TNA Ecological Overview
The Tumalo Natural Area lies immediately east of the Three Sisters wilderness in the rain
shadow of the Cascade mountains. It has a low rainfall, which is evident from the dry land vegetation you see around you. In the immediate area you will see sagebrush, bitter brush and some rabbit brush with bunch grasses and seasonal flowering plants forming the dominant vegetation across the southern flat area known as Bull Flat.
As you head further west toward the mountains more moisture is available and you will notice some slight changes in vegetation with increasing numbers of Ponderosa Pine, fewer Juniper trees and the appearance of Manzanita bushes. As you travel north along Sisemore Road, you will cross the Tumalo Dam to enter an area where junipers, sage brush and bitter bush dominate. Whereas the southern area is a large flat plain dominated by the foothills, the north has a wide of the Cascade Mountains unobstructed by the ridge.
Vegetation
The vegetation you see is well adapted to the prevailing dry conditions but is very sensitive to human disturbance. Please keep to the trails and roads to minimize damage to plant life and disturbance of insects, birds and animals. Rabbits, deer and many other species rely on plant material for food and in turn other animals and birds rely on these herbivores for their food. Please always consider this very fragile food chain as you visit the Tumalo Natural Area.
Wildlife
In addition to the dry-adapted plants and trees, look out for a variety of wildlife including insects (during the warmer months), reptiles such as lizards (the diminutive pigmy horned lizard is shown left) garter snakes (which are excellent swimmers and successful fishermen) and many birds and mammals.
Birds to look out for include members of the crow family, particularly ravens, Stellers’ jays, Clark’s nutcrackers and scrub jays. There are many woodpeckers and flickers and a range of raptors including golden and bald eagles, red tail hawks, kestrels and occasional northern harriers. The Golden Eagle shown on the right was one of a pair struggling against the wind and snow on Christmas morning.
The hawk flew over to check out our science teams, when we were planting the first of the Astrogalus peckii experimental plots.
Mammals living in the area include rabbit, ground squirrels and chipmunks, grey squirrels, coyote and cougars. Please see the ODF&W information on each of our information kiosks about cougar and black bears . The pamphlets explain what you should do in the highly unlikely event that you encounter one of these animals. The area is also home to numerous bats. Although local bats do carry rabies, their impact on the insect population provides a discernible net benefit. If you do find a bat flapping on the ground around your yard or deck it is prudent to treat it with caution and keep domestic pets clear.
Many plant and animal populations show multiyear cycles of ‘boom or bust.’ This year, even with the relative drought conditions and high average summer temperatures, we have had boom populations of many species, including frogs, ground squirrel, jack rabbits and even humming birds.
TNA and the Winter Range Cooperative Closure (WRCC)
The Tumalo Natural Area is also an important winter refuge and wildlife combining zone for Mule deer and elk. The deer come down from the higher slopes during the winter and spend their time in this area where food is more accessible during the colder months. This area is especially important for female deer during their winter pregnancy; they need all the food they can find during winter. Burning extra calories to escape potential danger puts their survival at risk. Please try and avoid disturbing them as much as possible. The WRCC is closed to all unauthorized motorized vehicle travel between December 1st and March 31st except Sisemore Road and roads marked green on the map.
Displacement of deer due to wildfire damage, poaching, urban development and increasing recreational use of their natural habitat by humans and their dogs has caused a decline in the deer population along with a seemingly paradoxical upswing in the number of deer to be found in urban backyards and a noticeable increase in the number of road deaths.