By Rob Ward

Slow-worm. Photo by Rob Ward

The grass snake is rare in Jersey, and has a restricted distribution particularly within the west and south-west of the island. This project aims to determine the status of Jersey’s populations, identify causes of decline, and provide information for conservation action and species recovery.

Aims

• Determine the distribution and population size of grass snakes and slow-worms across the island
• Investigate movements, range size and habitat use of both species, and undertake modelling
• Examine predator / prey relationships of grass snake populations
• Conduct genetic analysis of the grass snake populations
• Provide recommendations for species conservation and recovery
• Engage and educate the public in grass snake conservation in Jersey.

Background

A juvenile grass snake captured during surveys. Photo by Rob Ward

The grass snake (Natrix natrix) is a harmless non-venomous snake, and is the only snake species native to Jersey. Although relatively common in mainland Britain and Europe, in Jersey it is rare, and seemingly declining. Little research has previously been conducted on Jersey’s grass snake population, and so our knowledge of its ecology, conservation status, and relationships with other Island species is relatively lacking. Historic information regarding the distribution of this species is found in Frances Le Sueur’s A Natural History of Jersey (1976), which suggested that grass snakes were most numerous in the north-west and south-west of the Island, but also stated that they occurred throughout the Island in low numbers. More recent studies confirm grass snakes to have a stronghold in the west and south-west of the Island, with a further population in the south-east. However, no grass snakes have been seen in the north-west (Les Landes) since a juvenile at Grosnez pond in 1992. With such a lack of information, it is clear that much work still remains before a true picture of the grass snake’s ecology and population size in Jersey can be determined.

What is being done?

In order to deal with this paucity of information, a research project was developed between the States of Jersey Department of the Environment, the Durrell Institute of Conservation and Ecology (DICE) at the University of Kent, and Amphibian Research and Conservation (ARC), resulting in a PhD position. Research being carried out by Rob Ward, a student at the University of Kent, consists of four key activities:

1)      Determining distribution and population size

Green lizard basking on one of the survey materials. Photo by Rob Ward

Since March of this year, surveys have been taking place at multiple sites, particularly in the west and south-west of the island, in order to collect data on the Island’s slow-worm and grass snake populations. These surveys involve checking artificial materials that have been laid out to attract reptiles through the warmth and shelter they provide.

During the surveys, a number of environmental variables are recorded, as well as morphological data on each of the grass snakes and slow-worms found. These sightings are then plotted on a map, which can be used to study habitat use of the species.

In addition to the surveys conducted by Rob and his volunteers, a publicity campaign, “Think Grass Snake” was launched on the 22nd June 2014 to encourage the public to send in their sightings of grass snakes and slow-worms. A dedicated ‘Spotline‘ is in place to receive phone calls on 441628, as well as a website at www.ThinkGrassSnake.Je, and presence on social media. The campaign also aims to educate the public about the two species, and raise awareness of their decline.

2)      Investigating movements, range size and habitat use

A radio tag fitted to the tail of an adult grass snake. Photo by Rob Ward

Understanding the movements and habitat preferences of a species is an important factor for their conservation to ensure the right areas are protected and managed correctly. Grass snakes are known to move large distances, and so it is particularly important to know which habitat types they use during different times of the year and at different life stages, as well as the location of key habitat features such as feeding ponds, nesting sites, and hibernation sites. During this project, each captured snake and slow-worm has a number of pictures taken of its individual patterns. For grass snakes, this is the belly pattern, and so it is possible to tell when an individual is recaptured, and thus how far it has moved between captures.

Another way of studying the movement of grass snakes is to use radiotracking. Adult snakes are fitted with a small radio tag on their tail, and located two to three times per day until the tag falls off (normally when they shed their skin). This gives much more detailed information on the size of the areas they need to live in, the habitats they prefer, and their behaviour.

3)      Examining predator and prey relationships

Garden pond used by toads and newts, an excellent source of food for grass snakes. Photo by Rob Ward

Grass snakes primarily feed on amphibians and fish; however, in Jersey many of the amphibian species have undergone declines, especially the Agile frog. These declines in prey could be one of the reasons that the grass snake has declined, and so it is important to understand what the remaining grass snakes in Jersey are eating.

The project utilises two main methods of studying the diet of Jersey’s grass snakes. The first of which is to encourage captured snakes to regurgitate any recent meals. When this is successful, it gives an immediate insight in to the diet of the captured snake, and the prey item(s) can then be manipulated back in to the digestive tract of the snake so that the prey item is not lost.
The second method involves collection of faecal samples from captured snakes, from which DNA will be extracted to identify the species consumed.

Tadpoles and small agile frogs are regularly eaten by grass snakes. An adult toad too would make suitable prey for an adult grass snake. Photos by Rob Ward

4) Genetic analysis of the grass snake population

The unique belly pattern of a juvenile grass snake captured during surveys, with a ruler showing its size. Photo by Rob Ward

When populations become isolated for long periods of time, and especially when a population is of a small size, the genetic quality of the population can begin to deteriorate. In Jersey, grass snakes are at risk for both these reasons, and could be suffering from the founder effect, poor gene flow, and resulting inbreeding due to fragmentation. To determine if these problems are occurring, DNA samples are collected from captured grass snakes, shed skins, and dead individuals. These can then be used to investigate how individuals are related to one another, and give an insight in to any requirements for human intervention. Furthermore, the DNA can be compared to samples from grass snake populations elsewhere in Europe to see which are most closely related to those here in Jersey. This information is useful should there be a need for reintroduction, genetic restoration, or captive breeding of snakes to ensure the population’s survival.

Habitat management

A possible cause of snake decline is the loss of particular habitat features including feeding ponds, compost and manure heaps for egg-laying, and hibernation sites. Fragmentation may also be a factor as snakes are at risk whilst crossing boundaries such as roads, as well as having to travel further and using more energy when man-made obstacles may be in their way. We can, therefore, improve habitats for grass snakes by providing some of these features. Compost heaps in particular are of low cost, are easy to construct and maintain, and can be built in private gardens and allotments as well as public areas and reserves. In areas with large quantities of grass clippings such as on golf courses, the materials can be piled up to provide suitable nesting habitats for grass snakes as well as a home for a variety of other wildlife. As grass snakes nest around June, and eggs do not normally hatch until the September or occasionally even October, not disturbing potential nesting sites during these periods is important.

A pile of grass clippings (left) or a domestic compost heap could provide an important nest site for grass snakes. Photos by Rob Ward

Keep up to date with the Think Grass Snake campaign and Rob’s research by keeping an eye on the website blog and on social media:

Web – www.ThinkGrassSnake.Je
Spotline (if you see a grass snake) – 01534 441628
Facebook – https://www.facebook.com/ThinkGrassSnake
Twitter – @ThinkGrassSnake

By Cris Sellarés

Local ornithologists are investigating the possibility that Manx shearwaters may be trying to breed near Plémont, after a recent survey suggested once again that some of these birds might have been prospecting the area for nesting opportunities.

Manx shearwaters are shy, burrowing seabirds related to fulmars, petrels and albatrosses that spend most of their life at sea and only land to dig a burrow where they will lay a single white egg. Like that other burrowing seabird the puffin, shearwaters are susceptible to human disturbance and predation by introduced mammals such as rats, cats and dogs. In areas where these predators are found the seabirds favour coastal cliffs that are difficult to access. Even then, they will only visit their nests during the darkest nights, to avoid predation by gulls and other birds.

Their name comes from the Isle of Man, where once a large colony was found on the Calf of Man. The species became extinct there after a shipwreck in the 18^th century accidentally introduced rats onto the island. Rat eradication projects have succeeded in restoring the breeding colonies of this seabird not only on Calf of Man but also on Lundy (where the population has grown from 166 pairs in 2001 to over 1,000 in 2008), the Isles of Scilly and Ramsey Island (where its population grew from 850 pairs in 1998 to over 3,800 in 2012).

In the Channel Islands small numbers of Manx shearwaters have, in recent years, nested in Sark and Jethou, although no surveys have been undertaken recently. The closest colonies are in the Isles of Scilly and Brittany. In Jersey, small numbers have been recorded in the vicinity of Plémont almost every summer at the height of the breeding season. Unfortunately it is unclear whether they have actually nested here or are merely non-breeding individuals visiting the area looking for a potential future nest site.

This year’s survey detected more shearwaters (four were over the land after dark) in the area than in any previous years, and local biologists are eager to find out if the species is breeding in Jersey. Further surveys are planned for the next few weeks.

Whilst the birds may not be breeding this year, they might be prospecting the area for a suitable nesting site, and their presence is an encouraging sign. If shearwaters were to establish a small breeding colony in the Jersey it would greatly enhance the ecological value of our coastline and maintain seabird diversity of the Channel Islands. Pairs from this species form life-long monogamous bonds and can live for over 50 years, so it is hoped that a breeding colony would have a long and safe future in the coastal cliffs. Any possible restoration projects at Plémont like those mentioned above aimed to encourage nesting by shearwaters could only be beneficial to puffins as well.

It is timely that, as we in the Channel Islands, with our friends at Swift Conservation, become increasingly concerned about our breeding swifts (see post here); there is a UK-based survey to try to determine numbers of these birds in the British Isles.

Swifts are fantastic birds, just look at these details of their annual migrations from the BTO. They are amongst the last spring migrants to arrive, but the first to leave. You’ve probably seen them speeding through the air, screaming their heads off, or swooping into crevices in buildings.

But, as we have seen locally, they’re in trouble – they are birds of Conservation Concern. Their numbers have declined dramatically in the past 10 years; we’re not sure why, but one likely reason is that their nest sites are being destroyed.

The RSPB is working with swift groups around the UK and your information will help our knowledge of swifts so that more nest sites can be provided and protected. Tell us where you see swifts and help us to help them. The RSPB will make sure that Channel Islands records and provided for our use in future.

What to do

The RSPB would like to find out where swifts are seen and where they’re nesting. Look out for low-level screaming groups of swifts (that means they’re breeding nearby) or where you’ve seen swifts nesting – perhaps entering a roof or hole in a building (if you can see the nest, it’s not a swift). The best time to look is around dusk on a warm, still evening, or early morning.

You don’t need to report sightings of swifts that are either very high in the sky, feeding over water bodies or away from villages, towns and cities. These birds could have travelled some distance and may not be local breeding birds (our birds may commute to France daily).

Submitting your results

Please submit your results online here.

You can enter as many records as you like at different times from anywhere across the UK. You can even record those sightings you remember from the past. The more records the better. If you already have an account for the RSPB’s online community you can sign in and enter your swift sightings using those details when the survey is open. If not, don’t worry, you can still submit your sightings.

I’ve done this before

The National Swift Inventory will only work if information is kept up to date. You may have submitted records in previous years, but it is important to know if birds are still returning to the same areas and using the nests you recorded them at before. Please submit the latest information relating to the site, giving either numbers of screaming birds and/or nests. This helps us know if the birds are returning, if the colony is stable and if the site still in use.

Identifying swifts

Swifts are often confused with similar hirundines (swallow, house and sand martin). This helpful identification video from the BTO show’s the differences:

Swifts are with us just three months each summer, bringing vital action, drama and excitement to our islands’ skies. These amazing birds have shared our buildings ever since the Romans came to Britain. They still breed in our eaves and gables, but not for much longer, as modern and renovated buildings exclude them. Unless we do something about it, swifts will vanish from the Channel Islands. But not if we can do things to help them and Swift Conservation are giving a hand.

Most buildings put up since 1945 are swift proof. Re-roofed or pointed older buildings are swift proof too. Nesting in buildings, swifts do no damage, even adding aesthetic value to the neighbourhood. Last year Vic Froome gave an impressive talk to Channel Islanders on work being done in Guernsey to ensure that new and renovated buildings here included provision for swifts. There are also devious ways to encourage swifts to entirely new sites with specialised tape-lures.

Swifts are easy and cheap to encourage and a variety of novel techniques and specialised nest-boxes can be used. Boxes can be added to the outside of a building or special hollowed bricks can be built into the wall (these, from Bird Brick Houses, can be used for bats and house sparrows too). Existing structures can also be modified easily to let these tiny birds fit snugly out of site behind facia-boarding or under tiles. In older buildings there are often lots of potential sites that can be made more swift-friendly by narrowing entrances to ventilation or post holes or even just behind bricks – this will encourage swifts whilst also keeping out less welcome nesters like feral pigeons.

In Guernsey, swifts nest in a variety of buildings as they do in most places, while in Jersey they have, unexpectedly, at least in recent years, been restricted to our castles (Elizabeth and Mont Orgueil), Fort Regent, the Old Harbour and, something of a rarity, a fully natural colony on the north coast cliffs near Plémont. However, even here swift numbers have declined alarmingly. While swifts undoubtedly face challenges through bad weather and changing food supplies, even in Jersey’s heritage buildings improvements and restoration to walls and towers have, over the years, made these traditional sites less swift-friendly.

Following Vic’s lead in Guernsey, Swift Conservation have been invited to advise Jersey on ways of increasing nesting opportunities for swifts at existing colonies. Edward and Mandy Mayer visited the Island on 30^th April and, seeing first-hand why existing swift numbers might be low, looked around the castles finding numerous spots that could be used to encourage more nesting pairs at these sites. Our swifts arrive in early May so we hope to have some new opportunities ready for them in time for next year.

A healthy population of swifts can be recognised by their extraordinary screaming parties as many birds fly together at alarming speeds around their colony. Screaming! The screaming helps the birds bond and helps formation flying in restricted areas while creating a distraction for birds to slip un-noticed from predators to and from their nests. These parties are a much-loved feature of summer evenings and to many people they mean summer as much as cricket does! Let’s make sure that we don’t lose this wonder of nature from the Channel Islands.

By Cris Sellarés

In late March 2014, Jersey hit the mark of a thousand dead seabirds found on its shores; the Island total since reaching 1,022 with numbers in the Channel Islands overall to just under 1,300 birds.

In a regular winter we might expect between 10 and 40 dead seabirds on our shores over a few months, recorded by a few local birdwatchers that check the beaches regularly. But this year was different, and even when we did start to realise that things weren’t quite as usual, we never suspected we’d end up with over one thousand dead birds in Jersey alone. This kind of event with so many dead seabirds is known as a wreck.

It was late January when numbers began building up and we started finding dead birds by the dozens in single stretches of our coast. Other birds were found still alive and taken to the JSPCA. At the same time, members of the public started to report dead birds, asking why this was happening and wanting to help and become involved. A record system was set up with Dr Glyn Young from Durrell taking in the records via email, the Jerseybirds website or the Jersey Wildlife Facebook group. A protocol for photographing the carcasses and disposing of them was advised to the general public, so that the identification of the species could be confirmed and so that the same bird wasn’t reported again by another person.

As awareness of the wreck spread, more people started to look for birds to report. Predicting a surge of reports over the weekends, we set up a series of co-ordinated surveys on four consecutive Sundays. These searches involved a team of 25-30 volunteers checking sections of the Jersey coastline, collecting all the birds found and taking them to an arranged collection point, where carcasses were laid out, identified and examined. Much information was gained from these counts, as well as allowing many people see some bird species for the first time: such as razorbills, great northern divers, grebes, kittiwakes, and, of course, puffins, which were instantly recognizable with their tuxedo suits, short yellow feet and colourful beaks. Indeed it was a very sad occasion that many people commented on, that the first puffin they or their children had seen was a dead one on the beach.

With the numbers from surveys and individual reports piling up, a worrying picture started to develop, encompassing rare finds (common scoter, red-necked grebe, little auk) and ringed birds whose origin could be traced to colonies in Skomer Island, the Hebrides, Orkney, France and, for many shags, the Channel Islands.

Some birds that were examined post mortem were found to have drowned, starved, or both; while samples, frozen carcasses and photographic evidence were sent to various UK-based scientists to contribute towards their long-term research.

Many questions have arisen from this environmental disaster, here are some answers gathered from the scientific community.

What species have been affected?

Auks (guillemots, razorbills and puffins) made up the largest portion of the casualties, with significant numbers of shags, great northern divers, kittiwakes and gulls following behind. Here is a breakdown of the birds found in Jersey.

The combined total of all reported birds from the coasts of UK, France and Spain is a horrifying 32,156, which is a conservative minimum as many birds may have sunk in the oceans or been grounded on inaccessible shores. On top of that, news from France suggests this might still go up by 5,000 at least.

What is the cause of these deaths?

The unusual series of strong storms we saw this winter are to blame. Most seabirds spend these months at sea, moulting their flight feathers and feeding. The storms would have weakened them and make diving for fish difficult in high waves and 100mph winds. The effects of the storms did not cease after the bad weather, as the waters remained murky for many weeks, making fishing still difficult. Unfortunately, these storms have been predicted to increase in strength and frequency as part of new meteorological model accounting for climate change.

Thankfully, the number of reported birds has started to decrease as you can see on the graph. The columns in green mark survey dates, the ones in pink mark reports in bulk.

What effect will this have on seabird populations?

The effect this wreck has had on the populations of seabirds will only be seen when the survivors return to their breeding colonies in the UK, Scandinavia and other parts. Only then local researchers will be able to quantify the effect the storms have had on the breeding populations.

What are we doing about it?

Actions have been taken across the Channel Islands since news of the seabird wreck started to spread. In February a conference call was held between organizations and governments of the different Islands to discuss the findings and possible impacts on our breeding colonies. A few weeks later a workshop was organized by the Alderney Wildlife Trust that got together bird experts and vets from Guernsey, Jersey and France, to discuss survey methods and carcass examination techniques.

The Alderney Wildlife Trust has also set up a webpage (here) to report birds found on the beaches and thanks to them the links between the islands and France have become stronger. We have established common protocols to monitor beaches that will allow us to detect future events such as a seabird wreck or a pollution incident, as well as standardizing carcass examination and data collection.

Beyond dealing with the wreck itself, a call has been made to local governments to support an islands-wide survey of our local breeding colonies as well as to step up the current guidelines of protection of our colonies against human-caused disturbance, which is one of the main factors affecting their breeding success.

PS. This report had 1022 words, one for each dead bird found in Jersey.