Alpine Habitats are Unique and Under Threat
Habitats in the alpine zone are those habitats that exist at high elevations. They have “rugged, partially vegetated terrain with snowfields and rocky ridges, above the natural tree line,” (1). There is often less variety in plant species at these high elevations than there is at lower elevations. The alpine zone experiences “high winds, prolonged snow cover, steep terrain, extremes of heat and cold, and intense ultraviolet radiation,” (1).
For wildlife that live in these zones, this means shorter breeding periods, less predictable environmental conditions, and less oxygen. Because of this, wildlife engage in a short, but intense breeding season, and move seasonally from “patchy breeding habitats and wintering areas,” (1). Some animals spend their entire lives in alpine habitats, while others spend some part of their life history in different zones. In total, about one third of animals with backbones (vertebrate fauna) in the Pacific Northwest make use of alpine habitats. Conservation of alpine habitats is essential for the conservation of these species. Connectivity of habitats, in particular, must be prioritized.
Traditionally, the alpine zone in Canada has seen little human activity. While the alpine zone has been used for agriculture in much of Europe and Asia, the Canadian alpine zone was relatively untouched. Recently, there has been a marked increase in human activity in the alpine zone, causing significant deterioration in some areas. This damage can come from sustained recreational activities, from mining and grazing livestock, or from airborne contaminants, among other sources. When alpine vegetation is worn away to bare ground, it does not regenerate for decades.
Another threat to alpine habitats and alpine species is climate change. As temperatures increase even slightly, the tree line – the maximum elevation that trees occur – and shrubs can move up in elevation. This may mean there is more food available for some types of animals, but it also means that there is less alpine zone and it will exist in smaller patches that are farther away from each other. Animal populations that use alpine habitats will be smaller and will have to travel farther. Predators may be able to gain more access to them. Additionally, alpine species, in particular birds, are not well adapted for warm temperatures. They have difficulty cooling themselves in the summer, so they move on to snowfields, or burrow underground. If snowfields fail to remain year round, birds will not be able to find places to cool themselves.
Alpine species have adapted in many ways to their habitat. Some that spend only short periods of time in the alpine make behavioral adjustments such as seeking out sheltered areas to conserve energy.
Many alpine species have adapted “cryptic appearances and behaviors,” (6). Many have appearances that allow them to “disappear,” for example, ptarmigan, bighorn sheep, and coyotes, all blend well with the landscape. Some alpine species, such as marmots, pika, and ptarmigan, make calls that are difficult to locate, making it more difficult for a predator to find them. And, “like arctic wildlife, animals living at high elevations develop fat deposits, extra feathers, or thicker fur to increase insulation,” (6).
Certain species have developed structural adaptations. Some have higher red blood cell counts so that they can better access the smaller amounts of oxygen available to them. Some song bird species in the Himalayas, have long pointed wings to make flying more efficient.
Some species in alpine habitats have an altered life history. They may be larger, and live longer; but have less young, who have a better survival rate per year than other members of the same species who live in lower elevation habitats.
Animals breed in these habitats because there are low incidences of competition within or between species for food. In winter, wind exposes enough food for herbivores to survive, and in spring insects are abundant. For prey species, it is easier to detect a predator due to the lack of vegetation in which they can hide. Levels of parasites are lower. These tough alpine habitats, therefore, can be good places for animals to live if they are able to cope with the challenging environmental conditions.
This is a summary article authored by Chenoa Sly. For further information, please see the original published research:
K Martin, 2001. Wildlife in Alpine and Sub-Alpine Habitats In: D.H. Johnson and T.A. O’Neil (Managing Directors). Wildlife-Habitat Relationships in Oregon and Washington. Oregon State University Press. Pages 285-310/