Even as frost leaves its hard edges on our land our snowdrops are once again in flower, many of our birds singing, displaying and mating and spring is approaching with each lengthening day. The pace of nature’s progress follows a complex logic that is of great interest to scientists, some follow the changing day lengths, others react to changing temperatures or perhaps to cues regarding the maturation and or profusion of other organisms on their annual path to abundance. The science of this study is known as phenology, a word routed on the Latin word for appearance which also forms the word phenomena. Phenology is central to debates about global warming and the potential changes it may have on the natural world.
Snowdrops by Mike Malpass
Bird behaviour is known to respond to light levels for birds, in the battle to conserve weight for flight, have only vestigial gonads over winter, but now, enslaved by hormones they entertain us with their display behaviour and jealous conflicts, chasing around the canopy in uneasy threes. Although day and night follow the more fixed celestial progress of the sun and earth that is immune to human artifice, the prevalence of street lighting is thought to be encouraging birds such as robins and blackbirds to sing earlier than they used to.
By contrast the arrival of plants respond to temperature changes and spring seems to be arriving earlier by the year. An increase in temperature from minus one to plus one can push the world from a frozen dormancy to a fluid responsiveness, a more significant change than a two degree rise within the profound solidity of winter and so ‘equal’ changes of temperature are far from equal in effect and the importance of each change must be reckoned and weighed by science. By statistical methods we may try to predict the future although the reason that knots this thread of this logic may be even harder to understand.
As our world changes it is sure that the annual cycles of entwined organisms will be re-ordered or broken and there will be winners and losers. An early flower may die in the frost, an early bird may arrive to find no worm. Whatever unfathomably complex cocktail of physiology is mixed in the natural world, humanity, as contributor to spring’s progressively early arrival, must try to account for because there is no question that spring is arriving earlier and earlier in our land. Some of this data comes from the contributions of amateurs who submit their sightings to such “citizen science” projects as the Nature’s Calendar project, whose website and surveys will be sure also to connect people with the nuances and beauty of our seasons.
Whatever the subtleties of these changes many of us love watching the annual cascade of species that play across the land is a pleasure that all of us should enjoy.
Words by Andrew Francis, our residential warden, with his thoughts on the season.
Other Wildlife Highlights this week...
Wildlife around the reserve of late has been responding to the increasing signs of early spring with the first blackbirds starting to sing, the snowdrops in full flower and dunnocks in the hedges beating up their closest rivals. A highlight of the week included 16 avocets that dropped in at the Eric Morecambe and Allen hides for a short time before moving on. 11 avocets were back on the pools on Friday 23 following a few days absence. Many other birds are soon to be arriving back such as sand martins , chiffchaffs and wheatears. Others are currently settling back in, such as the black-headed gulls that have appeared in growing numbers from Causeway Hide and on Lillian's pool.
Great crested grebe by Richard Cousens
Although still or partially in winter plumage, a pair of great crested grebes were observed practicing their courtship ritual, spotted from the Causeway Hide in the last few days. Similar to last spring, bitterns have been tantalising us this week. Following the occasional sightings by visitors and staff, we would expect any male bittern in the area to start what is often referred to as 'tuning up'. Bitterns are perhaps best known for their deep booming call that they make when holding territory which is very powerful and resonant. 'Tuning up' could perhaps be referred to as a bittern clearing its throat and declaring its intention to other potential bitterns without committing. Rather than the deep boom they make a series of low key but audible deep but short vocalisations during early spring after dusk or indeed at any time of night. If you are so inclined to stand around in the dark, the causeway is the best place to help us listen out for any bittern activity. You will be surprised how different each night can be with some providing a still ambiance gently broken by the sound of wildfowl to nights where the sounds of teal and wigeon fill the night air, making hearing anything else a little more challenging.
Marsh Harrier by Mike Malpass
Back on daylight hours, there are at least four marsh harriers, including one male and a green wing-tagged juvenile, all becoming increasingly active, particularly to the north of the reserve. We would be grateful to anyone who can tell us the identification markings on the green wing tags so we can find out if this is the same or a different bird reported earlier in the season. The tags indicate that this marsh harrier is one of four young birds that fledged from a nest on the Norfolk/Suffolk border!
Starlings murmurating at Leighton Moss
Superb numbers of shoveler, wigeon, teal and in excess of 50 mute swans have been present on the reserve; the bulk of wildfowl is best observed from the Causeway Hide. The starlings remain on top form with estimates ranging from 30-60,000 murmurating and roosting within close range of the causeway. The best time to see them is from around 5:20pm although they vary with the conditions on the day. With the size of the roost decreasing now is the perfect time to visit before this spectacle is over for another year. Snipe on the reserve have been a highlight for many visitors this week and you may even see them flying around during the day. Red deer have been putting in appearances around the reserve along with daily otter sightings, even the first bats of the year have been active on milder evenings; with so much wildlife activity on offer you are sure of a great visit.
We hope to see you soon.
Steven and Andy
I'm pretty sure the tag is ZN