Category Archives: Blog

Chough report: July 2022

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By Charlotte Dean

A successful start to the month: Catch ups!
The start of July brought more ‘catch ups’ at the Sorel aviary. Great success as we caught five ‘choughlets’ in the space of two days – we really must have found them off guard! The most recent chicks in the ‘catch up’ belonged to Lee & Caûvette (one), Percy & Icho (one), Green & Pyrrho (two) and Bo & Flieur (two). Only three were left (see below).

Bidding farewell
This month we said goodbye to our second valued team member for the chough project this year. Jane, a fellow chough enthusiast and a chough field volunteer with Durrell who has dedicated five years of her life to the chough project. It’s sad for her time to be over on the project, like the other staff and volunteers who have been involved in the past but, with time comes growth and new career opportunities. They may be relocating but I’m sure they will miss the chatter within our wild flock. If you are a chough enthusiast, don’t forget that you can help by reporting your sightings of any choughs seen around. Anthony Morin took these wonderful photos at Les Landes:

Harvest season
There are eight species of small mammal in Jersey including four rodents. The choughs’ aviary is more active with rodents in different seasons of the year. At current, it is quite clear that, with all the harvesting being carried out in the surrounding fields, there is a greater abundance of rodent activity as of late. This can pose a problem through diseases they may carry and the holes they create around the overall structure of the aviary itself. A few of the small mammals that have been spotted in Sorel are protected under the Wildlife (Jersey) Law 2021 including the Jersey bank vole Myodes (Clethrionomys) glareolus caesarius, lesser white-toothed shrew Crocidura suaveolens and Millet’s shrew Sorex coronatus. The best way for us to keep the rodents out of the aviary is by reinforcing any entry and exits by repairing aviary netting, covering over holes and, the main factor, keeping any food at the aviary out of reach and/or secured in rodent-proof containers.

Drought
This July, Jersey was officially considered to be in a drought. A drought in Jersey is confirmed by 15 consecutive days without measurable rainfall. The last measurable rainfall recorded occurred on Saturday 2nd July. Jersey is known for its limited underground reserves of water and no links to external water networks; therefore, it is important for Islanders to preserve water were possible. Anyone who is environmentally conscious will tell you that we should be using water wisely on a daily basis regardless of the weather; but it is even more important to when the Island is in a drought. There are many ways in which homeowners can reduce their water waste; here are some examples:
• If its yellow, let it mellow – resist the urge to flush a toilet unless completely necessary
• Taking shorter showers, using plugs in sinks to avoid running taps for long periods of time
• Only using the washing machine and/or dishwasher when at full capacity
• Not washing your car (including the ‘choughmobile’) or leaving sprinklers on the grass as often
• Installing ‘low-flow’ equipment to all your water outputs
• Fix your holey clothes instead of throwing them out for new plus shopping in charity shops.

Ok, scrap last month’s “hottest day of the year”
Last month in Jersey we saw soaring temperatures of 33.1°C. However, on Monday 18th July, this was beaten by a scorching temperature of 37.9°! The highest temperature recorded in Jersey previously had been 36°C; this occurred 19 years ago. As summer is still in full swing, we worry what August’s temperatures will bring as things are only getting hotter with global warming. At the Sorel aviary we usually provide just the one water source for the choughs but with these rising temperatures, more water has been provided. The choughs, adults and chicks were all seen gular fluttering at the feed of the 18th; however, it was good to see that they were lining up next to the water trays to make use of the water provided in the aviary.

The last three chicks
It was nearing to the end of the month, and we still had three more un-ringed chicks left to catch up. By this point in chick catch ups; the chicks are getting clever. The choughs know that, when two keepers come to the aviary, they need to be extra cautious, especially those that have been captured recently. But it brings me great joy to state that we caught the last three chicks all together, so now all the chicks that have fledged this year have been captured and colour ringed. We are scheduling a licensed ringer to place Jersey metal rings on the chicks sometime next month. We’ve not seen any more chicks arrive at the aviary now, so our fledged chick count for this year is a very respectable 16. Which is certainly nice as during our Ronez Quarry visit we only counted 14 chicks in the five accessible nests of our breeding pairs.

Table 1. A comparison of chicks found in nests at Ronez Quarry (plus one pair from Plémont), to the number of chicks that have fledged to the aviary this year. 

Study charts global decline of great black-backed gull

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From BirdGuides

A newly published study has estimated that the global great black-backed gull population has almost halved within the past four decades.

Using the most recent population counts from across the species’ range, Sam Langlois Lopez and his colleagues analysed population trends at a global, continental, and national scale between 1985 and 2021.

Their results confirmed recent concerns among conservationists that great black-backed gull has been faring badly at both local and regional scales, with widespread declines noted across its North American and European range. The global population is estimated to have declined by up to 48% over the study period from an estimated 291,000 breeding pairs in 1985 to 152,000-165,000 breeding pairs in 2021.

The losses have been most pronounced in North American populations, where the species may have declined by up to 68% since 1985. Although faring comparatively better, European populations have still decreased by up to 28% over the same period.

While there were populations that showed growth between 1985 and 2021, these tended to be smaller and/or were present within a larger state or country where most populations declined. Most increases were recorded in populations on the periphery of great black-backed gull’s range, or in areas that have been recently colonised. These include Spain, Germany and The Netherlands in Europe, as well as North Carolina and Virginia in the US.

The reasons for the decrease are not clear, although are suspected in part to be related to a reduction in the availability of discards from the fishing industry, as well as an overall decline in food availability in the natural environment.

As a result of the findings, Langlois and his colleagues recommend that great black-backed gull should be uplisted from Least Concern to Vulnerable on the IUCN Red List of Threatened Species under criterion A2 (an estimated reduction in population size of more than 30% over three generations).

Read Global population and conservation status of the Great Black-backed Gull Larus marinus here 

Why you should have more sympathy for seagulls

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Why you should have more sympathy for seagulls – and how to stop them stealing your chips

From Madeleine Goumas in The Conversation

On a summer’s day at the beach, the sound of seagulls is part of the ambience. But what about when they’re in the middle of a city, or when they’ve just taken your lunch? Not a lot of people like seagulls. They’re loud, messy and quite partial to whatever you’re eating. As annoying as they may be, their reputation for brash behaviour masks a different story.

There are many different species of gulls. The birds most people think of as seagulls, the ones with silver backs and pink legs, are herring gulls.

They’re the species most likely to nest on houses and steal your chips. Because these gulls are increasingly nesting in urban areas, people see them more often. Although it might seem like there are plenty of them, the population is decreasing. Gulls that nest in natural places rather than manmade structures are in dire straits.

All seven gull species that breed in the UK are of conservation concern. Herring gulls are on the UK red list, the highest level of concern.

Some people believe the availability of food from landfills had artificially boosted the number of gulls in previous years, but in reality food poisoning from feeding at landfills as well as culling has contributed to their decline.

A different view

Gulls get a lot of hate for swooping at people, either to get food or when protecting their chicks. Madeleine Goumas thinks people would be more understanding if they imagined themselves in the position of a gull. Most of us were pretty lucky to be born human, and we sometimes take things like food and safety for granted. Gulls can’t rely on a steady supply of food from the supermarket, or know that you aren’t going to hurt their chicks, which both parents diligently care for.

When a female and male pair up, they tend to do so until death. Each pair defends a nesting and foraging territory. The loud calls they make might seem annoying and pointless, but it is the gulls’ way of telling others where their territories lie.

Gulls are what is known as kleptoparasites. They steal food from each other and from other species. This is not unusual in birds but gulls are unusual in that they take food from humans. This is risky behaviour. An animal the weight of a bag of sugar is massively disadvantaged against a human. In fact, only a small minority of gulls are bold enough to do it.

People perceive gulls as greedy. They seem to gobble up anything they can find in one big gulp. But what they’re actually doing is storing food in their crop, a pouch that functions in a similar way to a shopping bag, from which food can be eaten later. From a gull’s point of view, if you don’t take the food that’s in front of you, you might go hungry. It is a result of need, not greed.

They don’t have it in for you, they are trying to find enough food to survive. A study found these clever birds have learned a complicated process to make sea squirts safe to eat. A herring gull has even been observed using bread to bait fish.

Making sense of gulls

Gulls living in towns are very adaptable and savvy. They even learn patterns of human activity to decide where and when to forage. A few years ago Madeleine started a research project to understand gulls’ food-related interactions with humans. She had noticed gulls would often snatch food from people by catching them unaware. Previous research showed several bird species are attentive to human gaze and she wondered if gulls pay attention to where people are looking and prefer to approach food when they aren’t being watched (Project C-Gull).

Madeleine designed a study to test this idea, and timed how long it took gulls to peck at a sealed bag of chips she had placed on the ground in front of herself – once when she was looking at them and once when she was looking away. She found gulls took longer to peck at the chips when she was watching them. Madeleine also found gulls are attracted to food they have seen humans handling, probably because they have learned we often leave food waste lying around.

What does this mean for our interactions with gulls? Well, we can reduce unwanted encounters by disposing of our food waste properly. If we choose to eat our food in a gull hotspot being vigilant will help: look for where gulls are and watch them. Check behind you, sit under an umbrella or by a high wall so that gulls can’t swoop in from out of your sight.

Gulls’ behaviour may seem bad, but we have a lot of scope to change it without resorting to extreme measures. Gulls are making the best of a bad situation caused by our own activities, and our towns may be their last refuge.

Chough report: June 2022

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By Charlotte Dean

1st June

The choughs greeted the keeper closer than ever! It’s quite clear at this time of year that the choughs recognise the keepers. They spot you on the walk up the coastal path towards the aviary, circling and vocalising loudly, following you along the foot path before finding a place to land. As you can see, the closest and safest spot was the entrance gate to the National Trust’s land. The choughs wing-begged and shouted, they really do know how to welcome their food providers!

Aviary maintenance

Now is an even more important time than ever to be keeping up to date on our aviary maintenance. At this time of year, we are eagerly anticipating the arrival of ‘choughlets’ (chough fledglings) at the aviary. About four weeks after fledging, the chicks’ parents will stop feeding them so it’s essential for the chicks to watch their parents and learn how to forage for themselves. Choughs forage over coastal grasslands; they are often spotted in shorter grass fields, and this is because the insect abundance is generally higher where grass is short. Therefore, mowing the grass, strimming the hedgerows and neatening edges within and outside the aviary is important as it acts as a natural food source for the choughs and chicks that come to the aviary. Along with keeping the grass length short, we also provide ‘enrichment squares’; this is an added foraging obstacle which includes pinecones, slates and branches. These squares engage the choughs to lift and move objects to find the scattered insects – enabling them to work for their ‘free food’.

Is that a ‘choughlet’ I can see?!

Exciting news! We had our first ‘choughlet’ appearance at the Sorel aviary on 10th June! But there wasn’t just one chick, there were three! Our first sighting of the fledglings was in a field opposite the aviary – they were causing quite a stir in the flock. It wasn’t long until they flew in and landed on the aviary roof with Kevin & Wally. We assumed that these three must be theirs as they arrived together, and we had predicted this pair’s fledging dates back in May when we visited their nests to ring and age them! While monitoring the choughs at the aviary, it became clear that these three chicks were definitely from Kevin & Wally’s nest as we’ve witnessed many parent to chick feedings on top of the aviary. It wasn’t long, however, that more fledglings started arriving at the aviary. The next breeding pair’s chicks to arrive at the aviary belonged to Dusty & Chickay – four chicks on the 13th! Dusty & Chickay have always been pretty consistent with four chicks in the past; but it’s exciting to see the chicks that we saw in the nest arrive at the aviary happy and healthy!

Since those first arrivals, we’ve had Trevor & Noirmont’s chick, Manitou arrive at the aviary being very vocal, much like the majority of the chicks. It’s good to see the one chick we managed to ring at the nest arrive safely. By mid-month we started to see other breeding pairs bringing their chicks too, including Green & Pyrrho and Percy & Icho with their two chicks and Lee & Cauvette seen with one chick so far. It’s safe to say that the supplementary feeds at the aviary have been very loud and eventful this month! We may not have seen all of the chicks that were viewed at the quarry nests yet; we are still hopeful for more arrivals!

Time flies

The past few weeks have been pretty hectic, but our former colleague Paul has been very useful in helping us monitor our chough activity in Ronez Quarry. We had our estimated fledging dates but hadn’t seen all chicks arrive at the aviary. But sure, enough there were plenty of chicks flying around the Sorel Lighthouse and quarry as acknowledged by Paul. The chicks will practice their flying before they are strong enough and brave enough to join their parents at the aviary for the supplementary feeds. We greatly appreciate the many chough enthusiasts that help us with our chough project; but don’t forget that anyone can help.

Follow this link and you can do your bit by sending in public sightings of any choughs you see around Jersey Island!

Catch up time!

As the chough chicks keep arriving; it was time to take action and loosen up the hatch wires for the first chick ‘catch ups’ at the aviary. Why are we catching them up you ask? It’s to be able to identify each individual for monitoring with the use of colour-rings (which in turn allows us to know which breeding pair the chick belongs to through observations – see below), to indicate that they are owned and thrive in Jersey, to measure their bills, tarsus and weight. This is essential information we collect and keep records of for all the individuals in the wild free-flying flock. We haven’t needed to ‘catch up’ any choughs in quite some time so it took a few tries to loosen the hatch wires! But between the team, we’ve currently caught eight of the current fifteen chicks floating around with their parents.

Not something we want to see

One of Kevin & Wally’s fledglings had been limping since the first time it was seen arriving at the aviary. It was clear it had quite a large laceration to its left tarsus; but to be able to examine it properly we had to wait until the fledglings were more confident in going in and out of the aviary to carry out a ‘catch up’. We closely monitored the chick until we could catch it up within the aviary. On close examination it was clear how large the injury was but thankfully it had already scabbed over nicely and had no sign of infection, therefore, no additional action was needed. Fledglings are not always the most agile in flight and/or landing at first, something that is learnt over time. One can only assume that it crash-landed somewhere causing itself an injury. But one thing is for sure, it’s now a much better flier!

During these catch-ups we also quickly put the temporary, coloured plastic, rings on the chicks. We only have a short window of opportunity to see exactly which chick belongs to which pair of adults. After only a fairly short time, the chicks start to feed themselves, beg from their parents less and join groups of other juveniles. Groups who take great delight in begging from any passing adults (adults who aren’t fooled) and confusing the patient observer. As opportunities to catch newly arriving chicks inside the aviary are hard to predict, we do these catch-ups fairly randomly – often with long frustrating periods of watching a chick stare imploringly at their parents through the netting, through an open hatch, field etc and our sitting in the bracken or lying in a spot on a field that the sheep have only recently vacated. With everyone identified and, in a few weeks’ time, more likely to go into the aviary when we want them to, we will ask the licenced ringers from the Channel Islands Ringing Scheme to put permanent, numbered metal rings on.

Hottest day on record since 1894!

Between our catch ups, on Friday 17th June 2022, we had the highest June temperature in Jersey since records began in 1894. The temperatures hit a scorching 33.1 degrees Celsius. It’s not surprising that on this day most of the choughs were seen with their beaks wide open. This is because unlike most mammals; birds lack sweat glands and, therefore, they cool themselves down by keeping their beaks open. This is called ‘gular fluttering’ it is the avian equivalent of panting. Gular fluttering is just one of the few behaviours bird species express to stay cool in those hot weather days. Birds also submerge themselves in water either to swim and/or bathe. Sometimes you’ll catch a chough all wet and puffed up sitting on top of the aviary; this is their way of letting the breeze through their wet feathers to help them stay cool. As much as the choughs distinct jet-black plumage and striking red beak are beautiful; I do not envy them their plumage in that heat!



Rising temperatures implicated in decline of the willow warbler

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From Rare Bird Alert

New research from BTO implicates rising temperatures in the steep decline of the willow warbler, one of the UK’s most tuneful harbingers of spring.

The study shows that willow warblers are doing better in Scotland, where temperatures are cooler. Evidence is building to suggest the population in southern Britain is a casualty of recent anthropogenic climate change.

BTO researchers used volunteer bird counts and habitat data from the BTO/JNCC/RSPB Breeding Bird Survey to separate the impacts of climate change and habitat change on willow warbler and chiffchaff populations. The analysis revealed that willow warbler numbers across the UK fell by 41% between 1994 and 2018, while those of the closely related chiffchaff grew by 133%. The picture was very different in Scotland, where temperatures are cooler than the UK average. North of the border, willow warblers increased by 77% and chiffchaffs by 244%.

During the period studied, the mean breeding season temperature was 12.7°C in England and 10.2°C in Scotland, close to the optimum breeding temperatures for chiffchaff (13.5°C) and willow warbler (11°C), respectively. However, UK Met Office data show that UK temperatures in the last 30 years have been about 1°C warmer than those during the three preceding decades. Changes like these can have impacts including producing a mismatch between young birds’ food requirements and insect abundance, an overall reduction in food abundance and shifts in habitat suitability.

The BBS habitat data showed that woodland and scrub, the preferred habitat for willow warblers and chiffchaffs, increased across the UK, with more habitat improvements in Scotland. However, this study showed that the increases in Scotland were more likely to be linked to climate change than habitat change.

Its UK decline means willow warbler has been on the Birds of Conservation Concern Amber List since 2002. With global temperatures forecast to keep rising, studies like this demonstrate the importance of long-term monitoring to ensure conservation measures are targeted effectively. More woodland and scrub, for example, would be more likely to be taken up by breeding willow warblers if it were concentrated in cooler areas of the UK.

Blaise Martay, BTO lead author on the paper, said: ‘We’ve discovered that these two superficially similar warblers have quite different temperature requirements during the breeding season. Climate change means willow warblers are now faring worse in warmer parts of the country, something that has implications for future conservation measures, such as habitat creation. The connection we’ve uncovered between temperature and breeding success suggests that conservation interventions for this species should be targeted in cooler parts of the UK.

She added, “I’d like to thank all the volunteers who take part in the BTO/JNCC/RSPB Breeding Bird Survey. Their records allow scientists like me to undertake analyses like this one and help us understand the pressures birds face as a result of climate change.’

In Jersey we have lost willow warbler as a breeding species although we still see birds in spring and autumn on migration. The annual north coast bird survey carried out in May or June each year when willow warblers and chiffchaffs would be nesting highlights the status of both these species. In Jersey, willow warbler is on the Red List. 

See the abstract of Breeding ground temperature rises, more than habitat change, are associated with spatially variable population trends in two species of migratory bird here

Infrastructure, hunting and climate change linked to huge migratory bird declines

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From Rare Bird Alert

Migratory birds are declining globally because of the way that humans have modified the landscape over recent decades – according to new research.

The new study reveals that population declines have been greatest among species that migrate to areas with more human infrastructure – roads, buildings, power lines, wind turbines – as well as higher population densities and hunting levels.

Habitat degradation and climate change have also played a part in driving long-term declines.

The research team hope their work will help inform how best to target conservation efforts. James Gilroy, from UEA’s School of Environmental Sciences, said: “We know that migratory birds are in greater decline than non-migratory species, but it’s not clear why.

“We wanted to find out where in their life cycles these migratory species are most exposed to human impacts.”

The team identified 16 human-induced threats to migratory birds, including infrastructure associated with bird disturbance and collisions, conversion of land from natural habitat to human land use, and climate change. Advances in satellite imagery allowed the team to map each of the 16 threats across Europe, Africa and Western Asia. The team also created the first ever large-scale map of hunting pressure across the region.

A total of 103 species of migrating birds were studied, including many rapidly declining species like turtle dove and the common cuckoo, using large-scale datasets.

The team calculated “threat scores” for factors such as habitat loss and climate change, across breeding locations, as well as non-breeding ranges. They then explored the relationships between these threat scores and bird population trends calculated from 1985 to 2018 by the Pan-European Common Bird Monitoring Scheme (PECBMS).

Claire Buchan from UEA, said: “One of the biggest impacts seems to be caused by things that would kill a bird outright – for example flying into a wind turbine, a building, being electrocuted on a powerline, hit by a vehicle or hunted. We found that exposure to these human-induced ‘direct mortality’ threats in the bird’s wintering ranges are reflected in population decreases in breeding birds.”

Aldina Franco, also from UEA, said: “Our findings are important because we need to understand where declining species are being most impacted by humans across their seasonal migrations. Pinpointing where birds are most exposed to these threats could help us target conservation actions.”

Download the paper Spatially explicit risk mapping reveals direct anthropogenic impacts on migratory birds here

The Pen Llŷn & Iveragh Chough Count

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By Fiach Byrne

Jersey Island’s striking landscape shares many similarities with the Llŷn Peninsula in northwest Wales and the Iveragh Peninsula in southwest Ireland. Each of these regions are popular tourist destinations that are heavily influenced by agriculture and their connection to the sea. Their coastal landscapes are also extremely important to many forms of wildlife, not least our favourite corvid, the red-billed chough. The choughs’ iconic call, coupled with their bright red beaks and legs are a staple of the Llŷn and Iveragh Peninsulas. And these birds are clearly held in high regard on Jersey since their reintroduction in 2013.

On the Llŷn and Iveragh Peninsulas, choughs nest within mines, quarries, farm buildings and along cliff faces. A short distance from these nest sites, choughs have access to a mix of foraging habitats such as beach, sand dune, earth banks, coastal and agricultural grasslands, coastal heath and some well-grazed upland sites. Here, choughs can find their favourite food items such as beetles, ants and spiders, as well as the larvae of beetles, butterflies and moths. The importance of Llŷn and Iveragh for choughs is one of the primary reasons why ‘Special Protection Areas’ (SPAs) have been designated on both peninsulas.

The most recent national chough censuses indicated that chough populations across the UK and Ireland are relatively stable, although there were some concerning declines in certain regions. These national surveys are usually conducted every ten years in the UK. However, there was nearly two decades of a gap between Ireland’s 2002/03 national chough census and the most recent census carried out in 2021. Although these censuses provide invaluable insights into the health of national and regional chough populations, more frequent updates would help us determine how our choughs are faring in the years between censuses.With this in mind, the University College Cork-led LIVE Project, in collaboration with the National Trust in Wales and the Royal Society for the Protection of Birds (RSPB) organised a cross-border ‘Chough Count’ on the Iveragh Peninsula in southwest Ireland and the Llŷn Peninsula in northwest Wales on 12th March 2022. This initiative typifies one of LIVE’s main objectives – the sharing of knowledge and best practice between our two peninsulas.

The Llŷn Peninsula’s second ‘Chough Count’ saw 51 volunteers record 254 choughs as the sun shone in north Wales. Iveragh’s inaugural count saw twenty-six volunteers record 64 choughs in quite challenging weather conditions. By conducting annual counts of Llŷn & Iveragh’s choughs, we can detect trends in these populations in the years between censuses and we can identify important habitats for this protected species. The 2022 chough count also gave our surveyors the opportunity to record some of our other native birds such as skylarks, fulmars, white-tailed sea eagles and a hen harrier in Iveragh, as well as red kites, peregrine falcons and a green woodpecker on Pen Llŷn.

Distribution of records during Pen Llŷn’s second ‘Chough Count’ held on 12th March 2022.

The LIVE Project (ecomuseumlive.eu) has received funding from the European Regional Development Fund through its Ireland Wales cooperation programme. Led by the School of Biological, Earth and Environmental Sciences in University College Cork, LIVE works to enable the coastal communities of Llŷn and Iveragh to promote their natural and cultural assets, with the aim of encouraging more sustainable tourism opportunities in these rural regions of Ireland and Wales.

Chough report: May 2022

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By Charlotte Dean

Bon voyage to Liz

The sun has set on the Red-billed Chough Project officer’s time here in Jersey with Birds On The Edge and with Durrell. Her absence from Jersey Zoo Bird Department and at the Sorel aviary is undeniable. We can only strive to be as dedicated to the Jersey free-flying choughs as she once was. But despite this saddening farewell; the chough show must go on! Updates on the choughs will continue; and what an exciting month it has been!

Native reptile sightings

While the Island’s starting to heat up with all this fantastic summery weather; there have been many green lizard sightings. Jersey is the only place in the British Isles where green lizards occur naturally and are one of the three species of lizards which are protected under the Conservation Wildlife (Jersey) Law 2021. Green lizards can be seen between spring and summer. Green lizards are sexually dimorphic; meaning, they encompass differences in appearance, shape and/or size between the sexes, they are easily distinguishable: the male green lizard (as seen in the image) is bright green with a bright blue throat but is also larger than the female. In contrast, the female lizard is smaller, less vibrant and has creamy and/or brown lines running down the body. So, now that we’re in May, it is the perfect time to keep your eyes peeled when walking in and around any of the Island’s coastal paths. If you happen to spot a green lizard or the other lizards native to Jersey; Jersey Amphibian and Reptile Group (JARG) and Jersey Biodiversity Centre (JBC) would love to know, so make sure you send your sighting details to them as it will help with the protection and monitoring of the reptile species on the Island.

Butterfly season

If reptiles aren’t your ‘cup of tea’ then not to worry, the summer also brings out our beautiful butterflies. Between the months of April and September you’ll find butterflies are very abundant across the whole of the countryside. We’ve already come across some dedicated volunteers conducting butterfly surveys for Jersey Butterfly Monitoring Scheme (JBMS) along the coastal path from Sorel Point carpark. Butterflies are used as great environmental indicators; this is because they live in specific habitats and can indicate the general health of the land by their presence or absence. As Butterflies are generally a widely abundant terrestrial insect that are often admired for their large size and distinct appearances; they are the ideal insect for surveying. In and around Sorel we’ve seen butterflies such as: speckled wood, small heath and small copper. All three of these butterflies’ ideal habitat is semi-natural heaths and agricultural environments; indicating that the area around the Sorel aviary is relatively adequate land for foraging habitat for our red-billed choughs.

Moulting time for non-breeders

But, enough about the Island’s non-chough native wildlife, what about the birds themselves?! It’s that time of year again when the non-breeding choughs start to moult – this is becoming readily apparent by all the feathers we can now collect from the Sorel aviary and by the less than perfect looking feathering on some of the non-breeding choughs. Choughs generally start their moult between May and/or early June. They start moulting their central tail feathers first working outwards. They then start moulting and growing their wing feathers, the primaries, around the same time as their tail; but complete their tail moult first. The moulting process for an adult chough can take up to 152 days.Monday, 9th May

On 9th May, Jersey celebrates Liberation Day and Jersey puts on quite a show with flags at many houses and businesses as well a spectacular parade. But Jersey Zoo had another cause of celebration, the bird flu restrictions were finally dropped by the Government. Therefore, Jersey Zoo was given the green light to move any of birds temporarily sheltered back out into their original enclosures; enabling the public to enjoy some missing birds from the collection. It was good to see all the Chilean flamingos and red-breasted geese back in their valley. But this brought the chough project good news too; as it meant the arranged Ronez Quarry visit could go forward and this year’s hatched chicks could potentially be ringed!

Ronez Quarry visit

Jerseys free-flying choughs have had another productive nesting season. There are eleven breeding pairs in the group this year and with help from Ronez Quarry we discovered twelve nests in the quarry buildings. Unfortunately, from the twelve nests there were only hungry chick vocalizations from seven out of the twelve nests. But worry not! Some of the other breeding pairs have settled in other locations around Jersey. These seven nests are owned by the known breeding pairs that have been presumed incubating (absentees at supplementary feeds can be a give-away). Choughs are well-known for being faithful when it comes to their nest sites; but it’s always worth a check of the new nests. None of the new nests found by quarry personnel this year were being used by our breeding pairs. This could indicate that some of the younger choughs are practicing for when they start nesting in the near future! Once the incubation period is over, the female will still spend the majority of her time on the nest but as the chicks get older and/or gain vital feathering she spends less time sat on the nest; allowing us to see both the female and male take alternate feeding trips to the aviary. A good indication that the chough chicks will be of good size is the appearance of the female within the breeding pair also leaving the nest to forage, or in our case, visit the aviary for the supplementary feed. As we’ve been seeing both sexes of each breeding pair of late and have estimated all the breeding pairs’ end of incubation dates, we knew that most would have chicks old enough to ring around the end of May.

With help of loaned equipment provided by 4Hire, Ronez’s Assistant Operations Manager, Toby and Durrell Chough Intern, Charlotte were able to reach great heights and see into five of the seven nests in the quarry. Two of these nests were inaccessible due to high winds and/or the position of nests in buildings. But worry not, when visiting the quarry, we could clearly hear hungry chicks from all seven active nests!

The first nest we checked was Lee & Caûvette’s. They had three chicks, no older than nine days old! This meant they were not old enough to be ringed, but at least we knew that this breeding pair has been successful in hatching three chicks this year. The second nest we visited was Trevor & Noirmont’s which only had one chick inside, but it was old enough to be removed from the nest to be health-checked and become the first chick to be given temporary rings this year. This chick was ringed with this year’s ringing colour; dark green and will be identified as ‘white over dark green’ and/or Manitou (named after the cherry-picker which gave us access to the nest).

Our third nest site to visit was going to be Percy & Icho’s nest; however, high winds picked up and both the quarry staff and Durrell staff knew it was going to be too dangerous for us and the chicks to attempt to visit their nest box. It was clear though that the breeding pair were visiting this nest and there were definite sounds of hungry chicks coming from inside; the big question will be how many will we greet around their fledging date! The fourth nest we looked at was Kevin & Wally’s. We had previously been sent a photo of this nest from Toby – in this picture, we thought there were only two chicks but while at the quarry we got a lovely surprise from the video we took of inside the nest. There were definitely three of the oldest chicks we’d seen in a nest around the quarry so far! Due to the nest being out of sight; we did not attempt to ring these chicks for their own safety – but we hope to see them all at the start of June at Sorel aviary!

The fifth nest visited, that of Green & Pyrrho, was accessed with the stair lift; they had three chicks which were also old enough to ring. However, again, due to the positioning of the nest and the supporting beams of the building, we could not get up high enough to reach into their nest box – and again, the chicks were left alone. The sixth nest visited was Bo & Flieur’s, in a very noisy and dusty building; surprising how the adults and/or chicks survive inside it! There was no way of accessing this nest but we could hear some very noisy chicks indicating their reproductive success. We may not know how many chicks are in this nest; but we know to expect some to arrive in the coming month. The seventh and final nest we visited was Dusty & Chickay’s. They have four hungry chicks in their nest but because of their placement in the building, this nest was inaccessible to cherry-pickers and stair lift equipment. It’s almost as if the choughs build their nests so that no one can access them!As much as our visit didn’t go completely to plan, thanks to mother nature and the breeding pairs’ chicks’ ability to latch onto their nests making us unable to remove them to ring them before they fledge’ it’s clear that this year our choughs have been very productive; most if not all have had three or more chicks. We currently know of 14 chicks in the quarry; but let’s not forget that we still have an unknown number of chicks from two other breeding pairs! Going from our breeding population’s clutch sizes in the past (our choughs usually lay up to four eggs), there could be at least three or four chicks in each of the other two nests that were inaccessible. Which could bring this year’s hatched chick count to 22!! This may be wishful thinking, but it’s always good to expect the unexpected!

Nest

Nest location

Pair

Chicks

1

Ronez Quarry

Lee & Cauvette

Three chicks

2

Ronez Quarry

Trevor & Noirmont

One chick

3

Ronez Quarry

Percy & Icho

Noisy chicks but no visual

4

Ronez Quarry

Kevin & Wally

Three chicks

5

Ronez Quarry

Green & Pyrrho

Three chicks

6

Ronez Quarry

Bo & Flieur

Noisy chicks but no visuals

7

Ronez Quarry

Dusty & Chickay

Four chicks

8

Ronez Quarry

Red & Dingle

No sign of nesting this year

9

Ronez Quarry

Nest built but unused

None

10

Ronez Quarry

Nest built but unused

None

11

Ronez Quarry

Nest half built and unused

None

12

Ronez Quarry

Unused nesting site this year

None

13

Plémont

Minty & Rey

Three chicks

14

Trinity

Vicq & Pinel

None

15

Corbière

Danny & Jaune

Unknown

Chough report: April 2022

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By Liz Corry

Success at Plémont!

For a second year in a row the chough pair at Plémont have successfully hatched three chicks. We discovered the happy news at the end of the month. Using a very, very, very, long lens we were able to get photos of the chicks’ heads whilst begging for food.

It is hard to give a precise age without seeing the rest of their body, but best guess is a week-old give or take a day. This would also match up with nest observations we made over April; our estimated hatch date was the 22nd.  Returning the following week further confirmed our age estimate as their little heads were still relatively bald.

Both Plémont parents are now out and about in search of food for their young. Concerns were raised when we started seeing both parents at the Sorel supplemental feed desperate for food. Choughs nesting at Plémont do not normally return to Sorel until their chicks fledge or the nest fails. This was the first time in five years. Chough chicks devour a lot of insects whilst in the nest, so chough parents tend to forage close-by to conserve their energy.

Petit Plémont and grassland above the cliff path are used by choughs searching for food. Photo by Liz Corry.

There has been a big increase in footfall at Plémont this month which could deter the choughs from foraging close-by. It has also been relatively dry so the soils around Plémont are not as favourable to soil-dwelling invertebrates. There are many other reasons why the parents might be visiting Sorel, the good news is that the chicks are still alive and begging well.

All being well the chicks should fledge at the end of May, start of June. We will be monitoring more closely this year around the fledging period. Last year we knew that two of the three chicks fledged, but don’t know what happened to the third. Then one disappeared within the first week of being out. If that happens again this year, it would be good to try and understand why.

Potential success at Ronez once again

We believe at least five of the eight nests in the quarry have chicks. This is based on behaviour of the pairs at the feeds and in the quarry. The females had been suspiciously absent. Then when they did turn up, they were very noisy. Pyrrho and Icho in particular would fly in vocalising, then follow their partner like a noisy shadow demanding food and being fed instantly. It’s quite an interesting sound they make trying to beg and swallow the food at the same time!

Ronez Quarry continues to be a successful breeding site for choughs in Jersey. Photo by Liz Corry.

At the end of the month, we were then seeing the male and female in a pair making repeat trips between aviary and nest site. This tends to be when they are feeding chicks although we have no definitive proof yet. We are trying to arrange a quarry visit for May.

Zoo chicks

Our Jersey Zoo pair also had success this month with their first chick hatching on the 28th followed by number two the next day and number three shortly after.

Nest cam footage showed the moment the first chick hatched whilst mum looked on. Photo credit Durrell.

There was a fourth egg…spoiler alert…it failed to hatch. The nest camera shows the parents still holding out hope until May 2nd. Mum took the executive decision to remove the egg from the nest around lunchtime. You can see this in the video below around 40 seconds in.

We may send the chicks over to the UK shortly after they fledge so they can become part of the release project in Kent. This is very much dependent on the Jersey and UK Government’s rulings over exports and imports of birds from a bird flu protection zone. Restrictions for indoor housing of poultry will be lifted in Jersey on May 9th.

No success in the new territories

The Trinity pair appear to have abandoned their nest and are spending more time at Sorel. They still visit the stables but the nest is now being used by doves. We had hoped that the choughs had found a more favourable site in the Parish yet their casual behaviour at the aviary suggests they’ve given up.

An article will be published in the summer edition of the Trinity Tattler magazine asking residents to report any sightings. This might shed some retrospective light on the situation. I’m not holding out hope that there will be a surprise nest discovered.

In similar circumstances, we are now seeing the ‘Corbière pair’ back at Sorel. Their suspected nest was last seen being used by pigeons. We are used to seeing choughs fail at establishing territories in the south west. Food supply, or lack thereof, may play a role in this. The cliff tops are choked with invasive sour fig (or Hottentot fig) (Carpobrotus edulis) and the exposed ground isn’t very accommodating to soil invertebrates.

Cliffs around Corbière could offer potential nest sites for choughs. Photo by Liz Corry.

Sour fig (Hottentot fig) might look pretty when flowering, but its choking Jersey’s cliff tops in the south west. Photo by Liz Corry.

Return visit to Guernsey

We have seen another report of chough posted on the Guernsey Birdwatching Facebook group. Dated 16th April, it is clear that the bird is one of ours from the red and white striped ring, but that is all we know unfortunately. They were foraging at Pleinmont again. Clearly a popular site.

A chough was spotted at Pleinmont, Guernsey this month. Photo by Chris Wilkinson/Facebook

It just so happens that Portelet and Archirondel were missing from the Sorel feed that day. Coincidence? This is very exciting news if they have made a second round trip between islands to forage.

Sark and Guernsey can be seen on the horizon from Sorel. Photo by Liz Corry.

Aviary maintenance

Boring but necessary aviary stuff. April has brought sea fog, hail, downpours of rain, but mainly sunny days perfect for grass growing which means we do lots of grass mowing; weekly almost daily depending on how much time we have spare and how long the strimmer battery lasts.

Keeping the grass short inside the aviary has multiple benefits. Photo by Liz Corry.

The holes in the netting we had repaired earlier in the year have reopened with extra wear and tear. Nothing to do with rodents just weathering and strain on the netting. We need to get the henchman ladder back up to Sorel to carry out the repairs.

We have replaced a couple of rotting hatches, rusted door bolts, replaced food stands and repaired benches for accessing hatches.

Holes have reappeared in the netting along the central pole. Photo by Liz Corry.

Random fact

Park House Thai restaurant in St. Helier, Jersey, appear to feature red-billed choughs in their interior décor…

Unexpected restaurant décor in Jersey. Photo by Liz Corry.

And finally

This will be my last chough report for Birds On The Edge and Durrell.  I’ve been with Durrell for eighteen years and worked with the choughs since they arrived in the Zoo in 2010. It was a hard decision to make as I’m leaving both my job and the island I’ve called home for the last sixteen years.

I’m not quite leaving the choughs though as I will be taking up a new role as chough release supervisor in Kent for The Wildwood Trust. No doubt I will keep popping up from time to time on Birds On The Edge or at the Inter-Island Environment meetings. Like Where’s Wally minus the red and white striped top.

I’m extremely proud of what the team has achieved over the years, and I often forget letting the day to day stresses of running the project take over. Plémont is the perfect place to remind me. When I first visited the bay in 2006, I didn’t know the Channel Islands were once home to choughs. Eight years later I remember visiting Plémont café with friends and musing over the idea of one day seeing the then recently released choughs utilise the cliff tops and caves. And now, well why don’t you find out for yourself. Head to the café (I recommend the waffles), sit outside, soak up the rays, and listen… 

 

Around the world with invasive species

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By Glyn Young for Jersey Invasive Species Week 2022

I cannot remember not being interested in (ok, obsessed with) the world’s birds. I’ve long wanted to see as many as I can, wherever I can. I’ve been very lucky in that I’ve been able to get close to birds as a profession too. In fact, my profession has changed my involvement with birds from simply watching them to wanting to save them from dying out, to help the rarest of the rare from becoming extinct. Working at Durrell has involved me with some serious problems and three times I’ve worked with birds considered the rarest on earth. That they aren’t the rarest now is not because they died out but because Durrell and its partners succeeded in getting them through the crisis. They are still rare but there is hope.

At Durrell, we typically become involved with a species when it is already very rare and it is considered that our involvement can help it turn the corner. Planning a recovery project requires us to look at three key things: pressure, state and response. That is, why is our bird so rare and what are the drivers of its decline? How many are there and exactly where do they live? And then, what can we do to change the future for the species? However, while we need to map our species’ current distribution, count how many there are and then determine what we can do for them and who we will work with, we generally have a pretty good idea what is making them so rare.

We think of habitat loss and conversion, of hunting and persecution as drivers of bird decline. But inevitably, invasive alien species (IAS) are going to be in there somewhere. So many of the world’s animals and plants are now being pushed towards extinction by alien species, the ones we call invasives or often, quite correctly, exotic species. All species that are not native and have come from somewhere else, introduced either deliberately or accidentally, are exotic, whereas only those that have a negative impact on native species by outcompeting with them or directly killing them or their eggs and young are called invasive species. The trouble is, it’s often very hard to tell whether an exotic species is harmless or whether you just haven’t looked closely enough (ruddy ducks in the UK were once considered a benign introduction and we know what happened with them).

At Durrell, my work has been to look at the pressures on and the state of a bird population and then use the findings towards establishing the responses. The first bits we might lead on, but the responses are more likely to involve a wider group, partners with their own particular skills like Island Conservation. Increasingly, where the role of one or more invasive species is key to our bird’s situation, we will work with partners who may be directly involved with reduction, or hopefully total eradication, of the invasive threat. If our bird lives on a small island, threatened by rats, or cats or a whole host of other invasives, its best chance of survival will be the complete removal of all the invasives. And here, Durrell may work to ensure the survival of the native species while its habitat is made safe by our partners. This is where we’ve been involved in recent years in the Galápagos.

I first cut my teeth in Mauritius in the 1980s where I joined our small team on the island working with birds on the very edge of extinction. My tasks were in observing and recording nesting echo parakeets (less than 20 birds in the world) and taking young into captivity. This was the first known nest in many years. I also made notes on pink pigeons and Mauritius kestrels, two further species with wild populations of under 20. Although a dire history of habitat loss, hunting and pesticide use had pushed these birds into ever smaller areas of forest it was the non-native rats, cats, mongooses, monkeys, mynahs and dense thickets of privet and guava in the forest remnants that would finish the job. Today, these birds can be found in much healthier numbers through some serious hard work and the establishment of captive populations. I also made trips out to Round Island shortly after the removal of goats and rabbits, animals put out there as food for ships and responsible for the near extinction of several reptiles and plant species extinct on the main island, and the last populations in the country of several seabirds. The mammals went in the nick of time and the saved reptiles and plants have gone on to repopulate other recovered islets.

From Mauritius, in 1989, I searched a lake system in Madagascar for Madagascar pochard. This lake, Alaotra, was the only known site of the duck which, although formerly widespread, had been considered common here only a few years before. But that was before a whole series of exotic fish were released into the lake. Fish that went on to see the loss of many native species as they out-competed many and disastrously altered the habitat needed for many others. We couldn’t find the previously common pochard or find any hope of its survival and declared it ‘probably extinct’ in 2004 despite constant effort. To say that I was excited on its rediscovery in 2006 would be an understatement!

Changing emphasis to Madagascar’s west coast in 1992 I began to focus on the Madagascar teal. Even this mangrove specialist faced threats from rats and cats – we found cat tracks in mangrove islands cut off at high tide. Through this work I was sponsored by New Zealand’s Department of Conservation (DOC) to visit many of their bird restoration projects in 1996. New Zealand has a long and awful history of invasive species and so each programme included work with invasives – some expected like brown teal (rats, cats, stoats etc), some more specialised like blue duck (rainbow trout) and some much less obvious like black stilt (lupins). Who would have guessed that lupins could be such a threat! 

I was quickly on the scene when around 20 wild Madagascar pochards were found in a distant, fish-free, mountain lake in 2006. With little hope of long term survival, with partners including Wildfowl & Wetlands Trust we collected eggs in 2009 to start a captive population in Madagascar. The Durrell run breeding centres have bred many ducks and we began to return birds to another lake in 2018, a lake that they’ve been breeding at ever since.

In 2006 I also spent time surveying the remnant population of Saint Lucia’s white-breasted thrasher. A species that had also been considered extinct in the past until found in areas of eastern dry forest earmarked for development. While the final straw for this species might have been the development, it was the introduction of mongooses that had pushed it towards oblivion. The mongooses had done a good job on a lot of other native animals too.

The year before, in 2005, I began working in Isabela in the Galápagos. Durrell had been invited to look at the mangrove finch, the rarest bird in the islands and one that had not been recorded breeding in several years. The entire population of this finch, well under 100 birds, was living in a couple of tiny mangrove patches. Mangroves full of rats which we quickly proved were eating the eggs. The rats were removed, and the finches bred again. Our excitement was, however, short-lived as another invasive species, the parasitic vampire fly took over and killed chicks that the rats had previously prevented from ever hatching. No one has yet stopped the flies but they are working on control methods. In the meantime, other agencies in the Galápagos have taken on our work and the mangrove finch is still there. Isabela is a very big island and despite an incredible effort to remove a large and destructive population of goats, rats can only be kept out of the mangroves and survive elsewhere on the island.

In 2007 I was asked by the Galápagos authorities to look at the Floreana mockingbird. This incredible bird was the inspiration behind Charles Darwin’s theory of evolution by natural selection. However, since Darwin met the mockingbirds on Floreana, the population had died out through loss of natural vegetation, eaten by cattle, goats and donkeys and predation of nests by rats and of adults by cats. The loss was not complete though as a few mockingbirds remained on two tiny islets. The challenge, to get them back safely on to the main island. We took on the challenge but, despite some great plans and plenty of research, only the complete removal of Floreana’s unwelcome mammals would allow the return. And that’s where we are right now, the removal is scheduled although it was delayed by the pandemic. Durrell has taken on safeguarding Floreana’s many native finch populations to make sure that they aren’t caught up in the rodent and cat programmes. We have two aviary complexes ready on the island and have trialled catching large numbers of finches, holding them in the aviaries, releasing them and tracking them later. All bodes well for Floreana, the mockingbird and other native animals and plants. Later in 2022 we will start drawing up plans for the return of 13 missing animal species.

So, that’s work. What about free time? Well, it’s surprising how the two can meet and it’s lucky that I have a family happy to go along. And that they like seeing wild bird populations (often puffins it seems) and learning what it takes to ensure that these will survive. We don’t dislike rats, cats, mongooses, cichlid fishes and lupins etc but we know we need to keep them away from the birds.