From BirdGuides

Climate change has advanced the breeding season of many species in the UK – but just how much varies markedly across the country, according to a major new study.

The first in-depth analysis into the seasonal timing of certain bird and insect behaviours has confirmed that spring is indeed getting earlier each year – but that exactly how much earlier these events now start depends on where in the UK and in which habitat they occur.

The authors of the report have warned these trends could have serious ramifications for ecosystems, as significant variation between groups of animals in the rates of advance means populations are becoming out of sync with the life cycles of their prey. The 50-year study into natural cycles of egg laying and migration has also dashed environmentalists’ hopes that shaded habitats such as forests are shielding some populations from the destabilising effects of global warming.

Lead author Dr James Bell, who heads up the Rothamsted Insect Survey, said: “There was already good evidence that spring is coming earlier each year, but what we didn’t expect to find was that it was advancing as much in forests as it is in open areas such as grassland.

“Equally, in areas where we’d expect to see much greater acceleration, such as urban parkland, the rates of advance appear to be the same.

“This all points to a complex picture emerging under climate change, which makes ecosystem responses hard to predict, and even harder for conservationists to prepare for.”

An earlier study by the group looking at a 30-year period had shown the average rate of advance varied from about a week earlier for birds and a month earlier for aphids, but the new paper reveals an even more complex picture.

Dr Stephen Thackeray of the Centre for Ecology & Hydrology (CEH) explained: “Our previous research has shown that, in the UK, many signs of spring have been shifting earlier over the last few decades and that this is likely to be driven by climatic change.

“However, we have never before had such a detailed picture of how these changes vary across the UK and its major habitats.”

The study charts the seasonal habits of more than 250 UK species of birds and insects, and shows clear evidence that aphids, moths and butterflies are now on the wing, and birds are laying their eggs, much earlier than they were in the middle of the 20th century.

The researchers, including scientists from CEH, the British Trust for Ornithology (BTO), Butterfly Conservation, and Science and Advice for Scottish Agriculture (SASA), analysed data collected between 1960 and 2010 from three national monitoring networks – the Rothamsted Insect Survey, the UK Butterfly Monitoring Scheme and the Nest Record Scheme.

The long-term changes they uncovered broadly confirm similar effects being observed the world over – that as global temperatures rise, natural phenomena such as flowering, or emergence from hibernation, are occurring earlier each year. But by looking in detail at this long-term data, the team has revealed that the responses of some species to climate change are not straightforward, nor necessarily predictable.

Moths provide a good example of this. As those species that turn from caterpillars to adults early in the year appear to be doing so much earlier. Professor Tom Brereton of Butterfly Conservation said it was unclear what was behind these specific patterns, nor why butterflies did not show something similar: “Whatever the reasons, we should be concerned about how dramatically climate change is affecting butterfly and moth life cycles.”

Bucking this trend towards earlier onset are those birds and butterflies that inhabit farmland, as well as birds who live in coastal habitats – providing possible evidence that other factors, such as declining food availability, are applying a different pressure on these populations and delaying the onset of breeding.

Dr James Pearce-Higgins, Director of Science at the BTO, said: “Birds are at the top of many food chains, and are sensitive to the impacts of climate change on the availability of their insect prey. This work shows how changing spring conditions may affect the ability of birds to find food, and that those impacts are likely to vary across the country.”

A particularly worrying finding of the study is that the rate at which these seasonal behaviours are shifting is the same in open habitats, such as grasslands, as it is in shady ones, such as forests. It had been thought forests might offer some protection for species against rising temperatures. “The work is important because it shows us that we cannot rely on habitat to slow down climate change impacts, even in woodlands and forests where the conditions are more stable, and which were expected to buffer against adverse changes,” explained Dr Bell.

As well as providing more evidence of the effects of climate change, the study also provides the most detailed assessment yet of how many species’ life cycles are determined by geography and altitude. It shows that rather than tracking the simple north-south trend of increasing temperatures and earlier onset of spring, the date of key behaviours of many species follow more complex patterns. So, while aphid activity simply becomes progressively later the further north you go, the same was only true for birds and butterflies up to the likes of Derry, Gretna or Newcastle.

Beyond that point, butterflies become active earlier in the warmer, wetter west than the colder, drier east, while for birds laying eggs, the opposite is true. Dr Jon Pickup, lead aphid researcher at SASA said: “As pests, it remains a concern that aphid migrations are getting earlier at a dramatic rate, and this piece of work shows us that signal across the UK very clearly.”

The study is the result of many years work analysing and interpreting huge data sets, and now lays the ground work for some urgent new research into what is driving these impacts at habitat levels.

“There is unlikely to be a more comprehensive analysis that address both spatial and habitat variations in seasonal timings,” concluded Dr Bell.

Read or download the paper Spatial and habitat variation in aphid, butterfly, moth and bird phenologies over the last half century here

The Birds On The Edge Farmland Bird Monitoring project passed another impressive milestone this month when the 5,000th data sheet was input to the database. That’s 5,000 visits to our 23 transects at 21 sites since 2005. Birds have been recorded in all weather, come hell, high water, horizontal rain, snow and the strange things that go on at some sites around dawn. The exact number of bird records is less easy to count off but, and a record can be one individual bird or a flock of hundreds, it must be well over 250,000 by now. And the number of birds themselves? It may be over 1 million although there are some robins that have been counted more than once. Even on the same day!

During the project we have recorded 171 species and that’s without gulls or birds like gannets that although sometimes visible don’t count if they are way out to sea. Mind you, if any gannet chose to fly over land like the cormorants do then we’d record it! We have never included black swans either but I’ve often thought that we should have – we do count other riffraff like pheasants, bar-headed and barnacle geese and those feral greylag geese that have made themselves at home in Jersey. And a couple of escaped cagebirds, although, with peafowl but unlike those geese, don’t feature in the 171.

The project’s first detailed report Trends in Jersey landbirds 2005‐2015 can be read or downloaded from here.

In 2019 the project will continue to collect data, giving incredible strength to our understanding of the current status of Jersey’s landbirds. So, why not come and join our current stalwart counters Harri, Will, Jon, Jonny, Tony, Miranda, Neil and Ali, Glyn, Hester, Cris, Tim, Hannah and Bea, Neil and Richard. We would like to introduce a couple of new counters into the team to make sure every site is well covered. We are particularly keen for someone to do the count at Sorel (see description here). There are actually two transects at Sorel but you simply walk west along the coastal path for one and back to the carpark through the fields for the other. Its not a hard walk and can be a beautiful site (ok, its not always beautiful if the weather is bad) and is famous for its migratory birds at times of the year and its (definitely countable) choughs throughout the year. As with all our transects, the walk isn’t too difficult and should ideally be visited twice a month.

As a bird surveyor you should be able to identify by sight and sound all of our common birds. It is the common birds that are most important to us as long-term assessment of their status and identification of population trends (up, down or staying the same) are the most important in conservation planning. That’s not to say though that we don’t want to hear about rarer birds – however much I can justify the need to get out there and count the wrens and dunnocks I’m the first to admit that stumbling across a long-eared owl or finding a yellow-browed warbler is always a thrill and, yes, it can be the hope of seeing something like this that sometimes keeps the interest going. But, don’t worry if you think you can’t identify the rarer stuff right now – start with the important birds like robins and wood pigeons and the Richards’ pipits and buff-breasted sandpipers will come. If you are interested in joining the gallant team of counters please read the Jersey Farmland Bird Monitoring Manual and email Glyn at birdsote@gmail.com

For several years now we have compiled a combined list of all birds recorded in the Channel Islands thanks to the recorders from Jersey, Guernsey, Alderney and Sark. Each year we’ve seen the lists grow longer and the order the species are listed in keep changing. Today we launch the updated list, updated to the end of 2017 (the Islands don’t review any year’s birds until after the next one starts). Download the list here.

The updated list includes four (well, five) new species, three of which, excitingly, were recorded on two islands each: marsh sandpiper (Alderney and Jersey), (American) royal tern (Guernsey and Alderney) and Iberian chiffchaff (Alderney and Jersey). In fact, the royal tern became quite a celebrity in Guernsey, Alderney and even in Sussex. The tern went just about everywhere. Except Jersey that is. Editor’s note its been around in 2018. And still not been to Jersey!

The other obvious feature for regular readers of this or any other bird list is the changes to the order, relationships and even the birds’ scientific names. Many of us grew up with long held understanding of the order we put the birds in (start with divers and end with crows) and how they were related (divers and grebes, herons and storks). However, new technologies have made it much easier to look closely at every species and get a much better idea of who’s who and where they sit in the order. Wildfowl are first, and not just because they’re very cool but because they and the gamebirds are not that closely related to every other bird. And hawks and falcons aren’t related? No, and strangely that split should have been obvious before.

The list actually includes one, or two, other new species. That goose formerly known as the bean goose has become two species: taiga bean goose and tundra bean goose. Luckily for the list compilers, the Islands’ ornithologists had in recent years recorded which of the two bean geese, then considered the lower rank of subspecies, were being seen. The split, and upgrade to full species status, wasn’t hard to fit in. If everything was always so easy. Our other new bird was a Caspian gull. This eastern version of the herring gull was once considered just herring gull until analysis found that it was quite distinct. Only unlike the geese it doesn’t always look distinct and takes a real enthusiast to pick one out of the flock. Luckily this one’s finder and photographer not only knows his gulls but got a little assist in that it was ringed!

And the totals? Well, overall we’ve recorded 376 species with Jersey still edging in front with 335. So enjoy the new list, tick off your sightings and try to fill the gaps in each Island’s list. And play ‘what will be Alderney’s 300th species’ (I’m going with little bunting). Why not check out the gaps in the list and try to fill them (we’d recommend seawatching in Sark first). But remember, if you visit the islands please send in your records to the relevant recorder – they’re all there on the list. 

A Working List of the Birds of the Channel Islands (updated to December 2017) can be downloaded here

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