M ARCH saw the arrival of our first "real" summer migrants. The first were wheatears, with birds seen in Colsterdale and at Nosterfield on the relatively early date of the 18th.

The following day, a sand martin was seen at Nosterfield, with a flock of 50 birds at Bolton on Swale on the 20th. Little ringed plover and chiffchaff were seen on the 23rd and then, unusually early, two swallows at Nosterfield on March 25.

With sightings at two other sites before the month end, this confirms the trend for earlier arrival of this species over recent years.

Back in the 1880s, James Carter, an ornithologist who lived just outside Masham, recorded an average arrival date for swallows of April 12. A century later, I had an average first arrival on April 5, though part of this change will almost certainly have reflected better observer coverage.

However, in the decade since then, the date has shifted back towards the end of March. Whether this is down to global warming is a moot point, but there does seem to be evidence for some quite rapid change in behaviour over recent years.

Other changes are also evident, a recent and rather depressing article in British Birds magazine outlined the sharp decline in some woodland species over recent years. Locally, there has been some dramatic evidence of this. The fine woodlands along the Swale used to be home to an excellent population of wood warblers. Up to 25 singing birds were recorded in the mid-1990s, but they have now virtually disappeared as a breeding bird.

Because of the concern about certain key species the British Trust for Ornithology has requested any sightings of firecrest, hawfinch, redpoll, lesser spotted woodpecker, redstart, tree pipit, willow tit and wood warbler. Records can be entered on the trust's Birdtrack web site (www.birdtrack.net).

Rarities were in rather short supply in March, but there were still some interesting sightings. Movements of wildfowl were particularly noteworthy. The whooper swan flock at Kirby Fleetham had risen to 27 birds by mid-month, and there was also an unprecedented movement of whoopers through the area towards the end of the month.

These included birds at Nosterfield and Bolton on Swale, and two huge fly-over flocks with 108 birds seen over Kirklington and 90 birds north over Leeming Bar. Pink-footed geese were also on the move with a skein of 580 birds over Nosterfield.

Other sightings of note during the month included at Nosterfield male stonechat, Iceland, Mediterranean and yellow-legged gulls, a pair of long-staying scaup and a single snow bunting. Two male common scoters were seen at Bolton on Swale and a "northern" bullfinch was seen in the grounds of County Hall, Northallerton.