will soil type, disease, climatic events and a limited food supply be sufficient to keep rabbit numbers at current levels? There’s a lot going on and it’s all inter-related. Competition for food from other herbivores (eg grazing stock) and within a rabbit population, also limits how high rabbit numbers can get before starvation causes a population crash. Sick or starving rabbits and those flooded from their burrows, are a lot easier for feral cats and ferrets to catch, but they may have died anyway. High rainfall floods rabbit burrows and drowns their young. Disease outbreaks can also cause rabbit populations to crash and residual disease levels probably have an ongoing limiting effect.ĭrought limits food supply and breeding success. Habitat and soil type (the soil’s suitability for burrowing) has an effect on how many rabbits live in a particular area. Predation is only one of the factors that can potentially limit rabbit populations. So what’s the situation with rabbits in New Zealand and what will happen to rabbit numbers if their introduced predators – ferrets, stoats, weasels and feral cats – are removed? In other words, the number of prey controls the number of predators which can co-exist with and feed on that prey population. Scientists today would argue that it’s often the other way around that predator numbers are limited by food availability. But do predators really control rabbit populations? It was an understandable response for the knowledge people had at the time. When introduced rabbit numbers were booming in the 1870s-1880s, New Zealand introduced stoats, ferrets and weasels – their natural predators – to keep rabbits under control. It’s the same intuitive logic that led to ferrets, stoats and weasels being introduced in the first place. Some are asking who will pay for the additional rabbit control needed. Farmers are understandably concerned that if introduced predators are eradicated from their land, rabbit numbers will increase dramatically. Rabbits Without Predators: the likely consequences Kate Guthrieĭo cats and ferrets control rabbits – or do rabbit numbers control their predators? It’s an important question. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |