Woodland bird projects
Woodland bird survey 2008
In 2008, staff and volunteers from the RSPB, DNPA and Natural England surveyed the breeding birds of a selection of upland oak woods. The aim of the survey was to carry out a baseline assessment of bird populations in woodlands that were being entered into management agreements or those where there is ongoing management and where a survey would provide a useful update on bird populations.
The surveys were in response to national studies which have revealed that birds of the upland oak woods, notably wood warbler, pied flycatcher and redstart, have declined nationally since the mid 1980s. Of particular significance in the South West is wood warbler, which has suffered a 63% decline in Devon and Somerset over this period, whereas the other species have remained relatively stable. Research is underway to understand the reasons behind the declines, and advice is now available to guide woodland management to benefit bird populations.
Of the six woodlands that were surveyed in 2008, wood warblers were recorded in four of them, with the Bovey Valley and Yarner Wood appearing to hold the highest densities.
Pied flycatcher nestbox scheme
The pied flycatcher is a migratory bird species, spending the winters in sub-Saharan Africa, and coming here to breed in summer. It prefers Western oak woodlands where it nests in tree-holes, but it also readily takes up breeding in nestboxes. In woodland near Okehampton, the pied flycatcher has been monitored ever since they bred in the first nestboxes in 1974, and thousands of them have been ringed, their movements followed and their life-spans calculated. The bird is fairly site faithful, so it is quite likely it will return there to breed. By visiting the site year-on-year it is possible to calculate the return-rate from Africa, and thus survival rates and longevity of the species.
Weekly visits are carried out to the site in May and June, and the progress of a breeding pair followed - from making the nest through to fledging of the young. In addition, the adult pair and their brood are ringed on the nest, as part of the British Trust for Ornithology’s bird ringing scheme.
The pied flycatcher has proven to be a valuable species to research, enabling studies of mating, breeding and productivity. In the longer-term, information gathered on return dates, laying dates, and breeding success can be evaluated and calculated, providing valuable information for conservation organisations and enabling decisions to be made on how to best conserve Britain’s wildlife in the face of a changing climate.
There are also well-established nestbox schemes running in other Dartmoor woodlands such as Yarner Wood, Dendles Wood and Dunsford Wood.
Willow tit survey
The willow tit is one of the rarest species of tit in the UK. It is easily confused with the more common marsh tit, in that it has a large sooty-black cap extending to the back of the neck and a small black bib. It is mid-brown above, with white cheeks and pale buff-grey underparts. However, the song of the two species is quite different, and this is the safest way to tell the two apart in the field.
Willow tits live in wet scrubby woodland, with plenty of standing dead wood, and stands of impenetrable birch or willow carr. They require dead wood in which to excavate their own nestholes, rather than using existing holes in trees like most other tit species. On Dartmoor, this sort of habitat occurs in patches within ancient woodland, but more commonly along the scrubby edges of Rhôs pasture. Although occasional sightings of willow tits are reported, no real baseline exists for the distribution on Dartmoor. So, between 2009 and 2011, in the early springs - the period of peak activity for willow tits - nine volunteer surveyors and a National Park ecologist surveyed fifteen wet woodlands on the edges of Dartmoor. The sites were surveyed using a tape lure playing willow tit song – on the one hand to attract the birds to the surveyor and make it more likely to be counted, and also to make sure that the bird was in fact a willow tit, and not a marsh tit. The surveyors found eleven singing individuals (which indicates eleven pairs) on six sites. It appears that the wet scrub surrounding Rhôs pasture is the most suitable habitat for this species on Dartmoor.
Further work is now being carried out on the site that had the highest density of willow tits: special nestboxes have been made and erected in suitable habitat to encourage willow tits to use them, and to allow the project team to monitor their breeding success. A netting and ringing project is being undertaken to help gain an understanding of their movements and juvenile dispersal. The project is also planning to link in with other partnerships and organisations, such as Action for Wildlife, the RSPB and Natural England to ensure that expertise is pooled, landowners are advised on their requirements, and ultimately, that suitable habitat for willow tits remains and the species does not decline yet further.