TYTTENHANGER GRAVEL PITS SITE GUIDE
Text by Alan Gardiner
Photographs by Robin Pearson (unless otherwise stated)
TYTTENHANGER GRAVEL PITS SITE GUIDE
Text by Alan Gardiner
Photographs by Robin Pearson (unless otherwise stated)
Access to site
There are several possible points of access to the area. It is possible to park outside water pumping station in Colney Heath at TL 198058 and walk down the track to the SW which will take you into the north end of the site. Another access point is from the end of the unmade gravel pit entry road beside the petrol garage on the A405 (map) where it is possible to park outside the entrance to the fishing lakes. However there has been some fly tipping at this location and it is a less secure location than the first in my view. Finally there is a car park at London Colney by the church at TL 181037 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.
UPDATE: Advice from the fishing warden suggests breakins being committed by men on bikes recently. He suggests birder park in the car park adjacent to the warden's caravan. The caravan is always occupied and there is CCTV. This is accessed by entering the site via the A405 LaFarge entrance before the petrol station.
It should be noted 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 above map has been taken from the OS 1:25000 map and modified to show the current layout and footpath network. The footpath network is generally well marked but in the area around Tyttenhanger farm is not well defined at present as the route of these paths is about to be modified and an additional permissive path created which will run to the NE of the lakes. 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. It is worth noting that this footpath will be closed eventually once diversionary paths have been created. Some of the footpath diversions are being opposed (not by the Bird Club) and this is delaying the completion of this work.
 |
| Birds and industry co-exist at Tyttenhanger - gravel is still being extracted close by |
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.
The Birds
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 and Lapwings are usually present. Golden Plover 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 feed put out for the Red-legged Partridges released by the shooting syndicate. This also attracts other finches and buntings which can include Brambling. The club has provided its own feeder for the Tree Sparrows from last year and erected a number of nest boxes and intends to expand this scheme. The site also attracts irregular visits from Merlin and Peregrine and Common Buzzards are seen regularly.
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 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.
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 4 Black -tailed Godwits and two Spotted Redshanks visited the site for less than 30 minutes in August 2003.
  | |
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
Although this wood does not form part of the site it does contain Marsh Tits and other woodland species that are difficult to see elsewhere in the area (it is a SSSI). Garden Wood is less interesting as it is used for Paintball games and there is therefore a high level of disturbance at times.