Hertfordshire’s increasing breeding population of the spectacular Peregrine Falcon and the influence of climate change on wintering wildfowl in the Lee Valley were among topics highlighted at the annual Herts Bird Club / BTO conference.

More than 70 members and their guests joined the event online to hear Barry Trevis talk about steps being taken to monitor and assist breeding Peregrines, illustrated with his own impressive, close-up photographs.

Peregrines are strictly protected and Barry is the only ornithologist in Herts currently licensed to (briefly) handle and ring their chicks. He has also been active in building and installing bespoke platforms at sites after potential breeding pairs are located. These include gravel for an egg-laying scrape and a sun shelter for growing chicks.

Featured photograph: Sand Martin feeding at Wilstone in 2021 ©Ian Williams. Herts Bird Photograph of the Year (see below)

Barry described an exciting decade in which spring Peregrine records in Herts have advanced from sightings of individual birds in 2012 to anticipated breeding this year at six sites. He noted that although nests are not necessarily high-up in absolute terms, they are always on the highest building or structure in a locality.

He also referred to his role explaining tactfully to the owners of buildings chosen by Peregrines that they have a legal duty to prevent human disturbance to the nest on pain of a maximum £5,000 fine or imprisonment. In the case of church buildings this has required towers to be closed to the public.

In another keynote presentation, Graham White – the RSPB’s recently retired Head of Reserves Ecology – reported on trends from 30 years of winter bird records gathered in the Lee Valley as part of the BTO’s Wetland Bird Survey (WeBS). His title ‘The Rise and Fall of the Coot Mugger’ referred to kleptoparasitic behaviour by Gadwall ducks, grabbing tasty weeds brought to surface by diving Coots.

Graham recalled the 1960s when he would not have expected to see more than a handful of Gadwall in a day. Yet in the 1970s and 1980s their numbers increased dramatically to a point where the Lee Valley held 10 per cent of the estimated UK population. Winter counts increased to more than a thousand and Gadwall were one of the index species for the area’s designation as a Specially Protected Area.

In the past 10 years, the Lee Valley Gadwalls account for just 2 per cent of the national population. In association with milder winters, maximum counts tend to occur at the start of winter and birds are more likely to pay ‘short stopping’ visits instead of remaining throughout the season. The lack of sustained cold weather also appears responsible for lower numbers of migrant birds arriving from continental Europe.

Winter numbers of Wigeon and Teal have also declined, while sightings of the much rarer Smew are much reduced. Black-necked Grebe numbers on Girling Reservoir, once a fifth of the British wintering population, have dropped markedly, and there have been fewer wintering Bitterns. But not all waterfowl have been in local decline, including Tufted Duck which show a liking for invasive Zebra and Quagga Mussels.

Natural vegetation succession, turning open water margins into tree-lined lakes has been among predictable changes to the area’s ecology. The introduction of non-native Carp by anglers – stirring up mud and reducing the availability of pond weeds eaten by wildfowl – less so. Better bio-security and active management to maintain reedbeds and wet grassland were among Graham’s recommended steps for protecting and extending biodiversity.

Also at the conference, Graham Knight reviewed the bird record highlights of 2021 – a non-vintage year for which around 192 species are likely to be verified. These included Green-winged Teal, Rough-legged Buzzard, Wryneck, White Stork, Grey Phalarope and a flock of 15 Spoonbills at Wilstone Reservoir in October. There was also confirmed breeding for Hawfinch – emblematic species of the Herts Bird Club – for the first time in some years.

Congratulations, meanwhile, to Ian Williams, winner of the 2021 Herts Bird Photograph of the Year competition for his picture of a Sand Martin feeding in flight and reflected in the water at Wilstone (see above).

Mark Rayment’s close-up photo of a Great White Egret (left) was the worthy runner-up.

Thanks go to the speakers, Rupert Evershed who chaired the conference, events organiser Tim Hill and Dan Fletcher for online hosting. Members who missed the conference and would like to see a recording should contact David Utting.