Category Archives: Bird monitoring

The 18th annual Jersey Great Garden Bird Watch 2-3 February 2019

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As another year rolls around its time for this year’s annual Jersey Great Garden Bird Watch with Action for Wildlife and the Jersey Evening Post. This year it will be held over the weekend of 2nd and 3rd February. Of course, notification of the coming watch typically leads to a serious change in the weather. Not that it’s been all that nice in Jersey recently anyway but you probably should expect horizontal bird feeders in non-stop hail now at the start of February!

Cold and unfavourable weather is when the birds in your garden become most reliant on your support and so, with them coming to feeders it’s a very good time to count them. I’m often asked whether we should feed the birds, are we making them too dependent on us? Are we affecting their natural behaviour? Well, having done a good job of impacting on their world and starving them out of a lot of it, perhaps we may have to accept becoming a lifeline to many species in an uncertain future. Some of our garden favourites may not die out without us but their ranges may change dramatically and we might have to work hard to see some of them. Add to that a changing climate and those acts of kindness to our garden friends can become a lifeline.

The Great Garden Bird Watch is in its 18th year so we have plenty of counts to use in assessing the recent trends in Jersey’s garden birds. And things aren’t so good really. If we just look at the most recorded species (house sparrow, greenfinch and chaffinch, blue tit and great tit, blackcap, blackbird, song thrush and robin, starling, wood pigeon and collared dove and a few others like pheasant, magpie, jay and great spotted woodpeckers) we see a slow decline throughout the period since 2002. However, if we take out that great garden success story, the wood pigeon, we see a much more dramatic picture. Most people know about the changes in starling numbers, and the disappearance of sparrows from many gardens (strangely, if you’ve got sparrows you probably have lots of them and they have staged a recovery) but blue and great tits aren’t doing so well either. It’s not all bad news though, blackbirds and robins are holding their own. The picture in the UK is much the same where 40 years of the RSPB’s Big Garden Birdwatch shows the winners and losers there.

The method of the count is very straight forward. Basically you just need to look out into the garden for a few minutes and write down what birds you see and the maximum number of each species. Oh, and for one weekend a year, red squirrels are birds. I’m not sure what they think about that, maybe they accept that it’s an honour!

 

 

Once you’ve counted the birds on your chosen day please fill out the form that you can download here and email in to birdsote@gmail.com or print and send in to the JEP or drop off at their office. Alternatively pick up a form from one of the Island’s garden centres (Ransoms, St Peters, Pet Cabin at Le Quesnes) or Animal Kingdom and leave it with them.

Everyone who takes part in the count is a citizen scientist and doing their own small bit to help us understand our garden birds that bit better. Most of all though, it’s fun and will remind you how important our birds are to us and how much we need them to help us feel alive and well. And they’ll take your mind off Brexit. So, please fill out your form on one day over the weekend and help us see how our birds are doing. Oh, and don’t forget, squirrels are birds!

 

 

Jersey multi-species distribution, habitat suitability and connectivity modelling

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From Natural Environment, Growth, Housing and Environment, States of Jersey

Populations of some of Jersey’s rarest plants and animals survive in isolated pockets across the Island, often in places which remain unprotected, and are, therefore, at threat from the growing anthropological impacts on habitats across the land surface.

The Natural Environment, Growth, Housing and Environment, States of Jersey (formerly Department of the Environment) commissioned the Amphibian and Reptile Conservation Trust (ARC) to determine priority areas for protected species and habitats, and connecting routes between them, in order to aid spatial planning and future protected area designation. The outcomes are based on cost / benefit analysis, providing best economic and conservation value. The report’s authors, Rob Ward and John Wilkinson are frequent visitors to Jersey and well known to Birds On The Edge supporters.

Whilst individual species have previously been assessed on their conservation requirements in Jersey, this is the first time that multiple species (17) have been assessed in the same project.

This study expands on previous efforts by incorporating a wide range of species of varying taxa, ecological roles, traits and conservation status in order to inform an Island-wide plan for maintaining, improving and designating wildlife areas. It highlights areas where improvements to connectivity are most beneficial, and how these may be tied in with other efforts in parallel for maximum return on investment.

In this report, spatial modelling approaches are used to carry out the following tasks:

  • predict and map the distribution on 17 selected species including toad, grass snake, Jersey bank vole, red squirrel, common pipistrelle, field cricket, lizard orchid and ragged robin
  • identify the areas of highest habitat suitability for the 17 species, and evaluate how those areas are currently protected
  • assess which factors, e.g. habitat type, influence the species’ distributions
  • separately assess species associated with urban environments so conservation priorities can be identified for both urban and non-urban environments
  • map the most likely wildlife corridors
  • identify landscape priorities for protection based on their value to wildlife connectivity and current protected status.

The (17) focal species or species groups (genera) selected for species distribution modelling were among Jersey’s protected species and assessed in view of dispersal and movement capabilities. Plants were dominated by orchid species (class Liliopsida) which appear to be better recorded than other flora; perhaps due to their charismatic and overt appearance and specific habitats making them easier to locate and be of greater popularity. Although several invertebrate species were recommended for this study, only the field cricket (Gryllus campestris) had sufficient records. Those species that could not be included at this stage are evaluated later on through other approaches. Long-eared bat roosts (Plecotus spp.) and waxcap fungi (Hygrocybe spp.) were modelled at the genus level as intra-genus members were considered to have similar habitat associations.

Birds were excluded due to a lack of data on nesting sites and their ability to traverse across the Island with ease. However, their needs are accounted for in the report.

The protected species reviewed were highly variable in their movement and dispersal abilities. Given these findings and the overall aim of producing a well-connected network for a wide variety of species, the report authors used a precautionary approach that would allow movement of dispersal-limited species, but that also contained patches with sufficient size to support the most wide-ranging species. Although referring to individual distances and ranges in the review, the area encompassed by a functioning population is considerably larger than that of an individual. Therefore, to provide areas that are suitable for not only individuals, but also entire populations to move through and inhabit, Jersey must ensure those areas are of a sufficient magnitude.

This work supports the decision making processes within Growth, Housing and Environment, States of Jersey, with implications for wildlife conservation, planning and building.

Download the report Jersey multi-species distribution, habitat suitability & connectivity modelling, executive summary and appendices

Plastic found in ‘almost 100%’ of Alderney’s gannet nests

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From BBC News and Alderney Wildlife Trust

Nearly all of Alderney’s 8,000 gannet nests are contaminated with plastic pollution. As recently as 20 years ago, only small quantities were seen in the nests, the Alderney Wildlife Trust (AWT) said. The plastic build-up in the breeding colonies is killing the seabirds, with some entangled gannets found hung or missing legs, it added. The plastics found in the nests are largely from fishing industry rope or line and gannets are known to forage as far as 20 nautical miles to collect nesting materials

The island, 10 miles (15km) from France and home to 2,000 people, hosts around 2% of the global gannet population. “Over the last 20, 30 years we’ve gone from little bits of plastics here and there to every nest now, pretty much, having a significant quantity of plastic in it,” the Trust’s Roland Gauvain said. The plastic build-up is posing a “significant risk to chicks and adults alike as they become entangled or end up eating it”.

“It’s not uncommon to find gannets hung – to lose legs, to find their wings entangled.”

AWT further highlighted concerns over plastic pollution across the British Isles, along with sewage spills and a build up of waste on beaches (see The Wildlife Trusts).

Alderney’s gannet population is still growing, but Mr Gauvain said the Island’s position in the English Channel meant it was particularly vulnerable to plastic pollution. “Most of these plastics aren’t going to be coming from Alderney,” he said.

“We have a population of 2,000 people and we’re talking about upwards of 8,000 nests on the colonies. “Really, the tale is that we are impacting our waters so much more than we ever realised.”

Our farmland bird monitoring reaches new milestone and you can help

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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

 

Want nesting petrels or puffins? Get rid of invasive mammals from their colonies!

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It’s long been known that nesting seabirds and mammals don’t mix well. That’s why most species choose islands free of rodents and carnivores to nest. Smaller seabirds and those that nest down burrows are particularly vulnerable. And, if mammals get to those otherwise safe seabird colonies, you can expect the pretty rapid disappearance of the birds – they are either killed and eaten or they just don’t even try and nest. Unwanted species like this are called invasive and you can read all about this well studied issue through some titles below.

Birds On The Edge has covered several successful projects to remove unwanted mammals from seabird sites around the British Isles in Lundy Island, the Isles of Scilly, Calf of Man and the Shiant Isles. In Jersey we believe that mammals currently prevent breeding of storm petrel (they breed in good numbers in Alderney) and Manx shearwater and severely suppress our tiny Atlantic puffin population.

Storm petrel chick calling on the Shiant Isles from RSPB

A storm petrel chick has been recorded calling on the Shiant Isles for the very first time. This is an important step for the Shiant Isles Recovery Project as it’s the first known breeding of these seabirds on the islands. The EU LIFE+ funded project played an artificial call of an adult storm petrel outside the suspected burrow nest site to record the chick’s reply call and confirm its presence.

The project, a partnership between RSPB Scotland, Scottish Natural Heritage and the Nicolson family, the custodians of the islands, has been working over the last four years to make these islands, five miles off the coast of Harris, a safer place for Scotland’s globally threatened seabirds to breed. Island restoration projects such as this one are a key part of helping Scotland’s struggling seabird populations develop resilience to ensure their long term survival.

Storm petrels were not able to breed successfully at the Shiants because of their vulnerability to predation from the islands’ population of invasive non-native black rats. These were eradicated over the winter of 2015/16 and the islands were officially declared free of rats earlier this year.

Following the eradication, the project has been working to attract storm petrels to breed on the islands as it has ideal habitat for their nests in the many areas of boulders around the islands. These birds are little bigger than sparrows and only come to land in summer to breed. Scotland’s internationally important population currently nests at only a few offshore islands because of the presence of ground predators at other potential sites.

During the summer of 2017, calling storm petrels were recorded on the Shiants for the first time.

Dr Charlie Main, Senior Project Manager for the Shiant Isles Recovery Project said: “It’s fantastic that this storm petrel chick has been recorded on the Shiants. After the adult was recorded last year we thought it highly likely that they were breeding so to have this confirmed now is great for the project and for the species in Scotland. It’s also another vital step for making these islands a safer place for Scotland’s internationally important seabirds, many of which are struggling to cope with the impact of climate change and a lack of suitable secure breeding sites.

“We’ve strong hopes for the future that more storm petrels will breed here and a colony will be established. Three other calling adults were recorded this summer suggesting that there may have been more breeding attempts. This one chick is incredibly special to everyone who has been involved in the project since 2014; it means that all the work we’ve been doing to make and keep these islands free of invasive predators is paying off. It also shows just how quickly island restoration can make a difference to seabirds which is really positive for future projects like this one.”

And in Jersey?

In 2017, Kirsty Swinnerton, with Piers Sangan, undertook a preliminary review of the conditions available for nesting seabirds on Jersey’s north coast for Birds On The Edge. Kirsty’s report is now available here.

The recent establishment of the Jersey National Park and the acquisition of land at Plémont by the National Trust for Jersey has created some unique opportunities for seabird and habitat restoration. Historically, the north-west coast from La Tête de Plémont to Douët de la Mer supported 200-300 breeding pairs of Atlantic puffin but which have dwindled today to less than 10 pairs at most. The decline has probably been a result of an overall decline in the species’ southern range combined with the impacts of invasive species on Jersey including the brown rat, feral polecat/ferret, European hedgehog, European rabbit, and free ranging/feral cats. In addition, domestic dogs and agricultural stock (sheep and cows) could also prevent the re-establishment of puffins if not carefully managed at seabird nesting sites.

The report provides an overview of existing seabird recovery tools proven to re-establish breeding seabird colonies around the world. The primary focus is on the control of invasive vertebrates to increase the size and distribution of breeding colonies and reproductive success, and on hands-on species recovery techniques used to encourage seabirds to recolonise the area. However, during the study, it became apparent that much of the potential seabird recovery area does not support suitable habitat for puffins or other ground-nesting seabirds. The sites are choked with dense stands of bracken, and this may be the primary factor currently limiting colony growth of puffins and other burrow-nesting seabirds.

To understand more fully the impacts and interactions of invasive species, lack of suitable breeding habitat, and human disturbance on puffin colony re-establishment, the study recommended a pilot project combining species recovery techniques with research and monitoring. It further recommends initial small steps to maximise opportunities for feedback into recovery project development and the development of Species Action Plans for puffins and other seabirds by working groups in order to guide recovery efforts to include local seabird experts and stakeholders, and ensure best practices.

Download Kirsty’s full report Options for the recovery of nesting seabirds on Jersey, Channel Islands

Further reading on invasive mammals and seabirds:

Invasive mammal eradication on islands results in substantial conservation gains (2016)

Invasive predators and global biodiversity loss (2016)

Underlying impacts of invasive cats on islands: not only a question of predation (2014)

Severity of the Effects of Invasive Rats on Seabirds: A Global Review (2008)

Influences on recovery of seabirds on islands where invasive predators have been eradicated,with a focus on Procellariiformes (2016)

What is a “cough”?: A study into childrens’ awareness of Jersey’s chough project

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By Catherine Firth

Public awareness is essential if a conservation project is to succeed, particularly with species reintroductions. There was initial concern from the public when the idea of reintroducing choughs to Jersey was mentioned. Crows and magpies, close relatives of choughs, are considered pests by a lot of Islanders and can be controlled under Jersey law in order to protect agricultural produce. Choughs are highly specialised feeders only eating insects you tend to find in soil or animal dung.

A chough eating a dung beetle in Jersey. Photo by Liz Corry.

Public understanding and acceptance of choughs was, therefore, needed to ensure success.  In addition, support for the choughs should lead to support for the wider Birds On The Edge project. In turn attracting funding and resources such as public volunteers.

It has now been five years since the first choughs were released into Jersey. We wanted to find out if the Jersey public were aware and what they thought of the species. Two studies were conducted this summer by visiting graduate students; one focused on children, the other on adults.

I focused on children as they are a key demographic group at Jersey Zoo.  By engaging children in conservation education, they can be inspired to make well informed decisions affecting sustainability in the future, and in this case help to protect the red-billed choughs in Jersey.

To conduct the study, I visited eleven of Jersey’s primary schools with a questionnaire for the children to complete before and after an educational presentation on the  choughs and  Birds On The Edge. Being a Nottinghamshire lass, navigating the back roads of Jersey on a rusty borrowed bike was a challenge in itself!  But after a lot of wrong turns and frantic pedalling up and down hills, I manged to interview 16 teachers and 330 children across the Island. Teachers were generally very enthusiastic about including their classes in the study and the children seemed excited to learn about a new mysterious animal.

Reintroduced choughs and sheep in Jersey have been working together to improve the Island’s biodiversity. Photo by Liz Corry.

The results showed that only a very small percentage of the children interviewed were aware of the red-billed choughs in Jersey.  A proportion of the children guessed that it was a bird, but hardly any knew that choughs were living on the same island as them.  In fact, I had a lot of children reading their questionnaire and asking me “what is a cough?” accompanied by some fantastic drawings of what the children believed the choughs to look like including sloths, hedgehogs, monkeys and even a unicorn!  Likewise, most teachers confessed that they did not know about the project.

After the educational presentation, the results showed a huge increase in knowledge and understanding both of the choughs as a species and its history in Jersey. In their post-taught questionnaires, many children mentioned how the choughs became locally extinct, the habitat and resource needs of the choughs and what Birds On The Edge is doing to help. In addition, after the visits, there was some evidence of children sharing their new found knowledge of the red-billed choughs with other parties. This included two boys attending the chough keeper talk at Jersey Zoo, given that day by the Head of Birds, and practically presenting it for him!

There were other cases of children telling their parents and one child even identifying a chough on a family walk in St John!  This is very encouraging news, demonstrating how children can act as a catalyst for change by sharing their knowledge to influence their friends’ and family’s actions which affect conservation matters and help protect the choughs.

Moving forward, it would be fantastic to do more in-school workshops. Only a small percentage of the children in Jersey took part in the study but it showed how children can be massive assets for increasing awareness. It would also be great for teachers to include the choughs in more of their own lessons; a fantastic example of animals and their habitats which is a part of the Year’s 3, 4, 5 and 6 science curriculums.  However,  teachers had concerns about the time available to them to teach their classes about the choughs (particularly Year 6 teachers who face the pressure of SATs). To overcome this, we could provide schools with more resources, for instance red-billed chough reading comprehension resources: infiltrating classes without directly teaching about choughs whilst remaining focussed on the children’s upcoming exams.

As part of my workshops the children created posters to inform the public of Jersey all about the red-billed chough population, all completed posters were entered into a competition and were judged by a member of the Jersey Zoo education team. Grouville Primary School had the winning poster and the class had the opportunity to visit the choughs at Sorel.

The winning poster designed by a group of children at Grouville Primary School. Photo by Catherine Firth.

All entries were fantastic and can be seen here.  A big thank you to all the children who took part and the teachers who sent in all the entries!  Everyone at the Zoo particularly enjoyed this poster from Grouville:

Grouville children are clearly cut out for careers in conservation! Photo by Catherine Firth.

If only conservation were that easy!

Catherine Firth carried out this research for her MSc in Endangered Species Recovery and Conservation at Nottingham Trent University. She is currently working as a Conservation Knowledge intern at Jersey Zoo.

 

Birds in the Channel Islands: annual update

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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

 

 

Birds eat 400 to 500 million tons of insects annually

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Along with spiders, insectivorous birds play a vital role in consuming insects that would otherwise destroy forests or crops.

From ScienceDaily

Birds around the world eat 400 to 500 million metric tonnes of beetles, flies, ants, moths, aphids, grasshoppers, crickets and other anthropods per year. These numbers have been calculated in a study led by Martin Nyffeler of the University of Basel and published in The Science of Nature, highlights the important role birds play in keeping plant-eating insect populations under control.

Nyffeler and his colleagues based their figures on 103 studies that highlighted the volume of prey that insect-eating birds consume in seven of the world’s major ecological communities known as biomes. According to their estimations, this amounts to between 400 and 500 million tonnes of insects per year but is most likely to be on the lower end of the range. Their calculations are supported by a large number of experimental studies conducted by many different research teams in a variety of habitats in different parts of the world.

“The global population of insectivorous birds annually consumes as much energy as a megacity the size of New York. They get this energy by capturing billions of potentially harmful herbivorous insects and other arthropods,” says Nyffeler.

Forest-dwelling birds consume around 75 per cent of the insects eaten in total by birds which make up about 300 million tonnes of insects per year. About 100 million tonnes are eaten by birds in savanna areas, grasslands and croplands, and those living in the deserts and Arctic tundra. Birds actively hunt insects especially during the breeding season, when they need protein-rich prey to feed to their nestlings.

Further, the researchers estimated that insectivorous birds together only have a biomass of about three million tonnes. Nyffeler says the comparatively low value for the global biomass of wild birds can be partially explained through their very low production efficiency. This means that respiration takes a lot of energy and only leaves about one to two percent to be converted into biomass.

“The estimates presented in this paper emphasize the ecological and economic importance of insectivorous birds in suppressing potentially harmful insect pests on a global scale — especially in forested areas,” explains Nyffeler, who says that this is especially so for tropical, temperate and boreal forest ecosystems.

“Only a few other predator groups such as spiders and entomophagous insects (including in particular predaceous ants) can keep up with the insectivorous birds in their capacity to suppress plant-eating insect populations on a global scale,” he adds.

A study from 2017 which Nyffeler also led showed that spiders consume between 400 and 800 million tonnes of insects each year. Other predator groups like bats, primates, shrews, hedgehogs, frogs, salamanders, and lizards seem to be valuable yet less effective natural enemies of plant-eating insects. He says their influence seems to be more biome-specific rather than on a worldwide scale. For instance, lizards help to suppress insects on tropical islands, but less so on a broader scale.

“Birds are an endangered class of animals because they are heavily threatened by factors such as afforestation, intensification of agriculture, spread of systemic pesticides, predation by domestic cats, collisions with human-made structures, light pollution and climate change. If these global threats cannot soon be resolved, we must fear that the vital ecosystem services that birds provide — such as the suppression of insect pests — will be lost,” says Nyffeler.

Read the full paper Insectivorous birds consume an estimated 400–500 million tons of prey annually here

Painted lady’s roundtrip migratory flight is the longest recorded in butterflies

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Painted lady. Photo by Mick DrydenFrom ScienceDaily

The painted lady butterfly is a migratory species in Europe, and common visitor to the Channel Islands, previously known to migrate from Europe to the Afrotropics during the autumn. Butterflies are obviously much harder to track on migration than birds and the fate of this butterfly species and its offspring remained unknown. Butterfly migration can be very different to that in birds where a bird like the swallow moves between, often very distant but well demarcated, summer and winter areas. The best known butterfly migration is perhaps that of the monarch in North America where despite there being well known and well demarcated summer and winter areas, generations of monarchs will never see the winter areas but are essential in the species life cycle (see the fascinating story of the monarch here).

Researchers were now able to demonstrate that painted lady butterflies return from the Afrotropical region to recolonise the Mediterranean in early spring, travelling an annual distance of 12,000 km across the Sahara Desert.

While the Palearctic-African migratory circuit is typically associated with birds, scientists from the Institute of Evolutionary Biology (IBE), a joint research centre of the Spanish National Research Council (CSIC) and Pompeu Fabra University (UPF), in Barcelona, Spain, found that the painted lady Vanessa cardui endures annual trans-Saharan circuits like some birds do.

This butterfly species travels 12,000 km and crosses the Sahara Desert twice to seasonally exploit resources and favourable climates on both sides of the desert. Few species are known to perform annual long-range trans-Saharan circuits, and that of the painted lady is the longest migratory flight known in butterflies to date.

In a previously published study, the researchers demonstrated that painted lady butterflies migrate from Europe to tropical Africa by the end of summer, crossing the Mediterranean Sea and Sahara Desert.

The fate of these migrants and that of their offspring remained unknown. “Our hypothesis was that the species initiates a reverse northward migration towards Europe in spring, thus completing a regular migratory cycle,” states Roger Vila, one of the researchers.

Painted lady (2). Photo by Mick Dryden

The answer is in the wings

With the aim of confirming this hypothesis, they studied the natal origin of the butterflies that reached the Mediterranean region in early spring. To do so, they analysed the stable hydrogen isotopes of the butterflies sampled in Morocco, Andalusia and Catalonia in Spain, Crete, Egypt and Israel.

An isotope is a form of a chemical element whose atomic nucleus contains a different number of neutrons compared to protons in the nucleus. In water, the proportion of hydrogen and its stable isotope depends on the geographical location. When absorbing water, this proportion is maintained in plants; it later remains in the caterpillars that feed on these plants, and, eventually, in adult butterflies.

By analysing the hydrogen stable isotopes found in the wings of adult butterflies, the researchers could determine where they had developed as caterpillars.

“It is difficult to study the movement of insects by means of observations, marking or radio tracking, since there are millions of individuals and they are very small. This is why finding out where a butterfly grew up before undergoing the metamorphosis by means of stable isotope analysis turns out to be extremely useful. It feels like magic,” says Gerard Talavera, who led the research.

The results show a major proportion of specimens stay in the Afrotropics during winter and that those recolonising the Mediterranean are most probably their offspring. This scenario closes the loop for the Palearctic-African migratory system of Vanessa cardui and shows that the annual distance travelled by the successive generations may reach about 12,000 km, including crossing of the Sahara Desert twice.

Whether the painted lady does regular migratory circuits similar to those of the monarch butterfly in North America was a matter of scientific debate. This research reveals the parallelisms in such a unique evolutionary adaptation.

Access the paper Round-trip across the Sahara: Afrotropical Painted Lady butterflies recolonize the Mediterranean in early spring here

Painted lady (3). Photo by Mick Dryden

Channel Islands Bat Conference 2018

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Male Nathusius pipistrelle with ring 2From Annyctalus Ecology

The 2018 Channel Islands Bat Workshop is to be held in Guernsey on the 18th and 19th August 2018 with an optional extra night of trapping on the 17th August.

Processing kitThere will be a mixture of theory and practical workshops during the day and a research trapping session during the evening of the 18th August. The programme is still being finalised but includes bat identification, sound analysis, tree inspection and survey, use of IR and thermal cameras.

There is a very limited pool of skilled Harp Trapbat workers across the Channel Islands and consequently there is very limited knowledge of what bat species are present and their status across the islands. In Jersey we have discovered four new bat species for the island in the last three years, since we started to use advanced survey techniques and there is the potential for the same to happen in Guernsey! Species previously recorded in Guernsey are common, soprano and Nathusius pipistrelle, grey and brown long-eared bats, Natterer’s bat and greater horseshoe bat.

CI Bat Conference 2018

Tickets for the event are £35 (plus Eventbrite booking fee) and this includes all workshop sessions, refreshments and lunch on the 18th and 19th. Travel and accommodation are not included. Book tickets here

Information about Guernsey can be found here

Surveyors with mist net