Population of Honey Buzzards and Hobbies in Northumberland

Population data for Honey Buzzard Pernis apivorus from 1993-2001 are given in the paper:

Return of the Honey Buzzard by Nick Rossiter, Birds in Northumbria 2001, Northumberland & Tyneside Bird Club 169-172 (2002).

Data for later years is appended to the table. All the data in the table refers to the study area in south west Northumberland. In 2003 small numbers were found in casual visits to north Northumberland (3 localities, 4 adults, 1 juvenile). In 2004 one adult was found in north Northumberland.

Table 1: Numbers of Honey Buzzards found from 1993-2006

See also Honey Buzzard densities in Britain including Northumberland in 2001.

A more detailed summary is presented in Table 2 from the second full season (2005) with the benefit of the disturbance permit from English Nature. The study area is large comprising 16,600 hectare in the south west of the county.

Table 2: Results for Honey Buzzards in Northumberland by area in 2005

A significant majority of the sites are in private woodland on shooting estates. This is indeed deeply ironic in view of the history of birds of prey in the county. Reasons suggested for the success in such areas are the tendency for timber to be grown on to maturity, the habitat mosaic with heather moors adjacent to meadows and woods and the quietness of the land. Last, but not least, losses to their main predator, the Goshawk, are likely to be low because of ample numbers of easier targets for the hawk, such as corvids and pigeons. The highest numbers are found on land owned by the Allendale, Featherstone and Whitfield Estates and the National Trust. 11 of the 23 sites are in the North Pennines Area of Outstanding Natural Beauty. Eight types of call have now been analysed and related to behaviour and over five hours of video were taken this year during routine visits to the breeding sites.

In 2006 the survey of nest sites was intensified and ten nests were found. Five of these were in Norway Spruce Picea abies, two in Scots Pine Pinus sylvestris, two in Common Oak Quercus robur and one in Douglas Fir Pseudotsuga menziesii. In Holland Norway Spruce was also a popular choice with 36.5 % of nests in this species compared to 33.7% in Douglas Fir, 15.4% in Scots Pine and 12.5% in Larch (Bijlsma et al 1993, p.72) . The results for 2006 are summarised in Table 3.

Table 3: Results for Honey Buzzards in Northumberland by area in 2006

Some photographs of habitat used by Honey Buzzard in Northumberland are shown at Honey Buzzard habitat

Details of the timing of the season and the survey techniques used are given at Honey Buzzard techniques

Population data for Hobby Falco subbuteo are given for years up to 2002 in the various Birds in Northumbria Annual Reports. Hobby data provides an interesting further example of a raptor colonising an area of northern Britain not previously thought suitable for the species. Hobby colonisation started in 1996, three years later than the Honey Buzzard. All the data in the table refers to the study area in south west Northumberland.. Breeding success appeared to be poor in 2004 with few fledged young noted after the very wet August.

In 2003 one pair was found breeding in casual visits to north Northumberland (one locality, 2 adults, 2 juveniles). In 2004 none were found here.

Table 4: Numbers of Hobbies found from 1996-2006

Photographs of Hobbies in Northumberland (South Tyne):

Each line shows the same bird in a number of poses. These birds were frequenting woods along the edge of the moors. Note the short inner wing and long pointed outer wing; the medium-length square-cut tail and lightweight appearance. Peregrines Falco peregrinus also have a medium-length tail but would have a proportionately much heavier body, with pronounced chest, and a broader tail base. Peregrines would also still be in primary moult in August and September while Hobbies may start moult of inner primaries in late summer but most migrate south with old flight feathers intact (Forsman, 1999, p.508).

Although Hobbies do have shortish tails, the wing base can be so narrow that the tail is longer than the wing base (20-30% perhaps) while in Peregrine and Merlin Falco columbarius the wing base and tail length are more equal. As a Hobby moves away from you the tail length can look quite long at up to 1.5 times the wing width: see for instance Forsman, 1999, plate 644. The relatively long wings of Hobby give them a wingspan:length ratio of 2.5 compared to 2.2 for Peregrine (Ferguson-Lees & Christie, 2001, p. 882, 914). The first and third below show a ratio of about 2.5.

Female Hobbies are only slightly larger than males (3-5%) but they are not quite so slim or thin-winged and average over 30% heavier with the bulkiest 50% heavier (Ferguson-Lees & Christie, 2001, p. 882). Forsman (1999, p.510) notes that female Hobbies are stockier and broader-winged than males and may at times even resemble a slender Peregrine. On this basis the first two birds below could be male(s) and the third a female but the emphasis is probably on the could. In picture 2 the Barhaugh 12 July 2003 bird is mobbing a Common Buzzard: the size comparison clearly excludes Peregrine Falcon. Further the Common Buzzard has a length 1.75 times that of the falcon, very close to the 1.77 expected from the lengths given by Forsman (1999, p.267, p.506) of 51-57cm for Common Buzzard and 29-32cm for Hobby.

Sparrowhawk Accipiter nisus would show a broader wing with a rounded tip.

It has been suggested, perhaps rather extraordinarily, that these are Merlin Falco columbarius. Merlin are more compact with relatively short wings (wingspan:length ratio of 2.3 (Ferguson-Lees & Christie, 2001, p. 878)) and have a broader and shorter hand with a slightly blunt tip.

I am grateful to Martin Kitching for comments on these birds.

Barhaugh 23 June 2002, adult (male?) 1 2 3

Barhaugh 12 July 2003, adult (male?) with Common Buzzard in second one 1 2

Kirkhaugh 19 August 2003, adult (female?) 1 2 3 4

Kirkhaugh 12 September 2003, adult 1

For comparison, a Peregrine:

SW Northumberland 17 May 2003, adult 1

This bird shows a broader wing base, a broader tail base and apparently shorter tail with the wing base and tail being about equal in length. Also note the primary moult (around P4) and generally more powerful appearance.

The Hobby was regarded as a well-established recent colonist in Northumberland in 2003. See bulletins for reports by 22 observers in the monthly bulletins of the Northumberland & Tyneside Bird Club. Hobbies were also found in two field trips led by Nick Rossiter in south west Northumberland in 2001 and 2002. The report on the latter, published in the bulletin for September 2002, is available here.

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