Over the last 4 years I have recorded the number of months in which each species has been seen or heard in the 10 km square TL20. The geographical area is bounded by Hatfield Aerodrome at the north-western corner, Ridge to the south-west, Northaw to the south-east and Little Berkhamsted to the north-east.

The majority of records are from an area no further than 2.5 miles from Bradmore Green in the centre of Brookmans Park.

A total of 90 species has been noted over this period. Each species name is followed by the number of months it was seen in 96, 97, 98 and 99 followed by a total for the 4-year period. This gives an approximate idea of the likelihood of seeing the bird in the area. Naturally this does not take into account species, which may be common, but are with us for only part of the year.

2. Great Crested Grebe : 0,1,0,0 =1.
One individual on River Lea east of Hatfield in October 97.

3. Cormorant: 1,2,3,6 =12.
Singles or pairs flying overhead - usually early mornings Nov-March. In 99 occasionally seen on Gobions Pond.

4. Heron :6,10,7,10 = 33.
Singles can be seen anywhere in area. Often flying overhead or stalking mice and amphibians in pasture. Recorded as breeding within the 10km square by Atlas of British Breeding Birds 1988-91 , but site of heronry unknown.

5. Mute Swan : 0,2,3,2.=7.
Pairs or family parties have occasionally been seen in Bedwell Park, Essendon or on Gobions Pond. Reportedly also on lakes at Brookmans Park Golf Club. Breeding site unknown.

6. Canada Goose : 7,12,11,12 =42.
Population appears to be expanding rapidly. Over 90 were observed in late Sept 99 feeding on stubble between Hawkshead Road and Brookmans Park. 2 pairs with 9 young were on Gobions Pond, 27th June.

7. Teal : 0,1,0,0 =1.
One male on Gobions Pond in Nov 97.

8. Mallard : 12,12,12,12 =48.
Common resident, breeding on Gobions Pond.

9. Tufted Duck : 0,0,1,1 =2.
Atlas of British Breeding Birds 88-91 (ABBB) records species as breeding in 10km square. However I have only recorded it twice - at Bedwell Park, Essendon and on the new pond opposite North Mymms War Memorial.

10. Sparrowhawk: 9,11,12,12 =44.
Probably the commonest bird of prey in the area, visiting gardens to take small birds.

11. Buzzard : 0,0,1,1 =2.
Two records -both from North Mymms Park- single birds in Dec 98 and Nov 99. May be seen more commonly in future as it expands its range eastwards.

12. Kestrel : 8,12,12,12 =44.
Most likely to be seen over areas of rough grassland to the west of Brookmans Park where it hunts voles. Pair raised 2 young in North Mymms Park in 1999. Declining as agriculture becomes more intensive.

13. Hobby : 0,3,4,4 =11.
Has become notably commoner in recent years. Seen in several locations including Brookmans Park, North Mymms and Potters Bar between May and September. Almost certainly breeds locally.

14. Red Legged Partridge : 0,5,3,3 =11.
Small parties are most likely to be seen in the fields between Wildhill and Essendon. Also occasionally around Colney Heath.

15. Pheasant : 10,11,12,12 =45.
Quite common but not in the large numbers found elsewhere.

16. Moorhen :12,12,12,12=48.
Very common .

17. Coot : 12,11,12,12 =47.
One or two pairs breed at Bedwell Park and Gobions Pond (where numbers seemed to have decreased this year).

18. Golden Plover : 0,0,0,2 =2.
A flock of approx. 350 flew over North Mymms Park on Nov 7th this year. A small group of 5 birds flew over Brookmans Park on Dec 2nd.

19. Lapwing : 8,4,8,6 =26.
Usually seen in small flocks outside the breeding season. Approx 100 birds over Water End on Dec 11th was the biggest group seen this year. Two pairs attempted, but failed, to breed on the large field to the south of Bradmore Lane this year. Unfortunately the Lapwing is in serious decline as a breeding bird in Herts owing to modern agricultural methods.

20. Snipe : 0,0,0,1 =1.
One flew over Brookmans Park on Dec 18th this year.

21. Woodcock: 1,1,0,1 =3.
Three records - all in the winter months. A very shy and elusive bird which might turn up in any patch of damp, undisturbed woodland.

22. Black Headed Gull : 9,9,9,10 =37.
The commonest gull locally but rarely seen April - June when it returns to the coast to breed.

23. Common Gull : 4,5,7,6 =22.
Second commonest gull in winter, but rarely seen outside Oct-March. Big flocks of 150+ birds can be seen most winters on the fields adjacent to the Vet College playing fields.

24. Lesser Black Backed Gull : 7,9,11,12 =39.
The gull most likely to be seen in the Spring and early Summer. Mostly encountered singly or in small groups. Seems to be on the increase.

25. Herring Gull : 6,8,3,7 =24.
Usually seen in the Winter months and the most infrequently observed of the four gull species noted. Not as common as it used to be.

26. Common Tern : 0,2,2,3 =7.
Occasional visitor to Gobions Pond during the Summer months.

27. Stock Dove : 5,8,12,12 =37.
Relatively common but often overlooked. Breeds in Gobions Wood. Small flocks of up to 30 birds can be encountered in Autumn and Winter in the fields on either side of Bradmore Lane - often in the company of Wood Pigeons.

28. Wood Pigeon : 12,12,12,12 =48.
Abundant, particularly in Winter.

29. Collared Dove : 12,12,12,12 =48.
Very common around all local villages.

30. Cuckoo: 2,3,2,2 =9.
For the last two years I have only come across the Cuckoo in North Mymms Park. It seems to have disappeared from the rough grassland to the north of Gobions Wood. Yet another species under threat from modern agriculture.

31. Little Owl :1,0,1,2 =4.
Infrequently heard in North Mymms Park - mainly in Autumn.

32. Tawny Owl : 5,6,4,2 =17.
Breeds around Brookmans Park and probably in most suitable woodlands in 10km square. Heard much less in 1999, compared with previous years.

33. Short Eared Owl : 0,0,0,1 =1.
One bird seen at Hatfield Aerodrome on Dec 29th this year. Up to six were reported at this site earlier.

34. Swift : 4,4,4,4 =16.
Very common from the 2nd week in May to the third week in August. Probably breeds in Potters Bar and Hatfield.

35. Kingfisher : 3,4,4,7 =18.
Most frequently encountered near the North Mymms Pumping Station at Water End where it may have bred for at least the last two years. In Winter it can be found on any small stream and at this time of year it can also be seen regularly in Gobions Wood.

36. Green Woodpecker :12,12,12,12 =48.
Common. Often seen in grassland to north of Gobions Wood.

37. Great Spotted Woodpecker :12,12,12,12 =48.
Very common. Often visits gardens.

38. Lesser Spotted Woodpecker : 2,6,4,5 =17.
Elusive and probably commoner than it appears. Seen regularly in my Brookmans Park garden in Spring and early Summer when it draws attention to itself by calling. Also seen in Gobions Wood, Water End and North Mymms.

39. Skylark: 7,9,10,11 =37.
A few pairs still breed in fields around Brookmans Park - e.g. Bradmore Lane. Largest numbers are seen in October when European birds pass through on migration.

40. Sand Martin : 0,1,0,1 =2.
According to the Atlas of British Breeding Birds, the Sand Martin breeds in this 10km square. However the only birds observed have been passage migrants. Several were seen at North Mymms Pumping Station on Oct 2nd this year.

41. Swallow : 7,6,7,7 =27.
Common from around April 20th where there are cattle and unsprayed pastures. Last record for 1999 was on the relatively late date of Oct 17th.

42. House Martin : 6,6,6,6 =24.
Common Summer visitor arriving about 10 days after the first Swallows. Nested at United Reformed Church, Brookmans Park - 2nd brood not leaving the nest until Sept 18th. Overall number of nests seem to have decreased over the last four years.

43. Tree Pipit : 1,1,3,3 =8.
Only found on southern edge Hawkshead Wood, May-August. Two singing birds in 99.

44. Meadow Pipit : 5,8,8,7 =28.
Only recorded Sept-April, although it has bred in the 10km square. Heavy passage from mid-Sept to end-Oct when attention is usually drawn by its “peesp” call overhead. A few can be found in Winter in rough grassland throughout the area.

45. Yellow Wagtail : 1,1,1,1 =4.
Only seen on passage in May or, more usually, September. Migration route seems to follow the course of Mimmshall Brook. Two records in 99 on 5th and 12th Sept, both from North Mymms Cricket Club. Atlas of British Breeding Birds 88-91 recorded it as breeding in our 10km square, but it now appears to have been lost.

46. Grey Wagtail : 2,0,2,7.
Can turn up anywhere in Winter where there is running water. Infrequently noted until 1999 when a pair was regularly seen near Water End suggesting it may have tried to nest nearby.

47. Pied Wagtail : 10,12,12,12 =46.
Common. Often seen among horses at Vet College or around the Green in Brookmans Park.

48. Wren : 12,12,12,12 =48.
Very common in gardens, woods and hedgerows.

50. Robin : 12,12,12,12 =48.
Abundant, particularly in Winter when numbers are augmented by migrants from Europe.

51. Whinchat : 0,0,1,0 =1.
Two records - both on the same day in late August 98. Only likely to be observed on passage, near rough grassland or sparse scrub.

52. Blackbird : 12,12,12,12 =48.
Abundant.

53. Fieldfare : 6,6,4,6 =22.
Oct-March visitor. Flocks can build up to 300+ birds, especially in the fields south of Folly Arch and near the Vet College. Will visit gardens to feed on fallen apples in harsh weather.

54. Song Thrush: 11,9,11,12 =43.
Seen quite often on woodland/pasture edges, but by no means common and rarely seen in gardens (by this observer). It’s difficult to believe that only 60 years ago the Song Thrush was commoner than the Blackbird.

55. Redwing : 7,6,6,6 =25.
Common visitor from early Oct to early April. Can form large flocks, often in the company of Fieldfares. Also visits gardens in harsh weather.

56. Mistle Thrush : 11,11,11,11 =44.
Quite common and probably nests in Gobions Wood among others.

57. Lesser Whitethroat : 3,2,4,4 =13.
Quite common but elusive visitor from May to early Sept. The best place to find this species has been the area to the rear of the rail station, but now that much of the scrub has been ripped out it is unlikely to be as productive in future.

58. Whitethroat : 5,3,5,5 =18.
Common visitor from end of April to September. Whereas the Lesser prefers taller hedgerows, the Common Whitethroat is more partial to brambles and smaller hedges.

59. Garden Warbler : 0,1,3,2 =6.
Surprisingly uncommon in the area. Only found in the Cangsley Wood area of North Mymms Park - where two individuals were singing on May 25th.

60. Blackcap : 4,5,6,9 =24.
Very common summer visitor - the woods on the north-east side of Gobions Pond are a particularly good place to find this species. In 1999 the first male was recorded singing very early, on March 27th; and a male has visited this observer’s garden regularly in December to take peanuts and bread. Another sign of global warming!

61. Chiffchaff : 4,8,8,8 =28.
Very common summer visitor to most woods in the area. First song recorded on March 14th this year - again, earlier than usual.

62. Willow Warbler : 6,6,6,6 =24.
Common visitor from mid-April until about the third week in September. Again my first record for 1999 was earlier than usual (April 5th). Numbers have significantly decreased in recent years and it no longer appears to breed at one of its old sites at the south-west end of Gobions Wood. However there are still good numbers in Hawkshead Wood.

63. Goldcrest : 12,12,12,12 =48.
Very common, particularly in gardens with Leylandii.

64. Spotted Flycatcher : 0,2,1,1 =4.
Quite rare locally. The only record in 1999 was of a pair near St Mary’s Church on May 25th. They were not seen subsequently.

65. Pied Flycatcher : 1,0,0,0 =1.
Just one record - a male on April 13th 1996 to the north of the Vet College. This species is rarely seen in Herts.

66. Long Tailed Tit : 12,11,12,12 =47.
Very common.

67. Marsh Tit : 8,7,9,9 =33.
Quite common, especially in Gobions Wood where as many as three birds have been recorded calling (“pitchoo”) simultaneously. They can also be found regularly in North Mymms Park. The Herts Bird Report states that the very similar Willow Tit is commoner in the county, which is surprising given that this observer has never recorded one in our 10km square.

68. Coal Tit : 11,12,12,12 =47.
Very common, regularly visiting bird feeders.

69. Blue Tit : 12,12,12,12 =48.
Abundant.

70. Great Tit : 12,12,12,12 =48.
Abundant.

71. Nuthatch : 11,10,11,12 =44.
Common in broad-leaved woodland e.g. Gobions Wood and Cuffley Great Wood.

72. Tree Creeper : 11,9,8,11 =39.
Common but can be difficult to find. Like the Nuthatch it will visit gardens if there are mature trees.

73. Jay : 12,12,12,12 =48.
Common in all woods in the area.

74. Magpie : 12,12,12,12 =48.
Abundant.

75. Jackdaw : 12,12,12,12 =48.
Very common with up to 200 birds forming flocks with other corvids after the breeding season. There is a colony of about 40 birds at Saint Mary’s Church, North Mymms.

76. Rook : 5,7,8,10 =30.
Uncommon. During Spring and Summer the only places where Rooks can be seen regularly are the grass verges at South Mimms Services. This is probably due to the planting of autumn-sown cereals and/or heavy spraying with insecticides. The site of the nearest rookery is unknown. The species has rarely been seen to the east of Brookmans Park. Rooks are more likely to be seen in Autumn and Winter, possibly due to an influx of Continental birds.

77. Carrion Crow : 12,12,12,12 =48.
Abundant , forming flocks of up to 100 birds.

78. Starling :12,12,12,12 =48.
Very common, especially in Winter.

79. House Sparrow : 12,12,12,12 =48.
Still common but it is now rare to see flocks of 20+ individuals. Small colonies are dotted around Brookmans Park, but they are not regular visitors to this observer’s garden. As elsewhere in the UK the House Sparrow has decreased at an alarming rate in Herts over the last 20 years.

80. Chaffinch : 12,12,12,12 =48.
Very common.

81. Brambling : 0,0,0,1 =1.
Recorded once -at Woodside, December 99. One male and a possible female in a flock of Chaffinches.

82. Greenfinch : 12,12,12,12 =48.
Common, especially in gardens.

83. Goldfinch : 10,12,12,12 =46.
Quite common on waste ground throughout the area.

84. Siskin : 7,8,6,6 =27.
Common visitor from mid-Sept to early April. A particularly good place to see Siskins is Gobions Pond where parties can be found in the waterside alders throughout the Winter. Numbers can vary from year to year - in 1999 flock sizes were smaller than usual with a maximum of approx 30 birds on Dec 4th.

85. Linnet : 8,8,11,11 =38.
Singles and pairs can be seen throughout the year. Linnets seem to breed in small numbers - particularly to the east of Essendon and around North Mymms. A notable flock of 120+ birds was present between the station and the Vet College in the Autumn of 98 , but nothing like these numbers were seen last year.

86. Redpoll : 2,2,2,3 =9.
Seen occasionally in small parties from mid-Oct to end-Feb. Redpolls are particularly attracted to silver birch scrub, so probably Cuffley Great Wood is as good a place as any to find them. The Atlas of British Breeding birds records Redpolls as having bred in this 10km square between 1988 -91. I suspect they no longer do so.

87. Common Crossbill : 0,3,0,0 =3.
The Crossbill is renowned for its irruptive behaviour and 1997 was just such a year. A party of approx 15 birds was seen in the vicinity of Hawkshead Wood between July and November - and they may well have bred. No Crossbills have been seen locally since.

88. Bullfinch : 11,10,11,11 =43.
Quite common in thick hedges throughout the area, and will sometimes visit gardens. Regularly seen in hedgerows to the north of Gobions Wood.

89. Yellowhammer : 10,11,12,12 =45.
Quite common, particularly in the hedges to the west of Welham Green and Brookmans Park. A good place to find Yellowhammers was the area to the south-west of the station. Unfortunately the clearance of scrub in December is likely to have severely reduced the number of potential breeding sites. Small Autumn flocks of 25-30 birds have been found in this area in the past.

90. Reed Bunting : 0,0,1,0 =1.
Just one record of a juvenile in pasture next to North Mymms Cricket Club in November 98. Recorded as a breeding bird in our 10km square in the 88-91 Atlas, but site unknown.

The following species were recorded as breeding birds for 10km square TL20 in the 88-91 Atlas, but have not been seen in the last four years by this observer on any occasion.

Wood Duck
Grey Partridge (was one of our commonest farmland birds, but now in steep decline)
Little Ringed Plover
Turtle Dove (another species in serious trouble)
Barn Owl (only 3 pairs bred in all Herts in 94 or 95)
Firecrest
Willow Tit
Tree Sparrow ( UK numbers have fallen by 90% in two or three decades )
Hawfinch (reputed to breed in Cuffley Great Wood).

I would be very interested if anyone has any details for these or any other species not covered earlier.