The season is terning...

Monday, 30 August

By now many of the terns which bred at Hayling Oysterbeds and in Langstone Harbour will have started on their annual migration back to wintering quarters in Africa. Others will hang around in British waters before they also leave. Whatever the status or location of these birds they have all departed their nesting areas. Well all but one pair that is. A very late nesting pair of Common Tern is still feeding two young on the north island of the Oysterbeds lagoon. They hatched their eggs on 08 August so the young are now almost three weeks old. I find it remarkable they have survived the last week of rainy and (at times) windy weather but they have. I visited the reserve last Friday and found them begging for food from their parents. The fact that the parents haven’t given up in the recent weather is admirable. Well, perhaps it’s more hormonally-led behaviour. A similarly late pair of Common Terns in 2006 eventually successfully fledged there two young in early September so this late nesting isn’t without precedent. The previous fledglings which I referred to in my previous post were finally led away from the lagoon on 16 August. I was lucky, and felt privileged, to witness their departure. One of the adults came in and fed one of its two young and then, without any calling that I could hear, started on its way back to the main harbour. As it got ten metres or so away from the lagoon islands one and then both youngsters flew up and followed it out. One was a bit smaller and blunter-winged than the other but, as a family group, they disappeared tentatively into the distance. They increased the total of fledged Common Terns from the reserve this year by two…. it currently stands at 82.

I’ve not been out much since last week but in sunnier conditions earlier this month there were a lot of hoverflies to be seen. I managed to get images of some of them, and even had a go at identifying a few. Having spent some time wandering around with a previous warden at Farlington Marshes in years gone by, someone who specialized in surveying and identifying these creatures, some of the identification stuff has rubbed off on me (I emphasize the “some” there!). Hoverflies I CAN get into, I suppose because many of them are very colourful and are a good subject for macro-photography. I even remembered some of the Latin names (most insects do not have common names, so you HAVE to learn the Latin). The key to locating the commoner species is to find some late-summer flowering plants, and look for them nectaring (and wait for the sun to come back out...not necessarily in that order….). Here’s a couple that I saw at the Oysterbeds, taking nectar from the yellow lowering Common Ragwort, an important source of nectar for many insects in the summer:

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Sphaerophoria scripta......................................Scaeva pyrastri

My visit to the reserve last Friday also coincided with a high spring tide and a good selection of autumn passage migrants. Along with several hundred Dunlin, Ringed Plovers, Redshanks and Turnstone a nice group of five juvenile Curlew Sandpipers and a Ruff had dropped in. The continued presence of an Osprey in the harbour had shifted the main roost of Oystercatchers in the harbour from the main harbour islands to the outer embankment of the Oysterbeds, with a total of 1276 counted. Quite impressive. A smaller number of Grey Plover (38) and Knot (3) were also seen. Seven Whimbrels, two Greenshanks and three Common Sandpipers completed the list of waders. Also of note were seven Little Terns with the gathering of Common Terns on the shingle spit just to the south of the lagoon, while single juvenile Black and Arctic Terns dropped in or flew past. Finally, the first returning Black-necked Grebe of the season was in the main harbour channel on the falling tide. Later I dropped by the Wildlife Trust reserve at Southmoor where at least 70 Yellow Wagtails had gathered to feed amongst the cattle. A Redstart and a couple of Wheatears were also here (four of the latter were also seen earlier at the Oysterbeds), while nearby three late Swifts were feeding over the pools at Budds Sewage Farm along with fifty or so Swallows and Sand Martins.

Still going....

Thursday, 05 August

Well, it’s almost the end of the breeding season for the sea birds at Hayling Oysterbeds but not quite! Currently the pair of Common Terns that I featured in my last update still has two half-grown young, while two other pairs are incubating eggs still… Three more young Black-headed Gulls have just made it onto the final total for fledging by this species as they can now fly around. They are of course still begging for food on the lagoon islands, but eventually as the adults bring in food less regularly they will learn to feed for themselves and move on (or follow their parents out to the main harbour).

During the last set of high daytime tides up to 300 Common Terns and 11 Little Terns gathered on the lagoon islands, making for a spectacular site especially when they all wheeled around in response to a passing Peregrine or distant soaring Buzzard. A few Sandwich Terns appeared more occasionally, while a few evenings ago an Arctic Skua flew through the reserve putting everything into temporary flight. These are rare visitors to the harbour (the nearest breeding grounds are in northern Scotland) and in five seasons of being one of the wardens at the Oysterbeds I have never seen one here in the summer. They feed by kleptoparasitism (literally, parasitism by theft). Typically they chase terns and gulls to force them to drop or disgorge their food, their agile and swift flight combined with larger size (compared with the smaller terns) aiding their success rate. The bird at the Oysterbeds was quickly pursued by one of two of the local gulls, and quickly continued on its way over the harbour.

Interestingly it has been suggested that young Oystercatchers can engage in intraspecific kleptoparasitism, steeling food from adults. However, I wonder if some of this can actually be attributed to observations of juveniles staying in the same vicinity as their parents for weeks if not months after their fledging and the loose family group still functioning in terms of the adults still supporting the youngsters? Certainly family groups can still be identified early in the autumn long after fledging has taken place, with the juveniles often begging for food from the adults, often successfully. At first the juveniles will feed exclusively on worms, but many will learn the adult skills of locating and cracking into the shells of crabs, cockles and mussels.

Late display from the Common Terns continues and I managed to capture the following images of some of the posturing the adults get involved in when courting.

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The next update, as the season finishes, may start deviating away from the breeding sea birds so what better way to start than to introduce a good place for seeing our smallest species of owl? The Little Owl is a scarce but well distributed resident breeding species on Hayling Island that can be seen hunting both day and night in the summer. Several pairs occur along the west side of the island, and the billyline track just inland and opposite the Oysterbeds is a good place to look for them. Currently the most regular place for easy views is from the gate on the east side of the track opposite (and just north of) the oysterbeds lagoon. Birds have recently been seen perched in adjacent trees and on the pile of old telegraph poles just in front of the gate. Look more distantly from the track before approaching the gate, as it is easy to flush birds off the lying poles before you see them there!