By Faith Hillsden, Survey Tech Summer Student and James Tansey PhD, AAg, Provincial Insect and Vertebrate Pest Management Specialist
It goes without saying that agricultural pests can be devastating to crops. These agricultural pests include insects and small rodents, which can be controlled physically, chemically, and biologically. Grasshoppers have devastated crops throughout Western Canada in recent years and are starting to emerge this year. High populations of grasshoppers can damage a broad assortment of crops. However, these insects are no match for the voracious northern grasshopper mouse (Onychomys leucogaster). Grasshopper mice feed on a variety of insects and small animals that are considered agricultural pests in Western Canada.
with their noise in the air and mouth open.
Photo from Bonnie Stevens.
These mice are highly aggressive, strongly territorial, and voracious, so are found in low population numbers. They have enlarged ears and eyes they use for seeing and hearing the motion of small insects and rodents, making them efficient predators. Agricultural pests can be small and an enhanced sense of smell and sight in the grasshopper mouse increases foraging efficiency.
Grasshopper mice can be considered a beneficial species to growers as they feed on agricultural pests in short-grass pastures, shrub steppes and desert grasslands throughout Western Canada. Northern grasshopper mice can be found in Southern Saskatchewan and these rodents prefer dry and hot areas. They inhabit burrows they make or take over abandoned burrows. They create a system of burrows with their strong claws. This includes nest burrows for primary activity, retreat burrows for fleeing, cache burrows for food storage and signpost burrows for glandular secretions that mark territory. Grasshopper mouse hunts, attacks and takes over the burrows of others at night.
The most distinctive and interesting feature of grasshopper mice is their incredible ability to make a high-pitched noise that sounds like a howl. Grasshopper mice have two distinctive noises: a predation howl and an answering call. When in hot pursuit of prey, they produce a short squeak uttered in rapid succession. Their answering call is a long, shrill whistle that is made with a raised nose and open mouth. This call is used for mating, hunting and territorial communication - listen below.
Photo from Matthew and Ashlee Rowe.
Grasshopper mice differ from close relatives, as they are obligate carnivores and insectivores. Most of their diet consists of insects and other small rodents, with only one-quarter of their diet composed of vegetation. They will attack and feed on any moving object that is not much larger than itself. They pounce on their prey, using their large claws to hold the prey in place and their sharp teeth to feed on the flesh. With larger prey, grasshopper mice penetrate the brain by using their long, keen incisors to quickly kill their prey. Grasshopper mice have also adapted a specialized stomach, to assist them in their carnivorous lifestyle. They have short legs and a heavy body, which makes them inefficient runners, but very agile predators. Their agility makes them quick at turning and dodging, easily catching prey in small spaces. With all these abilities at their disposal, grasshopper mice are a natural way to protect crops.
For additional information, reach out to the Agriculture Knowledge Centre at 1-866-457-2377.