Saturday, 21 January 2012

Beachy Head 2011 Summary No.22

2011: After the last 2 winters which were very severe, we were delighted to find and photograph a male in Shooters Bottom on the 23/10. We searched for this bird on subsequent dates without success. Per B.H.Log.
(Unfortunately, the pair which had taken up residence in late Autumn of  2010 when the male was seen in song flight in November, disappeared shortly after the severe cold spell in early December. In the 1960's & 70's it bred in several areas and in 1970, 4-5 breeding pairs were present, but breeding ceased in the late 1970's after several fires took place in the gorse).

2011: Spring: Recorded from 27/3 (1), with a daily maximum of 7 on the 10/4.
Breeding: Several pairs bred and on the 30/5 4 males were in song in the area.
Autumn: Recorded throughout the Autumn until the 13/11 (1). Large numbers were again ringed in Whitbread Hollow which is by far the main area for this species on Beachy Head, and the BHRG totals are included in this summary. Daily maximuns: 17/8 53 (19 ringed), 24/8 125 (42 ringed), 29/8 400 (119 ringed), 31/8 200 (84 ringed), 15/9 400 (84 ringed), 23/9 550 (141 trapped), 27/9 260 (73 ringed), 3/10 85 (34 ringed). Per B.H.Log.
(The August totals clearly shows how climate change is changing the Blackcap movements. During the 1970’s, the elderberries were ripening in mid-September and the Blackcap numbers being ringed in Whitbread Hollow were mainly concentrated in mid-September, but now with elderberries ripening in late August onwards far more Blackcaps are present in Whitbread Hollow now from mid-August onwards, although  mid September is still the main time. Unfortunately, the weather this year in mid-September was very unsettled and this effected the ringing effort in Whitbread Hollow.
Tony Quinn in his summary of the Blackcap Autumn migration in 1970, states that the numbers passing through Beachy Head, is no less than 8 times the total of the seven observatories considered by Peter Davis, and at least 50 times as many as at either Dungeness & Portland Bill. In the years from 1960 to 1970 a total of 4.471 Blackcaps were ringed on the Headland with the majority of these in mid- September. Last year a total of 1,243 Blackcaps were ringed in Whitbread Hollow).

2011: Spring: Just one Spring sighting on the early date of the 16/4.
Autumn: Recorded on 26 dates with 105 bird-days, from the 25/7 (1 ringed) to the 1/10 (1). Daily maximums: 6/8 12 (10 ringed), 10/8 10+ (8 ringed), 17/8 10+ (8 ringed). The totals from BHRG have been included, and this shows how Whitbread Hollow is by far the main site at Beachy for this species. Per B.H.Log.
(Sadly, since the 1980's numbers have been in sharp decline. In 1970 for example, it was recorded on 15 dates during the Spring with 71 bird-days and a daily maximum of 20 on the 13/5. During the Autumn, it was recorded on 52 dates with 1,323 bird-days with a daily maximum of 120 on the 14/8 and 130 on the 15/8. This compares with this years daily maximum of just 12 on the 6/8).

2011: Spring: Recorded from 9/4 (3). Daily maximums: 10/4 (12), 24/4 (50 in the whole area),
Breeding: On the 30/5 a full count was made in the whole area, with a total of 58 logged, 80% of these were singing males and a breeding population of approx. 40-45 breeding pairs.
Autumn: An excellent year. Recorded upto 4/10 (1). Daily maximums (which includes totals from the BHRG in Whitbread Hollow), 3/8 88 (19 ringed), 6/8 100 (23 ringed), 10/8 185 (54 ringed), 14/8 350 (79 ringed), 15/8 145 (30 ringed with only 1 re-trap from the previous day), 17/8 400 (89 ringed), 24/8 100 (33 ringed), 29/8 135 (22 ringed), 15/9 58 (10 ringed). Per B.H.Log.
(Pleasing to report that the population of Common Whitethroat appears very similar to what it was back in the 1960's when the breeding population was estimated between 20-40 pairs, although the peak numbers logged in  the Spring migration periods were considerably higher in the early 1960's, with the maximum number recorded in the Spring was in early May 1965 when 300 were logged. In the Autumn, numbers are fairly similar with this year, with 400 were logged during early August in both 1967 and 68. During the winter of 1968/69, there was a massive depletion of the population in the UK as a whole, due to a drought in the Sahel, and this was clearly shown in the numbers of migrants recorded on the Headland in 1969, and the slow rate of recovery in the 1970's. Between 1960-1971 a total of 4,671 Whitethroats had been ringed on the Headland averages nearly 400 a year and it was estimated that some 3,670 birds passed through our area during the Autumn migration period during the 60's. In 2010, a total of 274 birds were ringed by the BHRG although this year the number is in excess of 500 birds ringed).

2011: Spring: Recorded from 11/4 (1 in Cow Gap). On the 4/6 7 singing males were located in the area, and probably represents the breeding population.
Autumn: Recorded on 35 dates and last seen on the 27/9 (2). In total 121 bird-days, which includes the BHRG totals, with daily maximums of 10+ on the 14/8 (7 trapped), 17/8 17 (8 trapped). Per B.H.Log.
(Although the local breeding population has remained fairly stable, with up to 5 pairs during the 1960's and an estimated 12 pairs in 1970, the daily numbers recorded especially during the Autumn migration period has fallen dramatically since the early 1990's. Prior to this the daily maximums regularly recorded were between 80-100 per day and in 1982 the daily maximums were 200 on the 28/8 and 150 on the 5/9 this compares with the daily maximum in 2011 of just 17 on the 17/8. Between the years 1960-1971 a total of 1,336 birds were ringed an average of 110 birds per year, compared to approx. 36 being ringed by the BHRG in 2010).