Ornithologist Archives - Wild Frontier Ecology

Wintering bird surveys in an SPA

January 27, 2020
Blog

WFE was commissioned to undertake a study of foraging wintering birds on the River Deben Estuary SPA (Special Protection Area) in Suffolk, focusing on a particular area where a freshwater flow was pumped from a sluice at night into the river from surrounding arable land. Natural England were concerned that plans to redirect this waterflow away from the estuary may impact non-breeding waterfowl species such as brent goose and redshank for which the Deben is an internationally important site. Water birds have been found to preferentially associate with freshwater flows over mudflats due to accessibility of fresh water for bathing and drinking and an increase in invertebrate prey densities.

The River Deben is an internationally important site for bird species such as redshank and brent goose

The study compared the ornithological importance of the outfall site, which has intermittent flowing freshwater, with two control sites, one comprised an area of mudflat with no freshwater influence, while the other control was an area of mudflat with a permanent freshwater gravity flow. Two nocturnal surveys and one daylight survey were conducted per month between November and March on all three areas and involved the counting and identifying all bird species present with the assistance of thermal imaging cameras.

The study discovered that the area with the permanent freshwater flow hosted a significantly greater density of birds than the other two sites, which both had a very similar density of birds associated with both the nocturnal surveys and diurnal surveys. It was concluded that the site with the intermittent freshwater water flow had a negligible influence on the local bird communities providing equivalent habitat to a creek with no freshwater input and therefore the removal of the water flow would have no negative impacts on the wintering bird populations listed as interest features of the Deben Estuary SPA.

Heathland habitat assessment for stone curlew

April 22, 2019
Birds

Stone Curlews

Wild Frontier was commissioned by the RSPB and Natural England to conduct a survey and assessment of heathland habitat for stone curlews in the Norfolk and Suffolk Breckland. Stone curlews are a rare summer visitor in East Anglia, and are afforded special protection under Schedule 1 of the Wildlife and Countryside Act.

The survey involved visiting each site and categorising the habitat based on vegetation height – an important factor in determining suitability for stone curlew nesting. WFE then mapped the habitats on site and calculated which areas were suitable for stone curlew.

The assessment provided an indication of site condition and potential population capacity for stone curlew, which can now inform conservation efforts and habitat management for the species.

Waxwings

December 1, 2010
Blog

These chubby yet gaudy wanderers from Scandinavia are being seen in their hundreds this winter, with big arrivals along the east coast in the autumn from mid October onwards. They have long been a birders’ favourite, often allowing close approach and appearing in otherwise bird-barren urban areas such as supermarket car parks.

I had the excitement of seeing a flock of 18 flying in over the shingle bank at Cley marshes NWT in early November, as well as singles over our office, 3 on survey in Perthshire and 1 over Norwich Cathedral yesterday. Those tuned in to their call will find that it’s not unusual to encounter the odd roaming singleton flying over in these irruption years.

Waxwing spotted by Rob. Photo Jonny Rankin

Waxwings are an irruptive species, arriving in the UK in varying numbers each winter. The key driver to their movements would seem to be the supply of wild berries in Scandinavia. The 1965 irruption, according to Birds of the Western Palearctic, was a result of an “acute imbalance between population size and food supply in Fenno-Scandia”. An awesome set of photos from Fair Isle shows that birds crossing the North Sea were hungry enough to feed from the hand. Judging by the plethora of photos of waxwings appearing this autumn, once birds reach Britain, their favourite nosh would seem to be rowan berries, including ornamental varieties.

An interesting article in BirdGuides shows the movement through the country of a colour-ringed waxwing, from Orkney to Aberdeen in six days, and from Aberdeen to Cumbria in another seven. Previous patterns of invasion have shown that larger flocks tend to aggregate in city centres later in the winter, presumably because of the variety of food sources available.

And here’s the tenuous link; here is a piece of evidence that all the BREEAM assessments we undertake which recommend berry planting, and all the urban landscaping schemes which include berry-bearing shrubs and trees, do at least benefit this one species of bird in its hour of need. That is not to say that they do not benefit other birds in the same way. What sometimes seem like token efforts on small sites can cumulatively be of critical importance.

Rob

Robert Yaxley

Rob Yaxley started birdwatching at the age of 3 and saw his first waxwing in a garden in Costessey in 1985. Best memories including seeing a single waxwing in the trees at Guist Bridge in 1987, and hearing a flock go over while coppicing in Wayland Wood with the golden pheasants sometime in the early 1990s. Rob enjoys eating berries and hanging around in supermarket car parks.

Some Observations From a Vantage Point

March 2, 2010
Blog

The increasing rigour of pre-development surveys in the last ten years has led me to some strange places in which to watch birds. The particular form of survey which has predominated in my experience is associated with wind farm proposals, and is termed vantage point survey. The principle behind such surveys is to evaluate the use by birds of airspace to be occupied at some point in the future by wind turbines. In practice, for the observer, this means watching from a convenient and well placed spot, and counting birds flying over or across the landscape. While the science behind such an approach is clear, the experience of doing the survey can be anything from crushingly boring to intensely gripping, but always requiring 100% concentration.

Only rarely does the weather allow us the luxury of removing outer garments – standing still does not lend itself to keeping warm on all except the balmiest of days. For myself I remember a cold day in December when I decided to use a deck chair to observe from. All was well until the end of the watch when I tried to stand up and found I could not feel my legs for the cold, collapsing to the ground. It took me several hours and a hot bath to warm up again.

You get to know the vantage point regulars very quickly and eventually in great depth – the busy, hovering kestrel, monotonously circling buzzards, skittish golden plovers and buoyant lapwings. The odd rarer bird, such as the fleetingly seen large white (gyr?) falcon I saw last year, causes a racing of the pulse, and like fly fishing it keeps you hanging on for the next one. Estimating flying height and distance is difficult at first, and to my mind requires a good knowledge of the site, a knowledge of the bird species, due consideration to weather conditions and visibility. To say it becomes easier with experience is not to belittle the vigilance with which such estimations are made.

The sites are often that curious mixture of rural and industrial – the agribusiness farm with giant tractors hauling giant ploughs, or the landscape dominated by pylons and power lines, or criss-crossed by major roads and railways. All are tied together by the inherent openness and exposure to the wind, and other commonalities such as the predominance of wildlife of open spaces such as golden plovers, meadow pipits, brown hares and skylarks.

The solitary observer, motionless in the landscape, also has a great opportunity to observe wildlife without themselves being observed. Frequently, open fields are crossed by wary foxes, scattering hares and skylarks, or hedges are shadowed by sparrowhawks hoping to pick off the odd unlucky chaffinch. Sometimes the eyes are briefly averted as a motorist has a pee behind a hedge. Odder sites are provided by the wildlife, such as a bat being chased by crows in full daylight, or a kestrel repeatedly robbing a barn owl as it brings voles back to its nest, or the sudden convergence of hundreds of gulls seemingly from nowhere on a ploughing tractor.

More spectacular still are the dynamic cloudscapes and incidental movements of small parties of birds at great height, perhaps on non-stop migration to distant tundra nesting grounds. For consultants like us, with their feet very much on the ground, these surveys can provide a reminder that there is an immense aerial dimension that exists for birds about which we still know rather little.

Rob

Robert Yaxley