A slightly belated report from volunteer Phil (Sorry for my tardiness Phil!)
On the first day of meteorological autumn one of our less experienced visitors asked when the bird migration would begin. I replied that it had actually been under way for a few weeks and there were various signs of this around the reserve.
For a few weeks now we have had a good selection of wader species on the reserve and many of these birds will be passing through on migration. The feeding conditions are currently best on the North Brooks. From the Hanger and Jupps View on Friday I found greenshank, green sandpiper, common sandpiper, ruff, black tailed godwit, snipe, lapwing and dunlin, all in relatively small numbers. Other species seen recently include ringed and little ringed plover, spotted redshank, wood sandpiper and perhaps most notable of all a curlew sandpiper with its characteristic downcurved bill. I have yet to see one on the reserve.
There may be occasional sightings of some of these species throughout the winter but numbers of lapwings are likely to increase dramatically with overwintering birds coming from Europe. Depending on conditions black tailed godwit numbers may increase to several hundred with birds migrating south from Iceland.
Several groups of cattle can be seen on the brooks and I have been paying close attention to them to see if they are attracting migrating yellow wagtails to feed on invertebrates stirred up by their hooves. Sometimes these birds can be seen feeding on the soft muddy margins of the pools. I’ve not seen any yet this year but there has been at least one visitor report of a yellow wagtail in the last 2 weeks.
It is not unusual to see migrating redstarts at this time of year and there have been a few reports from the fence and hedge lines at Redstart Corner. So far it doesn’t appear that these birds have stayed for long, but it is not unusual for redstarts to stay for a few days, feeding to build up strength for the long journey south across the Channel.
On Friday I found 2 spotted flycatchers in the bushes bordering the field on the south side of Adder Alley. This photo from 2 years ago shows a spotted flycatcher in the same area.
The bushes in this area seem to be very attractive for migrating birds as I have seen redstarts there in previous years.
A whinchat was showing well in the brambles in front of Hail’s View along with a family party of stonechats. Another such family was present in the brambles by the ditch to left from Nettley’s Hide and several whinchats have been seen nearby recently. The whinchats will migrate to Africa but stonechats are relatively short distance migrants and a few will most likely spend the winter on the reserve.
Tractor mowing has been continuing all over the South Brooks, preparing the ground for winter wildfowl grazing and breeding waders next spring. The ground disturbance caused may be making it easier for raptors to find small mammals. Kestrels and buzzards have been particularly prominent on the South Brooks in recent weeks.
On Friday 25th I counted 4 buzzards from Hail’s View including one very strange looking bird with white head, neck and upper breast. I wondered if this bird might have been the source of the osprey entry for the same day on the recent sightings sheet at the Visitor Centre. However, ospreys do sometimes use the Arun Valley as a route to the coast and have been seen occasionally flying over. The time of year is certainly right for an osprey heading south.
At West Mead on Friday morning I and several visitors were treated to one of the reserve’s autumn and winter spectacles, this being a sudden influx of several different species of raptor. We had already been admiring kestrels and buzzards but in the short space of 15 minutes first a peregrine and then a hobby appeared, to be followed shortly by a red kite and then a marsh harrier.
The hobby stayed for a several minutes, first circling at some height and then picking up speed in several dive bombing runs, most likely taking dragonflies out of the air. I fancied I caught sight of one in its talons but couldn’t be sure as it was all happening at high speed, much too fast for an effective photo so here is one of a hobby circling overhead taken at Thursley Common 2 years ago.
The red kite circled slowly for several minutes allowing a rather distant photo of its striking plumage.
The marsh harrier drifted in classic mode low and slow over the brooks, its cream cap showing well in the sun even at some distance. In the meantime the peregrine had made several of its own dive bombing runs back and forth across the Brooks before settling on the ground out of sight, only to be flushed out by the marsh harrier.
Some of our more common resident birds are starting to form the flocks typically seen in the autumn and winter months. A mixed flock of tits (blue, great and coal) could be seen in Black Wood on Friday, being joined at the time by a party of long tailed tits, treecreeper, nuthatch and goldcrest. A sizeable flock of goldfinches was dancing around the thistles near Winpenny Hide
Having made several unsuccessful attempts to find brown hairstreak butterflies over the last few weeks I was rueing my luck after two of our regular Friday visitors reported seeing one just a few feet away on the brambles in front of West Mead hide shortly after I’d left. I concluded that I may just as well stop looking for them and just hope one would turn up. A little later I was in Adder Alley looking for the spotted flycatchers when suddenly a female brown hairstreak appeared just a few feet away on a blackthorn bush, thereby aptly vindicating my new approach.
With luck these scarce butterflies can be seen in many different parts of the reserve because of the widespread blackthorns where they lay their eggs.
Butterfly numbers are generally down but meadow browns, speckled woods and large and small whites are still easy to find, along with a few red admirals, peacocks and brimstones. The latter seem to have a particular liking for the purple loosestrife flower spikes by Nettley’s Hide.
Brown hawker dragonflies could still be seen in front of Nettleys and Winpenny Hides, although their peak flight period is nearly over. The dominant dragonfly species are now southern hawker and common darter. Recently I photographed a southern hawker in flight over Black Pond.
Studying this photo I can’t help wondering if dragonflies in flight may have inspired the design of the helicopter. Another southern hawker perched in classic vertical pose on the bushes by the path down to Nettley’s Hide.
The extraordinarily intricate colour patterns on the thorax and abdomen have presumably evolved as camouflage for precisely these moments, so it’s not easy to find hawker dragonflies in this position unless you see them land. Trying to do this by following their flight can require a lot of concentration.
Common darters can be seen all over the reserve and are much easier to see perched than the hawkers. Here a male is basking in the sun on the warm gravel in Fattengates courtyard.
This photo shows a female in typical pose on a perch from where she will dart to catch prey and then return.
At Winpenny on Friday 3 pairs of common darters could be seen flying coupled together (usually called “in tandem”) with the female at the rear laying eggs into the pool.
Finally, regular visitors will be familiar with the wonderful sight of large numbers of wetland birds swirling in the air having been disturbed by a raptor such a peregrine, or maybe a fox creeping up through the rushes. This is already occurring due to the flock of several hundred geese, mostly Canadas with many greylags mixed in, now on the reserve.
While there are still some of the delights of summer to be found I concluded that this day marked the return of serious autumn and winter birdwatching.