March is typically a fickle month for weather. And March 2004 certainly lived up to its reputation. The month opened with ice around the edges of the ponds, left over from a period of cold northerly winds at the end of the February, which had brought some late flurries of snow. It was hard to believe that in two weeks time, the temperatures would reach 17ºC. The initial cold spell was relieved by the arrival of milder air from the west on 3 March.
Temperatures regained their seasonal average by the end of that week in spite of some heavy wintery showers pushing southwards down the east coast. But winter still refused to give up its grip on the park as bitterly cold south-easterly winds battered the area from 8-12 March producing a serious wind chill. There was little hope of any migrant arrivals under such conditions. Signs of a significant change were apparent though from 14 March as warmer southerly air pushed north up the country raising daytime temperatures well above the seasonal norm to a peak of 17ºC on 16 March. Strong south-westerly winds accompanied the warm air mass and spells of rain became a feature of the mid-month period. However, temperatures dropped markedly following gales over 19-21 March as north-west then northerly winds set in dampening prospects of an early spring. The next warm spell did not arrive until the end of the month with a beautiful and hot day on 29 March bringing out the first over-wintered Small Tortoiseshell and Brimstone butterflies.
Expectations of migrant arrivals were high on 16 March as the exceptionally warm weather prevailed. But visible migration turned out to be more impressive with a mixed bag of Meadow Pipits, Chaffinches, Rooks, Pied Wagtails, Linnets and Lapwings heading west during the morning. Highlight of the day was the arrival of a new bird for the park in the form of a Twite. This bird dropped into the northern area by the sewage works where it fed briefly after drinking from one of the flood water pools. This small finch is a close relation of the Linnet but is a much rarer bird in British terms with the bulk of the English population nesting in the Pennines. The most southerly birds nest in the Peak District, but most of the population move out of the uplands to winter on saltmarshes on the east coast. The Lincolnshire coast and the Wash are particularly favoured. Twite is a scarce migrant along the upper Humber, usually occurring in October or November, but there have been a handful of early spring records at Barton in the past.
Another new arrival for the year on 16 March was a female Stonechat. This bird was part of a marked passage of this species through the area. Six different individuals were found along the foreshore between Barton and Barrow Haven on the same day and no less than ten birds the day after. Stonechats are characteristically an early migrant, as the birds involved are mainly British breeders moving back to upland nesting sites from their winter quarters on the coast. Being partial rather than true migrants that have left the country for the winter, the first birds back on territory gain the best nest sites for the coming summer so there is a real incentive to get back early. They are insectivorous and suffer major declines during cold winters, but the recent run of mild weather during the last ten winters has helped the population to achieve a very high level. In 2003, a pair even bred on the Humber near Winteringham, the first breeding in Lincolnshire since 1980.
Further confirmation that migration was underway on 16 March was the presence of a continental Song Thrush on the northern park. It provided a good comparison of plumage with a local bird that was also feeding on the area by the play park. Continental birds are of the race Turdus philomelus philomelus and are much greyer toned on the upperparts than local birds and lack the ochre wash on the underparts and the olive toned upperparts of breeding birds. The legs of the Waters’ Edge bird were also strikingly pale pink. Continental Song Thrushes are frequently found in the area during the autumn, from mid September through October and November but they are infrequently seen on spring passage. The first real signs of spring appeared on 17 March with a party of six Sand Martins gracing the northern park in the evening of what was a beautiful and rarely calm day. On the following morning, there were no less than five Chiffchaffs dotted around the scrub. Some broke into brief bursts of song in between their frantic search for insect food to replenish fat reserves used up on their northward migration. Three male Chiffchaffs quickly settled into their usual territories in the southern scrub, with four birds singing loudly by the month end. The only other true summer migrant arrivals though were a pair of Little Ringed Plovers which returned to their favoured areas on the northern park on 30 March.
A single Coal Tit had been an occasional visitor to the park woodlands during the winter but in mid March, it turned out to be a male. He set up a territory in the south-west woodland where he was singing loudly during the bird walk on 13 March. By 16 March he had attracted a mate with both birds being seen in the same area - possibly a sign of potential nesting. Two Goldcrest were also about the park early in the month, but the Siskin flock did not stay for long. Just three Siskins were found on 16 March but of these one was a fine male in full song.
After a winter with only irregular presence in the park, the sound of a drumming male Great Spotted Woodpecker was a real surprise. On 23 March a female was also present in the south-west woodland so there is the possibility that they may nest which would be a new breeding record for the park. The male continued drumming to the end of the month.
Waterfowl started to show signs of breeding behaviour, with the whinnying trill of Little Grebes again a feature of the western ponds as birds returned after their winter absence. The number of Tufted Duck and Pochard also picked up, while dapper blue-billed drake Ruddy Ducks began their bizarre bubbling routine attempting to impress the drab brown females. Goldeneye increased to four birds, with a fine plumaged adult drake courting two females in the eastern SSSI. Teal numbers fell sharply as winter migrants departed, but there was a fine show of Shoveler on the Middle Lagoon where they became quite confiding as they ploughed the muddy edges with their huge bills.
The number of Redshank roosting on the big pond at high tide varied daily, but peaked with 66 birds in mid-month. The increasing number of shanks coincided with the spring migration of Icelandic breeding birds which pass through the Humber estuary, gaining weight before the start of their long flight back to their island breeding grounds. Ringed Plovers have been absent from the park and the adjacent estuary during the winter. However, an early return saw five birds on the northern park in the first week, with one bird performing its typical butterfly display flights over last years nest sites.
Late in the month on warmer evenings the first Pipistrelle and Noctule bats were on the wing around the insect rich areas of the park.