Project Splatter

A talk by Dr Sarah Perkins to the Berkshire Mammal Group

9^th February 2017

Dr Sarah Perkins is a wildlife biologist at Cardiff University, having started her career as a conservation officer for the UK Wildlife Trust. In an entire year of working as an Otter Conservation Officer, Sarah only ever saw one otter – a road-killed one – and became interested in quantifying the number of animals killed on the roads each year. She worked abroad for several years, working on wildlife diseases, before returning to the UK and taking a position at Cardiff. There her interest in the number of animals killed, which species are the most vulnerable, and whether there were hotspots of roadkill that could be mitigated against, led her to establish Project Splatter in 2013, as a collaborative citizen science project – the subject of her talk to the Berkshire Mammal Group.

Sarah opened by acknowledging that road kill is a common sight and asking generally how we engage with wildlife, and what the impact of roads might be on animal mortality. She turned to the journal, Science, which in December had published a paper on roadlessness. On screen was a map plotting the incidence of roads in red, lined with 1 km buffers into the surrounding habitat, and the road-free areas in blue, in which roads would have no effect on wildlife. 80% of the globe is still roadless, but much of this area is composed of the Arctic regions, the Siberian tundra and deserts in north Africa and Australia and other inhospitable environments. And the rest is divided into 600,000 fragmented habitats, half of which are less than 1 km in extent and only 7% are of the largest size category). Only 9.3% are protected areas. So the clear conclusion was that roads have the potential for a major impact on wildlife and its habitats.

The scale of road deaths

What might be the scale of wildlife road deaths, she asked, pointing to illustrative graphics: 100s, 10,000s, or 1,000,000s. Answering her own question – after an uneasy pause – Sarah said we simply don’t know, but can look at studies in other countries that have measured the effects direct vehicle collisions. They propose some dramatically varying estimates:

USA 80m birds killed on US roads per annum

Netherlands 0.2 – 2m birds

Belgium 4m

Denmark 8.3m

Spain 100,000

In the UK a PTES survey was launched in 2001, which has since measured mammals on roads for a period each summer. Usefully it has reflected the decline of the hedgehog, and also picked up a fall in rabbit numbers. But this survey is just in the summer, and just of mammals. Were there any other figures? Well, yes, Deer Collisions (www.deercollisions.co.uk) estimates 42,000 to 74,000 collision deaths a year, information drawn from police and insurance reports. The Mammal Society has produced estimates of 50,000 badger deaths a year, and 100,000 fox deaths. For birds a BTO Road Deaths Enquiry in 1960, at a time when there was rather less traffic than now, concluded a total of 2.9m avian road deaths. Sarah noted it took until 1965 for the figures to be published.

Project Splatter

To draw together contemporary data on all species, Sarah introduced Project Splatter as a continuous, UK-wide survey, set up in January 2013. She explained that it started out as a final year project, undertaken with some reluctance at first by Sam Stafford, an undergraduate reading Zoology at Cardiff. He devised a social media to capture direct reporting by members of the public, and such was its early success that he become highly motivated and earned the soubriquet, “Splatter Sam”. This early success was cemented by the involvement of the press, in particular the publication of a two-page, full colour spread in the Independent, prompting

wider media attention. It was, in Sarah’s words, “a fantastic start”.

The social media platform is designed to make the task of reporting simple and accessible. Reports can be sent in by iPhone app, Android app, Facebook, Twitter and by email or through the web. The scheme accepts both occasional and regular reporting – there need be no on-going commitment, though many of the 2,000 participants are regular contributors – and on Monday the project offers feedback, drawing attention to some of the quirkier reports.

www.projectsplatter.co.uk

The project’s purpose is to quantify and map British roadkill, determining which species are the most observed, and identifying spatial and temporal hotspots: the ‘where’ and ‘when’. It aims to raise awareness of the roadkill problem, and encourage mitigation (such as green bridges). Ultimately it seeks to reduce the negative impact of roads on wildlife.

Findings

To date, Project Splatter has accumulated over 35,000 records. These include 33 mammal species, from shrews to wild boar, and these represent 62% of the records.. Representing another 34% are the 74 bird species, from blackcap to buzzard. There are very few reptiles and amphibians. The five species most recorded as roadkill are:

15% Badgers

14% Rabbits

11% Foxes

7% Hedgehogs

7% Pigeons

And as for distribution, the records come from throughout the country, probably reflecting abundance. However, any analysis needs to account for reporter bias; there are few reports from the Highlands of Scotland, whereas Sussex generates more records than any other county. (There, a paramedic has been involved from the start and is a prolific provider of records.) Double counting is not considered a problem at this stage; with 2,000 reporters and 8,000 reports a year, there are simply not enough reports for duplicated to occur to any degree.

Berkshire

A map of the county indicated ribbons of reports along the M4, A34 and Vale of the White Horse, with a cluster around Newbury and a broader blanket of sightings to the west of the Thames around Abingdon.

In Berkshire pheasants are the most prevalent casualties, at 39% of reports compared with 23% nationally. (At 25% for badgers the local and national tallies are in line, though other species tend to be under represented.) But what do the figures suggest about pheasants’ behaviour. A graph of the monthly figures produce a peak in September and October, when naïve young birds are released, and in March, when feral pheasants escape into the countryside.

 

Hotspots

Using SaTScan models, the Project has identified nine county clusters for mammals, some comprising single species and some of multiple species. There are obvious clusters, such as for badgers in Somerset, where they are presumed to relate to animal abundance, while others are as yet unexplained, such as the concentration of rats in northern England.

For birds there are seven such clusters. An analysis of these suggests some behaviours tends to endanger certain species. Blackbirds, for instance, have a tendency to last-minute flight from possible predators, and a low, undulating flight pattern, and so are innately vulnerable to vehicles. In discussion afterwards it was noted that, conversely, crows have an enhanced ability to judge the paths of approaching danger, and avoid on-coming vehicles.

Sarah asked which roads were the most deadly: Motorways, A roads or B roads. The answer was A roads. Is this the effect of lighting, she wondered, increasing visibility and causing animal avoidance? Hedgehogs were cited as an example of a vulnerable species, falling from 30m in 1950, when there were far fewer motorways and major roads, to 1.5m in 1995. 20-40,00 are killed on roads per annum – far too high a figure.

Peak reporting is in September, July and April, with winter the lowest. Perhaps unsurprisingly the peaks coincide with seasonal breeding and dispersal activity, while many creatures hibernate during the winter. Yet this varies from year to year, according, in part to temperature and the weather, which affects activity and therefore vulnerability to vehicles.

Disappearance of carcasses

It is accepted that scavengers clear carcases and therefore evidence, so establishing the rate of disappearance would give a useful correction factor when analysing the figures. One early study was by Fred Slater, who set out chicken carcasses and measured the tracks of scavengers left in a surrounding sand pit. He established the rate of disappearance was rapid, suggesting that reporting was underestimated 12-16 fold.

To extend this research for the project’s own purposes the University of Cardiff undertook to study the rate of disappearance. Chicken heads were distributed by student Harry Williams at twelve locations around the city, with camera traps set up: some in parks, some in streets. As an amusing aside, Sarah recounted how some of the cameras disappeared, then reappeared, many with footage of puzzled residents investigating the device, and then, having realised what it was, putting it back! The survey was carried out both day and night, and recorded 120 sessions.

Six principal species of scavenger were identified: corvids, foxes, dogs, cats and gulls. How long it took for the carcasses to be taken varied according to the time of day: in the daytime it was very quick, but at night it tended to lie untouched until at dawn, when scavenging was dominated by foxes and domestic cats. Quantifying that, it was established there was a 75.8% chance of removal within 12 hours. On average it took 2 hrs, 13 mins in the day; 8 hrs and 47 mins at night.

To illustrate which scavengers eat carcasses, Sarah showed a short video made up of day and night-time footage from the camera trips. During the day there were plenty of corvids (crows and magpies), cats and dogs; at night, there were rats, foxes, gulls, magpies and – surprisingly – wood mice (visible mainly by their large reflective eyes). Urban foxes were brazen, while rural foxes markedly more timid.

Associated Research

Project Splatter’s records are considered open source and available to share, and so feed into several other studies. Among these are the records of polecats, which are sent to the Vincent Wildlife Trust to help monitor the expansion of this species out from central Wales. Records have been used to help with mapping invasive species, eg Wallaby in Surrey; Wild Boar in Bristol. But perhaps the most systematic is the 20-year-old otter project run by Liz Chadwick, also at Cardiff University. 

Cardiff University Otter Project

In this project otter carcasses are taken to Cardiff for post mortem examination, where the livers and kidneys are checked for contaminants in habitat, parasites are identified, signs of fecundity noted. Rather sadly, Sarah noted the discovery of four nearly full-term foetuses that had died when their mother had been hit. The results of post mortems contribute to various study programmes, the decline of eels and the presence of Toxoplasma gondii, for instance. The otter is a sentinel for watercourse purity and so much can be gained by their examination.

Dead or Alive

A spin-off project, entitled ‘Dead or Alive’, was set up to quantify popular interaction with wildlife; do most people see wildlife alive, or just as roadkill? The project conducted a four-week survey, eliciting 1,400 responses! To take one of the top five roadkill species, the badger, it was possible to establish that 7% of respondents had never seen one, but 88% had seen one dead. As few as 5% had only ever seen live badgers.

Only seen alive Ever seen dead

5% Badger 88%

Respondents were invited to leave comments too, and the responses indicated a high level of concern about the spread of invasive species.

Roadkill Sub-culture

Touching on an interaction of a more unusual nature, Sarah spent a few minutes describing some aspects of roadkill’s place in art, design, clothing and food. She pointed to the activity of ‘freegans’, those who eat roadkill, and the existence of roadkill chefs and ‘badger balti’. She illustrated some of the work of Adam Morrigan, the roadkill artist, and of Jez East/ton Design

Conclusions

Returning to Project Splatter, Sarah drew together the various threads of her talk, summarising the role of roadkill research as a contributor to:

• Conservation
• Understanding populations and behaviours
• Academic research, eg. the otter project
• Identifying habitat contamination
• Mapping invasive species
• Public engagement

She ended by urging the audience to get involved, and supporting imminent moves for new legislation being led by Wendy Morton MP: the Local Authority Roads (Wildlife Protection) Bill.

April 2015 Mammal of the Month - The Badger

Photo credit: Matt Collis

 

Our April mammal of the month is the badger. The species we have in the UK is the European badger (scientific name Meles meles). It will be familiar to many of us from children's stories and lots of other sources but how many of you have seen one live in the wild? If you do spot one, please record it for us here. Any road-kill victims can also be entered as a record although of course we hope not to have many of those. Any other mammal records can be entered via the same page too.

Our top five badger facts are:

• They weigh around 8-9 kg in the spring but go up to about 11 to 12 kg in the autumn
• Social groups usually contain about 6 adults but groups of over 20 have been recorded
• Cubs are born bald and blind within the sett, usually in February, and do not emerge above ground for around 2 months (so look out soon!).
• They mark the edge of their territories with latrines - shallow pits in which they defecate
• The territory around a set is usually around 30 ha but can be up to 150 ha.

For more details, check out the very informative Mammal Society fact sheet on the species, including pictures of their tracks and signs.

If you are lucky enough to take a photo of a badger or have any that you've already taken, we'd love to see them - please share!

All about Badgers

A BMG talk by John Fennell (Binfield Badger Group), Tuesday 7^th October 2014

Opening the evening with a display of exhibits, John introduced our largest carnivore with some examples of road casualties, now stuffed and mounted for display, including a handsome albino. Death on the road is a big problem, he said – 50,000 are killed each year. They have defined routes and will repeatedly cross roads at the same crossing points. Their sense of smell is paramount, like that of a bloodhound – and though they have excellent hearing and good eyesight, they have little awareness of the dangers of the car. John then turned to his presentation.
 

He started with pictures of the Group’s sett in Binfield. At that date, despite the protection afforded badgers under the Wildlife & Countryside Act, their setts were not covered. Setts would be destroyed by pouring diesel and blocking them with soaked rags. At Binfield a group was convened by a local lady, Shirley Davis, who organised a campaign to save the long-established sett. The developer eventually fenced off the site, erecting a close-boarded fence around it. The site is only half a hectare, which is insufficient for a colony to survive, so gates were fitted allowing access to a nearby wood. As installed they were too narrow, and John showed a photograph of a circular yellow stain around the opening where the creatures had had to force their way through, the sandy earth in their coats acting as paint in a living paint brush. The gates have since been widened, and the site doubled with the acquisition of additional land from a neighbouring garden.

The site includes a tool shed for a lawn mower – as badgers prefer the shorter grass of grazing land – and a hide. John admitted (or boasted?) to have spent over 3000 hours watching badgers. The colony has also been filmed for television by Simon King. 
 

Setts

John then turned to describing the ecology of badgers in general, starting with the typical disposition of setts within a territory. Setts will have multiple entrances and be indicated by spoil heaps of sandy earth, chalk or clay. Badgers can dig out a burrow in a night or two. John displayed a 4kg flint which a badger had removed when digging. Tunnels may extend down 3 metres, opening into a nest chamber and on to the next. Ventilation shafts will rise straight up, just breaking the surface. Ideally these will be sited on a bank to achieve a chimney effect. Indeed in frosty weather the badgers’ breath can be seen rising into the air, betraying which chambers are occupied. Old holes are large (large enough for John to enter) and worn sooth from the badger’s preference for entering the burrow backwards when dragging nesting material into the sett.

Badgers sometimes share their sett with foxes. There are about 100 holes at Binfield, but only about eight are used at a time, so occasionally foxes occupy vacant holes on and, if not exactly welcomed, are at least tolerated. But only if are quiet, however, otherwise even cubs will chase the foxes away. (Foxes will sometimes reciprocate, but frightening the badgers from behind and causing them to run and hide.)

Artificial setts are sometimes used. John illustrated this with a picture of a concrete drainage pipe, in a roadside ditch, which was occupied for three months. Others are deliberately placed as part of developers’ mitigation measures, such as when Legoland was built near Windsor, or currently in Wokingham where a footpath has had to be closed. 
 

Signs of occupation

One sign of badger occupation is the presence of clumps of hair on barbed wire fences. They will be white with a dark band towards the white tip. They are oval in cross section, so will click when rolled between finger and thumb, and under a microscope it will seen that they are hollow. Another sign is abandoned balls of bedding material, usually grass or hay, but sometimes ivy or bluebell leaves.

Badgers have favourite scratching posts. They drag their forepaws down the tree, especially in damp weather when the wood is more receptive to the application of sent. This they achieve by shuffling backwards and raising their rears up the trunk above them, lifting their tales to secrete their scent. Badgers are very territorial and this is a way of marking their patch.

Paw prints are another sign. These are distinctive, though not easy to spot. Badgers have five, one-inch long, non-retractable claws, and therefore five pads. These are forward facing, in parallel, with a kidney-shaped palm behind, which is about 4.5 to 5 cm across. The rear paws are much less defined, and often obliterate the forepaw prints as the animal moves forward. John showed a marvellous picture of brown prints on a white background. Here leaves had fallen into a pond and an oily residue had built up on the water’s surface. When the pond froze over the oil lay on top of the ice and allowed clear impressions to be left in the snow when the badgers walked over it. Badger paths, while not distinctive, remain in use regardless of the weather, even in snow, and so provide an easily seen feature of their territory.

Another sign is damage to lawns, usually those with weeds among the grass which harbour the insects that badgers rely on for food: cranefly larvae and summer chafer grubs. During the night then, they will grub around, earning their old vernacular name “earth pig”. 
 

Badgers preferred food source is the lobworm, humbicus terrestris, of which they may eat between 100 and 200 a night. However, worms like warm and wet conditions so the badger has to have other sources to supplement its supply. This is especially true in the autumn, when they will put on as much as 3kg to see them through the winter. They will eat slugs (wiping them on the grass first, to remove the slime) and snails (crunching the shells). They will break open dead wood for larvae and insect eggs. They like brambles, elderberries (off the ground) and hard fruit (they will climb trees for apples and pears). Pausing for an anecdote, John referred to two badgers were found dead in a pond in West Surrey. On investigation it appeared they had eaten freely of apples in a nearby orchard; these had fermented and the badgers had become intoxicated with fatal consequences. Badgers will break into wasps’ nests and eat the larvae from the honeycomb. They do get stung, however, and are not immune, so will eat quickly and run. They enjoy eggs and will carry them back to the vicinity of the sett to eat in safety. 
 

Hygiene

Badgers are very fussy about hygiene. They dig latrines on the edge of their territory that all the family use, creating another alongside when the first is full. Their gelatinous, mash-like excrement is distinctive in appearance and smell. To establish occupancy and measure their territory it is a surveying practice to introduce coloured pellets into the badgers’ food, so the evidence will turn up in the peripheral latrines. An annotated photograph illustrated the contiguous territories of six neighbouring setts. Occasionally nature supplies a similar effect, as illustrated by a photograph of a latrine containing rose-hip tinted ordure!

Threat of traffic

Protection against road traffic is possible, though expensive. 2-metre tall, heavy-duty, chain link fencing can be installed, burying the lower part in a curve away from the road to deter any badgers from digging. A break in the fence is permitted where there is a tunnel for their use. On the M5 near Exeter there is even a tunnel slung below a bridge over the motorway; it is used regularly and not just by badgers, but by deer and hedgehogs too. Railways too are deadly obstructions. On a line near Tonbridge, in Kent, 100 badgers were killed in three months. Yet the third rail on an electrified line need not be continuous, so provision for badger crossings can be made if planned.
 

Reproduction

In April or May badger watchers play ‘spot the nipple’ as lactation is often the first sign of new cubs. Badgers undergo delayed implantation. The sow might mate, but the fertilised egg ‘sleeps’ until the time is propitious. She may gather three to six in a year, and then, if undisturbed, enter a two-month gestation in December (though delay can last up to 18 months.) The cubs are born in February, but not seen above ground for about eight weeks. Two or three cubs per sow is normal, but sometimes as many as four or five. At birth they are only 12cm long, blind, with ears closed and weighing only 100g. When they do make an appearance on the surface, it is usually to feed, as badgers don’t take food underground. (They will take toys, however, as suggested by the 150 golf balls in one sett near the local links; tennis balls get shredded.) Their heads are fully grown by August, but their bodies still smaller – 4kg, say, compared with an adult of 10 – 12 kg. (The heaviest John has encountered was a whopping 16kg.). Sexing is difficult without inspection, but John showed photographs of the essentials. The male has an extra bone, which traditionally gamekeepers used as a toggle on their jackets!

Rescue

Drawing to an end John illustrated a number of injured and disorientated creatures that the Binfield Group has helped over the years, including one from Finchampstead that was taken to the animal hospital in Somerset run by Pauline Kidner. Pauline tends to 50 to 70 cubs per annum, building up small groups of healthy animals (with minimal human intervention), for release back to the wild. Releases have to be carefully managed: the cubs have to have two tests for bovine TB and are chipped and tattooed. A release officer locates suitable sites – and not in cull areas!

To conclude, John set out a family tree of the Binfield badgers, noting visiting badgers and known deaths, and identifying al the cubs born at the sett. The tree was based on sightings over 25 years, from 8 June 1990 onwards, the number of badgers varying from three in 1999, down to one at times, to six in 2013.

QUESTIONS

Are badgers becoming urban, like foxes?

No, quite the opposite. They are easily driven away be development. Badgers are easily frightened by sounds and running is their defence. Otherwise they remain very settled in their rural locations. The sett at Binfield has been in occupation for at least 145 years.

Do they eat hedgehogs?

Yes, occasionally. Sometimes you can hear the hedgehogs scream. The badger will leave the spiney skin, which, as it dries, shrinks and inverts into a ball.

Bovine TB

In a hotspot only 1 in 7 is likely to have TB, so much of the culling is unproductive.

What is the extent of the national population: numbers and distribution?

250,000 to 350,000, according to estimates at the census last held eight years ago. The UK has the capacity for 600,000. They live in Scotland, but not in wetlands (and much damage was caused by last year’s flooding).

How big is a typical territory?

10 hectares constitute a normal sized territory for a female with cubs – and a football pitch is about 1.5 hectares – but it does depend on food sources. There have been some at 100 hectares, but generally badgers don’t like to go too far.

What is their average age?

3 years (because of high mortality on the roads). They seldom live long enough to become dominant. They can live to be 12 or 14, lifespan being limited by wear to their teeth (as worms are full of grit). Adults have 38 teeth on average, though individuals do vary.

Further information

There are 60 groups under the auspices of the Badger Trust, with at least one in each county. Ernest Neal is the authoritative author on the subject.