Life in the freezer

With the climate becoming ever more erratic and unpredictable, it’s hard to know what to expect of our seasons nowadays. In recent years, Scottish winters have tended to become milder, wetter and windier, the previous one being a case in point – remember Arwen, Malik and Corrie, anyone? This time around, however, we have experienced a couple of ‘proper’ wintry spells, and consequently had to hunt down our usually-redundant gloves, scarves and ice-grips for our boots. This past week, while not as viciously cold as the pre-Christmas period, delivered to Forvie another icy blast from the north-west. Fair to say that the Reserve has looked very photogenic, and felt very inhospitable.

Snow on the way

Mid-week saw a light snowfall over the course of a couple of days and nights. The resultant covering of icing-sugar transformed the landscape into something resembling a Christmas cake. This was the sort of powder snow that gets kicked up by your boots as you walk through it, feather-light and fine, sparkling in the low sun. Being out and about in conditions like these is another simple pleasure to add to the ones we listed in the previous week’s blog.

A fresh dusting of snow
Marram grass, snow and sky
Sparkling crystals

For reasons I don’t fully understand, snowy conditions often produce a beautiful pink hue to the sky. This may be an effect of light refraction by the ice crystals in the clouds, which results in more of the longer wavelengths of light (i.e. the red end of the spectrum) reaching the earth’s surface. Either way, this is a uniquely wintry phenomenon. It’s made all the more spectacular by the snow-covered landscape below, which reflects the rose-pinks and powder-blues of the sky above.

A snowy sky
Rose-pink and powder-blue
A pink winter dusk

A covering of snow means different things for different species of wildlife. For small mammals such as Field and Bank Voles, a bit of snow can be really helpful. They can continue with their everyday lives eating seeds, grasses and other vegetation, but can do so away from the prying eyes of predators. They construct a series of tunnels through the snow, where they can operate in complete safety unseen by aerial predators such as Kestrels and Short-eared Owls.

Of course, they still need to be wary of the presence of a Stoat or Weasel, which could easily follow their tunnel network – or a Fox, which could punch through the snow layer to reach them. But at least they have a bit more privacy than usual! Often, when the snow has thawed after a prolonged period of snow-cover, you can see the now-abandoned runs and tunnels chewed through the grass by the voles – evidence of a world beneath our feet that would otherwise go completely unnoticed.

Bank Vole popping up for a look around

For many species of birds, though, the snow is a serious impediment rather than a help. For seed-eaters like Yellowhammers, for instance, it means their food supply is buried under an impenetrable layer of ice, and they must change their tactics in order to survive. Abandoning their usual haunts in stubble fields and hedgerows, they gravitate towards animal troughs where the hooves of the sheep or cows disturb the ground and break up the snow, or instead head for garden feeding-stations where they gratefully accept our handouts of bird-seed.

Yellowhammers at a garden feeding-station

Meanwhile, fruit-eaters like Fieldfares also try their luck around human habitation – as we’ve said in our previous postings this winter, they have a voracious appetite for apples, and have practically eaten us out of house and home over the course of the past few weeks.

Another hungry Fieldfare

In between the snowfalls have been some clear, sharp, frosty nights, placing extra demands on our wildlife which must burn a lot of energy just to keep warm. Just about all the fresh water on the Reserve has been frozen over at least some of the time, including the lochs and all the flooded areas on the heath (including the footpaths in places!). This creates another problem for mammals and birds – where to drink and bathe?

Frozen Sand Loch
Ice patterns
Heath Trail – get your skates on

Down on the estuary, even the brackish water (i.e. the slightly salty stuff) was threatening to freeze, with ice accumulating on the high-water mark, and a fine coating of frost on the seaweeds along the strand line.

Frosted seaweeds

However, the salt influence and twice-daily tidal movement prevents the estuary from freezing over altogether, even in really cold conditions. The estuary therefore becomes even more important than usual, not just for the masses of wildlife it normally supports, but also for the additional cold-weather refugees from frozen inland waters. These include swollen numbers of ducks like Mallard and Teal, waders of pasture such as Lapwing and Curlew, and occasionally – as we did recently – we might chance to meet with a Kingfisher frozen off its usual freshwater haunts.

Waders on the estuary – how many different species can you spot here?
Kingfisher – hard-weather refugee

Another big positive about the cold and frosty nights is that the crystal-clear air allows for some great opportunities for star-gazing. Or if you’re really fortunate, a glimpse of the Northern Lights. We’ve had a few nights this winter when the aurora alert has sounded; most of the time it’s been too cloudy to see anything. But when it corresponds with a clear night, it’s well worth staying up late for.

Aurora at Forvie…
…and over the village of Collieston

If you’re planning on venturing out onto the Reserve during a cold snap, wrap up warm and be sure to take care in the icy underfoot conditions – but don’t forget to spare a thought for nature during these hard times, and please allow wildlife to feed and rest undisturbed. A little consideration goes a long way when the freeze is on.