Posts tagged ‘populations’
The return of the familiar House Martin is one of the highlights of spring. But will it be a familiar sight for future generations? In recent years, the numbers breeding in the UK have fallen by two-thirds, leading to the species being amber listed as a bird of conservation concern and in need of some help.
Although the decline hasn’t been quite as severe in Wales as it has been in England, we’ve also seen a substantial drop in numbers here too. The species was confirmed as breeding in only 98 tetrads in East Glamorgan between 2007-11, down from 173 tetrads between 1984-89 – that’s a drop of 43% (source: East Glamorgan Bird Atlas).
This recent decline prompted the BTO to launch a two- year research project which began in 2015, funded by BTO members and supporters through an appeal, to provide scientific evidence about House Martins to identify why they are in trouble, and hence start to look for solutions.
The survey in 2015: just how many House Martins are there in the UK?
In 2015, volunteers were asked to survey random i.e. pre-selected 1-km squares throughout the UK in order to produce a robust population estimate to monitor future changes. The survey proved popular amongst birders in East Glamorgan with 25 counters volunteering to search for, and count House Martin nests, in 28 1-kms squares in our region.
The survey in 2016: when do House Martins start breeding and how many broods do they have?
This summer, a brand new, yet complementary, House Martin Survey will be carried out to investigate the timing of breeding and the number of broods raised, and how this varies across the UK. We hope that this information will help us discover why trends are positive in some parts of the UK, and that this will in turn help us pinpoint the reasons for problems elsewhere.
This summer, you choose where you monitor House Martin nests
The BTO is looking for volunteers who are able to observe a nest (or a group of nests) for a few minutes, approximately once a week, throughout the breeding season (which can last from April to September). Volunteers do not need to be able to look inside the nests, as all observations can be made from ground level (or from another vantage point where the nests can be safely viewed without disturbing the birds). After recording a small amount of information about the site on their first visit, on each subsequent visit volunteers will simply need to record the condition of each nest and what activity is taking place at the nest.
Volunteers are free to pick their own study site, which can be anywhere where House Martins are nesting. The survey is therefore ideal for those who have House Martins nesting on or near their home or place of work, but nests elsewhere can be studied provided they can be visited regularly for the whole breeding season.
The survey launches today (17th March), when volunteers will be able to register for the survey via the BTO House Martin Survey pages, and the first survey visits should be carried out in the first half of April. If you’re interested (and why wouldn’t you be!), further information about the survey is available on the BTO House Martin website.
Between 1995-2008, Curlew has suffered a decline of 46% as a breeding bird in Wales (1). News has now emerged from Ireland of a dramatic decrease in their population of breeding Curlews over the last twenty years.
During the last Breeding Atlas, in 1988-91, the Irish population of Curlews was estimated at around 5,000 pairs. This spring, BirdWatch Ireland (2) carried out the first survey specifically to find breeding Curlew in Ireland. Over 60 sites in Donegal and Mayo that were occupied by breeding Curlews during the 1988-91 Atlas were revisited and, shockingly, the results indicated that only six still held breeding pairs. Just four pairs were recorded in Donegal and four in Mayo, indicating that there are likely to be fewer than 200 breeding pairs left in the whole country – a 96 percent decline in 20 years.
In East Glamorgan, we have 35 records of the species in the breeding season, with confirmed and probable breeding evidence reported from a few sites in the northern reaches of the region. Let’s hope that the evocative cry of the Curlew remains in our county.
- State of Birds in Wales 7, RSPB
- Catastrophic Curlew declines uncovered
The latest edition of the annual report State of Birds in Wales has just been published. It draws heavily on the wide range of BTO surveys undertaken by volunteers in Wales.
There’s a wealth of information to discover, with sections on seabirds, wintering waders, rare breeders and widespread breeders.
Population changes for species are outlined. Golden Plover is now a rare breeder in our country, and both Starling and Swift have seen declines of 50% or more since the mid-1990s. Notably, Stonechats have doubled in number, which may be just as well, given the harsh winter we’ve just come through.
Mediterranean Gulls look set to follow Little Egrets in becoming a breeding bird in Wales. That’s probably no surprise to our colleagues in West Glamorgan, who see this species throughout the year, most notably around Bracelet Bay.
It is always a thrill to see a Hen Harrier, be it a ring-tail or a magnificent grey male. Sadly, across the UK the species continues to be illegally persecuted and their numbers continue to fall at an alarming rate.
Wales is bucking this trend, with breeding pairs increasing to 57 in 2010.
The species does not breed in East Glamorgan, but fortunately it can be seen throughout the winter months at various locations throughout Mid Glamorgan, typically roaming across upland areas in search of prey. Eighteen reports have been collected during the Atlas period.
Marsh Tit has experienced a marked decline in the UK, and its conservation listing has recently been upgraded from amber to red. It is not a common bird in East Glamorgan, with presence being recorded in just 15 tetrads in winter and 17 in the breeding season during the current Bird Atlas project.
A new study, just published in Bird Study (Broughton, 2010) suggests that habitat fragmentation may be a contributory factor in the decline of the Marsh Tit population in Britain. Results suggest that dispersal behaviour was sensitive to habitat fragmentation, resulting in poor settling success outside of the natal wood.
Both natal (juveniles) and breeding (adults) dispersal of Marsh Tits in fragmented woodland in an English landscape dominated by intensive arable agriculture was recorded. Spatial distribution of movements and settling locations for adults and juveniles were also documented.
The study population had short dispersal distances. Juveniles disperse further than adults, and females disperse further than males. These distances are however, small. Often no more than 1-1.5kms or 3 territory widths. Few birds became established outside of their natal patch and few birds settled in vacant territories in peripheral outer woods. Its possible that birds are unwilling to cross areas of non-habitat.
Though suitable habitats may be available for this species then, the fragmented nature of these available areas may hinder this species ability to occupy them.
Broughton, Richard K. , Hill, Ross A. , Bellamy, Paul E. and Hinsley, Shelley A. (2010) Dispersal, ranging and settling behaviour of Marsh Tits Poecile palustris in a fragmented landscape in lowland England, Bird Study, 57 (4): pp 458 — 472. http://dx.doi.org/10.1080/00063657.2010.489316
Two passerines, so characteristic of our Welsh landscapes have suffered marked declines over the last 15 years.
Both Whinchat of our uplands and Pied Flycatcher of our broad-leaved woodlands have shown contractions of 50% and more and were amber listed in 2009. Data from 2010 BBS however, now demonstrates a 13 year change, with red-listing now possible.
Information about these and many more species may be found in the recently published Breeding Birds in the Wider Countryside: their Conservation Status 2010.