High Country Life

As seasons change, many species migrate. Migratory behavior allows animals to take advantage of seasonally and geographically variable resources while avoiding unfavorable environments.

With GPS-collared data from 15 Alpine bighorn Capra ibex populations, we characterized movement corridors linking summer and winter ranges. Movements were frequently short, concerted movements that occurred largely vertically. Bighorn selected steep south-facing slopes near escape terrain during spring/autumn migrations while avoiding areas likely to snow early.

Winter

Many alpine mammals migrate seasonally for food or to escape harsh winters, like mule deer (Odocoileus hemionus) and pronghorns (Antilocapra americana). Mule deer travel between sagebrush steppe and alpine meadows to feed during the summer before returning home in fall in preparation for winter. Other mammal species also perform these lengthy migrations in order to maintain herd health as well as gain access to new resources in spring.

Animals such as moose and caribou migrate great distances to find suitable breeding, calving, foraging, and winter resting habitats. Their prolonged journeys put immense strain on these animals’ energy stores while competing with each other for limited resources when they arrive at their destinations.

Wildlife populations that move seasonally between distinct ranges are commonly described as either residents or migrants, though in reality most populations fall somewhere along this continuum; most ungulate herds, for instance, consist of both resident and migratory individuals within one herd; one segment might migrate every season while the remainder remain on its seasonal range year-round.

Alpine Ibexes (Capra ibexes) are another prime example of this trend, having almost become extinct in modern times before being saved through policy changes and reintroduction projects. Now they live as part of a small herd in Gran Paradiso National Park before gradually being reintroduced back into other regions to reclaim ancestral homelands.

Researchers recently studied the movements of radio-tagged female willow ptarmigan Lagopus lagopus to gain more insight into what drives animal migrations. According to this research, migration patterns of these birds were determined by factors including proximity to escape terrain, availability of early growing vegetation and security from predators.

The research found that RTD wasn’t the most appropriate metric to compare migration vs nonmigration behaviors as its definition can be subjective and quantifiable. Instead, total cumulative annual distance traveled (TCAD) proved more useful for making comparisons among various behaviors.

Spring

Alpine mammals face the challenging task of surviving in an environment which increasingly restricts their habitat and breeding grounds. Once, Alpine mammal species could seek refuge in alpine glaciers or high-altitude refuges; now however, those areas have become the domain of ski resorts and roads – placing an immense strain on survival for these creatures.

As mammals face these obstacles, some hibernate or migrate long distances for food or protection from predators; the Alpine Ibex (Capra ibex) was nearly extinct but has recently made a comeback thanks to successful reintroduction. Other introduced species, like Lynx pardinus (Lynx pardinus), Bear (Ursus americanus), and Wolfs (Canis lupus), have established themselves within the Alpine environment but remain sensitive to environmental changes.

Migratory patterns can be further complicated by shifting weather conditions that alter migration corridors and routes (Goicolea et al., 2021). To account for such changes, researchers have devised methods of using GPS data to assess individual movements and habitat selection, though such assessments can be challenging when applied to multiple animals at once.

Researchers conducted this study to analyze ibex movements and habitat selection by tracking their GPS tracks. Researchers discovered that both in spring and autumn ibex tend to travel through areas with less elevation change than expected (by approximately 7% less over six hours of movement) while also tending to avoid areas associated with north orientation in the spring season and ridges during autumn migration. Ibex also sought shelter from predators while avoiding areas likely to accumulate snow during their migration patterns.

This study of Ibex showed differences between migratory and resident selection patterns that are consistent with their status-dependent limitations, with migrants prioritizing escape terrain while residents shifted toward areas with more green vegetation. Both selection patterns were affected by NDVI values indicating that understanding individual-level dynamics greatly improves our ability to detect and predict migration routes of these animals; ultimately understanding their drivers can assist wildlife connectivity models for conservation decisions regarding migratory species.

Summer

Alpine mammals migrate downward each summer in search of shelter from snow. They also search for sources of food and water in grasslands, riparian areas and marshes – essential movements in mountain environments with extreme temperatures and limited food sources.

Biologists study seasonal animal migration by tracking them with radio transmitters. Their aim is to understand why certain species migrate while others don’t, and how climate change might influence migration rates in future. Furthermore, biologists use “modeling” as a predictive technique: They create different scenarios of possible futures for habitat and wildlife and then compare results against each other until finding which results most closely represent reality.

Scientists are concerned about how warming in the Alps has altered animal populations that live there, fearing that as temperatures continue to increase many will experience swift declines and possible extinction.

Some animals such as the snowshoe hare (Lepus americanus) migrate only short distances; others, however, reside there permanently without migrating at all. Most wildlife populations consist of both migrants and residents living together peacefully in one ecosystem.

Recent research utilized GPS collars to monitor a large population of Alpine ibex. Researchers then analyzed their movement data to uncover corridors within mountain ranges. During both spring and autumn migrations, ibex preferred paths with less energetically costly elevation change, steep slopes for refuge against perceived predation risk, as well as roads or ski areas where navigation in deep soft snow may prove challenging for them.

These patterns of Ibex migration resemble those seen among long-distance migrating species like wildebeests and zebras in Africa, according to this study’s authors. They say their findings could inform conservation strategies for these and other migratory species such as birds, amphibians, and fish; additionally they intend to use their model to predict connectivity for these migratory groups but first need more data from animal movements in the Alps from volunteers tracking animals for research, communicating their work to a wider public audience.

Fall

From elk and moose to snow leopards, the remarkable array of species inhabiting mountain ranges around the world must contend with extreme weather conditions in order to survive and thrive in these harsh environments. Yet they’ve managed to do this thanks to evolution’s unparalleled adaptability and resilience – often manifested through seasonal movements for mountain animals.

These migrations typically consist of traversing various habitats and elevations in order to access resources, and are most frequently seen among ungulates and some herbivores and omnivores; they tend to be rare among terrestrial carnivores (with Arctic Foxes being an exception), possibly because their walking speeds tend to be slow and energy consumption high. Seasonal movements are especially essential in mountainous species that must adjust quickly to changes in climatic and environmental conditions.

Migration between different habitat types can dramatically enhance an animal’s fitness, and is one of the key forces driving seasonal movements. Yet its exact drivers remain poorly understood; migration differs among species. For example, some ungulates migrate between their resident and breeding areas while others do not; why this occurs is still under investigation.

Scientists conducted a new study that tracked radio-tagged Lagopus lagopus willow ptarmigans (Lagopus lagopus) through an alpine landscape in Central Norway, tracking their movements over four seasons. Their migration decisions were determined by state variables like age and body weight as well as by repeated migratory decisions made across seasons – it appears migration decisions can also be seen as a compromise between increasing forage quality in breeding territories versus decreasing predation risk, both options possibly offering advantages under certain situations.

Migration patterns varied significantly among residents and migrants; residents showed a preference for higher NDVI values and forage-free terrain while migrants preferred lower NDVI values and forests. Yet both models performed similarly when it came to predicting connectivity of migrating species; suggesting that accounting for population-specific habitat selection models can help predict connectivity in migrating species.

Understanding how climatic, environmental and anthropogenic factors influence seasonal movements is of vital importance for conserving mountain species. With most mountain ungulates facing greater threats in today’s increasingly hazardous landscape, keeping their movements intact is integral to maintaining ecosystem functions and services.