From BTO

Some bird species provide cultural services, being aesthetically pleasing and having behaviours that people find interesting to watch. Others provide disservices (e.g. gulls, pigeons and corvids) negative for well-being. By documenting how the abundance and richness of species in these two groups correlates with human population density it was apparent that socio-economically deprived areas support low ratios of birds to people, particularly of cultural service species. These results inform management of green space, and provision of feeding and nesting sites, to promote positive interactions between birds and people within urbanised landscapes.

Working in collaboration with the University of Exeter, and funded by NERC, researchers carried out extensive bird surveys within an urban area, centred on the towns of Milton Keynes, Luton and Bedford, as part of a wider project investigating urban ecosystem services. These provided measures of the abundance and richness of bird species within both the cultural services (35 species) and disservices (nine species) groups. The research team was able to look at the human population by using data from the 2011 National Census, and to assess socio-economic status by using information published by the Office of National Statistics. Since bird diversity is strongly associated with the structure and availability of urban green space, the team also had to factor in the green space present within the study area.

Analyses revealed that the abundance of cultural service species increased with human population density but peaked at c.1,100 people per 500m x 500m grid tile. The abundance also increased with the proportion of urban green space. Interestingly, the species richness of cultural service birds decreased with human population density but increased with percentage green space. There was a positive linear relationship between the abundance and richness of cultural disservice species and both human population density and the availability of green space.

When the researchers mapped how the abundance of service and disservice birds co-varied with human population density, they found that the two groups of birds showed distinctly different spatial patterns. Service species were most abundant in areas of medium housing density – the suburbs – while disservice birds were most abundant in areas of dense housing, such as those around urban centres.

While these different patterns are not a direct consequence of human population density per se, they probably result from spatial differences in urban form, the pattern and management of urban green space, levels of disturbance and the availability of resources, all of which are known to vary along socio-economic gradients. This underlines that people living in different parts of the urban landscape are likely to experience different relationships with wild birds, with the human communities in socially deprived areas exposed to more species with negative behaviours than wealthier communities. A consequence of this is that the increased frequency of negative interactions experienced by these people is likely to shape their connection with nature and support for the conservation of the natural world in a negative manner.

The study identifies opportunities to deliver management approaches to counter these unfavourable relationships. Investment in urban green space and its management for cultural service birds is one obvious option, but there are also opportunities at the householder level, through practices such as wildlife gardening. Such householder level approaches can be of wider benefit because their beneficial effects are likely to increase the abundance and richness of cultural service birds in neighbouring gardens, meaning that the actions of a small number of people can provide health benefits for the wider community.

Download the paper Covariation in urban birds providing cultural services or disservices and people here

From Annyctalus Ecology

We are delighted to announce that we have confirmed another new bat species for Jersey. A single Rhinolophus hipposideros, or Lesser horseshoe bat, was spotted during our final hibernation survey of the winter on Sunday 4th March 2018. This bat species can be found on the nearby Cherbourg Peninsula, as well as in south west England, and Wales, but it is a first for Jersey.

Lesser horseshoe bats are notoriously difficult to record on bat detectors due to having a very high frequency, directional call. A single file containing echolocation calls which appeared to be of this species was previously recorded at the same site in September 2016, but despite numerous surveys of the site, both visual and using capture techniques and almost constant deployment of static bat detectors at the site since June 2017 no further records of the species were made, until now.

Horseshoe bats are listed under Annex II of the Habitat Directive due to their rarity and specific habitat requirements. In most areas horseshoe bat summer colonies are usually found in the roofs of larger rural houses and stable blocks offering a range of roof spaces. They are very shy and require dark vegetated corridors in which to travel as well as woodland areas in which to feed.

Horseshoe bats are very distinctive in appearance and are the only UK bat species which hang freely when roosting. If you have seen horseshoe bats within your property, or elsewhere in the Island we would love to hear from you in order to allow us to learn more about this species. We would also welcome any information about other bat roosts! Please send your roost information to us at ani@jerseybatgirl.co.uk or to the Jersey Bat Group on enquiries@jerseybatgroup.org

From Rare Bird Alert and Alderney Bird Observatory

Britain’s birds are amongst the best monitored animals in the world, and it’s just about to get even better as a brand new bird observatory joins the nineteen others that are scattered around our coast.

Alderney Bird Observatory (ABO) received official accreditation at a recent meeting of the Bird Observatories Council (BOC), a gathering of all of the bird observatories, making it the twentieth in the country. Ranging from Fair Isle, Shetland, in the north to Alderney, Channel Islands, in the south, Britain’s bird observatories have kept an eye on the comings and goings of our birds since the first observatory Skokholm, Wales, opened in 1933 – these unbroken observations make them amongst the largest bird datasets in the world.

Many firsts for Britain have been found and documented at Bird Observatories but it is the day-to day observations of birds on the move that are the most important, birds making their way in and out of Britain on their migrations from far-flung destinations. Since the 1960s several of these have changed the timing of their migration as a response to a changing climate. The swallow now arrives back in the UK on average fifteen days earlier than it did in the 60s, and the sand martin over twenty days earlier, whilst for the cuckoo the timing hasn’t really changed. It is vital that we keep an eye out for changing patterns in the future if we are to fully understand the pressures that many of our birds might face and how we might help those that are showing declines.

John Horton, Warden at Alderney Bird Observatory, said, “It is such a privilege to be the first Warden of Alderney Bird Observatory and to know that the work we carry out here will make a real difference to our understanding of the birds that both live here, or pass through on migration. I look forward to ABO adding to the long-term observations gathered by my colleagues around Britain and Ireland. It is testament to the hard work of lots of volunteers that we have got this far and to them a huge thank you.”

John continues the story on the ABO Blog

Having got to where we are, many have asked; How has this all come about ? Well, in the autumn of 2015 The Alderney Wildlife Trust advertised a job vacancy for a Bird Recorder. The job description and requirements, however, went some way towards those required for a Bird Observatory warden. After doing a little homework and with particular consideration to Alderney’s geographical location that appeared ideally situated for attracting migrating birds, during an initial enquiry phone call with the Trust manager I suggested Alderney might consider setting up a bird observatory.  The immediate response was that an island resident and native Channel Islander Paul Veron was very much in tune with this idea and would be delighted to hear this.  I was asked to come back to the Trust with a proposal of how this might progress. It transpired that Paul (our observatory chairman) and I had a lot in common, both mad keen birders from our formative years, we both grew up visiting and staying at established British Bird Observatories and we are both experienced bird ringers.

Meeting Paul and his partner Catherine who accommodated Cathy and I for a long weekend first island visit in November 2015, was a major factor in Cathy and I deciding to move to Alderney from Kent in March 2016. These early discussions brought about a 2-year observatory establishing pilot project supported by the Wildlife Trust, its primary remit to try and achieve bird observatory accreditation status from the Bird Observatories Council. Local interest and support for this project from the outset was exceptional and largely through Paul’s contacts we soon had a very experienced and capable bird observatory committee driving things forward.

We won’t pretend it has been plain sailing over the last two years, but thanks to the States of Alderney and to too many people to mention here (and of course to the phenomenal numbers of birds we have recorded) Alderney is now officially positioned amongst the ornithological elite. Such is international interest in birds and in this project that the ABO blog is now read by people in over 100 countries worldwide. We are delighted that the opportunity is now open to you all to visit us and stay at our bird observatory, itself situated in a cracking spot for observing visual migration, all within the unique location of the walls of a 1,900 year old roman fort. Alderney Bird Observatory opens on 1st April 2018, bookings to stay with us can be made on this site. Thank you to all those involved in getting us so far so quickly, and in particular to all those who believed in this project taking up Alderney Bird Observatory membership, your continued support has made the difference and remains invaluable.  We hope to see you all soon.

From The Cornell Lab of Ornithology: All About Birds

Billions of birds undertake migratory journeys each spring and autumn. Most of these spectacular movements go unseen, occurring under the cover of darkness. A new study provides some of the most compelling evidence yet that artificial light at night causes radical changes in the behaviour of migrating birds.

“We found that migrating birds gather in large numbers because they’re attracted to the light,” says Benjamin Van Doren of Oxford University, a lead author of the study. “They slow down, start circling, and call more frequently. They end up burning energy without making any progress and risk colliding with nearby buildings or being caught by predators.”

Scientists from the University of Oxford, the Cornell Lab of Ornithology, and New York City Audubon studied migrant bird behaviour over seven years in a truly unique setting—Tribute in Light in New York City, held to commemorate the September 11, 2001, terrorist attack. Two beams of light–each with 44 xenon bulbs of 7,000 watts—rise into the night sky, mirroring the twin towers of the World Trade Center where nearly 3,000 lives were lost.

“This was a rare opportunity to witness the impact of powerful ground-based lights on nocturnally migrating birds,” says co-lead author Kyle Horton, Cornell Lab, but working at the University of Oklahoma during the study. “This analysis would not have been possible without the help of tribute organizers.”

Well before the results of the study highlighted the effects of the installation, New York City Audubon reached out to the original tribute organizers, the Municipal Art Society, to let them know about the impacts of artificial light on migratory birds. In 2002, the two organisations developed a protocol to save the affected birds. The tribute lights are turned off for approximately 20 minutes when more than 1,000 birds are seen circling in the beams or flying dangerously low with frequent calling. The National September 11 Memorial & Museum, which took over as tribute organisers in 2012, continued this practice.

These brief interludes of darkness during the nightlong tribute provide a unique opportunity for the scientists to quantify changes in bird behaviour in several ways during the alternating periods of light and darkness.

“We had more than 20 wonderful volunteers on the ground counting birds to confirm what was happening in the beams,” says co-author Andrew Farnsworth at the Cornell Lab. “We also used remote sensing tools, including data from local National Weather Service radars, to understand the density and movements of the birds. Acoustic monitors recorded call notes and captured the vocal behavior of birds in the beams. And we ran computer simulations to try to better understand the dynamics of the patterns we were observing.”

When the tribute was illuminated, the study’s authors found that densities of birds over lower Manhattan could reach 60 to 150 times the number that would typically be found in the area at that time. The concentrating effects of the intense light on the birds reached as high as 4 kilometres (2.5 miles). The impact on birds was consistent even on clear nights. (Many previous artificial-light studies focused on nights with poor visibility.) When the light beams were turned off, the birds dispersed within minutes to continue their migrations.

Although Tribute in Light provided a way to measure a specific instance of light attraction, bright nighttime lighting poses problems for birds, even in rural areas. The study’s authors point out that one solution is relatively simple.

“We recommend building lights be turned off for as much of the night as possible, but at least from midnight to dawn during migration season,” says study co-author Susan Elbin of New York City Audubon. “This is true for areas around homes as well as other brightly lit areas such as sports stadiums, construction sites, offshore oil rigs, and large buildings. Migrating is already hard enough for birds without this added danger from artificial light at night.”

The full paper High-intensity urban light installation dramatically alters nocturnal bird migration can be accessed here

In what has become a tradition, each year at around this time Birds On The Edge can unveil the updated list of Channel Islands birds. With kind support from our friends in the very active birding communities in Guernsey, Alderney, Sark and Jersey the list, updated to the end of 2016, can be downloaded here.

What has changed since the last list (to the end of 2015)? Well, that is very obvious to anyone looking closely at the species records and stems from the launch last year of the Alderney Bird Observatory. The team there in Alderney have started to immediately show big changes to our understanding of that island’s bird fauna and of bird migration through the Channel Islands in general. Several species joined Alderney’s list as it creeps up towards the numbers on the lists of the larger islands with first records of pomarine skua, penduline tit, Pallas’s warbler, western Bonelli’s warbler and Blyth’s reed warbler. And that was with less than 12 months activities – what will the next few years show? And where’s that CI first?

The other islands’ birders have been no slouches either. Jersey added squacco heron to its total while there were other notable sightings with Guernsey’s second spotted sandpiper and third black stork, Jersey’s second greenish warbler and Alderney’s second velvet scoter, third subalpine warbler and fourth black stork, red kite and Alpine swift. Sark is lagging a little these days and it would be nice if visiting birders (it really is a good spot to visit), who must at least be able to assist with understanding species’ statuses on the Island, would send in all their sightings to the Sark recorder – the address is on the download.

Of the breeding species it is nice to see the numbers of little grebes, marsh harriers, common buzzards, little egrets and stock doves continuing to rise. There are disappointments as well though with declines in house martin, turtle dove and skylark.

And the Island totals of this totally uncompetitive listing of species? The overall number sticks at 370 and Jersey now has a list of 331, Guernsey 323, Alderney 291 and Sark 227. Each island continues to have what appear, to birders anyway, some glaring omissions. Why no red-throated pipits, lesser grey shrike, marsh sandpiper or Wilson’s petrel? Come and visit one or all of the islands, you’ll be made very welcome and you can maybe add something to this list in future.

A working list of the birds of the Channel Islands can be downloaded here.