August here is all about migration. Birds which have spent the breeding season in northern England, Scotland, or even further north are heading back south, some just as far as southern England, some to mainland Europe, and some to Africa or beyond. Some of these birds will pass over the London area, often using natural landmarks such as the large water-bodies of the Lea Valley for navigation. With the southernmost of these water-bodies being only just over a mile north-east away, it is easy to see how migrating birds can end up here.
In early August we enjoyed an extended period of low water levels in the reservoir. The resulting mud was responsible for the first big highlight of the month when on the 3rd a green sandpiper (picture 1 below) was found in the mud along the northern edge of the reservoir. The bird stayed for five days, and was even joined briefly by a second bird on the 6th. This species has been less than annual in the last five years, although it was much more regular in the distant past, when birds would sometimes overwinter. Common sandpipers are much more regular here, but this year wasn’t good for them, being limited to a handful of sightings, mostly in the middle of the month.
Another wading bird highlight which wasn’t down to the low water levels was a flock of seven oystercatchers (2) which flew over on the 23rd, another species which is seen here less than annually.
The remaining migration highlights were passerine birds. This site is one of the best in London for seeing flycatchers, and this year was no exception. Both spotted flycatcher (main picture above) and pied flycatcher (3) were seen a few times each through the month. Chiffchaff and willow warbler were seen throughout August, with double-figure numbers of the former often present and the latter getting close to double-figures occasionally. The few sightings of sedge warbler were probably of migrating birds rather than locally bred ones, and the occasional sightings of common whitethroat and lesser whitethroat were certainly due to migration.
August is also the month when we say goodbye to most of our summer visitors. The only reed bunting sighting was on the 1st, although more birds should arrive to spend winter here. Common terns were only seen up to the middle of the month. Swift numbers dwindled through the month though a handful of birds could still be seen at the end of the month.
Raptor sightings continued the theme of the summer, with hobby being surprisingly regular, seen about as often as kestrel, with peregrine and sparrowhawk seen more frequently.
There was a distinct lack of interest amongst water birds in August, with the large flock of shoveler, sometimes as many as 25, being the only highlight. A teal was seen a few times amongst the lagoons.
The total number of bird species seen here in August was 69, which is exactly the average August total over the last five years, though down on the 74 of August 2019.