Migration began in earnest at the start of August with a Garden and a Reed Warbler in the Hawthorn Valley, the latter appearing in a typical habitat for this species which is not unusual during its migration. The first of a few Spotted Flycatchers was seen on the 3rd. Like many of the migrants passing through the Park they can occur almost anywhere, which makes finding them all the more difficult for birders. This was demonstrated by two on the 26th found at the edge of Gibbet Wood. A Sedge Warbler was glimpsed on the 8th and the first returning Willow Warbler was heard to sing briefly. Another of the latter on the 16th was accompanied by three of its close relative – the Chiffchaff. Both species have similar contact calls, but with practise the former's can be discerned to be disyllabic. Blackcaps and Whitethroats also pass through but cannot be distinguished from birds summering in the Park. Mid-month several parties of juvenile Whitethroats were found in areas where males had held territory so may have been their progeny. A few family parties of Goldfinches could be encountered feeding on thistle heads and some Reed Buntings were still attending to late broods secreted in the bracken.
Wheatear passage was light with never more than two being seen at one time. Whinchats, on the other hand, occurred in good numbers with peaks of three birds on the 18th and 31st. They could be found in any of the larger open areas containing bracken. A Yellow Wagtail, a much scarcer migrant, gave its distinctive call as it flew over the Pen Ponds on the 16th. A Collared Dove also flying over was probably a short distance from elsewhere in Greater London. The rarest migrant this month was found after dusk on the 23rd hawking insects in the area of Leg of Mutton pond. The Nightjar, as its name suggests, is a charismatic nocturnal bird of heathland. Its old English name of Goatsucker indicates the myth and mystery that surrounded it. The two previous records were both in 2006 and included a bird giving its ventriloquial 'churring' call, coincidentally in the same area. Prior to that year there were only three records since the 1920s when they regularly bred.
The pair of Common Terns graced the Pen Ponds until at least the 23rd, the male still presenting fish to the female. A Common Sandpiper interrupted its southward passage for a few days mid-month. The Great Crested Grebe's persistence finally paid off when, on their fourth nesting attempt, this time by the island in the Lower Pond, they hatched two young which were seen to hitch lifts on the backs of their parents. Several late broods of Mallard and Tufted Duck appeared as did the first wintering wildfowl, a Shoveler on the 12th and a Teal on the 16th. A pair of Hobbies hunted flying insects on the evening of the 19th and birds heard calling a few days later at the edge of the Park may have indicated breeding had taken place nearby.
The pair of Swallows, having returned to the Shire horse stables to attempt breeding again, successfully fledged three young. These harbingers of summer will themselves soon be heading south.
Jan Wilczur, August 2009