The Tyttenhanger area is one of the best places in Hertfordshire to see a wide variety of bird species, including wetland specialists. The site comprioses an area of active and restored gravel pits and woodland between London Colney and Colney Heath. There is plenty of other wildlife around too.
There are several points of access to the area.
- Park outside water pumping station in Colney Heath at TL198058 and walk down the track to the SW which will take you into the north end of the site.
- from the end of the unmade gravel pit entry road beside the petrol garage on the A405 (map) you can park outside the entrance to the fishing lakes; the fishing warden suggests birders use the car park adjacent to the bailiff’s caravan.
- from the car park at London Colney by the church at TL181037 which can be used; access to the lakes is via the public footpath running to the NE which takes you under the A1081.
- A possible access point is from Coursers Road but there is very limited car parking space.
- It is also possible to park at Willows Farm itself; however these car parks are reserved for customers using the farm facilities or visiting the attached retail outlets.
Please note that although there are car parks around the fishing lakes these are for the use of the fishermen and should only be used if you have purchased a car parking permit.
The map has been taken from the OS 1:25000 map and modified to show the current layout and footpath network. The footpaths are generally well marked although many of the paths are permissive in nature and not public rights of way. Some of the public paths around the fishing lakes were not diverted when the lakes were created so they are under water. The main area of ornithological interest is the easternmost lake on the maps on the east side of the River Colne. The lakes on the west are used extensively for fishing and are currently of less interest although in the past they have produced interesting records when the water level was very low.
The red squares on the map show where reasonable views of the main lake are available; however it is one of those sites where possession of a telescope is highly desirable. Water levels on this lake fluctuate considerably as it is used by Lafarge to collect groundwater from their nearby active workings and also as a source of water to wash the extracted gravel. Water can be pumped out from this lake into the River Colne to ensure levels do not get too high. There is also a flood relief outlet from the River Colne into the lake which has recently been completed and should reduce the chance of flooding in London Colney. The South East of the lake is very shallow and the area to the east of the footpath crossing the lake is often dry. At present there is no change likely in the footpath arrangements since the proposed changes were rejected as the council used the wrong provisions in the relevant Act of Parliament to make the changes. To my knowledge no new proposals have been submitted.
A small pond has formed by the Willows Farm car park which has attracted Common Cranes, Bewick’s Swan and a range of waders in 2008. It is not known if this pond will be filled in or will be left as it is; the pond was not an intentional creation when the gravel workings were restored. It is definitely worth a careful look particularly in Spring and Autumn.
Lafarge have an agreement with Hertfordshire County Council over the restoration of these pits that should maintain the attractiveness of the area to birds and specifically the breeding wader population. This will mean that areas of the land will need to be kept bare and it is hoped that this can be achieved by agreement. Lafarge are also keen to provide a hide at a suitable location although the risk of vandalism has been pointed out to the company.
As a general point this site attracts a wide range of species. In the 2008 London Birders’ challenge it came second to Rainham RSPB reserve in the number of species seen with 131 compared to 140 at Rainham. This excluded the Common Cranes since they were of unknown origin.
Winter (December to February)
This time of the year is generally uneventful. The lakes tend not to attract large numbers of duck but there are generally small numbers of Tufted Duck, Pochard, Wigeon, Shoveler, Teal and Gadwall present with other species such as Shelduck and Pintail appearing occasionally. Smew and Goldeneye have also been seen but these are unusual visitors to the site. Wading birds seen include Green Sandpiper, Snipe and Jack Snipe although the last species is often very difficult to locate. Greenshanks have over wintered at the site in the past although not in recent years and Lapwings are usually present. Golden Plovers are seen regularly as there are often large flocks on the nearby fields south of Coursers Road or on the old airfield at Hatfield (adjacent to Beech Farm).
The site is well known for its breeding waders and Redshank and Ringed Plover turn up towards the end of February. The area around Tyttenhanger Farm holds a flock of Tree Sparrows, attracted by the feeder in the former game rearing enclosure (see photo). This also attracts other finches and buntings which can include Brambling. The Herts Bird Club maintains the feeders for the Tree Sparrows both here and at Coursers Farm and has installed a number of nest boxes with the aim of increasing the resident population; more information on this project. The site also attracts irregular visits from Merlin and Peregrine and Common Buzzards are seen regularly.
Spring (March to May)
This season produces a lot of interest particularly with arrival of breeding waders. Little Ringed Plover arrive in early March and during this season it is also possible to see Redshank, Greenshank, Green Sandpiper, Snipe, Lapwing, Ringed Plover, Dunlin and Golden Plover with the possible sighting of more unusual species, which in the past have included Temmincks Stint, Wood Sandpiper, Avocet and Stone Curlew. For passerines, Wheatears are regularly seen in the fields and sandy banks as are Yellow Wagtail and the common warblers can be seen or heard over the whole site. Common Terns used the new shingle island/peninsular to breed in 2003 and in following years and Black Terns are also seen regularly on passage. Apart from the usual raptor species Hobby are frequent visitors to the site particularly if there are large numbers of damsel and dragonflies present. Occasional reports of passage Ospreys are reported during this period. Tyttenhanger used to hold a large colony of Sand Martins but since the removal of the sandbank this is no longer the case, although the species is still seen regularly along with the other hirundines.
Summer (June to August)
In June and July most interest is with the breeding success of Redshank, Ringed Plover, Little Ringed Plover and Lapwing. Most of the common warblers breed around the site and Yellow Wagtails sometimes breed; in 2003 they favoured a bean field to the west of the southernmost fishing lake near Bowman's Farm (now called Willows Farm). Green Sandpipers return to the site towards the end of June.
August sees the start of the autumn migration and a similar range of species can be seen to those in spring although the water level has a considerable bearing on the attractiveness of the site. Sometimes visits can be fleeting; as an example four Black -tailed Godwits and two Spotted Redshanks visited the site for less than 30 minutes in August 2003.
Autumn (September to November)
The migration continues in September with passerines such as Whinchat, being occasional visitors and by the end of the month the first returning wintering Golden Plover make an appearance. By October the range of species is broadly similar to those seen during the winter months although winter flocks of Fieldfare and Redwing are still building up.
Coppice Wood/Garden Wood
This wood is now considered to be part of the site as it does contain a good range of woodland species (it is a SSSI); however Marsh Tits appear to have vanished.
Garden Wood used to be used for paintball games, this has now ceased and additional trees have been planted. This area may well become more attractive due to the reduced disturbance and improved habitat.
Text provided by Alan Gardiner.