14-Jan Nature's Resilience Tile Image

14-Jan Nature's Resilience

Summary

Join us on January 14th for a captivating exploration of the coldest day of the year, St Hilary's Day. Discover how wildlife adapts to the harsh winter conditions, from birds seeking food in unexpected places to plants employing unique survival strategies. Learn about the fascinating phenomena of frosts and the impact of extreme cold on nature. This article will reveal the beauty and resilience of the natural world in the face of winter's chill. Don't miss out on this enlightening journey into the heart of winter!

Article

‘A winter such as when birds die
In the deep forests, and the fishes lie
Stiffened in the translucent ice, which makes
Even the mud and slime of the warm lakes
A wrinkled clod, as hard as brick; and when
Among their children, comfortable men
Gather about great fires, and yet feel cold;
Alas! then, for the homeless beggar old.’


                  (Shelley)

Cold Weather

This is St Hilary’s day and by tradition it should be the coldest day of the year, the coldest moment of a day being generally thought to be half an hour after sunrise.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

It often has an uncanny knack of living up to its reputation. Until the middle of the eighteenth century it was not unusual for the Thames to freeze over. Poor weather induces cold weather movements in many birds. Some just move from frozen lakes to the edges of reservoirs or estuaries where there is a better chance of food. This can result in huge congregations of birds on exposed mudflats, particularly near high tide.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

Kingfishers are known to move from rivers to estuaries, snipe to lakes and herons even turn up in gardens. Insect eaters such as stonechats and wagtails also suffer badly and are seen near compost heaps looking desperately for some insects to eat. Goldcrests sometimes leave their usual home among tall conifers and can now be seen moving around in small flocks feeding on birch catkins.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

Much rarer birds such as mealy redpoll, osprey, goshawk, firecrest and hawfinches are all recorded from time to time, especially during severe spells of weather. Hawfinches are now exceedingly rare, having disappeared from the cherry orchards they used to inhabit a century ago. They are the largest of all our finches and particularly finely coloured.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

The head is chestnut with a grey shawl and a jet black bib. The wings are blue and black with a white wing bar and tail tip. The underparts are peach-coloured and the legs pink. Their enormous beak is the first thing you notice. It is as deep as it is broad, gunmetal blue in the summer and yellow in the winter.

These birds are easily capable of crushing beech and hornbeam seeds and so tend to favour those woods, especially in north London. Epping forest is a popular place they sometimes can be seen, as is Bookham common. As colourful as they are they are notoriously secretive and tend to keep to the tree tops, occasionally revealing themselves with an explosive ‘tic’.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

If January is colder than usual there are far less flowers to be seen and birdsong is substantially reduced. The whole procession of animal activity and plant growth is put on pause till better weather returns. This makes a bright, warm day after a prolonged cold spell one of the best times to take a walk.

Cold can cause the foliage of some plants to droop, causing them to become limp and often giving them a glassy appearance. Other plants such as rhodedendrons and the false castor oil plant Fatsia japonica just bend their leaves by adjusting the base of their petioles. This allows any snow to fall off and then the leaves are raised again when good weather returns. Other plants have different ways of coping with the cold. They can sometimes fertilise themselves without the help of insects or reproduce asexually as many bulbs do.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

Others can withdraw water from their cells into intercellular spaces where it then freezes, producing its dangerous spear-shaped crystals which are now able to pierce any delicate cell membranes. When the thaw occurs the cells then re-absorb the water, having avoided any cell damage.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

Walks on frosty mornings can be the most rewarding. Best of all are rime frosts. These are caused by freezing fogs and large, soft, ice crystals are produced which can occasionally create a ‘powdered diamond effect’ as they melt slowly in the early morning sunlight. Hoar and ground frosts are caused by frozen dew and give the landscape a much starker beauty.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

When dew freezes very quickly due to excessively cold conditions whole rounded dew drops freeze intact keeping their shape and forming what is referred to as ‘white’ frost. If it is so cold that rain freezes on contact with the ground it then produces black ice. This is also known as a glazed frost or even an ice storm if sufficiently prolonged and severe.

14-Jan Nature's Resilience Section Image

14-Jan Nature's Resilience Section Image

Black frosts are caused when there is not sufficient moisture to produce any white dusting of ice crystals. In such conditions the food source for many birds is drastically reduced. If the birds do not migrate they will suffer badly. This means it is important to tend to London’s bird tables which may not only be life-giving but also receiving unusual visitors.