The return passage of waders starts early in the year with their ‘autumn’ getting underway by the first week in July. Indeed for some failed breeders and immature birds, Africa can be on the agenda by early August. It was thus no surprise to find one or two Common Sandpipers on the northern ponds from 2 July with the first Green Sandpiper putting in an appearance from 10-12 July.
Two Greenshanks put down during some bad weather on 8 July and another landed briefly with roosting Redshanks on 20 July. However, the new lagoon area that attracted a steady stream of waders in the spring proved to be very disappointing as vegetation quickly grew over the exposed mud. Redshank returned to feed on the estuary and a high tide roost built up to 23 birds by 20 July, exceeding the peak of 18 Dunlin recorded on 8 July. A flock of 22 Black-tailed Godwits flew west on 20 July and a juvenile Avocet was roosting on the adjacent foreshore on 13 July.
Waterfowl had very varied fortunes. Good numbers of Mallard fledged and the two broods of Mute Swans survived with the loss of just one cygnet. However, only one of the 33 young Pochard that hatched survived to fledging. By contrast, Tufted Ducks are having a bumper season with 15 broods having hatched 83 young, of which 18 have already fledged. No less than three broods hatched in the third week of the month and all quickly moved onto to the big northern pond. Ruddy Ducks are also doing well with 11 young having fledged, but there have been no broods of Shoveler or Gadwall this year. This is rather disappointing, especially given the good numbers of Gadwall present in the spring.
As the Middle Lagoon was brought back into good condition through pumping, the number of young Little Grebes surviving increased markedly, with one brood of four being present in the north-east corner. Two to three Great Crested Grebes remained on the big northern pond for most of the period. There were few surprises in the way of waterfowl with the first returning Teal being the only addition to the month’s list of species. Odd Grey Herons continued to appear on in the western Site of Special Scientific Interest (SSSI) along with 1-2 Cormorants. The Cormorants could, as usual, be seen drying out on top of the nest box.
A Little Egret flying west over the northern park at 6.45am on 30 July was the fourth record in the park in the last five years. Bitterns continued to be seen frequently, with the western SSSI being the most frequented site. The bird walk on 17 July even produced two sightings of this elusive reedbed dweller. Kingfishers also made occasional visits to the site and a single Marsh Harrier flew over on a few dates.
The surviving juvenile Common Tern took its first flight on 10 July and soon adopted the eastern side of the big northern pond as its new home. The adults continued to bring it an ample supply of small fish. One Ringed Plover chick also fledged successfully and left the area in the third week along with the remaining adult birds.
Good numbers of Swallows and House Martins continued to feed over the northern meadows. Several broods of fledged Swallows sat around in the vegetation waiting to be fed by their parents. A few Sand Martins also returned early in the month with their numbers increasing towards the month end. A Grey Wagtail was on the northern park on 6 July, while Yellow Wagtails increased to five birds and Pied to 14 individuals. Several fledged broods of young Pied Wagtails frequented the insect rich meadows.
Sky Larks bred for the first time in 2004 and reared at least one chick to fledging. A very early migrant was a juvenile Northern Wheatear seen on 10 July. This species breeds no closer than the North Yorkshire Moors and the Pennines, so this youngster had already travelled a small part of its first journey to winter in North Africa.
The butterfly highlight of the year to date was the discovery of two White-letter Hairstreaks in the south-west corner of the park on 4 July. This butterfly relies upon the presence of young elm leaves on which to lay its eggs. The caterpillars then feed on the elm leaves before they pupate. The loss of the majority of the English Elms in the 1970’s due to the ravages of Dutch Elm disease threatened the survival of this delightful butterfly. However, where elms have been left to regenerate from sucker growth, White-letter Hairstreaks have shown that they can survive. In the last five years, there has even been some spread back to some of their former breeding sites as elm sucker growth has reached a suitable age. Unfortunately Dutch Elm disease continues to kill back suckered elms. There is ample evidence of the attacks on the Water’s Edge elms, several of which show dead or dying top branches.
The line of elms along Maltkiln Lane have long been a target for my Hairstreak hunting, so it was particularly satisfying to locate them in the ash trees next to the elms this year. The adult butterflies feed on aphid honeydew in the tops of the ash trees. This is the sugary substance secreted by aphids as a by-product of their feeding on plant sap. Hairstreak eggs are laid on the new growth on the adjacent elms. Hopefully if they have laid eggs this year the population may increase next year as long as enough elms survive.
On the same day as the Hairstreaks were located, there were the first records of three other species for the year; Comma, an overdue occurrence, Small Skipper and Gatekeeper. Also on the wing, were lots of Meadow Browns and Ringlets. Later in the month, a second hatch of Speckled Woods occurred on 20 July . More than 20 Speckled Woods were seen around the plantations along with the first numbers of Small Tortoiseshells and Large Whites. In all there have been sightings of 21 species of butterfly in the park so far this year. The full list with first dates is given below:
- Small tortoiseshell Aglais urticae - 29 March
- Brimstone Gonepteryx rhamni - 12 April
- Peacock Inachis io - 12 April
- Speckled wood Pararge aegeria - 22 April
- Small white Pieris rapae - 26 April
- Green-veined white Pieris napi - 26 April
- Orange tip Anthocharis cardamines - 1 May
- Large white Pieris brassicae - 18 May
- Wall brown Lasiommata megera - 18 May
- Common blue Polymmatus icarus - 25 May
- Small copper Lycaena phlaes - 27 May
- Red admiral Vanessa atalanta - 30 May
- Large skipper Ochlodes venatus - 6 June
- Painted lady Vanessa cardui - 6 June
- Brown Argus Aricia agestis - 6 June
- Meadow brown Maniola jurtina - 13 June
- Ringlet Aphantopus hyperantus - 20 June
- Comma Polygonia c-album - 4 July
- Gatekeeper Pyronia tithonus - 4 July
- Small skipper Thymelicu sylvestris - 4 July
- White-letter Hairstreak Satyrium w-album - 4 July