Singles nights

The texts will tell you first summer non-breeding Grey Herons will attend their heronry, staying mainly to the edges, being tolerated (just) by the adults there, with only a small handful breeding (most first attempt breed at the age of two).

Some locals fail to read these texts and go awol each spring.

From about the time the adult birds start displaying, right up until the eggs are hatched, a small roost comes into operation in Berengrave LNR. Small indeed, only getting up to around double figures, but regular, happening each year since I started counting the Magpie roost there in 2013.

One or two might already be in position an hour before sunset, with the last join in nigh-blackness. I say the last, Herons are famous for arriving at roost at all sorts of time of day and night, depending on their feeding preferences (some crepuscular feeders, a few, nocturnal).

During the 90  minutes or so I'll spend there, squabbling always happens. Birds might join in aerial chases for ten, fifteen minutes over the old flooded chalkpit, but eventually they all settle down together, high up in the trees along the water's edge. This favoured area is extremely close to the main path, but they have learned to ignore the few dogwalkers that pass by, heads down.

If I mention the Grey Herons, birders go '...didn't know they nested there, how many pairs?'. And then have trouble computing the answer 'none'. Such roosts are simply not on the radar of many birders.

'Club Loser' will be closed down by the end of the month. Perhaps this roost behaviour, at its start, is similar to something seen in many other colonial species- recognisably immature birds aren't really wanted in the heart of a colony. Perhaps at its end, those adult breeders who drove them off are way too busy providing food for their young to waste time bossing the immatures about. No need to play 'who's the daddy?' now the eggs have hatched.

The old text of 'Birds of the Western Palearctic' hints at limited information on nocturnal roosting but goes on to say that youngsters roost close to the colony throughout the year. The main local colony here is, of course, Northward Hill, the UK's largest. As the Crow flies, some six miles away. The crow's route suits the Herons perfectly throughout most of the year. The estuary is only really beginning to close at Pinup Reach, but has the western island complex scattered around it, and many non-waterbirds choose to cross in this area rather than over more open waters. Of course, the yellow line on the map below is only representative, birds in transit being more widespread than shown, but you get the idea.

The two spurs marked show routes less often used to join that flyway. Interestingly, used more times for 'returning' towards Hoo and Northward Hill than leaving. To me, that implies the birds may well be spreading east during the course of a day, away from the concrete of the Medway Towns, checking a series of feeding areas as they go, before returning direct. Studies have shown adults not only know the better spots, they also know the best times to be there. Youngsters might spend a big part of their hunting time staking out one good spot, not yet appreciating the subtle skills of the seasoned angler. Which might be another appeal for Berengrave- as well escape from all that harassment, somewhere a lot closer to what remains of the southside marshes off to the east.

It also knocks holes in the 'migrating Herons' cognitive bias I suffer when lines of mainly young birds cross Pinup on an early autumn morning.
"Hey, you at the back, you all migrating?"
"Nah, just hungry, that one in front found something yesterday, just following him."

All highly fanciful thinking of course, from my mantra of 'not all movement is migration'. But dreaming about Herons helps pass the time counting the Magpie roost right now. Those numbers are in freefall with their own nesting underway. Couples are coming in together though, feeling safer at the old communal roost than risking a night in a still egg-less nest. But of course there's quite a few single Magpies turning up. Quite a few. 'Club Loser' is open to all, 365 nights a year.