It was the wettest spring - but orchids flourish in Cambridge and our rarest bird of prey was seen over the city
Nature Notes: Bob Jarman discusses sightings in and around Cambridge during spring 2024.
It’s been one of our wettest and warmest springs on record.
For England and Wales rainfall was 150 per cent of the average for March and 155 per cent for April. Cloudy rain-filled skies kept the night-time air temperatures also above average. Yet despite the dismal wet weather there have been wildlife highlights.
Early morning watchers of the peregrine falcon nest in the city centre on 1 June photographed a probable Montagu’s harrier flying over Pembroke College. This was a remarkable observation. Montagu’s harriers are one of the UK’s rarest breeding birds - probably the rarest! A last confirmed breeding in the UK was in 2019 and in Cambridgeshire in 1995, although non-breeding birds occasionally spend the summer here.
At RSPB Ouse Fen nature reserve near Earith, a great reed warbler appeared. Great reed warblers are rare vagrants - the last one turned up at nearby Fen Drayton Lakes in 2018. The Ouse Fen bird sang its strident grating song from dawn to dusk from 16 May until mid-June in the forlorn hope of attracting a mate.
Ouse Fen reserve is a joint project between the RSPB and Hanson Aggregates, which extracts the river terrace gravels for the construction industry. It will become the biggest inland reedbed in the country and is a brilliant reserve.
Ouse Fen in mid-May attracts up to 30 hobbies – summer visitor falcons – that hawk the first emerging dragonflies. They spend their winters hunting over the grasslands of southern Africa catching crickets and locusts. I have seen them catch swallows and martins and they occasionally even take swifts. Hobbies are very secretive nesters and by the end of May they vanish!
In June, birds with a browner plumage appear. These are probably second-year birds that fledged last year and return to scout possible nest sites for a return to breed in 2025 or to disrupt an existing pair with a random mating and the off-chance of raising young.
Ouse Fen is also excellent for seeing and hearing “booming” bitterns. From late May to mid-June adult bitterns can be seen flying over the reedbeds on “feeding flights”, like huge brown owls.
A farm site between Girton and Impington has three raptor nest boxes. I checked one box in March and disturbed a pair of barn owls, but the box was reoccupied by kestrels. Recently, all three boxes were checked: the box I disturbed had three kestrel chicks and the other two boxes each had a pair of barn owls with seven chicks in total. This is fantastic news for a location on the edge of the city so close to major housing developments. It also rewards the farm management for establishing conservation headlands.
Heavy saturating rains in March and April may have stimulated the exceptional flush of orchids that have appeared this year. Near Barnwell, about 400 bee orchids have appeared on a roadside verge with pyramidal orchids.
But the real majesty of this verge is a huge rare lizard orchid nearly a metre tall. I have often seen lizard orchids in a well recorded colony on the Devil’s Dyke but never as tall as this rarity. I was astonished when I found it!
In Chesterton, a central reservation is peppered with bee-orchids that last flowered seven years ago, and there are more bee orchids on a protected roadside border at Addenbrooke’s Hospital. At Haslingfield clunch pit, a record number of common spotted orchids and (rare) man orchids, have appeared this year.
Many of the orchids have appeared in uncut roadside verges. In Milton, a verge has been strimmed, and pyramidal orchids have been destroyed. Let’s keep our verges uncut for as long as possible!
The corn bunting is a farmland bird that has declined by 89 per cent in the last 40 years. There is a flourishing population at Nine Wells and this colony may be the reason why corn buntings are expanding their range around the city. The same farm site with the occupied nest boxes had three singing male corn buntings this spring, and birds were singing on Gog Magog Down, near Babraham and Coton, and for the first time at Trumpington Meadows Wildlife Trust reserve.
