Chough report: November 2021

November afternoons at Sorel. Photo by Liz Corry.

By Liz Corry

At the start of November, I was still wearing shorts to work. By the end, several layers, gloves, a woolly hat, and the obligatory waterproofs. The choughs also noticed the change in weather. The entire flock are now waiting for supplemental food each afternoon. Some birds even wing-begging for food. Clearly, wild supplies of invertebrates were not meeting energy demands for birds battling winds and trying to stay warm.

The sheep left. Not necessarily related to the weather, I think they have been moved to St Ouen. This might add to the choughs’ hunger if there are less dung invertebrates around Sorel in the sheeps’ absence.

Hungry choughs waiting for the supplemental food. Photo by Liz Corry.

Storm Arwen caused more minor damaged at the aviary. Of note, the keeper door had been blown wide open when the force of the wind bent the bolt out of place!

I was quite surprised we didn’t suffer more, especially considering last month’s gale damage. Luckily, I managed to fix the damaged panelling before Storm Arwen hit.

Lily leaves the flock

Lily, a three-year old female, appears to have either perished or left the Island. She was last seen on 5th November at Sorel. She has not been reported elsewhere.

Lily is an example of how post-release management has played an important role in the project’s success. Lily hatched in the wild in 2018. We had to catch her up in December that year when we spotted her digit caught in her ring. Durrell vets had to intervene as the toe needed amputating (click here to learn more). She was released back into the wild the same day and formed a partnership with another female looking out for each other over the years.

Lily and Vicq hanging out together this summer. Photo by Liz Corry.

New partnerships

Since Lily disappeared, her ‘partner’ Vicq has been seen preening Pinel. He is a wild hatched bird from 2020. If this new partnership continues over winter, it could mean a new breeding pair. 

Likewise, Danny and Portelet are also showing promising signs of being a new pair for 2022. Both pairings will need to find a nest site and establish a new breeding territory. No doubt keeping the project team on their toes next season.

Roost monitoring

We have been without a student placement all November which has restricted certain tasks, one being the biannual roost checks. I’ve not been able to check all the known roost sites due to sunset times clashing with the supplemental feed.

I have been able to monitor the aviary and, as suspected, several of the quarry birds are roosting at the aviary again. I suspect they will switch back to the quarry once sunset times start occurring after Ronez have clocked off for the day.

Leg rings

We finally managed to trap Monvie in the aviary to fit her metal ring. This is engraved with details of Jersey Museum in case the bird is recovered by a member of the public. Also, it comes in really useful when a plastic colour ring drops off and we can’t be sure on identity. Case in point, Archirondel, who we also managed to catch the same day and replace her white ring.

Monvie having a metal leg ring fitted by a licensed ringer. Photo by Liz Corry.

Bo and Minty evaded several catch-up attempts this month. We will keep trying although, at least for now, we can still distinguish them in the flock. Then on the 29th, Lee arrived missing one of his rings so he gets added to the ‘to do’ list for December. 

French news

Our friend Yann commented on last months’ report to say he has not seen Cappy since spring. Disappointing if she has perished although not a surprise. It would be nice to think she has moved south, along the coast towards Brittany under the radar of French birders. 

And finally

Camera trap footage at Sorel often throws up a few surprises. This month it was the camera itself with the surprise. I found an orb weaver (spider) and ladybird ‘hiding’ behind the camera. The spider’s full name is Nuctenea umbratica, commonly known as a walnut orb-weaver. Apparently also known as the toad spider although I’m not sure why – a tendency to hide behind things?

I logged the find with the Jersey Biodiversity Centre using the iRecord app. Both are common species but it is still important to record when you can.

Camera traps throw up all sorts of surprises at the aviary. Photo by Liz Corry.

 

 

December volunteer activity

Sunday 12th December 2021 –– Mourier Valley 10:15-12.30

From Jersey Conservation Volunteers 

Task Join the National Trust for Jersey’s Lands team to help maintain some of the many trees planted over the last two years and see how the new woodland is progressing. There will also hopefully be an opportunity to plant some new trees as the final planting phase of the three year project is reached.

We would ask all participants to please book a space on Eventbrite by following this link

If you have any questions, or if you wish to be added to the Wild About Jersey email list, please contact either Julia Clively (tel: 441600; j.clively@gov.je) or Jon Parkes (tel: 483193; jon.parkes@nationaltrust.je).

The site Meet at Sorel Point car park at 10:15 for a 10:30 start. We will finish at approximately 12:30.

Jersey phone directory Map 3, R2 and Google Maps here

Parking There is parking close at Sorel Point.

Tools needed Equipment will be provided but if you have a pair of gardening gloves, or any garden forks, rakes, sickles or spades, it could be helpful if you could bring them along with you.

Clothing needed Please dress for the weather and wear sturdy footwear. We can supply a pair of gardening gloves if you don’t have them.

Children All are welcome although we do ask that volunteers under 16 years of age are accompanied by an adult.

Refreshments Unfortunately, Kim will not be able to join us on Sunday, but the Trust Rangers will be happy to offer a mince pie and a cuppa for the workers. Unless one of them does some baking!
*Please make sure you bring your own mug or reusable cup*

We very much look forward to seeing you on the day.

Birds of Conservation Concern

From British Trust for Ornithology, British Ornithologists’ Union and British Birds

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 leaflet here 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 Britain here