What is the best site for rare birds in Berkshire?

8 September 2008 | Marek Walford

In a thread on the Yahoo Group the question of what is the best site in Berkshire was raised, or more specifically is Theale GP better than QMR? This analysis is based on the number of "rares" found at different sites in Berkshire. Chris Heard pointed out that QMR has never had a BB rarity (Theale GP has had several). However, in a Berkshire context Long-tailed Skua is a mega rarity so for the purposes of this analysis a "rare" is defined as "a less than annual visitor". Clearly rare birds aren't everything and if an analysis was undertaken based on the number of breeding species the results would be very different.

Fig 1. Top 10 sites for "rares" historically
Pos.SiteNo. Rares
1Theale GP100
2Queen Mother Reservoir75
3Wraysbury GP23
5Manor Farm SF21
6Dinton Pastures CP19
7Slough SF18
8Moor Green Lakes17
9Ham SF13
10Windsor Great Park12

As the above table shows historically there have been more rare birds seen at Theale GP than at QMR. The inclusion of Newbury is perhaps a little surprising but if you look at the historical records it's surprising just how many seabirds have been found wandering down Newbury's streets!

Fig 2. Top 8 sites for "rares" in the last 10 years
Pos.SiteNo. Rares
1Queen Mother Reservoir37
2Theale GP25
3Moor Green Lakes LNR12
4Dorney Wetlands8
5Dinton Pastures CP6
7Lower Farm GP3
8Bracknell, Cockmarsh, Maidenhead, Reading, Slough SF, West Ilsley, Windsor Great Park, Wraysbury GP2

However, you're only as good as your last match and if you look at the number of rares found in the last 10 years (fig 2) QMR leap frogs over Theale GP into first place. Interestingly Wraysbury GP drops down to eighth from an historical position of third to be replaced by Moor Green Lakes. Wraysbury's fall from grace is probably a combination of encroaching scrub and decreased observer coverage. Ironically Moor Green's rise is probably a combination of improved habitat and increased observer coverage!

Dorney Wetlands takes fourth place, though sadly it is already well past it's best. Manor Farm SF drops out of the top 10 from an historical position of fifth but this is not surprising as it hasn't existed since the early eighties. Dinton Pastures CP takes fifth place. Ham SF drops out of the top 10 having followed the same fate as Manor Farm. Slough SF, Windsor Great Park and Wraysbury GP just about cling on in eighth place.