Macropod Management: Maria Island National Park. Annual Report 2016

It is recommended that there is no cull of any species of macropod on Maria Island for 2016. This recommendation does not equate to a cessation of all culling as a management action on Maria Island National Park, rather it is within the scope of the Maria Island Macropod Management Program (MMMP) evidence-based adaptive management principles. In addition, the decision tree that guides the decision making process, together with the results from the integrated monitoring strategy, do not include the presence of a top order predator nor the common wombat population that has doubled in number since 2010 - both issues that need to be addressed in the forthcoming MMMP review. This review provides an opportunity to address the imbalance in the overall management of marsupial herbivores on Maria Island. Of primary concern is the lack of knowledge on the health and reproductive status of the common wombat population despite this species potentially carrying infectious diseases such as sarcoptic mange and toxoplasmosis.

The recommendation for 2016 has been determined by: the continuing decline in the Forester kangaroo population; a request from the Save the Tasmanian Devil Team to quarantine the Tasmanian pademelon as a primary source of prey; and, the increasing predation on Bennetts wallaby since 2014 as indicated by devil scat surveys. There are also a high number of adult Tasmanian devils on Maria Island, estimated to have exceeded the upper limit of the predicted carrying capacity (prior to a recent trapping and removal event in May 2016).

Population monitoring does indicate a lower population trend estimate for all four marsupial herbivores, which may be a result of increased predation and the presence of a high number of adult Tasmanian devils, but this hypothesis cannot be confirmed due to estimates not being comparable between years. However, the results of biological monitoring do indicate high parasite loads and high levels of anaemia which are indications of nutritional stress. An increasing population trend for the common wombat, the other introduced primary grazer on the island, limits any potential for reduced grazing pressure by continuing to cull macropods on Maria Island National Park. Predictions for this year’s La Niña weather outlook indicate an equal probability of either drier or wetter conditions in Tasmania during 2016.