Etruscan Shrew Profile
The tiny Etruscan shrew is arguably the smallest of all terrestrial mammals in the world, with only one other mammal, the bumblebee bat, being smaller in length.
These minute shrews have a large distribution that includes Europe, North Africa and Asia. Like most shrews they have sharp, pointed noses with prominent whiskers and have short legs and slender bodies.
They are covered in soft, pale brown fur with grey underparts and their tails are long and covered in short fur. Compared to other shrew species, Etruscan shrews have relatively large ears and their hind limbs are comparatively short compared to their front legs.
Etruscan ShrewFacts Overview
|Warm and damp forests and grasslands
|Southern Europe, North Africa and Asia
|2 years in the wild
|Average 4cm in length excluding tail. Tail around 2.5cm
|Average 2 grams
|Tiny shrew, covered with grey to brown, soft fur. Hind legs are relatively small and ears relatively large
|Mainly Insectivorous, feeding on small insects. May also feed on worms and small lizards
|Owls and other nocturnal predators
|Not recorded but can cover short distances very quickly
|No. of Species:
Etruscan shrews are found in a variety of habitats, but show a preference for damp and warm forests with plenty of ground cover. They avoid overly cultivated areas, but will readily inhabit abandoned or less intensively farmed areas.
These shrews are often found near boulders, stone walls and hills, where hiding places are easier to find. They will avoid particularly dense forest and arid areas, preferring the boundary between forest and grassland or river banks.
Etruscan shrews do not generally dig their own burrows, rather selecting rock crevices, or tunnels dug by other animals to shelter or nest in.
Etruscan shrews are not great climbers, so spend almost all their time on the ground – but they are excellent swimmers. They rely mainly on their sense of smell and touch to navigate their home range, as their vision is quite poor.
Like most shrew species, the Etruscan shrew is a nocturnal insectivore. They are voracious hunters and due to their tiny size and lifestyle, they need to eat over 5 times their body weight in insects every day.
Like most shrews they are generally solitary and can be fiercely territorial. Outside of the breeding season, Etruscan shrews will warm intruders off their territory by making rapid chirping sounds and darts towards the intruder. If this fails, shrews will often fight one another and it is not uncommon for the loser to be killed in the battle.
Etruscan shrews breed throughout the year, but most breeding occurs when environmental conditions, such as weather, and food availability are ideal.
As they are so minute and are most active during darkness, studying Etruscan shrews in the wild can be difficult. They can also be very challenging to keep in captivity as they require almost constant feeding and steady climatic conditions.
Interesting Etruscan Shrew Facts
1. They are the smallest terrestrial mammal in the world
Weighing less than 1.8 grams and measuring 4cm in length, Etruscan shrews are smaller than many insect species.
2. They can eat prey heavier than themselves
Despite their small size, Etruscan shrews are able to kill and eat prey almost as large as themselves. They are efficient hunters, usually killing their target instantly with a single bite to the back of the head.
Although insects such as ants form much of their diet, Etruscan shrews will also eat large crickets and small lizards, some of which may be even heavier than the shrew itself. Due to their high food demands, Etruscan shrews help control insect populations.
They are also prey themselves to many nocturnal predators, especially owls. Weasels and other small carnivores will also feed on these fast-moving shrews.
3. They have huge appetites
They spend the day alternating between frantic activity and resting, although they seldom rest for longer than 30 minutes.
Etruscan shrews therefore rarely sleep for more than a few minutes at a time and cannot survive without a meal for more than a few hours. Due to the amount of energy they burn off from constant activity, they have to eat 5 times their own body weight in insects every day.
Due to their high-paced lifestyle, Etruscan shrews usually live for only a year or two in the wild.
4. In very cold weather or when food is scarce, Etruscan shrews can slow down their bodily processes
Due to their small size, Etruscan shrews do not tolerate rapid change in temperatures and could easily freeze to death in cold spells if not for their high metabolic rate which keeps their body temperature high.
For survival, they can enter a state of torpor, which means that they can lower their body temperature so as to reduce the amount of energy they need to survive. 2
5. Families walk in a line, which resembles a train
Due to their poor eyesight and to not risk getting lost, baby shrews hold on to their mothers’ and each other’s tails, forming a train as they search for food.
6. Baby shrews are called shrewlets
Although they are commonly called pups, baby shrews are more correctly called shrewlets.
7. Shrewlets can weigh as little as 0.2 grams
The breeding season is the only time these tiny mammals tolerate one another and males may help build nests before the female gives birth. Etruscan shrews usually produce around 4 offspring, who are completely helpless when born and may weigh as little as 0.2 grams.
Within a month, the babies already accompany their mother when searching for food, forming a train by holding on to one another’s tails. After another month the juveniles leave their mother and become fully independent.
8. Their heart beats over 1,000 times a minute
In order to maintain their high activity levels, an Etruscan shrew heart can beat around 1,200 times every minute, keeping blood and oxygen pumping around the body.
These shrews can also release a very large amount of oxygen from their blood which allows them to be almost constantly active. 3
9. They have extremely sensitive whiskers
Their whiskers play a crucial role when hunting and moving through the undergrowth as these appendages are particularly sensitive; providing the ability to distinguish prey from non-prey as well as determining suitable hiding spots from a single touch.
Their whiskers can even pick up vibrations from air currents, warning the shrew of potential danger and they can detect the spikes on cricket legs, which are then ripped off so the cricket cannot easily escape. These adaptations as well as particularly sharp, pointed teeth are highly important to an animal with such high food requirements.
10. Shrews release a foul odour to deter predators
Like other shrew species, Etruscan shrews emit an unpleasant odour that mammalian predators find very unpleasant. 4
11. Their teeth are particularly white
Etruscan shrews are members of the white-toothed shrew family, which have white teeth compared to the red-toothed shrews which have red teeth as a result of iron pigments.
12. There are well over 300 species of shrew worldwide
Scientists estimate that there are many millions or even billions of individual shrews across the world.
13. Etruscan shrews have helped scientists understand how the brain works
Due to their tiny size, Etruscan shrew brains are easily scanned and give clues to how mammal brains work.
14. They are not closely related to mice
Although they look superficially similar to mice, shrews are in fact more closely related to moles and hedgehogs. 5
Etruscan Shrew Fact-File Summary
Fact Sources & References
- “Etruscan shrew”, Thai National Parks.
- Andleeb Batool (2019), “Shrews from Moist Temperate Forests of Azad Jammu and Kashmir”, Journal of Bioresource Management.
- “Etruscan Shrew”, Science Direct.
- Maria Teresa Galán-Puchades (2021), “First Data on the Helminth Community of the Smallest Living Mammal on Earth, the Etruscan Pygmy Shrew, Suncus etruscus”, MDPI.
- Melissa Berg (2016), “A miniscule model for research”, labanimal.