Deep snows in the high country push bison, elk and mule deer to lower altitudes.
These have been getting brighter and more common in recent years, and also seem to be moving to lower altitudes.
A lengthy Swarm mission, with the satellites gradually moving to lower altitudes, thus holds great promise.
Most of our teammates had removed to lower altitudes.
Long-distance flights were resumed, but were limited to lower altitudes until corrections had been made.
Its wintering grounds are unknown, but birds in Taiwan just move to lower altitudes in winter.
Within its range it is largely sedentary, although some populations at higher altitudes may move to lower altitudes during winter.
In fog the sound appears at a lower altitude.
But they are normally flying at a much lower altitude, little noticed outside places like Iowa and New Hampshire.
'If you get ill, they run you down to a lower altitude on a stretcher.
They were sent to lower altitude to recover along with five adults who were also sick.
