Window watching, serendipity and a tiny moth

The playwright Katori Hall wrote that serendipity always rewards the prepared.

There I was, shortly before lunchtime on Thursday 14th April 2016, sitting at my desk in Southover House, pausing mid-letter to watch the Rooks zip from their rookery at the front of the office past my window towards Pelham House and back again with their beaks stuffed with food, when a much smaller movement caught my eye. There, on the inside of my opened window was a small dark moth. Of all the 200-odd windows in all the rooms at Southover House, it chose mine! I dashed to the Rangers' desks close by, grabbed a pot and, a few seconds later, the little moth was safely inside.

Dan and I spent a few minutes of our lunch break checking through the list of species belonging to the Gracilariidae family of moths until Dan suggested that our little moth was Phyllonorycter rajella. It was confirmed the next day by County Recorder Colin Pratt.

Phyllonorycter rajella - the Common Alder Midget, found on Alder trees and on the insides of office windows

Phyllonorycter rajella (or the Common Alder Midget) is new to me - I had never previously seen it, mainly because its food-plant, Alder (Alnus), doesn't grow on the chalk Downs where I do most of my entomology. There are plenty of Alders close to Southover House though, in the Southover Grange Gardens and the Railway Land Local Nature Reserve. It is a widespread species, fairly common where Alders grow, but apparently easily overlooked - like most micro-moths.

The adult is on the wing during two generations each year, during May and again in August. It is very small: about 5mm in length with a wingspan of about 8mm. They have a white face and, if you look carefully in the photograph above, you can see that it has white tips to its antennae. The larvae feed on the inside of an Alder leaf, forming a mine on the underside and causing a mottled appearance on the upperside. This is described well, with photographs, on the British Leafminers website.

On checking Colin Pratt's A Complete History of the Butterflies and Moths of Sussex, P. rajella was first recorded in Sussex sometime just before 1859 by the eminent entomologist H.T. Swainton. That was the last time it was recorded in Lewes. I wonder how Stainton would have felt if he had been told that a gap of 160-odd years would be broken by a chance finding on the inside of someone's office window? Would he have chuckled or would he have shaken his head and mumbled something Latin in a hushed tone?

Most Sussex records of P. rajella are of leaf-mines. There is one record of a larva and, before yesterday, the only adult record was made in 1984, meaning yesterday's record appears to be the first adult seen in Sussex in 32 years.

When one considers the many miles trodden in the dark by Lepidopterists, burdened with heavy equipment, the hours of work dedicated to searching for an elusive species, the disappointment felt trudging back home after a fruitless search, this particular record of a moth which flew into the human world for the first time in more than three decades feels something like cheating. Sometimes serendipitous records such as this are a reward for those barren times.

Of all the windows in all the rooms at Southover House, this little fella had to fly in through mine.

References:

Pratt, C.R.P. 2011. A Complete History of the Butterflies and Moths of Sussex. Volume One. Independently published.

Pratt, C.R.P. 2015. A Complete History of the Butterflies and Moths of Sussex. Volume Four. Independently published.

Secrets of a small rookery, part one: Common Ground

Humans often seem to share a negative emotion when it comes to the crow family: indifference, mistrust, fear, dislike or even hatred. Where do these emotions come from? Are they inherent or acquired - weaved into our cultural DNA? The corvids are, to me, the most appealing and fascinating of bird families; the Rook is my favourite.

One of the things which makes rooks a favourite bird is that they stick around; they are constant, ancient and as much a part of the landscape as the Downs themselves. When one thinks Rook, one should also think rootedness. Like their trees, Rooks are rooted in the landscape. Many rookeries have existed longer than living memory - those which have avoided the axe and chainsaw. I have been told that many rookeries are ancient. When the Romans looked fearfully upon Silva Anderida and, later, the Saxons towards Andredsweald - the ancient, seemingly endless, impenetrable southern woodland - the eastern extent of the Sussex Downs remained treeless and formed an open spit of land between the trees and the sea, and possibly had been this way since the tundra retreated north at the end of the ice age, when mud and melt-water carved dykes and plugged valleys. These are the high, open vistas chosen by the Neolithic tribes to bury their kinfolk in the tumuli which punctuate the hills today.

I fancy that the rooks took root soon after those first post-ice age trees, watched by the first hunters, foragers and farmers, flying out of those ancient leaves and onto the ancient turf doing then the same that we can watch them do today and what they will continue to do for as long as the trees and the turf remain neighbourly.

What did those ancient birds think of us plundering their resources? What did they call us for doing so?

Late-February is a good time of year to begin watching rooks.  One might possess a keen eye for them year-round, yet spy on them with an enhanced interest from about mid-February. They are waiting to begin the nest-building season. From my office window in Lewes I am blessed with an almost nest-eye view of the thirty five-odd pairs which cluster together with Jackdaws in the tops of the tallest trees, apparently waiting for some circadian rhythm to pulse, to pass unseen to human eyes as we struggle along in our frantic races. I call these birds the Southover Rookery.

The Southover Rookery in February - the nests seen were built during the warmest, most confusing December on record

The rooks stoop against late winter rains, hanging from the treetops like great black drips of water, waiting. Taking flight as winter gales roar through the trees, they bend flat-backed into the wind and, with an efficiency of effort, launch away with wings bent like cupid's bow, gliding and wheeling in numbers behind a well-fed kinsman to its happy hunting ground to plunder the worms with their bald faces pressed deep into the turf.

They are fierce birds and, to the Buzzard, they are legion. I have seen no bird stand up to them, yet their smaller Jackdaw cousins are tolerated, bullied, integrated separately but within the rookery. But it is still called 'The Rookery' wherever the two birds are present.

One of the more ironic aspects of watching an urban parliament is that the signs showing the start of nest-building are underfoot on the paving when one walks beneath the turmoil above: thousands of fallen twigs cast like runes on the paving appear in a sudden shower. Look down to understand what is afoot above. We have taken their land and paved it, but they treat it like any other woodland floor. 

For a week or two prior to this the birds sit in the trees, newly paired, and tenderly and quietly occupy the fork of the branch upon which they will construct their nest of twigs and raise their young. As I observe from the office windows, I see one of the pair hop clumsily along the bough to a twig and grasp it between its bill, tearing and tugging it loose, hop back to its mate, but avoiding the lunge of its hostile neighbours. This raucous bird now shows its tender side; together they assess the suitability of the twig as nest material, eye it closely, place it on the fork of the bough. The twig falls, but balances precariously on a lower branch; the owner hops down to where it comes to rest, collects it, returns to the nest-site, repeats its work. The twig falls again, but this time to the road below, littering the pavement.

The following day the birds can be entirely absent. But the very beginning of a proto-nest has appeared in the crook of a bough. Another is close by. They are where I observed the two pairs the previous day. Does this mean they have staked their claim to the tree? Is it now their right in rook-law to return at their leisure and be assured of their place? Dominant above subordinate. Whatever purpose it may serve, a strong wind at this early stage can wipe the trees clean of incomplete nests.

Proto-nests

Proto-nests

The waiting recommences. The pavement may be more or less bare in the morning as I walk into the office and littered with twigs at lunchtime, or I may walk out of work in the evening on a clear path only to return the next morning to the spectacle. From this time of year I begin to pace back and forth expectantly beneath the rookery, looking up; and the sign that it has started is always so clear that one could literally trip over it and, when one does, it has begun.

Above, the birds fly in straight spoke-like lines, chessboard straight, back and forth repeatedly to and from the hub, swooping low over the rooftops with twigs snapped off trees in the gardens at Pelham House and Southover Grange, the Convent Field, the Priory ruins, the Dripping Pan where their namesakes play football, the Railway Land and anywhere else arboreal. Their nests are built from scratch and they appear to prefer green wood to brittle deadwood. Each year, without fail, after the nests begin to take shape, each bird begins to take an interest in their neighbours' nests. Like all the corvid species, the rook is both intelligent and observant. After a while temptation gets the better of it and, while its neighbours are away, it steals a twig from their nest for its own. Time and energy saved! Then it takes another. After a few thefts its own nest is plundered by another observant bird who has cottoned onto the caper. The scheme, the rookery, quickly descends into a melee with pairs of birds screaming from their own nest in defence while attempting to steal from the others, clattering through the trees. The cacophony, the comedy, is an annual rite that I rejoice in whenever I see it.

Throughout the winter, when the previous year's fledglings are shocked by the stark truth that endless autumn days and harvest gleanings are finite, the flock seems subdued. They still wheel and cavort across the sky, mob the buzzard and bully the jackdaws, but they are clearly waiting for something. Today, though, they are nowhere near and I too must wait.