Every year natural resources agencies across the west survey elk from the air
It’s early March. Elk are still congregated on their winter ranges, awaiting a signal known only to them to migrate back to their high-country summer habitats. The past year, including the winter that is now nearly over, has largely shaped next year’s elk population, except for the next generation of newborns that will arrive around June.
Concentrated in areas with open, grassy slopes just beginning to green up, the elk herds are as visible as they ever get each year. For these reasons — fall and winter mortality is over, and the elk are very visible — it is the best time for biologists to count and classify the individual elk by flying over the herds.
Why use a helicopter?
Aerial surveys are done annually in virtually every western state that have elk. Usually helicopters are used because they can fly slowly and relatively low to provide good classification of the elk. Low-flying helicopters over wildlife aren’t a common sight to members of the public though, so there is sometimes concern that something unlawful or detrimental to wildlife is happening.
Are Aerial Surveys Harmful to Wildlife?
When a group of elk is sighted, the helicopter circles it. People onboard collect data on herd abundance and the strength of the coming year’s juvenile recruitment into adult elk. The animals hear or see the helicopter; they alert and usually run temporarily, but the disturbance is over quickly and the animals settle down again.
Some people believe this disturbance can be harmful to the animals, as it is the time of year when they are in the lowest physical condition due to the impacts of winter. In the momentary fight or flight response, the elk will run a brief distance, their energy coming from the burning of blood glucose and muscle glycogen. While quickly mobilized, it is also momentarily depleted. Lower intensity, but sustained, activity would use fat for fuel; fat the elk are often low on this time of year.
It is the same for humans. If we want to burn fat and lose weight, we jog or bike or walk briskly — sustained aerobic exercise. Hundred-yard dashes don’t help with weight loss. The energy for sprinting comes from the wrong fuel — not fat. Fortunately, the elk response to the helicopter fades quickly, and their fat stores are untouched. They are none the worse for a few moments of alarm behavior
Evolved to escape danger
Most adult female elk at this time are pregnant; in their second trimester. A thousand generations of elk have become well adapted for fleeing from threats without harm to the fetus. A pregnant elk must be able to evade a cougar or a wolf or a human for her and her calf to survive. There would be no elk today if running while pregnant harmed calves.
Elk aerial count protocol
The surveys flights are guided by distinct protocols designed to produce valid data, minimize disturbance to the elk, and avoid counting a group more than once. Depending on the herd area size, surveying the wintering population can often be completed in 2 or 3 days; large wintering areas with lots of elk might take a week at the longest.
Each elk group seen will contribute data to the assessment. For a few moments they will be disturbed by the aircraft, but only once per group. Crucial decisions about habitat, effects of weather on productivity and mortality, and the harvest the herd can sustain in the coming year are better informed because of annual aerial surveys.
As winter turns to spring, wildflowers begin to bloom, grasses turn a deeper green, and the days get longer. Elk forage daily increases in nutritional value. Elk begin to gain weight again, and fetal elk enter their period of most rapid growth. Last year’s annual cycle is ending — a new one is beginning. One by one, the elk move uphill, heading to areas each knows as summer range. They have forgotten about the strange noisy bird of a few weeks ago, and they never realized people were actually inside it. Those biologists — passionately dedicated to the welfare of the elk herds — will analyze and reanalyze the data collected during the surveys. Elk conservation and informed management moves steadily onward.