mers expect to see some rodent activity, however grain growers in NSW are battling “significantly higher numbers” of mice than usual, according to Brett Hosking, chair of the Grain Growers Association. “We are hearing some growers saying that they’re expecting to reduce the number of hectares that they sow this year. We’re also hearing that those crops that are sown already, at this early stage, those yields may be reduced simply because of mouse damage,” Hosking told Inside Retail.  He said growers in NSW are baiting heavily in an effort to reduce the numbers of active mice in the paddock. Even on his own farm in northern Victoria, where he grows wheat and barley, he has baited a quarter of his crops.  Last month, the NSW Government announced a $50 million package to assist farmers, households and small businesses in battling the plague after lobby groups labelled it an “economic and public health crisis”. Free baiting will be made available to primary producers, while households and small businesses can apply for rebates on the cost of purchasing mouse baits. Ideal conditions The increased mouse population is largely due to a bumper crop last year, Hosking explained.  “All the machinery involved in harvesting that crop was pushed to its limit. When that happens, sometimes a lot of the grain falls on the ground. That extra food source, combined with crop residue, provides this ideal combination of plenty of readily available food and plenty of protection from the elements. That creates the ideal breeding environment for mice.” He said that recently sown crops are particularly vulnerable because mice will burrow along the line of seeds. “It’s like an all-you-can-eat buffet,” Hosking said. And it’s not just the seeds; the mice are also feasting on young and mature plants. “In northern NSW, the mice are actually climbing up the mature sorghum plant and eating the grains. We’re finding mouse droppings in the harvest grain.” Sorghum is largely used for stock feed but is also exported for use in spirits in China and Japan. Some growers are having to thoroughly clean the grain before delivering it to make sure it’s in a suitable condition. Out of control  According to CSIRO researcher and leading mouse expert, Steve Henry, a plague of this sort happens every 10 years or so in response to seasonal conditions.  “The mild and moist summer particularly in northern NSW helped mice breed through the summer months into autumn. Usually, mice breed in early spring and usually finish breeding in autumn. Breeding tails off through winter,” he said.    Henry says changes to farming practices in recent years have also impacted conditions.  “Water conservation and environmentally sustainable methods, such as minimum or zero tillage have resulted in significant increase in both available shelter and alternative food sources for mice in fields,” he said. Given the frequency at which mice can reproduce, every 19 to 21 days, the problem can quickly get out of control. “While they are rearing a litter, they are gestating the next … There is no break in pup production.” Natural order While crops will be reduced, Hosking quelled concerns over shortages. “We will see reduced crop this year, it’s just difficult at this early stage to ascertain how much that will be. But we aren’t anticipating any shortages at this time,” he said.  When this plague will come to an end is dependent on weather, but Hosking is hopeful that predators such as owls and foxes can help natural order to be restored.  “We know that nature will do its best to restore balance where it can, but if we can help it out anyway we can, that makes for a better outcome for everyone.” “But rain would be great. We’d love rain.”