Common summer visitor and passage migrant, with increasing records of overwintering.

Blackcaps winter further north than other related warbler species and while most winter in Africa north of the Equator, some occur in Mediterranean Europe and western Europe including Britain. British breeding birds migrate south but others from northern and eastern Europe winter here, these are believed to be German breeding birds that have evolved a successful east – west migration strategy. Most wintering Blackcaps are seen feeding in gardens on bread, biscuit crumbs, ivy and other berries, apples and fat. They appear from mid-December onwards and it is thought that these are local birds from the nearby countryside, in search of food at the onset of cold weather.

The first record of a Blackcap over wintering in Stevenage was on 24 December 1976 when a male was seen on a bird table. There were a further four records during the 1970’s and 80’s, three records in the 1990’s, one in 2007 and, almost annually since 2009: (four records), 2010 (one record), 2011 (four records), 2012 (three records), 2013 (two records), 2014 (three records), 2015 (one record), 2016 (one record), 2017 (five records), 2018 (one record), 2019 (one record), 2022 (one record), 2023 (three records), 2024 (four records). Apart from birds seen at Watery Grove Ditchmore Lane, Fairlands Valley Lakes and, the Stevenage Brook, all the records relate to birds seen in gardens. The most seen together in winter is three at Broadwater on 4 February 2014 and, 17 December 2017.

The 1973 Breeding Atlas confirmed breeding from five of the tetrads covering Stevenage, 1992 Atlas from eight and, the 2012 Atlas from one.

In 2016 breeding was proven at Chells Manor, Fairlands Valley Park and, Norton Green. In 2017 breeding was proven at Fairlands Valley Park and, Norton Green. In 2018 breeding was proven at Fairlands Valley Park, Norton Green and the Poplars. In 2025 fledged young were seen at Astonbury Wood.

They were recorded annually, between 1972 and 1999, as holding breeding territories at Watery Grove by the Common Bird Census. The most territories held were five in 1995, 1996 and 1997. Blackcaps were able to colonize the interior of wood as a result of coppicing. 

In 1980 50+ pairs were recorded in Box Wood.

The earliest spring arrival date at Stevenage is 10 March 2025 at Fairlands Valley Park. The latest autumn date is 28 November 2025 at Fairlands Valley Lakes.

In 1979 55 birds were ringed in Box Wood, one of which was recovered at Canterbury. 28 were ringed in Box Wood in 1980. A female ringed in Hitchin on 22 May 1980 was, “controlled” at Box Wood on 10 August 1980, a female ringed at the Dungeness Bird Observatory, Kent on 7 May 1980 was breeding in Box Wood in 1981, and an adult female ringed in Box Wood on 1 June 1980 was a road casualty near Wingrave, Buckinghamshire on 18 June 1981.

Uncommon summer visitor and passage migrant.

Foster (1914) recorded that Garden Warblers had been, “Reported from the Stevenage District”.

In 1964 20 pairs were reported from Box Wood. Other records for the 1960s came from Chesfield and a Rockingham Way Garden.

In the 1970s and 80s records came from: Astonbury Wood; Box Wood; Brooches Wood; Fairlands Valley Lakes; Hertford Road; Monks Wood; New Wood, Aston End; Watery Grove; Whomerley Wood.

19 were ringed in Box Wood during 1979 seven of which had brood patches indicating breeding in the wood.

In the 1990s they were recorded from: The Football Ground, Broadhall Way; Norton Green; Watery Grove.

Since 2000 they have been recorded from: Fairlands Valley Lakes and Park; Norton Green Tip; Shackledell, Upper Kitching Spring; Watery Grove; Whomerley Wood

The 1973 Breeding Atlas confirmed breeding from four of Stevenage’s tetrads and, the 1992 Atlas from five. The 2012 Atlas only considered breeding as possible from the tetrad covering Norton Green.

The Common Bird Census at Watery Grove recorded them holding between one and three breeding territories annually between 1972 and 1999, with the exception of 1986 and 1998 when only their presence was recorded.

The earliest spring arrival date at Stevenage is 4 April 2002 at an unknown location, the latest departure date is 21 September 2020 at Norton Green.

There is a winter record of a one seen in a York Road garden on 27 February 1974. This was the first occurrence of an over wintering Garden Warbler in Hertfordshire.

Uncommon passage migrant and summer visitor that has bred.

The earliest record for Stevenage is of one at Astonbury on 27 April 1908.

Foster (1914) described Lesser Whitethroats as, “not so common in the Stevenage district as the Common Whitethroat.” Gladwin (1985) recorded that due partly to the removal and machine cutting of hedgerows Lesser Whitethroats had declined significantly in the cereal dominated arable farmlands of the County, but had spread into dense woodland edges and scrub along railway and motorway embankments, and were particularly common around Stevenage. 

They were recorded during the 1963 breeding season at Aston End and in the 1966 breeding season near Stevenage. Up to two were seen at Box Wood between 17 August and 26 September 1965 and, one was seen there on 26 June and 2 August 1966. One was seen at the Hertford Road on 17 June 1966.

In the 1970s and 80s records came from: Astonbury, Bedwell School, Box Wood (where 10 were ringed in 1980), Chells, Chells Manor, King George Playing Fields, Ridlins Marsh, Watery Grove.

In the 1990s they were recorded from: The Railway Station, Watery Grove.

Since 2000 they have been recorded from: Aston, Astonbury Manor, Aston End, Aston End Lane, Chesfield Park, Fairlands Valley Lakes and Park, Fishers Green, Glaxo, Great Ashby, Norton Green Tip, Novotel next to the A1m, Old London Road, Pryors Wood, Railway Station, Sainsbury’s Car Park Poplars, Shackledell, Warren Springs, Watery Grove, Weston Road.

The 1992 Breeding Atlas confirmed breeding from four of the town’s tetrads, which was an increase from one in 1973. The 2012 Atlas only considered breeding as probable from the tetrad covering Norton Green.

The Common Bird Census recorded their presence at Watery Grove during the 1973, 1975, 1977, 1979, 1981, 1996 and 1997 breeding seasons, and three singing males were recorded there in 1988. 

The earliest spring arrival date is 12 April 2002 behind the Magistrates Court, and the latest departure date is 29 September 1979 at Box Wood.

An over-wintering bird was seen in the Old London, Road behind the Magistrates Court between 11 and 13 February 2002. This was the first record of this species over-wintering in Hertfordshire, and is a rare event in Britain. Possibly the same bird was seen at the same location on 12 and 16 April 2002.

Summer visitor and passage migrant. 

In the nineteenth century the Common Whitethroat was considered to be the commonest of Britain’s Warblers, nesting in field hedgerows, rough land, bramble patches and nettle beds. Since the 1950’s they have suffered considerable loss as a result of the removal of hedgerows, particularly in the arable farmland of the east and south east of England. In 1968 a worse fate befell them when they were badly affected by the drought in the Sahel zone of Africa. In 1969 the Common Bird Census revealed that 77% of the 1968 breeding population had failed to return to Britain and there was only one record for the Stevenage area that year. In 1976 and 1977 there were signs of a recovery but this was not sustained and a further drought in the Sahel in 1983/1984 caused the population to crash further to around 20% of what it was in the early 1960’s. The population gradually increased again until another sharp decline in 1991. The species is now increasing again.

A female was seen in a Raleigh Crescent Garden on 21 and 22 August 1965. Other records from the 1960’s came from Box Wood (1966 and 1967) and, Astonbury (1969).

A nest with young was found in Fairlands Valley near Whomerley Wood on 7 July 1970.

In the 1970s and 80s other records came from: Aston, Astonbury, Botany Bay, Box Wood, Broadhall Way, Fairlands Valley Lakes, Norton Green Tip, Railway Station, Ridlins Marsh, Roebuck, Symonds Green, Watery Grove, Wellfield Wood. Five were ringed at Box Wood in 1979.

In the 1990s they were recorded from: Edmonds Drive and, Norton Green Tip.

Since 2000 they have been recorded from: Aston Allotments, Astonbury Lane, Aston End, Bragbury End, Chells Manor, Fairlands Valley Lakes and Park, Fairview Road, Great Ashby Park, London Road, Norton Green Tip, Pryors Wood, Railway Station.

19 were seen at Norton Green Tip on 8 August 2015 and, two family parties with recently fledged young were seen there in 2017. In 2018 20 were seen at Norton Green Tip on 5 August and, breeding  was confirmed from there. Breeding was also confirmed in 2019.

The earliest spring arrival date is 10 April 1974 at Astonbury Wood, 10 April 2016 at Aston End and, 10 April 2017 at Norton Green Tip and, the latest departure date is 29 September 2021 at Norton Green Tip.

The 1973 Breeding Atlas confirmed breeding from five of Stevenage’s tetrads, the 1992 Atlas from seven and, the 2012 Atlas from six.

Very Rare Visitor

Two records from Norton Green Tip: a juvenile seen from 6 to 13 September 2016 and a female or immature bird seen from 6 to 8 January 2021.