Mole Talpa europaea

Moles have evolved a subterranean lifestyle, spending almost their entire lives underground. Tthey dig extensive burrows systems, running from just below the surface to well over a metre down and covering several thousand square metres. Their strong, broad forefeet are used one at a time as shovels, while the mole braces itself against the tunnel walls with its hindfeet.

The tunnel system acts as a pit-fall trap, collecting earthworms and insect larvae, which are caught by the patrolling resident before they can escape. In the darkness of the tunnels, moles locate prey with their fleshy snout, which is exquisitely sensitive to touch. Smell too is probably used to find food at short distances, and sensory hairs on their face, forelimbs and tail also detect their surroundings.

Molehills – the spoils from excavations and tunnel maintenance -- are more an indication of activity than of the number of moles in an area, and the reasons for their appearance at some times rather than others may be to do with the abundance of food, the type of soil, weather conditions or the season. One idea is that when prey is plentiful, moles are inconspicuous because the existing tunnels provide sufficient food and there is little need to excavate new ones.  When food is scarce, or in cold weather when earthworms move to greater depths, tunnels are extended in search of food, turning up fresh molehills. At least one study1 however has shown the opposite effect: reducing earthworm numbers (by encouraging an acidic soil or by mowing or grazing) gives rise to fewer molehills.

Moles are frequently demonised but it is a moot point whether their reputation as pests is deserved, or whether the measures used to control them are justified. In gardens, lawns tend to show the brunt of moles’ handiwork and gardeners have waged a largely fruitless war to control their numbers. Neither kill-traps nor gassing (with phosphine) are always humane. The array of deterrents available, from the high-tech to the homespun, has mixed success: there is evidence that mechanical devices, which create vibrations through the soil, have no effect at all and no evidence that alliums and plants such as stinking hellebore Helleborus foetidus, crown imperial Fritillaria imperialis and castor oil plant Ricinus communis act as repellents either.

For most gardeners, moles pose little problem: soil heaps are easily cleared away, avoiding an invasion of weeds, and damage to growing plants is only temporary. Moreover, killing or live-trapping and removing moles is unlikely to be effective – other moles move in to empty territories and may exacerbate the situation by extending existing tunnels. Instead, the best policy is to put moles to good use. Most of the soil pushed up into molehills comes from beneath the seed bank so is free of weeds and their seeds,  and once the birds have been at it, is largely free of insect larvae. It is also soft and broken up so the textured soil of molehils is excellent for potting plants.

Appearance and activity Moles have short, black fur that can lie in either direction (allowing the mole to move easily forwards and backwards through tunnels). Very small eyes are hidden in the fur. At most times of the year, males and females forage for three 3-4 hour periods in each 24 hours, returning to their nest after each to rest for a similar length of time. In some instances, the activity patterns of neighbouring moles are synchronised. Moles are active throughout the year but molehills are most abundant in spring and autumn.

Status, population size and distribution Native, common and widespread. GB population 31,000,000. The population trend is unclear. There is an indication that numbers have declined since 2000. Moles are widespread on mainland Britain and the islands of Skye, Mull, Anglesey, Wight, Alderney and Jersey. They are absent from Ireland.



Shrews

Three species of shrew are found in gardens – common shrew, pygmy shrew and water shrew – and they are frequently the prey of domestic cats, accounting for about a fifth of mammals caught by the latter during the summer, although few are actually eaten because of an unpleasant-smelling secretion from shrews’ scent glands.  Despite their relative abundance, a licence is necessary to trap shrews, which can starve to death overnight if trapped.


Insectivores

David Wembridge, People’s Trust for Endangered Species                          reviewed by Steve Head



The insectivores are an ancient group of mammals, probably similar in lifestyle to the early mammal ancestors. They are all relatively small carnivores, specialising on hunting invertebrates, but the shrews in particular take life at the run, with a very fast metabolism.

Hedgehog Erinaceus europaeus

Hedgehogs can be familiar garden visitors and their distinctive spiny appearance means they are unlikely to be mistaken for anything else.  Hedgehogs are active mostly during the night and can be heard snuffling through undergrowth or snorting during courtship and fights. The hedgehog’s loose skin allows it to roll up into a tight ball, drawing in its head, tail and legs so that they are entirely concealed, and by pulling the spines upright so that they point outwards, hedgehogs can protect themselves against most natural enemies. They are vulnerable however to garden strimmers and care should be taken when cutting long grass, where hedgehogs tend to nest during the day in loosely constructed nests.
Urban hedgehogs prefer the invertebrate-rich gardens of semi-detached and terraced houses over those of detached houses and roadside verges, occupying home ranges of 10–30ha (25–75 acres). Home ranges overlap with each other and although they are not defended as exclusive territories, hedgehogs will have scuffles with other individuals if they meet (sometimes involving head-butting between males). In a typical night, males might travel 1–3km in open areas such as golf courses but probably travel shorter distances in built-up areas.

Recent work by Oxford University’s Wildlife Conservation Research Unit, funded by PTES and British Hedgehog Preservation Society, suggests that the minimum suburban area necessary to support a population of hedgehogs is 0.9–2.4km2 (90-240ha) of continuous habitat, highlighting the need for conservation to be on a neighbourhood-scale – ‘thinking over the garden fence’.  You can download the report here.

One project that is doing this is Hedgehog Street, run jointly by PTES and the British Hedgehog Preservation Society. It aims to connect up habitats by encouraging neighbours to make their gardens accessible to hedgehogs (leaving a small gap, 20 by 20cm, at the base of fences and walls) and to co-operate on hedgehog-friendly approaches to garden management. The project’s excellent website is available here, and is full of useful facts and ways to help urban hedgehogs.


Appearance and activity Hedgehogs have a short inconspicuous tail, small ears and surprisingly long legs, usually hidden under a ’skirt’ of long hairs. On their underside, they have coarse grey-brown fur. Bulky winter nests (hibernacula) are built in October and hedgehogs hibernate from about November through to March/April, remaining largely inactive. Occasionally, they will move between nest sites during the winter. During the rest of the year, they are active mostly at night or after heavy rainfall. Urban hedgehogs tend to be more active after midnight when the risk of encountering people or road traffic is less.

Between November and the end of March, when food is scarce, hedgehogs hibernate to conserve energy. Their heart rate falls from 190 to 20 beats per minute and their body temperature falls to just a few degrees Celsius. The exact timing of hibernation depends on the age and sex of individuals as well as the outside temperature. Leaving leaf piles or brushwood in the garden over winter provides good hibernation sites.

Diet They feed on soil invertebrates, such as earthworms and beetles, and the mown grass of garden lawns and recreation grounds can be an ideal foraging habitat. Their consumption of slugs and caterpillars, which together make up about a quarter of their prey, is particularly appreciated by gardeners. 


Status, population size and distribution Native; hedgehogs were made a priority species in the UK Biodiversity Action Plan in 2007. GB population in 1995 was estimated to be 1,500,000 but it is likely to have declined since then. A recent report by the British Trust for Ornithology, available here , found that five separate surveys between 1996 and 2010 showed declines in both urban and rural areas. PTES’ survey of gardens and urban green spaces, Living with Mammals, suggests that the population fell by a third between 2003 and 2012.  A recent summary of this ongoing survey by David Wembridge and Steve Langton is available here

Hedgehogs are found throughout the Britain and Ireland but are absent from some of the Scottish Islands.

Helping hedgehogs   Many people like to see hedgehogs and want to support them in their gardens.  In general, making sure that there are gaps in your and your neighbours' fences (see above) to let them forage over a large area is perhaps the most useful.  If you have a pond, make sure it is easy for hedgehogs (and other small animals) to climb out or they can drown.  Don't leave netting around in which they can become entangled.

Feeding hedgehogs Don't give them bread and milk!  Milk gives them spectacular diarrhoea.  They do appreciate meat based cat food, but be aware so do rats and next door's cat.  Juvenile hedgehogs in the autumn may not have gained enough body fat to take them through the winter, they need to weigh 500g or more.   If you find a distressed juvenile, you can find feeding and support instructions on the RSPCA leaflet Caring for autumn juvenile hedgehogs.


Common shrew Sorex araneus

Common shrews are one of the most abundant mammals in Britain. They average 6-8cm in body length, and weigh up to 15gm. They use a network of runways through long vegetation, finding prey, such as earthworms, insect larvae and slugs, by probing and sniffing the soil with their snout. Prey can be located up to 12cm below the surface. In urban environments, they are found in the hedge bottoms and compost heaps of gardens, on road verges and grassy banks, and are frequently found on derelict wasteland. More widely, they are most abundant in thick grass, hedgerows and deciduous woodland. They make nests under logs and grass tussocks or in the burrows of other species.

Although rarely seen, they can be heard, producing soft, high-pitched twitters while they forage and just-audible raucous shrieks and ‘churls’ in aggressive encounters with other shrews.

Appearance and activity Shrews have a distinctive narrow, pointed snout. Common shrews have brown (never black) fur on their back, with a paler, grey underside. The tails of adults tend to be bare and are often scarred. They are active during the day and night, although are most active during darkness. One- to two-hour bursts of activity are followed by periods of rest, usually in the nest but sometimes ‘cat-napping’ elsewhere.

Diet   Earthworms, insect larvae, beetles, spiders, slugs and carrion

Status, population size and distribution Native, widespread and common.  GB population 41,700,000. The population trend is unknown. They are found throughout Britain but are absent from Ireland, Shetland, Orkney, the Outer Hebrides, the Isle of Man, Scilly Isles and Channel Islands.


Pygmy shrew Sorex minutus

Pygmy shrews are one of Britain’s smallest mammals, with a body length of 4 to 6.5cm. During the summer, when they breed, they can be up to 10 g in weight, but are typically 3.5-7 g, between that of a one and two pence coin, and only pipistrelle bats weigh as little. They have grey-brown fur, paler than that of the common shrew, and a long, slightly hairy tail. Pygmy shrews are active both day and night, but rest frequently. They use a network of runways like common shrews but do not dig for prey beneath the soil surface and never eat earthworms, which are probably too large to tackle.

Appearance and activity They are paler than the common shrew, with a long slightly hairy tail.

Diet Pygmy shrews consume one and a quarter times their body weight each day in order to maintain their energetic metabolisms, and beetles, spiders and woodlice make up most of their diet.

Status, population size and distribution Native and common. Population trend is unknown.   They are one of two species of shrew  found in Ireland; the other – the greater white-toothed shrew – was reported there for the first time in 2008.


Water shrew Neomys fodiens

Water shrews are found by clean clear streams and rivers, and also in lakes and wetlands.  They have dark brown fur and white-tufted ears than can be closed in the water.  Their tail has a fringe of stiff hairs that acts as a rudder, and they paddle using their hind feet, swimming and hunting to 70cm depth.

Diet Fresh water crustaceans such as amphipods ("water shrimp"), small snails, insect larvae and small fish and frogs.

Status, population size and distribution  GB population is about 1,900,000, possibly declining.  They are commonest in England, and absent from Ireland and most islands.




Reference

1.   Edwards, G.R., Crawley, M.J., Heard, M.S. (1999) Factors influencing molehill distribution in grassland:
      implications for controlling the damage caused by molehills. Journal of Applied Ecology 36 (3): 434-442
Garden shrews. 

Above left:    Common shrew (dead)
Above right:  Pygmy shrew

Right:           Water shrew (dead)

If you can provide photos of living shrews please contact us!
Insectivores

David Wembridge, People’s Trust for Endangered Species          Reviewed by Steve Head


The insectivores are an ancient group of mammals, probably similar in lifestyle to the early mammal ancestors. They are all relatively small carnivores, specialising on hunting invertebrates, but the shrews in particular take life at the run, with a very fast metabolism.

Hedgehog Erinaceus europaeus

Hedgehogs can be familiar garden visitors and their distinctive spiny appearance means they are unlikely to be mistaken for anything else.  Hedgehogs are active mostly during the night and can be heard snuffling through undergrowth or snorting during courtship and fights. The hedgehog’s loose skin allows it to roll up into a tight ball, drawing in its head, tail and legs so that they are entirely concealed, and by pulling the spines upright so that they point outwards, hedgehogs can protect themselves against most natural enemies. They are vulnerable however to garden strimmers and care should be taken when cutting long grass, where hedgehogs tend to nest during the day in loosely constructed nests.

Recent work by Oxford University’s Wildlife Conservation Research Unit, funded by PTES and British Hedgehog Preservation Society, suggests that the minimum suburban area necessary to support a population of hedgehogs is 0.9–2.4km2 (90-240ha) of continuous habitat, highlighting the neeUrban hedgehogs prefer the invertebrate-rich gardens of semi-detached and terraced houses over those of detached houses and roadside verges, occupying home ranges of 10–30ha (25–75 acres). Home ranges overlap with each other and although they are not defended as exclusive territories, hedgehogs will have scuffles with other individuals if they meet (sometimes involving head-butting between males). In a typical night, males might travel 1–3km in open areas such as golf courses but probably travel shorter distances in built-up areas.
d for conservation to be on a neighbourhood-scale – ‘thinking over the garden fence’.  You can download the report here.

One project that is doing this is Hedgehog Street, run jointly by PTES and the British Hedgehog Preservation Society. It aims to connect up habitats by encouraging neighbours to make their gardens accessible to hedgehogs (leaving a small gap, 20 by 20cm, at the base of fences and walls) and to co-operate on hedgehog-friendly approaches to garden management. The project’s excellent website is available here, and is full of useful facts and ways to help urban hedgehogs.


Appearance and activity Hedgehogs have a short inconspicuous tail, small ears and surprisingly long legs, usually hidden under a ’skirt’ of long hairs. On their underside, they have coarse grey-brown fur. Bulky winter nests (hibernacula) are built in October and hedgehogs hibernate from about November through to March/April, remaining largely inactive. Occasionally, they will move between nest sites during the winter. During the rest of the year, they are active mostly at night or after heavy rainfall. Urban hedgehogs tend to be more active after midnight when the risk of encountering people or road traffic is less.

Between November and the end of March, when food is scarce, hedgehogs hibernate to conserve energy. Their heart rate falls from 190 to 20 beats per minute and their body temperature falls to just a few degrees Celsius. The exact timing of hibernation depends on the age and sex of individuals as well as the outside temperature. Leaving leaf piles or brushwood in the garden over winter provides good hibernation sites.

Diet They feed on soil invertebrates, such as earthworms and beetles, and the mown grass of garden lawns and recreation grounds can be an ideal foraging habitat. Their consumption of slugs and caterpillars, which together make up about a quarter of their prey, is particularly appreciated by gardeners. 


Status, population size and distribution Native; hedgehogs were made a priority species in the UK Biodiversity Action Plan in 2007. GB population in 1995 was estimated to be 1,500,000 but it is likely to have declined since then. A recent report by the British Trust for Ornithology, available here , found that five separate surveys between 1996 and 2010 showed declines in both urban and rural areas. PTES’ survey of gardens and urban green spaces, Living with Mammals, suggests that the population fell by a third between 2003 and 2012.  A recent summary of this ongoing survey by David Wembridge and Steve Langton is available here

Hedgehogs are found throughout the Britain and Ireland but are absent from some of the Scottish Islands.

Helping hedgehogs   Many people like to see hedgehogs and want to support them in their gardens.  In general, making sure that there are gaps in your and your neighbours' fences (see above) to let them forage over a large area is perhaps the most useful.  If you have a pond, make sure it is easy for hedgehogs (and other small animals) to climb out or they can drown.  Don't leave netting around in which they can become entangled.

Feeding hedgehogs Don't give them bread and milk!  Milk gives them spectacular diarrhoea.  They do appreciate meat based cat food, but be aware so do rats and next door's cat.  Juvenile hedgehogs in the autumn may not have gained enough body fat to take them through the winter, they need to weigh 500g or more.   If you find a distressed juvenile, you can find feeding and support instructions on the RSPCA leaflet Caring for autumn juvenile hedgehogs.


Mole Talpa europaea

Moles have evolved a subterranean lifestyle, spending almost their entire lives underground. Tthey dig extensive burrows systems, running from just below the surface to well over a metre down and covering several thousand square metres. Their strong, broad forefeet are used one at a time as shovels, while the mole braces itself against the tunnel walls with its hindfeet.

The tunnel system acts as a pit-fall trap, collecting earthworms and insect larvae, which are caught by the patrolling resident before they can escape. In the darkness of the tunnels, moles locate prey with their fleshy snout, which is exquisitely sensitive to touch. Smell too is probably used to find food at short distances, and sensory hairs on their face, forelimbs and tail also detect their surroundings.

Molehills – the spoils from excavations and tunnel maintenance -- are more an indication of activity than of the number of moles in an area, and the reasons for their appearance at some times rather than others may be to do with the abundance of food, the type of soil, weather conditions or the season. One idea is that when prey is plentiful, moles are inconspicuous because the existing tunnels provide sufficient food and there is little need to excavate new ones.  When food is scarce, or in cold weather when earthworms move to greater depths, tunnels are extended in search of food, turning up fresh molehills. At least one study1 however has shown the opposite effect: reducing earthworm numbers (by encouraging an acidic soil or by mowing or grazing) gives rise to fewer molehills.

Moles are frequently demonised but it is a moot point whether their reputation as pests is deserved, or whether the measures used to control them are justified. In gardens, lawns tend to show the brunt of moles’ handiwork and gardeners have waged a largely fruitless war to control their numbers. Neither kill-traps nor gassing (with phosphine) are always humane. The array of deterrents available, from the high-tech to the homespun, has mixed success: there is evidence that mechanical devices, which create vibrations through the soil, have no effect at all and no evidence that alliums and plants such as stinking hellebore Helleborus foetidus, crown imperial Fritillaria imperialis and castor oil plant Ricinus communis act as repellents either.

For most gardeners, moles pose little problem: soil heaps are easily cleared away, avoiding an invasion of weeds, and damage to growing plants is only temporary. Moreover, killing or live-trapping and removing moles is unlikely to be effective – other moles move in to empty territories and may exacerbate the situation by extending existing tunnels. Instead, the best policy is to put moles to good use. Most of the soil pushed up into molehills comes from beneath the seed bank so is free of weeds and their seeds,  and once the birds have been at it, is largely free of insect larvae. It is also soft and broken up so the textured soil of molehils is excellent for potting plants.

Appearance and activity Moles have short, black fur that can lie in either direction (allowing the mole to move easily forwards and backwards through tunnels). Very small eyes are hidden in the fur. At most times of the year, males and females forage for three 3-4 hour periods in each 24 hours, returning to their nest after each to rest for a similar length of time. In some instances, the activity patterns of neighbouring moles are synchronised. Moles are active throughout the year but molehills are most abundant in spring and autumn.

Status, population size and distribution Native, common and widespread. GB population 31,000,000. The population trend is unclear. There is an indication that numbers have declined since 2000. Moles are widespread on mainland Britain and the islands of Skye, Mull, Anglesey, Wight, Alderney and Jersey. They are absent from Ireland.



Shrews

Three species of shrew are found in gardens – common shrew, pygmy shrew and water shrew – and they are frequently the prey of domestic cats, accounting for about a fifth of mammals caught by the latter during the summer, although few are actually eaten because of an unpleasant-smelling secretion from shrews’ scent glands.  Despite their relative abundance, a licence is necessary to trap shrews, which can starve to death overnight if trapped.


Garden shrews. 

Above left:    Common shrew (dead)
Above right:  Pygmy shrew

Right:           Water shrew (dead)

If you can provide photos of living shrews please contact us!
Common shrew Sorex araneus

Common shrews are one of the most abundant mammals in Britain. They average 6-8cm in body length, and weigh up to 15gm. They use a network of runways through long vegetation, finding prey, such as earthworms, insect larvae and slugs, by probing and sniffing the soil with their snout. Prey can be located up to 12cm below the surface. In urban environments, they are found in the hedge bottoms and compost heaps of gardens, on road verges and grassy banks, and are frequently found on derelict wasteland. More widely, they are most abundant in thick grass, hedgerows and deciduous woodland. They make nests under logs and grass tussocks or in the burrows of other species.

Although rarely seen, they can be heard, producing soft, high-pitched twitters while they forage and just-audible raucous shrieks and ‘churls’ in aggressive encounters with other shrews.

Appearance and activity Shrews have a distinctive narrow, pointed snout. Common shrews have brown (never black) fur on their back, with a paler, grey underside. The tails of adults tend to be bare and are often scarred. They are active during the day and night, although are most active during darkness. One- to two-hour bursts of activity are followed by periods of rest, usually in the nest but sometimes ‘cat-napping’ elsewhere.

Diet   Earthworms, insect larvae, beetles, spiders, slugs and carrion

Status, population size and distribution Native, widespread and common.  GB population 41,700,000. The population trend is unknown. They are found throughout Britain but are absent from Ireland, Shetland, Orkney, the Outer Hebrides, the Isle of Man, Scilly Isles and Channel Islands.


Pygmy shrew Sorex minutus

Pygmy shrews are one of Britain’s smallest mammals, with a body length of 4 to 6.5cm. During the summer, when they breed, they can be up to 10 g in weight, but are typically 3.5-7 g, between that of a one and two pence coin, and only pipistrelle bats weigh as little. They have grey-brown fur, paler than that of the common shrew, and a long, slightly hairy tail. Pygmy shrews are active both day and night, but rest frequently. They use a network of runways like common shrews but do not dig for prey beneath the soil surface and never eat earthworms, which are probably too large to tackle.

Appearance and activity They are paler than the common shrew, with a long slightly hairy tail.

Diet Pygmy shrews consume one and a quarter times their body weight each day in order to maintain their energetic metabolisms, and beetles, spiders and woodlice make up most of their diet.

Status, population size and distribution Native and common. Population trend is unknown.   They are one of two species of shrew  found in Ireland; the other – the greater white-toothed shrew – was reported there for the first time in 2008.


Water shrew Neomys fodiens

Water shrews are found by clean clear streams and rivers, and also in lakes and wetlands.  They have dark brown fur and white-tufted ears than can be closed in the water.  Their tail has a fringe of stiff hairs that acts as a rudder, and they paddle using their hind feet, swimming and hunting to 70cm depth.

Diet Fresh water crustaceans such as amphipods ("water shrimp"), small snails, insect larvae and small fish and frogs.

Status, population size and distribution  GB population is about 1,900,000, possibly declining.  They are commonest in England, and absent from Ireland and most islands.




Reference

1.   Edwards, G.R., Crawley, M.J., Heard, M.S. (1999) Factors influencing molehill
      distribution in grassland: implications for controlling the damage caused by
      molehills. Journal of Applied Ecology 36 (3): 434-442
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