Species Spotlight: Ord’s kangaroo rat
By Raymond Schmidt
Common name: Ord’s kangaroo rat
Latin name: Dipodomys ordii
Status under SARA:Special Concern; Endangered by COSEWIC (up-listed from Special Concern in April 2006)
Range: The isolated Canadian population (a separate and slightly different US population exists) of Dipodomys ordii occupies a small area in southwestern Saskatchewan and southeastern Alberta. Kangaroo rats occupy sparsely vegetated, sandy habitat as a part of the mixed grassland eco-region of the prairie eco-zone in the vicinities of the Great Sand Hills, Saskatchewan and the Middle Sand Hills, Alberta.
Life Span: Most Ord’s kangaroo rats in Canada survive less than one year.
Size: Weight from between 68 – 71 g. Total length (including tail) between 260 – 263 mm.
Population Estimate: Canadian population drops to 1,000 or fewer during its seasonal low-point in early spring.
- The kangaroo rat is not a direct relative of the common rat. Unlike domestic rats, these rats don’t spread disease or have a negative effect on crops. In fact “K-Rats” need to live in open arid landscapes that are so marginal for farming that they could scarcely cause any trouble to humans.
- The nocturnal rodent’s hearing is tuned to low frequency sounds, which help detect an owl’s wing beat. Their tufted tail, which accounts for more than half its length, helps them jump – yes, like a kangaroo – from place to place to avoid prey. They can leap as far as six feet (1.8 m) and rise 1.3 feet (40 cm).
- Breeding whenever favourable conditions arise, an average three-rat litter arrives after one month of gestation. Lactating females can even conceive before their previous litter is weaned, resulting in 4-litter years. Less than two months after birth, maturing rats are ready to produce a family of their own.
- Most kangaroo rats travel less than 500 m in their lifetime and Canadian populations occupy as little as 53 km2 of total land area. The nearest population in the US is 270 km away, so it is extremely unlikely the populations will ever merge.
- Canadian Ord’s kangaroo rats are the only ones of their kind to “hibernate” in winter when the ground is snow covered or if temperatures are too severe. Sleep can last 17 hours and happen about 70 times a winter. High death rates occur through starvation and freezing. Kangaroo rats have, however, been spotted outside at –19 degrees Celsius during snow-free periods.
- Kangaroo Rats help maintain balance in their dune community. Removing seeds and grasses disturbs soil; their seed collection and caching behaviour leads to a large number of abandoned seed caches for germination or for other granivores to exploit.
For 52 years, Alberta’s Rat Patrol has been using shotguns, shovels and poison to eradicate rats. Patrollers protect the province from these pesky destroyers of crops, harbinger of disease and epitome of urban neglect along the Saskatchewan border, helping Alberta remain the only rat-free region in North America. One species of rat has escaped the Rat-Patrol’s radar – Ord’s kangaroo rat. That’s surprising because they live in one of the most heavily inspected and guarded areas in the province: Canadian Forces Base Suffield. More than half of the population’s range is amongst the dunes and low scrub in the eastern buffer zone of the military base.
Kangaroo rats have recently been placed on COSEWIC’s endangered species list and may soon meet the same fate provincially as their distant rodent brethren. Kangaroo rats live primarily in actively eroding sand dunes and sand flats. These areas are sensitive to both climatic change and human land-uses; areas that may be gone within 10 years.
Combine shrinking dunes and a population susceptible to winter kill and you have the makings of a foreboding future. Add EnCana Corporation’s plans to drill 1,275 new gas wells near rat habitat – doubling its current fleet – and you have a recipe for extirpation.
Although 458 km2 of the eastern buffer of Canadian Forces Base Suffield was designated a National Wildlife Area (NWA) in 2003, EnCana Corporation is still planning to drill within that same protected area. Learn what you can do to stop this.
EnCana’s application proposes buffer zones around rat habitat and promises not to build more roads, but increased traffic and the construction of new pipelines to connect the wells to existing and new infrastructure may cause problems.
“Roads create unnatural open-area habitat that rats are attracted to,” says Andy Teucher, a researcher studying the effects of unnatural vs. natural habitats for the rats.
These ‘linear dunes’ create habitat but they also act as highly efficient corridors for predators like coyotes, badgers and foxes. Non-native plants along the artificial dunes lead to less optimal forage, which means survival rates for rats that live along roadways, are not sustainable. “Rats in natural sites have a higher body condition; they seem to be fitter,” says Teucher.
Losing kangaroo rats would eliminate a critical link in the prairie ecosystem. “We just don’t know how many species we can lose before the ecosystem collapses,” explains Teucher.
What is Being Done
Your letters and support have allowed Nature Canada and its coalition partners to force public hearings into plans to expand gas well drilling inside Alberta’s Suffield National Wildlife Area, a unique prairie refuge for endangered species like the Ord’s kangaroo rat and the Burrowing Owl. Then, with your help, we mounted a strong case against such development before a government-appointed panel, which recommended against granting a permit to drill, and imposed strict conditions on future plans. Nature Canada is now hard at work to ensure that the government accepts this ruling, and that drilling is permanently prohibited inside Suffield and all protected areas.
What You Can Do
Ord’s kangaroo rats are a key focal species for the conservation of prairie sand dunes. Many other species at risk depend on these declining habitats.
- Visit the Royal Alberta Museum in Edmonton to learn more about prairie ecosystems.
- Appreciate the prairie ecosystem in person. You cannot visit Suffield NWA, but Saskatchewan’s Great Sand Hills are open to the public.