A season shaped by cold temperatures and long nights might seem like a time to watch wildlife in warmer places on TV or read about it in books. Yet for some wild animals and plants winter weather is a time of activity and growth. Although our swims are shorter in winter, while we are in water – and on our way to and from it – wildlife still offers seasonal highlights.
On land, it is not until May that deciduous trees are fully clad in leaves. On grey winter days, the place for lush fresh growth is in the sea. Cuvie kelp (Laminaria hyperborea) starts to grow its new blades in November. Over the course of months being tossed in sea currents and nibbled on by herbivores old blades of cuvie become frayed at the edges and overall look quite worn. In summer, just before the old blades are shed, cuvie kelp beds look tattered and dull. For sea beech (Delesseria sanguinea) new growth starts in February. Dabberlocks (Alaria esculenta) has its fastest growth rates in spring, by June its growth slows. A seaweed safari during cooler months of the year might be briefer than a summer seaweed hunt, but more rewarding in terms of seeing fresh growth.
Many seaweeds dry well and winter harvest can be stored for use year round in a forager’s kitchen. A particularly wintery use of Irish moss (Chondrus crispus) is the traditional soothing remedy of infusing it in herbal tea when cold air and coughs are harsh on throats.
A seaweed safari during cooler months of the year might be briefer than a summer seaweed hunt, but more rewarding in terms of seeing fresh growth.
Before springtime sap rising in trees winterbournes come back to life. These streams that run dry in summer burgeon in cooler months. As autumn turns into winter, little leaves appear between blades of grass in the streambed. These belong to seedlings of watercress. Invisible to the surface view, water is increasing in the stream channel’s substrate as groundwater that feeds the winterbourne is recharged by rain. On a wintery visit, puddles that were previously a thin layer of water on mud start to have depth and stretch along the stream channel. A trickle of water connects puddles, and aquatic plants grow rapidly as a winterbourne re-emerges into full flow. Winterbournes tend to be too small for swimming, but they refresh downstream swimming spots with aquifer filtered clear water.
Many river swims in the cold months of November to January are paused by a strong, sweet scent in the air whose origin is not obvious. Damp ground along riverbanks is a favoured haunt of winter heliotrope (Petasites fragrans), which has inconspicuous but strongly scented flowers. Although spring and summer are the time of floral abundance in Britain and Ireland, there are several winter blooming plants that enliven winter swims with colour and fragrance.
Bog myrtle (Myrica gale) might be a familiar name to some swimmers as an aromatic leaf used in gin. Its flowers were a key bittering agent in beer before the advent of hops. Swimmers are most likely to encounter bog myrtle along the shores of lakes where it grows in damp or boggy ground. Before its leaves sprout in spring, bog myrtle flowers on bare twigs. Pick a flower and crush it to release bog myrtle’s strong resinous scent that is more concentrated in its flowers than its leaves.
Swimmers are most likely to encounter bog myrtle along the shores of lakes where it grows in damp or boggy ground.
Coltsfoot (Tussilago farfara) splashes bright yellow flowers around waterside locations at the end of winter. Its aquatic location is not because of a need for moisture—it is drought-tolerant—it grows by rivers and on seashores because they share the feature of disturbed ground. Crumbling riverbanks, slumping soil at the base of cliffs, landslides, shifting sand dunes and shingle all offer the chance to grow with little competition. Spreading vegetatively via rhizomes allows it to keep purchase in unstable land.
Perhaps the most vibrant colour along seashores comes from a lichen. Named for its typical location and colour maritime sunburst lichen (Xanthoria parietina) grows on walls, stones and branches near the sea. Its orange-deep yellow colour is caused by parietin, a pigment that absorbs blue light and provides protection against UV-B light.
Winter brings seasonal visitors to our shores. In the north of England, Scotland, and Northern Ireland eider ducks (Somateria mollisima) can be seen all year round. Winter cold swells their ranks as many eider ducks overwinter in Britain rather than their Nordic breeding grounds, and some will travel as far south as Cornwall. By-the-wind-sailors (Velalla velalla) are accidental visitors, brought to our coast by strong winter storms. Their adult life is spent floating on the sea surface driven by wind blowing on their triangular fin. They can be encountered while swimming, though storm waves mean that swimmers are more likely to find them on the tide line on days when swimming is better avoided.
Much resident aquatic wildlife plunges into breeding behaviour in winter, timed to provide offspring with advantages of hatching in spring. February is peak time for seeing Great Crested grebes (Podiceps cristatus) performing their elaborate courting dance. In choreographed and co-ordinated movements of head-shaking, turns, and feather flicks they move together dancing across their lake’s surface. Diving deep, they collect waterweeds and meet on the surface to display leafy offerings to each other. It is a short-lived moment of romance as after mating and taking it on turns to sit on their nest, the chicks hatch and within a month the parents split up taking a chick or two with them. After this time standard territorial rules apply and family members can be hostile to each other.
By-the-wind-sailors (Velalla velalla) are accidental visitors, brought to our coast by strong winter storms. They can be encountered while swimming, though storm waves mean that swimmers are more likely to find them on the tide line on days when swimming is better avoided.
Mounds of gelatinous eggs in ponds are the work of spawning frogs. Common frogs (Rana temporaria) offer a British and Irish version of Japan’s spring progression of cherry blossom bloom. In southern and sheltered areas frogspawn spawn can appear in February. In northern and more exposed areas frogspawn might not be seen until April. As winter eases and freshwater warms, pike (Esox lucius) being congregating at the shallow margins of rivers and lakes where there are waterweeds to lay their eggs. It’s a rare opportunity to see this usually solitary fish in number.
As in warmer months there is wildlife that benefits from awareness of its needs and restraint from people enjoying wild places in winter. For example, salmon (Salmo salar) spawn in autumn, leaving their eggs in gravel patches in rivers. After 40 to 145 days of incubation juvenile fish emerge. So swimmers enjoying salmon rivers should take care to avoid disturbing areas of gravel from late autumn through to late spring as the stability of the gravel in which eggs are laid is essential for embryos to develop and successfully hatch into juvenile fish.
It’s natural for swims to be curtailed in length by cold temperatures. But there is no need to think the natural world around us is bleak during this season. Winter conditions drive growth and behaviour, and wildlife still offers much to enjoy in the coldest months of the year.
On this website see also the Swimming Without a Trace post for more about respecting the environment and the Outdoor Swimmers Code for ways that swimmers can be responsible towards the environment and in considering others and safety.