January on reserves

January on reserves

Frosty reeds (credit: Roger Tidman)

Our Reserves Officer, Robert Morgan, shares the crucial work happening on our reserves this winter, along with the wildlife emerging as spring approaches.

Although Norfolk missed the early January snow enjoyed by many others, we did have a spell of freezing weather that included some spectacular hoar frosts. An increasingly rare occurrence now. This left our reserves looking resplendent in their sparkling crystal coats. Those undertaking the monthly Wetland Bird Surveys (WeBS) were challenged by broads that were near frozen over. Although, the crack of ice as a boat’s bow breaks through it is a very satisfying sound on an icy morning. 

Habitat improvement ground work has taken place at NWT Narborough railway line reserve - if anyone was wondering why it has been closed! Machine Operator, Paul Lambert, with the help of a 360-degree digger, has been hard at work under the instructions of Reserves Manager Ash Murray. Ash explained, “Bare ground is a vital habitat, but has experienced significant decline in recent decades due to the fertilising effect of nitrogen pollution, and warmer, wetter winters. This promotes monocultures of vigorous ‘weeds’ at the expense of species rich plant communities. We have been creating a varied set of bare ground conditions at Narborough Railway Line”. The areas of bare chalky ground, south facing clifflets, compacted chalk rubble and ‘discrete’ turf-stripped patches will be excellent for an array of chalkland plants and their associated invertebrates, particularly dingy skipper butterflies and several rare moth species. Ash continued, “Narborough is a phenomenal place for invertebrates, including several for which this is the only known site in the county. Of the 762 known invertebrates here, 32% are associated with this type of bare ground.” 

Pulses were racing for birdwatchers in late January at NWT Thorpe Marshes, when a red-necked grebe arrived on St. Andrew’s Broad (actually a former gravel pit). It is the rarest of the regular UK grebes and the first one in the Norfolk Broads for many years. Although its rather annoying, but quite funny, habit of nipping across the river to neighbouring Whitlingham Broad for a few hours then coming back again left some local birders twitching with frustration.   

February can seem a rather dull, unnecessary month, particularly as we start to turn our attention to a new season. The middle of the month often delivers a ‘fool’s-spring’, before turning cold again. The month is certainly caprice of character. February never fails to provide harsh winds and hard frosts, but its temper can quickly change to a light breeze and gentle sunshine; tempting us time and again that winter is finally over. As nature sighs with relief, February, with the spite of a Greek god, will plunge her back into freezing bitter weather. 

If one of February’s sunny spells does persist, it can encourage adders and brimstone butterflies to emerge from hibernation. Hazel catkins are already long and drooping like lamb’s tails, and clusters of snowdrops peek jauntily at a strengthening sun. A drive through a country lane on a mild February evening may find the season’s last swarm of male winter moths caught in the headlights. This moth has no stomach and, like the mayfly, their purpose is to mate then die. The wingless female, safe in the knowledge that she will attract several suitors, sits on an oak trunk wafting her pheromones into the night air. Our resident birds start to pick up their song, with territories already being contested in readiness for the spring. But beware, old wives’ tales often ring true: ‘When the cat lies in the sun in February, she will creep behind the stove in March’. 

A blue tit perched on a branch of catkins.

A blue tit perched on a branch of catkins (credit: Bob Coyle)

On the reserves in February, the finishing touches of scrub clearance is underway and the last few blocks of reed are being cut. Although the growth of the new colt (young shoots) is always noted, fine weather can bring the reed shooting up earlier than expected, and too many heavy boots can damage a reed bed in its tender youth. Dykes and ponds will have been cleared of excessive plant growth by the first week of February, as frogs and toads will already be joining the smooth newts that chose to remain in the water over winter. Seeing frog spawn in February is now a common sight. Whatever the whim of the weather, by the close of the month our heronries will already have eggs in the nest, with chicks very soon to follow. The heronries at NWT Barton Broad and Upton Broad have been monitored by NWT staff every year through the British Trust for Ornithology (BTO) recording scheme for several decades. Although, when a heron colony is deep in an alder carr and high in the canopy, it can be difficult to see any activity in the nest without causing too much disturbance. A good estimate of the number of chicks can be ascertained by searching for the discarded egg shells at the base of the nesting tree. Alternatively, listening for the loud bill claps made by the hungry chicks is good way of judging breeding success.