In the quiet of a Norwegian spruce forest, a flash of russet fur and a twitching tail betray the presence of one of our most beloved mammals: the Eurasian red squirrel (Sciurus vulgaris), known simply as ekorn. While red squirrels have suffered dramatic declines in the United Kingdom and parts of mainland Europe due to the introduced American grey squirrel (Sciurus carolinensis), Norway remains a haven where the native species thrives. This article explores the ecological reasons behind this success and the ongoing vigilance needed to keep it that way.
The Boreal Stronghold
Norway's vast boreal forest, dominated by spruce (gran) and pine (furu), provides an ideal habitat for the red squirrel. These coniferous forests offer a reliable supply of seeds and cones, the squirrel's primary food source. The red squirrel has evolved alongside these trees, with a digestive system and behaviour finely tuned to exploit this resource. In contrast, the grey squirrel is a generalist, better adapted to deciduous woodlands and urban parks, which are less common in the Norwegian landscape.
The sheer extent and continuity of Norway's forests also play a crucial role. Red squirrel populations can move across large areas, finding food and shelter without the fragmentation that plagues many other European habitats. This connectivity helps maintain genetic diversity and allows populations to recover from natural fluctuations, such as harsh winters or poor cone years.
The Grey Squirrel Threat
The American grey squirrel, introduced to the UK in the late 19th century, has been a disaster for native reds. Greys are larger, more aggressive, and more adaptable, outcompeting reds for food and habitat. They also carry the squirrelpox virus, which is lethal to red squirrels but harmless to greys. This combination of competition and disease has driven red squirrels to the brink in many areas, with only a few strongholds remaining in the UK.
In Norway, the grey squirrel has never established a population. The reasons are partly geographical: the North Sea and the Scandinavian mountain range (Kjølen) act as natural barriers. Additionally, Norway's climate, with its long, cold winters and deep snow, is less hospitable to the grey squirrel, which is adapted to milder conditions. Strict import regulations and public awareness have also prevented accidental introductions.
The Red Squirrel's Diet and Caching Behaviour
The red squirrel's survival in Norway is closely tied to its feeding ecology. It primarily feeds on the seeds of Norway spruce and Scots pine, extracting them from cones with remarkable dexterity. During autumn, when cones are abundant, red squirrels engage in intensive food caching, burying or hiding thousands of cones in scattered locations. This behaviour, known as scatter-hoarding, ensures a food supply through the winter and early spring.
This caching strategy is highly effective in boreal forests, where cone production fluctuates from year to year. By storing surplus cones, red squirrels buffer themselves against poor seed years. The grey squirrel, in contrast, relies more on a diverse diet that includes tree bark, buds, and even bird eggs, making it less dependent on conifer seeds. In Norway's monochrome conifer forests, the red squirrel's specialization gives it an edge.
Seasonal Adaptations and Behaviour
Norwegian red squirrels exhibit remarkable seasonal adaptations. In winter, they grow thicker fur and develop prominent ear tufts, which are thought to enhance their hearing or provide insulation. They remain active throughout the year, even in the depths of winter, relying on their cached food and the occasional warm spell to forage. Their nests, called drey, are built high in spruce trees, often using twigs and moss, and provide shelter from the cold.
During the breeding season, which peaks in late winter and early summer, red squirrels become more visible as males chase females through the trees. Females may produce two litters per year, with young dispersing in search of their own territories. This reproductive resilience, combined with a stable food supply, helps maintain healthy populations across Norway.
Observing Red Squirrels Respectfully
For wildlife enthusiasts, watching red squirrels in their natural habitat is a delight. The best times are early morning or late afternoon, especially in conifer forests with a mix of spruce and pine. Look for signs of activity, such as discarded cone cores (known as 'squirrel middens') at the base of trees, or listen for their sharp 'chuck-chuck' calls. Patience is key; squirrels are wary and may freeze or hide if they sense disturbance.
It is crucial to observe without interfering. Never feed red squirrels, as human food can harm their health and alter their natural foraging behaviour. Keep a respectful distance and use binoculars or a telephoto lens for a closer look. Dogs should be kept on a leash to avoid stressing wildlife. By following these guidelines, you can enjoy the presence of these charming animals while ensuring their continued well-being.
The Future: Vigilance and Conservation
While Norway currently remains free of grey squirrels, the threat is not entirely absent. Climate change could make Norwegian habitats more suitable for greys, and human transport can inadvertently introduce them. Conservation efforts, therefore, focus on prevention and early detection. The Norwegian Environment Agency and wildlife organisations monitor for any signs of grey squirrel sightings, and public reporting is encouraged.
Protecting the red squirrel also means protecting its habitat. Sustainable forest management that maintains a mix of tree species and age classes ensures a steady supply of cones. Leaving dead wood and old trees provides nesting sites and foraging opportunities. By valuing the red squirrel as an indicator of healthy boreal ecosystems, we can ensure that future generations will still hear the rustle of an ekorn in the Norwegian woods.
About Lars Haugen
Lars Haugen is a field ornithologist and writer from Trondheim. He has led birdwatching tours in Trøndelag for over ten years and writes about birds, equipment, and great locations in Norway.