There are changes afoot, or should I say under your foot, at Les Landes this month! The Government of Jersey has closed some of the footpaths around Les Landes to help protect Jersey’s rare Crapaud.
Jersey’s crapaud aka the western toad. Photo by John Wilkinson
For those not in the know, the crapaud is not a mythical beast but the Jèrriais name given to the western toad (Bufo spinosus). Les Landes is a very important breeding site for the toad. Seasonal ponds and puddles scattered around the site, often across public footpaths, are used for spawning. With adult toads on the move to reach these water bodies it is important we remove as many threats as possible and protect spawn, hence the closures.
Seasonal water bodies like this one at Les Landes are spawning sites for toads.
The toad is one of Jersey’s most abundant amphibian species and possibly most surveyed. However, there is still a lot we don’t know, especially when it comes to urban environments and coastal heathland. Particularly the importance of connectivity between sites. There is little point in protecting a spawning site if the adults get squished before reaching it. “Build it and they will come” isn’t always applicable!
If you find yourself out and about at Les Landes, please respect the area, follow the rules sign-posted on the footpaths…and report any choughs you see (ok so the last bit is not mandatory). Click here to see the public countryside access map and learn about the codes of conduct.
If you want to know more or way you can help Jersey’s crapaud and other amphibian islanders, then head to PondwatchJE. There will also be an in-person training event on the 12th of February at the Frances Le Sueur Centre, St. Ouen. Islanders can register via Eventbrite using the link below.
The fifth edition of Birds of Conservation Concern (BoCC) has been published. Undertaken every five years, BoCC covers the population status of birds regularly found in the UK, Channel Islands and the Isle of Man to provide an up-to-date assessment of conservation priorities. This fifth review has assessed a total of 246 species and placed them onto one of three lists, red, amber or green, according to their level of conservation concern (see RSPB for explanation of categories). 52 species are red-listed (up from 40 at the previous review), 126 are amber-listed (previously 121) and 68 are green-listed (down from 86).
Seven quantitative criteria have been used to assess the population status of each species and to place it on the red, amber or green list: global conservation status, recent decline, historical decline, European conservation status, rare breeders, localised species and international importance.
Most of the data for these assessments are based on bird surveys undertaken by volunteers, such as those run by the British Trust for Ornithology.
A parallel exercise was undertaken to assess the extinction risk of all bird species for Great Britain (the geographical area at which all other taxa are assessed) using the criteria and protocols established globally by the International Union for the Conservation of Nature (IUCN). This resulted in the assessment of 235 regularly occurring species (breeding or wintering or both), the total number assessed differing slightly from BOCC5 due to different rules on the inclusion of scarce breeders and colonisation patterns. The results of this second IUCN assessment (IUCN2) are provided in the same paper as BOCC5.
How the lists are decided
The BOCC assessment is based on the most up-to-date evidence available. Criteria include conservation status at global and European levels and, within the UK: historical decline, trends in population and range, rarity, localised distribution and international importance. Golden oriole (previously Red-listed but which has not bred in the UK since 2009) now joins a Black List of eight other species now considered to have ceased breeding in the UK (including serin, Temminck’s stint and the once widespread wryneck). Four new species that have more recently become sufficiently established, as well as yellow-browed warbler (no longer considered a scarce migrant), were assessed by BOCC5 – little bittern, cattle egret, great white egret and black-winged stilt – and all went onto the Amber list due to criteria related to scarcity and localisation.
The IUCN assessment process uses the same underlying data on population trends and population size but the time periods over which change is assessed differs and is linked to generation length and also population size. With their focus on extinction risk, the IUCN assessments also consider the potential for populations in Great Britain to be rescued by immigration from increasing populations in surrounding geographical areas.
The growing Red List
This update shows that the UK’s bird species are increasingly at risk, with the Red List growing from 67 to 70. By contrast, the first Red List, published in 1996, had only 36 species. Eleven species have been Red-listed for the first time in 2021, six due to worsening declines in breeding populations (greenfinch, swift, house martin, ptarmigan, purple sandpiper and Montagu’s harrier), four due to worsening declines in non-breeding wintering populations (Bewick’s swan, goldeneye, smew and dunlin) and one (Leach’s storm-petrel) because it is assessed according to IUCN criteria as Globally Vulnerable, and due to evidence of severe declines since 2000 based on new surveys on St Kilda, which holds more than 90% of the UK’s populations. The evidence for the changes in the other species come from the UK’s key monitoring schemes such as BTO/JNCC/RSPB Breeding Bird Survey (BBS) for terrestrial birds, the BTO/RSPB/JNCC Wetland Bird Survey (WeBS) for wintering populations and the Rare Breeding Bird Panel (RBBP) for scarce breeding species such as purple sandpiper.
From green to red
Two species moved directly from the Green to Red List: greenfinch and ptarmigan. Increasingly severe declines in greenfinch numbers have been reported in BBS reports for more than a decade, and the initial regional pattern of declines was associated with outbreaks of the disease Trichomonosis. This disease of the digestive tract is widespread in greenfinch populations across Europe and may also be starting to affect other species such as collared dove, sparrowhawk and chaffinch.
The IUCN assessment resulted in 108 (46%) of regularly occurring species being assessed as threatened with extinction in Great Britain, meaning that their population status was classed as Critically Endangered, Endangered, or Vulnerable, as opposed to Near Threatened or of Least Concern. Of those 108 species, 21 were considered Critically Endangered, 41 Endangered and 46 Vulnerable. There is considerable overlap between the lists but unlike the Red List in BOCC5, IUCN2 highlights the vulnerability of some stable but small and hence vulnerable populations as well as declines in species over much shorter recent time periods, as seen for chaffinch and swallow.
What kinds of birds are in the most trouble?
How does the Red List break down across habitats or taxonomic groupings? Unlike previous BOCC assessments, where there was a clearer pattern of influx to the Red List, with upland and woodland species joining the already listed farmland species, this update is more of a mixed bag. However, the worsening status of Afro-Palearctic migrants continues with two aerial insectivores – swift and house martin – joining other migrants such as cuckoo and nightingale on the Red List. Although deteriorating conditions on the wintering grounds and on stopover sites are likely factors, the reliance of many long-distance migrants on insects and other invertebrates suggests that declines in those could also play a role.
The other group joining the Red List also encompasses migrants, in this case, wintering wildfowl and waders that breed at higher latitudes and to the east, but winter in the UK. Climate change and milder winters in regions such as the Baltic Sea have resulted in many of these species being less likely to migrate as far west and south as the UK, in a pattern termed ‘short-stopping’. This is likely the case for Red List newcomers dunlin and smew, but can be further complicated by broader declines in populations, as is known for the Eastern flyway populations of Bewick’s swan.
Can conservation action work?
There is also better news. In addition to white-tailed eagle, which no longer qualifies for ‘historical decline’ thanks to further recovery of the breeding population and intense conservation efforts, five previously Red-listed species (pied flycatcher, song thrush, black redstart, grey wagtail and redwing) have shown modest but sufficient improvements in breeding population status to have moved from Red to Amber. Red grouse, mute swan and kingfisher also move from the Amber to Green. Overall, the Amber List has increased from 96 in BOCC4 to 103 in BOCC5, this difference reflecting both negative (moves to the Red List) and positive changes (moves to the Green List). The Green list, now 72 species long, includes a range of common garden species such as blue tit, blackbird and robin, and saw a net loss of nine species since BOCC4.
The full lists are available in the Birds of Conservation Concern 5 – Summary leaflethere and the full paper The status of our bird populations: the fifth Birds of Conservation Concern in the United Kingdom, Channel Islands and Isle of Man and second IUCN Red List assessment of extinction risk for Great Britainhere
A new study on breeding birds in the EU and UK shows one out of every six birds over nearly a 40 -year period has been lost. Overall, we have lost around 600 million breeding birds since 1980.
Between 1980 to 2017, the authors estimate an overall population decline between 17% and 19%, equating to a loss of between 560 and 620 million individual birds. In fact, some 900 million birds have been lost during that period, however, this is set against an increase of around 340 million in certain species. Very large declines in a small number of common species account for a large proportion of these losses and the same is true of the increases.
The once ubiquitous house sparrow has been the worst hit. It has lost 50% of its population since 1980, a total of 247 million birds. Its close relative, the tree sparrow, has also lost 30 million birds. Both have been affected by changes in agricultural policy and management, however, house sparrows in cities have also declined. The reasons for these urban declines are not clear but may be linked to food shortage, the spread of avian malaria or the effects of air pollution.
When comparing populations by habitat, the highest total losses were seen amongst farmland and grassland birds. It is widely recognised that changes in farming practices driven by policy are responsible for a precipitous decline in wildlife. As a group, long-distance migrants such as willow warbler and yellow wagtail have also declined proportionally more than other groups, as have shorebirds such as lapwing and dotterel.
Whilst much of the decline in bird numbers occurred during the 1980s and 1990s, in the last decade the rate has slowed. In the EU, the Birds Directive and the Habitats Directive provide legal protection to priority species and habitats and have been shown to benefit bird species, as well as enhancing habitat protection.
As an example, seven species of birds of prey have increased in recent decades following increased protection and reductions in pesticides and persecution, as well as from the introduction of targeted recovery projects. Without the introduction of these directives, there is little doubt that declines in many species would have been much worse.
However, this work supports previous research showing substantial recent biodiversity loss. The decline of common and abundant birds shows that further broader scale conservation work is still required. There is an urgent need to conserve birds associated with agriculture, as well as long distance migrant birds across their migratory journeys.
Importantly, the loss of common and abundant species is a concern because it implies damage to our ecosystems and their function, and potentially to the delivery of ecosystem services upon which humanity depends. The dominance of common species means that changes in their populations may have large implications for the health our of our ecosystems.
Fiona Burns, RSPB Senior Conservation Scientist and lead author of the study said: “Next year the United Nations Convention of Biological Diversity will be meeting to discuss the future of our global biodiversity, and create a framework which calls for increasing conservation efforts to be targeted towards preventing extinctions and recovering species abundance. Our study is a wake-up call to the very real threat of extinctions and of a Silent Spring, and we are fully supportive of ensuring a strong framework which puts conservation front and centre of any global plans.
“We need transformative action across society to tackle the nature and climate crises together. That means increasing the scale and ambition of nature-friendly farming, species protection, sustainable forestry and fisheries, and rapidly expanding the protected area network.”
Anna Staneva, BirdLife Europe Interim Head of Conservation said: “This report loudly and clearly shows that nature is sounding the alarm. While protecting birds that are already rare or endangered has resulted in some successful recoveries, this doesn’t seem to be enough to sustain the populations of abundant species.
“Common birds are becoming less and less common, largely because the spaces they depend on are being wiped out by humans. Nature has been eradicated from our farmland, sea and cities. Governments across all of Europe must establish legally binding targets for nature restoration, otherwise, the consequences will be severe, including for our own species.”
Read the paper Abundance decline in the avifauna of the European Union reveals cross-continental similarities in biodiversity changehere
A newly published study from the British Trust for Ornithology indicates that many of the UK’s seabird populations including that of the Atlantic puffin could plunge by as much as 90% by 2050 because of changes in the marine environment caused by rising temperatures, if global warming is not checked.
“This could represent a loss of over a million birds,” warned the BTO’s CEO, Professor Juliet Vickery.
Increasing water temperatures are having a negative impact on sandeel numbers in British waters, the small fish which are the puffin’s main prey species – meaning that the breeding productivity of the puffins themselves is being adversely affected.
According to the BTO report, this is also affecting other seabirds, such as kittiwake; in all, 11 of our 20 breeding seabird species are regarded as being highly vulnerable to future climate change. The seabird numbers that the UK holds are internationally important.
Professor Vickery added: “If we are to hold onto our important bird populations then we need governments to make the right decisions for nature and the climate after COP26, and to invest in real action towards meeting these commitments. We will also need to continue to monitor the results of our actions – to evaluate what works and what doesn’t.”
Dr James Pearce-Higgins, Director of Science at BTO and author of the report, explained: “This new analysis reveals that, overall, one in five UK bird species will be affected by climate change. It is not just our seabirds that will be impacted; we will lose some of our best-loved summer visitors too. Once familiar migrants, such as common cuckoo and spotted flycatcher, have already seen their breeding populations more than halved during the last 25 years.”
Pearce-Higgins added: “Changing conditions here in the UK may have some impact, but the effects of changing weather patterns on the wintering grounds in Africa and along the migration routes used by these migrant birds may also be important. Projecting the future fortunes of these and other migrant birds is challenging given their complicated lives that cross continents. Securing their future will require international collaboration right along their flyway.”
Importantly, the report highlights those species that could be impacted by attempts to mitigate climate change, such as increased development of offshore renewables and widespread tree planting on upland habitats. Knowledge of bird numbers and distributions, gathered by BTO’s network of 60,000 citizen scientists, can help to inform how and where these approaches can be used in ways that minimise any potentially damaging impacts on declining species. We need to maintain our efforts to safeguard our seabirds, like the puffins, and other birds to ensure that they get as much support as we can give them.
The full report, Climate Change and the UK’s Birds, can be read here.
We have great pleasure in circulating the updated Channel Islands bird list. It may be a little late (blame shortages, difficulties in the supply chain, lack of lorry drivers etc, etc) but it’s well worth it. We have new birds, unexpected birds and some unclear changes to our songbird list (i.e. subalpine warblers). Jersey lost a species while Guernsey’s increase of one came through the sighting of an African species, Egyptian goose, that through human intervention is fast developing a population close to us (and in London’s city parks).
Besides the new species on the list, we always get to see the way our avifauna is changing. Glossy ibis? Black-winged stilts? We almost doubled the total number of dusky warblers in the islands’ history in one year too.
Oh, and there have been the annual changes to the list order and some new scientifics. If a species isn’t where you expect it, keep looking!
An unexpected colonist In the Channel Islands, nightjars have long been considered rare passage migrants. Few hung around for very long, many were only recorded after being flushed off the ground. Occasionally one was seen flying around at dusk or the distinctive churring call was heard.
As our bird fauna changes, with old favourites disappearing and new, often long-legged waterbirds, colonising, who had nightjar down as a breeder? Nightjars are relatively specialised in their habitat choice and diet and have suffered bad years in the north of their range as insect populations decline. However, in the last few years, they have been found more regularly in the islands and in 2020, not one but two territories were held in Jersey. Of these, while the birds were carefully monitored to avoid any disturbance, and to protect from misuse of the sites, one pair definitely raised young. Will they return, will numbers increase? Will the other islands see more? Well, you’ll need to wait until the next list update – spoiler alert, it’s worth waiting for!
You saw what? Alderney’s list continues to increase
Since the establishment of the Alderney Bird Observatory we’ve begun to expect new additions to theirs and the CI List. The black-winged kites were good, but followed increasing reports in NW France and one in Jersey. While they haven’t reached the UK, we might expect to see them more often here.
The first white-rumped sandpiper for the islands was another good bird but it will take a while to surpass the bearded vulture. Bearded vultures, formerly known as lammergeier, are big birds and block out daylight. They are spreading through some successful reintroduction projects in several places in Europe. As young are joining the new populations, dispersal is to be expected but the sudden sight of one flying by when you aren’t expecting it will long live in the memory. As the Alderney bird was watched leaving over the coast, I was one of several people on Jersey’s north coast hoping, just hoping!
But of course, our quest to identify the birds that live here is never, in any way competitive. Which is why we are so pleased to see Alderney catching up. And we won’t begrudge them that vulture! And we don’t want something even more impressive on our island!
Download the Working List of the Birds of the Channel Islands 2020 here
At the start of September, a group of Durrell volunteers responded to the call for help at Sorel to remove bracken alongside the aviary and patch up holes in the netting.
Volunteers removed bracken at Sorel, ruining Dot’s game of hide and seek. Photo by Emily Hewinson.
The weather was less forgiving than anticipated with soaring temperatures and no shade other than the shadow of the choughs occasionally flying overhead. Fuelled by caffeine, cold water, and chocolate digestives they managed to finish the tasks in time for the choughs’ supplemental feed.
Sewing skills were put to the test on the aviary netting. Photo by Emily Hewinson.
The only real challenge that day was working out how many bags of bracken can fit in the back of a Dacia. Spoiler alert – its two. Which meant two trips to the burn pile at the Zoo as we had managed to fill four bags clearing the one tiny strip.
The project vehicle was put to the test this month transporting bracken. Photo by Liz Corry.
Having the holes in the netting closed up will allow us to start catching up choughs again to replace leg rings. We still have one youngster in need of a metal ring.
To catch a chough in the aviary first requires the chough to enter the aviary. Something the Jersey birds decided they didn’t want to do this month. At least not in front of staff.
Preliminary study
We are hoping to setup a postgraduate research project next year that investigates the choughs’ use of the supplemental feed site with the help of RFID technology. From bank cards to cat flaps, the day-to-day use of chip reading technology is increasingly being applied to wildlife conservation and research.
We can potentially use the technology to tell us which birds are visiting the aviary, how often, for how long and what times of day, the list goes on. There is even the possibility of remotely weighing individuals and calculating how much food they take on, on an individual and group basis. The challenge is designing a setup suitable for choughs, their behaviour, and their environment. A perfect puzzle for a post-grad.
In the meantime, we are kick starting the study by finding out what size and shape antennae we could use to read the RFID chips attached to the birds as a leg ring. An off-the-shelf bird counter is available using a square antennae. Will a chough happily walk through this?
Instead of spending £800 up front to find out the answer is no, we are going to play around with hatch sizes at the aviary. They already pass through a 40cm by 60cm rectangle. Can they cope with 25cm by 25cm?
This means we need to spend lots of time watching, recording, and trawling through camera trap footage. It’s actually more entertaining than it sounds.
WildSnap! at Sorel
Speaking of camera trap footage…Durrell launched a nature connections programme in summer called WildSnap aimed at teenagers and their tech savvy brains. In partnership with My Naturewatch using a combination of Raspberry Pi electronics and Blue Peter magic, you build your own camera trap then go out and see what wildlife you can find.
The kit costs roughly the same price as a cheap bog-standard camera trap you can buy from the site that rhymes with Glamazon (especially if you live in a VAT-free country). Naturally we were keen to put one to the test and see how useful it could be on the chough project.
Image quality is equal if not better than a budget priced shop-bought camera. The design might not be the most robust, but it does the job taking video or photo.
For any non-teens who want to try building their own camera, check out the how to video below. Raspberry Pi products are widely available these days. Just remember to drop the ‘e’ when Googling!
Chough travels
Whilst staff attention focused on the aviary, the choughs decided September was best spent away from Sorel. Once again, Les Landes to Plémont became a popular playground as well as food source.
Portelet looking for food at Les Landes. Media by Jo Bramley/Jersey Wildlife Facebook group.
There were several consistent reports of choughs in the south west of the Island too. Enough to suggest a small group had made the visit their daily morning routine.
One colleague reported her delight in seeing the birds outside her window whilst staying at the Corbière radio tower. Quite an impressive view made even more memorable by the charismatic choughs.
Not so many reports from east of Sorel. It’s unclear if the parish of Trinity still has a resident chough or two. We are entering the time of year when choughs tend to disperse further afield. Residents in the other Channel Islands and the French coast should start keeping their eyes peeled!
“Sing, Fly, Soar – Like a Bird!” is the theme of this year’s World Migratory Bird Day, an annual global campaign dedicated to raising awareness of migratory birds and the need for international cooperation to conserve them will be held on 9th October. The Global Bird Weekend will be held over the weekend (8-10 October) to coincide with World Migratory Bird Day.
This year’s World Migratory Bird Day will focus on the phenomena of “bird song” and “bird flight” as a way to inspire and connect people of all ages around the world in their shared desire to celebrate migratory birds and to unite in a common, global effort to protect birds and the habitats they need to survive.
The 2021 World Migratory Bird Day theme is an invitation to people everywhere to connect and re-connect with nature by actively listening to – and watching birds – wherever they are. At the same time the theme appeals to people around the world to use their own voices and creativity to express their shared appreciation of birds and nature.
Birds can be found everywhere: in cities and in the countryside; in parks and backyards, in forests and mountains, and in wetlands and along the shores. They connect all these habitats and they connect us, reminding us of our own connection to the planet, the environment, wildlife and each other. Through their seasonal movements, migratory birds are also regularly reminding us of nature’s cycles.
As global ambassadors of nature, migratory birds not only connect different places across the planet, they also re-connect people to nature and to themselves like no other animals on the planet.
In fact, billions of migratory birds have continued to sing, fly and soar between their breeding and non-breeding sites. During the pandemic, which slowed down many activities by limiting our movements, people across the world have been listening to and watching birds like never before. For many people around the world, bird song has also been a source of comfort and joy during the pandemic, connecting people to each other and to nature as they remain in place.
Scientists around the world have also been studying the impact the pandemic is having on birds and other wildlife, looking at how “the anthropause” – the so-called global shutdown in human activity resulting from the COVID-19 pandemic – has affected birds and other wildlife around the world. At the same time, scientists have also been looking at the positive health benefits of birds and nature on humans.
Clearly, the pandemic has been an unprecedented challenge for humankind. At the same time, it has also brought a whole new level of awareness and appreciation of birds and the importance of nature for our own well-being.
World Migratory Bird Day 2021 is therefore not only a celebration of birds, it is also an important moment to reflect on our own global relationship with nature and to highlight our collective desire to do more to protect birds and nature in a post-pandemic world.
Celebrated across the world on two peak days each year – on the second Saturday in May and second Saturday in October – World Migratory Bird Day is the only international awareness-raising and education program that celebrates the migration of bird species along all the major flyways of the world.
Take part and make your sightings count – register for Global Bird Weekend here or set up a team on eBird
Just in case their calls were not loud enough. Photo by Liz Corry.
By Liz Corry
Breeding season roundup
Don’t let the sound of a begging youngster fool you. The 2021 chicks are now fully independent. They just like to try their hand (or wing) once in a while with their parents.
Four youngsters have survived. This is a disappointing number although four is better than none. Thankfully, each from a different family which helps a little to spread the genetics around. Speaking of which, their DNA sexing results came in at the start of August. We have one male and three females. They all have names now too:
Rocky, breaking gender conformity with his bright pink leg ring, is the offspring of Dusty and Chickay.
Rémi, as reported last month, is wild-hatched Minty and Rey‘s first chick. She might be a St Ouen parishioner, but certainly isn’t seen as an outsider by the St John residents.
Wally Jnr. shares a lot of characteristics with her mother Wally when she was a fledgling at the aviary. There may have been a Kevin Jnr. but we never managed to sample the second chick before it perished.
Monvie is Bo and Flieur‘s girl who sports a mauve over yellow ring. Her name is taken from the Jèrriais greeting Man vyi meaning my old mate/friend (if addressing a woman it is Ma vielle). Its pronounced a little like you are saying ‘mauvey’ which helps to remember her leg ring colour. Learn more about the language at L’Office du Jèrriais.
Sadly, but not surprisingly, the body of the missing fifth chick was found by Ronez Quarry staff on the 16th. We ringed it on 30th June so we knew it was Dusty’s and now know it was male. Judging from the state of the body he had died when we first reported it absent from the feed.
Two breeding pairs at Sorel resting in the rocky shade. Photo by Liz Corry.
Not all of the breeding pairs survived the season. We lost a male resulting in a ‘divorce’ of another pair and the re-joining of old flames. It also looks like we have lost the female who roosted and tried building a nest in Trinity. She has not been seen anywhere since early summer.
All being well, we will have two new pairings attempt to nest in 2022 bringing it to eleven pairs. The same as in 2021 despite our losses.
West is best
View of Grosnez with the other Channel Islands on the horizon. Photo by Liz Corry.
The choughs still preferred to hang out on the north west coast in August. Who could blame them with the views.
Cliffs from Grosnez to Plémont are frequently visited by choughs. Photo by Liz Corry.
Not to mention the ‘playground’ that is Les Landes with the racecourse, stables, paddocks, rooftops, and scattered WW2 German-made structures.
As long as they keep out of the way of the occasional model aircraft and, more permanent, resident peregrines!
This peregrine at Grosnez might be more familiar with choughs than I would like. Photo by Liz Corry.
Food for thought
From March to July this year we had a student placement working on the project. Riccardo rose to the challenge of re-establishing our breeding colony of mealworms for the supplemental feed.
We have never really had enough continuity and/or success to fully rely on in-house production. We buy in 1.5kg-2kg of mealworms per week from the UK to supplement the choughs’ diet. We get a discount since it comes with the bulk order for Jersey Zoo’s residents. Yet this still equates to hundreds of pounds a year.
Thanks to Riccardo’s efforts we might be making a breakthrough. After a month of breeding we have produced about 500g of mealworms. Not enough to cancel the UK order, but it should keep our costs down.
There is potential to expand the operation…providing a certain DIY store continues to stock our ‘high-tech’ housing facility aka drawers.
Mealworm breeding setup for the supplemental feed. Photo by Liz Corry.
It’s a delicate balance of temperature, humidity, and the right amount of nutrients appropriate for each of the four life stages. Fingers crossed; we can continue Riccardo’s good work now he has returned home to Italy.
Next time you see an advert for ITV’s I’m a Celebrity….just think about the effort and expense that goes into raising mealworms. And then the waste!
Oregon State University researchers have some good news for those of us well-meaning who place bird feeders in their gardens: the small songbirds who visit the feeders seem unlikely to develop an unhealthy reliance on them.
“There’s still much we don’t know about how intentional feeding might induce changes in wild bird populations, but our study suggests that putting out food for small birds in winter will not lead to an increased dependence on human-provided food,” said Jim Rivers, an animal ecologist with the OSU College of Forestry.
Around the globe each year, hundreds of millions of people put out food for wildlife, including 50 million in the United States alone, driving a $4 billion industry based on food, feeders, and other accessories.
But the popular pastime has long raised concerns about making animals dependent on human-provided food—especially during wintertime and other parts of the annual cycle that require animals to expend a lot of energy.
“The extensive and widespread nature of people intentionally feeding wildlife can have unintended consequences for free-ranging animal populations, and those consequences are best documented in birds,” Rivers said.
“On the negative side, it can facilitate disease transmission, restructure local communities, and alter migration behavior, for example. There’s even evidence that it can lead to changes to birds’ bill structure. On the other hand, it can also have positive effects, such as enhanced body condition, wintertime survival, and reproductive output.”
Bird feeding is especially popular in the northern latitudes, particularly during winter, when cold, stormy weather and minimal daylight reduce the time that birds have for locating natural foods. But not much is known, Rivers said, about whether birds become reliant on the feed their human friends put out for them.
“The only manipulative experiment to test that, using the black-capped chickadee (a species similar to the great tit), was 30 years ago,” he said. “It found no reductions in apparent survival after removal of bird feeders that had provided supplemental food in winter for 25 years, leading to the conclusion that bird feeding did not promote feeder dependency.”
Rivers and colleagues studied the feeder use habits of 67 black-capped chickadees subjected to one of three flight-feather-clipping treatments: heavy clipping, light clipping or, as the control, no clipping. Experimental removal of primary flight feathers is an established technique for altering wing loading and increasing the energy costs of flight, Rivers said.
The birds were tagged with RFID (radio frequency identification) chips, and 21 bird feeders along a 3.2 kilometre riparian zone were filled with sunflower seeds and equipped with chip readers to measure feeder visits by tagged birds.
Scientists chose the chickadee because it is a small songbird (it weighs less than half an ounce) that frequents bird feeders during winter throughout its range; has high daily energy requirements; and typically takes one seed at each feeder visit, allowing for a clear measure of feeder visitation rate.
“It’s an ideal species for evaluating how energetic challenges lead to behavioural changes in feeder use during winter,” Rivers said. “Our study found that the experimentally handicapped chickadees, those experiencing elevated flight costs, did not increase their rates of visitation to the feeders.”
Instead, feather-clipped birds actually decreased their feeder use for a couple of weeks— possibly to reduce exposure to predation—but after that used the feeders at levels similar to the unclipped control birds. The researchers looked at number of feeder visits, number of feeders used and timing of feeder visits and found little difference between clipped and non-clipped chickadees.
“Feather-clipped chickadees reducing their use of feeders relative to control birds suggests that foods in the environment—like seeds, berries and small invertebrates—were sufficiently available to compensate for increased flight costs and allowed them to cut back on feeder use,” Rivers said.
“It’s clear that the chickadees in our study did not increase their visitation rates nor did they increase their reliance on supplemental feed during a period when they might have benefited from it the most.”
The paper Experimentally induced flight costs do not lead to increased reliance on supplemental food in winter by a small songbird can be accessed here
We’ve filled feeders with seeds and nuts since many of us were children and loved seeing which birds arrive. And, we’re not alone – around half of all UK households do the same nowadays, spending £250 million on 150,000 tonnes of bird food each year. That’s enough to feed three times the breeding populations of the ten commonest garden species if they ate nothing else all year, with one feeder for every nine birds that use them.
Have you ever wondered how all of that additional food might be affecting wild birds? How much has our generosity changed their natural diet, and what of the bird species we don’t see visiting garden feeders?
If you live in the UK and the Channel Islands, one garden visitor you’re probably used to seeing is the blue tit. Blue tits are small, fast and often feed high in trees on tiny insects. Seeing exactly what they eat is tough. But with new molecular technology, it has been possible to test blue tit faeces from 39 woodlands across Scotland – some close to houses, some on remote mountainsides and some by the sea – and gain a fascinating insight into their average diet.
What was found, came as a surprise. A small moth caterpillar (Argyresthia goedartella) that lives on birch trees was their most common natural prey item, present in a third of the faeces sampled. But among hundreds of species of insect prey, there was also garden bird food – and lots of it.
Peanuts were present in half of all the faeces – the most common food item for Scottish blue tits – and sunflower seeds in a fifth. And the birds weren’t just popping next door to find these garden treats. Some were travelling as much as 1.4km from remote areas to nibble on their favourite garden snacks. Clearly this has become part of their staple diet.
A blue tit bonanza
Eating the food we provide gives blue tits more energy to lay eggs – five days earlier than blue tits that don’t. These earlier breeders are likely to raise more healthy chicks. Eating bird food was also linked to a nearly four-fold increase in the proportion of adults available to breed in a given area. Where there used to be one pair of blue tits nesting, garden bird feeders nearby meant there was now likely to be almost four pairs sharing the same space.
Other woodland species such as great tits, nuthatches and great spotted woodpeckers that enjoy garden bird food are doing very well too. Their UK populations have increased on average over the last 25 years that bird feeding has really taken off.
All this feeding might be giving these species an unfair advantage. These species have natural competitors in the woods that aren’t using bird feeders as much or at all, either because they’re shy or because they’re bullied by more dominant species, or because they don’t like the food people provide. These species include the marsh tit, willow tit, pied flycatcher, wood warbler and lesser spotted woodpecker. What’s happening to them is, sadly, not such good news.
How to help all woodland birds
On average, woodland birds that don’t use garden bird feeders have declined over the past 25 years, some to the point where they have almost disappeared from the UK countryside. Nobody knows exactly why, and while this may be partly due to their habitat fragmenting and the climate warming, garden bird-feeding may have also played a role.
Due to people feeding them, there are now more dominant blue and great tits in the woods than 25 years ago, eating more of the limited natural food and evicting other species from their nests. There are also more great spotted woodpeckers and squirrels, which eat the chicks of some birds. Perhaps an extra 700,000 pairs of very healthy and dominant great tits in woodlands is too much for the UK’s remaining 2,000 pairs of shy and subordinate willow tits.
While results suggest there’s a link between how much woodland birds visit feeders and their population trends, they don’t show a direct cause, so we shouldn’t panic yet. While scientists study this problem, responsible bird lovers can help.
Consider contributing to the garden bird surveys organised by the RSPB, British Trust for Ornithology and Action for Wildlife Jersey/Birds On The Edge to help scientists keep track of where birds are, in what numbers and what they’re doing. If you’re lucky enough to live where rare woodland bird species can still be found, consider providing less bird food to common species and cleaning your feeders regularly.
Meanwhile, there are more natural ways to encourage wild birds into your garden. Planting native shrubs and trees like rowan, hawthorn, silver birch, spindle and guelder rose is one option. They are all beautiful year-round, fairly small and provide excellent habitats for wild birds. Other ideas include mowing lawns less often and digging ponds.
As some rare species nest close to the ground, please keep dogs on leads while walking in woodlands during the spring too. But most importantly, keep enjoying these beautiful birds – in all their miraculous diversity.
