Reported Honey-buzzards: Totals by Month 2001 and Comments
|
month |
SW |
SE |
EA |
Mid |
NE |
NW |
Scot |
Wale |
NI |
Total |
|
April |
|
3 |
|
|
|
|
|
|
|
3 |
|
May |
7 |
21 |
(9) |
9 |
10 |
4 |
1 |
1 |
|
62 |
|
June |
(1) |
7 |
(6) |
3 |
4 |
(2) |
|
|
|
23 |
|
July |
(1) |
2 |
(3) |
2+ |
(2) |
|
4 |
|
|
14 |
|
Aug |
(2) |
17 |
(3) |
10 |
(4) |
(3) |
|
|
|
39 |
|
Sept |
(7) |
27 |
(9) |
1 |
(11) |
|
|
(2) |
|
57 |
|
Oct |
|
8 |
(7) |
1 |
|
|
2 |
|
2 |
20 |
|
Nov |
|
|
|
|
|
|
|
|
|
0 |
|
Total |
18 |
85 |
37 |
26 |
31 |
9 |
7 |
3 |
2 |
218 |
Figures from Birdwatch regional reports except those in brackets where from Birdguides.
These totals are not directly comparable with the presumed migrant totals compiled by British Birds. The records above are unchecked and may include breeding sites, though each breeding site will only feature once per month. On the other hand not all records are submitted to the Birdguides/Birdwatch systems.
The interesting features for 2001 are:
The relatively high totals historically for both spring and autumn.
The concentration on south-east England in both seasons.
Other favoured areas are East Anglia, north-east England and the midlands.
Very few are reported from Scotland, Wales and Northern Ireland. Numbers in western England are also evidently relatively low. However, significant breeding populations are found in some of these areas, for example Wales and Scotland.
The seasonal pattern is as expected for a breeding summer visitor with the highest numbers on arrival and departure and low numbers when nesting.
Significant numbers remained into October.
Weather-wise, persistent northerly winds in the main migration season for juveniles in September will have given some an easy exit, with a reduced chance of being detected.
Wasp populations appeared to be low in north-east England this year perhaps leading to a drop in productivity. However, actual productivity did not decline as much as expected perhaps because of alternative food sources, such as frogs and young pigeons (Roberts & Coleman 2001).
A further rise was noted in the Northumberland population in 2001, in spite of survey difficulties through the foot-and-mouth virus.
Reference:
Roberts, S J, & Coleman, M, Some Observations on the Diet of European Honey-buzzards in Britain, British Birds, 94(9) 433-436 (2001).
Notes from reference:
Honey-buzzards breed successfully throughout Britain, from Scotland to southern England, and from west Wales to Kent (M. Cowland in litt, Brian Etheridge in litt). So how do they manage in such diverse habitats? Photography at a nest site in Wales showed large numbers of Common Frogs Rana temporaria brought in as prey, comparable at site studied to volume of hymenoptera. All feeding done by male. Other prey includes Common Lizard Lacerta vivipara, Slow Worm Anguis fragilis, Common Pheasant, Wood Pigeon, Meadow Pipit and Song Thrush. Wasp items were from seven of the common species including Hornet Vespa crabro. German Wasp Vespa germanica was surprisingly poorly represented. Common Wasp Vespa vulgaris and Norwegian Wasp Dolichovespula norwegica made up bulk of hymenoptera.
