9 August 2015

Bumblebee queen hibernation hole

In August or so, the new bumblebee queens go off to find a hibernation site. They usually dig a tunnel about 10 cm long, ending in a small chamber. They will then hibernate from end of August to March/April. The new queens are the only bumblebees that hibernate - the rest of the colony, the males and the old queen all die off at the end of summer!

By chance whilst out surveying a badger sett, I saw this large Buff-tailed Bumblebee (Bombus terrestris) queen flying about above the grass and when she landed I thought I would take a few photos but realised she had entered a small hole with a bit of earth dug out. So I watched and waited... And sure enough a minute or so later her back-end emerged, digging earth out of the hole! I realised she must be digging a hibernation tunnel.

I've seen bumblebee nests in the past, but I can't recall ever seeing this before!

26 July 2015

The Wood Mouse - very common but rarely seen or appreciated!

Spot the Wood Mouse...
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After attending a small mammal trapping event recently I've grown to appreciate just how common the wood mouse (Apodemus sylvaticus) is. It is literally everywhere. And apparently, it loves hanging round people because we are messy so there is plenty of opportunity for food and shelter. So what's so special about the Wood Mouse?

Wood Mice live in large social (family) groups in a  burrow, and have a territory they defend from other social groups. They are highly adaptable to different living situations but as they preferably eat grains and seeds, they are mostly prevalent in agricultural settings, and are considered a serious agricultural pest species. Normal life span of a wild mouse is about 9 months, and they are mature at 21 days. This means that a female mouse can breed several times in the year and can produce up to 30 young in her lifetime. That is why some years mice can reach plague proportions in farm settings, as was the case in Australia in 1993. It is not easy to control mice numbers with trapping or poison, and with their rapid rate of reproduction they are almost unbeatable.

Mice are naturally heavily predated upon by cats, birds of prey, foxes and various mustelids. This will in a naturally balanced setting control the population but in an artificial environment like an intensively farmed area, predation cannot control the numbers of mice.

A lot of people are afraid of mice, perhaps because in our distant past they could be a cause of famine due to their effect on agriculture and also carriers of disease. In terms of health, humans can contract leptospirosis from contact with mouse urine. Leptospirosis is a bacterial infection and in 90% of cases, it only causes mild flu-like symptoms, such as a headache, chills and muscle pain but in some cases it can cause more serious complication called Weil's Disease. Mice are also a carrier of Lyme's Disease that can transfer to people through tick bites, although in many places deer is the main source of ticks infected with Lyme's. Mice are also reportedly responsible for a lot of fires, as they have a penchant for chewing electrical wires and cables! In a modern domestic setting however you are most likely to get in contact with a mouse through 'presents' your pet cat may bring you occasionally, so you shouldn't need to worry about mice.

Despite being called House Mouse (Mus domesticus) the mice you would usually find in and around your house is not House Mouse but rather Wood Mouse! House Mice are considered fairly rare nowadays, possibly due to competition with the more aggressive, highly adaptable Wood Mouse. So how do you tell what mouse your cat has graced you with?... Wood Mice are brown on the top and have white-grey fur on the belly. A House Mouse will have a dark greyish fur all over. And how can you easily tell them apart from voles? As opposed to voles, mice have a very long tail, easily the length of their body. Voles have very small ears which cannot really be seen through their fur, but a mouse's ears are large and protrude from their head. The mouse's bouncy gait also separates them from the more bumbling run of the voles.

This video from our training day shows the characteristic face and ears of the Wood Mouse, and it's unmistakable pale tummy that separates it from the House Mouse!

For scientific study, Wood Mice are trapped the same as most other small mammals, using a humane trap. The one used in our course was a Longworth trap with a shrew hole. It is a legal requirement to have a shrew hole on your trap unless you intend to capture shrews, in which case you need a license to do so in both England/Wales and Scotland. The shrew hole allows all species of shrews to escape as they cannot tolerate capture for more than 4 hours due to their high metabolic rate.

The traps are usually baited with peanut butter and porridge oats. The peanut butter has a strong smell so attracts the mice in from as far away as 25 meters. The porridge oats gives them some food and there should also be some straw/hay in the trap chamber to keep them warm during the night. It is not wise to use shredded paper as insulating material as this gets damp very quickly and then won't provide the warmth and it also absorbs urine and becomes soggy.

Trail cameras can be used to great effect to see if mice are present. Just bait, and wait...


Again, if using trail cameras, peanut butter and raisins are good bait. Cats don't tend care for these so leaves the site alone, but foxes apparently love it and of course, most small mammals will take any opportunity. Peanuts can attract squirrels and badgers, dog food and dried mealworms will also attract hedgehogs, however dog food is also likely to attract cats so it might be an idea to hide the bait in a box where cats can't get access! As the season progresses we will work on a post on how to use camera trapping to record wildlife, so stay tuned.

Footprint tunnel insert with the ink pads at the entrances and the bait in the middle.
You can also check for small mammals including Wood Mouse in your garden using a footprint tunnel! These are messy things but can made easily enough and be fun to check. A quick internet search will let you know how to make one. Use ink powder mixed with vegetable oil (won't harm the animals) on the 'ink pads' and just plain printer paper for the impressions, bait it with peanut butter, oats and peanuts and wait to see what visits! You can also place a camera in the tunnel if you want to actually see what's been visiting, as the footprints of various small mammals can be very hard to tell apart...

A little known fact to finish off is that bumblebee queens favour old mouse nesting sites for their nests, so they hone in on the smell of mice when they search for nest sites. So if you do find an old bit of a mouse nest in your garage or shed, use it to make a bumblebee nest to help the bees! :)

12 July 2015

What does the fox say? Something pungent!

Red fox (Vulpes vulpes) observing from the long grass and scrub close to RGU at Garthdee

I have been taking more of an interest in red foxes (Vulpes vulpes) of late having seen by far many more foxes in and around Aberdeen in the last 3-4 years than I can remember seeing in all of my life before. Whether this reflects an actual change in urban numbers or fox behaviour (or perhaps my own behaviour) I do not know.

The red fox is native across Europe, Asia and North America ranging between arctic and near desert habitats and is found in lowland and upland areas across the UK.

Fox earths (fox dens) are often described as being taller and narrower than badger (Meles meles) entrances. This allows foxes to emerge in a more or less standing posture. They are described as being of 20 to 25 cm diameter with a fan shaped arc of excavated soil from the entrance. Foxes are not as capable at digging as badgers or rabbits (Oryctolagus cuniculus) and will often occupy disused or used badger setts - it is not unusual for both animals to emerge from the same entrance! Foxes also enlarge rabbit holes or make use of spaces under buildings or under trees. 

Mistakenly presuming I could use a slightly modified badger sett survey technique to locate earths, I have since established from the Mammals of the British Isles Handbook (4th edition) that the use of earths is very variable. Outside of the breeding season many foxes lie above ground in dense cover but they may use earths during bad weather. Breeding earths are most conspicuous during the period when fox cubs have food brought to them in the earths (food remains may be in the entrance and the earth may smell of fox), or as cubs begin to emerge between May-June and trample down vegetation around entrance(s) through play. Being mid-way through July, I should probably not feel too disheartened not to have found an entrance matching the textbook descriptions.

Secondly, I presumed that as many sightings of adult foxes are of single animals, that they are solitary outside of the breeding season. The dog fox (male) brings food to the vixen (female) and cubs in the earth. I was surprised to also find from the mammal handbook that they are a social animal which live in family groups across a joint territory. A family has a dominant male and dominant female who will breed and may be supported in better conditions by one or more subordinate adults which could be female or male.

Red foxes reputedly use at least 28 categories of sounds though more recent research suggests 12 adult sounds and 8 cub sounds). They use barks, which they would do with a higher pitch than dogs. They are more renowned (or infamous) for 'vixens screams' during the late winter (their mating season) - though it would appear both dog foxes and vixens use screams. Cubs may also be heard making 'gekker' noises during play and similar sounds are made when fighting.

Most of the time you are more likely to smell foxes than hear them - they are notorious for using scent with great effect - both urine and faeces - often marking conspicuous objects such as large stones or tussocks or along pathways (particularly at junctions) where they can be found by other foxes. The scats (faeces) are more often than not the most obvious field sign of fox presence. I do not have a particularly good sense of smell but once I get a wiff of the acrid smell of their scat or urine I find it is difficult to get rid of!

Being omnivores, droppings can contain animal and fruit remains - particularly berries. They eat birds, rabbits and smaller mammals such as voles. In common with other carnivores, faeces are often long and twisted with remains of fur and feathers or insects, or can even be purplish with berries. This contrasts with dog droppings which are not twisted and do not tend to have obvious remains of contents. The droppings start off a dark colour but can go white over time due to the high bone content.

Variability in red fox (Vulpes vulpes) scats - all photographs taken on the same day at the same site: Top - White patches in contents which could be bones of prey or bits of feathers
Middle - Obvious fur content and superficially resembling a bird of prey pellet
Bottom - A more dog like fox scat. Very much whiter due to the high bone content

There is a huge overlap between fox scat forms and those of other carnivores. It is not unknown for professionals to mistake fox scat for something more exotic such as pine marten (Martes martes) or Scottish wildcat (Felis sylvestris grampia) scat - so scats are never the best field sign for identification unless supported by DNA testing.

They may also mark urine over emptied food caches or leave droppings on food remains.

Red fox (Vulpes vulpes) scat over an abandoned meal adjacent to the Lunan Water

A distinctive feeding sign of foxes is that they shear the feathers off from birds that they eat, tearing them off with their teeth leaving broken or ragged quill tips. Birds of prey also remove feathers from birds but pluck them leaving the quill tips intact.

The feathers of a pheasant sheared off by a red fox (Vulpes vulpes), leaving ragged quill tips, Hill of Canterland

Fox hairs may also be caught in barb wire fences, but not having the distinctive nature of badger or deer hairs, I have never yet confidently identified fox hair on its own.

A further sign is foot prints. The clarity of the print can be dependent on the substrate and age of the print. Foxes have a relatively narrow print compared to most types of dogs. You will often hear people talking about drawing a line (or imagining) a line or cross over the print - the lines of which will not touch any pads. The picture below shows an actual fox print (unfortunately I do not have any clear photos of fox prints at the time of writing), with the picture below showing approximately the location and shape of heel pad, toe pads and claws superimposed along with both techniques of drawing lines across the print. It is not possible to use either technique on a dog print without touching/crossing one or more pads.

Demonstration of the two techniques of drawing lines between the toe pads and heel pads of red fox (Vulpes vulpes) without any pads touching the line. This is not possible to do with a dog print without a pad touching the line(s)

Country foxes tend to be very shy and secretive, which is hardly surprising given their persecution. Urban foxes can be quite bold. I have encountered a pair of foxes being playful with people - something I saw a few years ago at Aberdeen Pleasure Beach. As charismatic as they are, I would not encourage anyone to entice foxes into becoming more comfortable with approaching people - they can be a nuisance around gardens uprooting garden plants and interfering with bins. I am also sure that anyone with a sense of smell will come to regret closer contact!

One of a pair of playful red fox (Vulpes vulpes) which spent time being chased and chasing a party of people down at Aberdeen Pleasure Beach in the early hours of the morning

There is an excellent website about foxes - which promotes itself as "the one site with all the answers about foxes". I would thoroughly recommend it to learn more about foxes and to separate fact from fiction - particularly at this time of debate about fox hunting with dogs in England and Wales.

7 June 2015

On the trail of the red squirrel

Squirel (Sciurus sp.) eaten spruce in the grounds of Haddo House. Some cones appear to have been subsequently eaten by wood mouse (Apodemus sylvaticus

With some time to spare yesterday in the grounds of Haddo House, I opportunistically found a quiet looking path adjacent to a tree plantation to slowly creep past looking for wild mammals and their field signs.

There is a very obvious clue to amateur trackers of any skill level that red squirrels (Sciurus vulgaris) use the grounds at Haddo -  there are road signs along the drive to the car park which state "Kill your speed NOT a red squirrel."

Following a mammal path under a canopy of spruce trees (with the occasional beech tree), I quickly found an abundance of spruce cones which displayed clear squirrel feeding signs on the woodland floor and on tree stumps.

Squirrels like to sit on a tree stump or mound whilst eating for a good view for predators. Around a third to half of the cones were found on top this stump already, whilst the others were found within around 1.5 metres or so around the stump and placed on top of the stump for the photo just to give an impression of the density of feeding signs in one small space.

Some of the spruce cones  have probably also been eaten by another species after the squirrels! Cones which have been fed on by squirrels alone have frayed ends where the scales have been removed. Wood mouse (Apodemus sylvaticus) will often feed on the cone after the squirrel, removing ragged and frayed ends and removing the tip of the base of the cone leaving a rounded base. The mice often move the cones to a more concealed place to feed on them.

Encouraged by the abundance of squirrel feeding signs, my attention changed from looking at the ground to looking into the canopy for squirrel dreys (their nests). Dreys are constructed from twigs and leaves and are almost spherical (or flattened to be wider than tall). They are usually around 25 to 50 cm in diameter (football size and larger) and normally found against the trunk of the tree (held up from where a branch leaves the trunk) from around 6 metres above ground upwards, though they can also be at a fork in branches.

The darker object is approximately football sized and is a squirrel (Sciurus sp.) drey. Seen in the grounds of Haddo House

The squirrel (Sciurus sp.) drey is the darker object behind many living branches and twigs in the forefront. Seen in the grounds of Haddo House

Crow and magpie nests can be superficially similar in appearance but tend to be found further from the trunk and are usually made of dead twigs without leaves.

A squirrel may use three, four or occasionally more dreys in their territory. Reds and greys are both also known to use more open saucer like dreys during the summer as resting places. I could not decide if another structure that I saw in the woodland was one of those or just an old drey which had started as a spherical form and fallen apart.

Red squirrel (Sciurus vulgaris) and grey squirrel (Sciurus carolinensis) feeding signs cannot be told apart and there are no obvious and reliable differences in the appearance of their dreys to tell them apart. Both species may even use the same drey at different times!

Unfortunately the strong wind at the time of the visit made detecting squirrels themselves difficult and survey guidance suggests that they are less active in those conditions anyway. I will take the word of the road signs on the drive and presume that I was looking at the field signs of red squirrels.

Saving Scotland's Red Squirrels is an award winning partnership project led by the Scottish Wildlife Trust and includes Scottish Natural Heritage, Forestry Commission Scotland, Scottish Land and Estates and the Red Squirrel Survival Trust. It is directed at conserving our native red squirrel and managing the grey squirrels which threaten the reds through competition and disease. SSRS welcome records of sightings of both species to help target efforts where they can make the greatest difference.

9 May 2015

Water Voles - signs and tracks

A Scottish water vole at Glen Callater
The Water Vole (Arvicola terrestris) is a herbivorous rodent that inhabits the banks of small running waters. You usually do not see the animal themselves but the signs of them are easy to spot and record! Sometimes you can hear them 'plop' into the water as you approach. They are not so common as they used to be due to habitat loss and predation by mink.

In Scotland, there should be no need for a licence to carry out a basic survey for water voles providing that you take reasonable precaution to avoid intentionally or recklessly disturbing these animals in their burrows, or possibly damaging their burrows (from the SNH webpage). Poking things into the holes (including your hand) could be considered disturbance.

Water voles are about 14-22 cm long and weigh 150-300 grams. They have a tapering tail like a rat. Water voles in Scotland appear to have a different genetic background to the ones in England and are also commonly much darker brown in colour, sometimes black. They dig burrows in soft banking along running water and they then collect rushes and grasses which they feed on, leaving a distinct 45 degree cut (very clean, not ragged). Like many small mammals they create latrines, i.e. they deposit their poop in specific places. The droppings are about the size and shape of a Tic Tac and green/dark green in colour. Usually they like waters less than 3m in width and 1m deep, but are also found in the highlands in very small watercourses. They like a steep bank that's easy to burrow into and a plentiful supply of soft rushes and sedges along the edge of the water. 

Signs of other small mammals can easily be confused with those of the water vole, namely the brown rat (of similar size so can be very confusing) and other voles (much smaller burrow entrances and poop). The most distinct sign there is a water vole around is the presence of their very green, Tic Tac sized/shaped poop!

Below are some signs to look out for if you find yourself in suitable habitat:

Note the surgically cut rushes, and some little poops too!

Holes are usually wider than they are high, about 4-8cm.
You may find clippings of food near the entrance.

Spot the droppings! The latrines are usually made on bare earth/mud.
You can read more about the water vole here!

12 April 2015

Froglife Amphibian Identification and Survey Training @ Crombie Country Park

Froglife is a charity for amphibians and reptiles covering the whole of the UK that has been going since 1989. On Sunday 12th April we attended one of their amphibian training days at Crombie Country Park in Angus taught by their Scottish Dragon Finder Project Officer James Stead. We have attended training before as part of our volunteer surveying commitment for National Amphibian and Reptile Recording Scheme (NARRS) but it's always good to get some refresher training now and then! Plus no one surely passes up the opportunity to see some amphibians up close?

The weather was cold but fairly still and sunny. Half the afternoon was theory with some quizzes on identification. The other half was pond dipping for amphibians in a couple of ponds on the estate including the Heron Pond which Froglife has been involved in restoring.

We saw frog spawn but saw no adult frogs. However we did catch quite a newts including this amazing male Palmate Newt (Lissotriton helveticus). He has textbook 'palmate' black feet, tail filament and accentuated colouring on his tummy and flanks. He also has a distinct crest along his back but it's hard to see - the cresting on his tail is easier to see as he moves.

9 April 2015

Investigating suspected badger sett

We had a request from Scottish Badgers to go out and see a suspected badger sett that had seemingly been dug out in the side of a road over night.

Upon arriving, multiple rabbit holes and runs were discovered right on the roadside, next to a field entrance. It appears on inspection that the suspected badger sett is in fact a Eurasian rabbit (Oryctolagus cuniculus) 'stop' - a breeding nest lined with fur from the rabbit doe's belly as insulation for the young rabbits - has been excavated by a predator. Fur from the nest lining is visible on the surface of the spoil. The hole narrows quickly to rabbit-sized tunnels.

Fur lining the nest of rabbit

Rabbit hole!
A red fox (Vulpes vulpes) had visited the scene, but it may originally have been dug out by a badger (Meles meles) given the quantity of spoil and size of stones moved. The slope is very steep and the spoil and several large stones were still on the road.

Red fox (Vulpes vulpes) track on top of spoil heap
The stones currently in the hole look like they have simply been put in there to get the sizeable stones off the busy road, no malice intended. Had we felt this was indeed a badger sett we would have escalated the matter as a possible wildlife crime. If rabbits are still using this hole (unlikely if their young have been taken) there is still plenty of room for them to get in and out.

So no badger sett but still a little mystery to solve - you never know what you will get when you go out! :)

Scottish Badgers rely on casual sightings from members of the public,
please report badger setts or roadkill you see on their website!


Welcome to Ecology+! I've been blogging about "other things" for over 6 years now, always kind of incorporating my ecological forays into those posts. This year however I've decided I need to ramp it up, as I really want to give something back after years of learning from volunteering opportunities with some of the best people in their field!

I am passionate about citizen science and want to inject a bit more 'science' into it but still keep people interested enough to keep recording.

I will feature outings we do and there will be photos and tips for identifying things in the field spanning a wide variety of animal/plant species and also habitats. No matter who you are, beginner or seasoned naturalist, I hope the blog will inspire you to go out and record! :)

See you soon again!