Wildlife at Aigas
We are very fortunate to have a superb array of wildlife right here on the property. This page is dedicated to some of the stars of our woods and waters: our beavers, pine martens, badgers and red squirrels.
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The Aigas Beaver Project
Please be aware that beavers are only visible at Aigas during the long summer days of May until 1st September. Outside this period you will see lots of beaver habitat, including lodges, dams, canals and felled trees, but are unlikely to see the animals themselves.
On the 14th April 2006 we started a beaver demonstration project. After a lot of research and consultations with experts we released a pair of beavers into a large 200 acre enclosure here at Aigas. These were to be the first beavers in the Highlands for 450 years. The habitat is ideal for beavers, with a large freshwater loch and plenty of food in the form of their favourite trees (birch, willow and rowan) in the surrounding deciduous woodland and and vegetation (water lilies and horsetails) in the loch.
As a member of the Scottish Beaver Network, this project’s aims are not to re-introduce beavers (although we hope that does happen in the future), but to demonstrate to the public and authorities that beavers are good for Scotland’s natural heritage. This will be achieved through:
1. Education – both adults and children are educated about the natural history and ecology of
beavers on their visits to Aigas.
2. Monitoring – recording the developments of the beaver in their semi-natural environment.
3. Accessibility – visitors to Aigas get the opportunity to watch beavers in their natural
environment with a qualified ranger.
4. Measuring biodiversity – we expect the biodiversity to increase as beavers are keystone
species (they create habitats for other species).
Since the beavers were released into the Aigas loch, we have seen them build their own lodges and dams, fell trees, feed on willow, birch and water lilies and have kits over the successive years! It has been very interesting to follow their behaviour in an accessible wild-like situation. We do not feed the beavers, we leave them to their own devices within their large enclosure.
Over the years we have had hundreds of visitors (including the BBC) viewing and photographing these unique beavers in their ‘wild’ surroundings. It is not only beavers that are seen during our hide visits, but also otters and ospreys which are frequent visitors to our loch.
Beavers are the second largest rodents in world, weighing up 38 kg and growing up to 4 feet long! There are two species of Beaver; the North American Beaver Castor canadensis found in Canada, the USA and northern Mexico and the European Beaver Castor fiber found across Europe to China and Mongolia.
Beavers are nocturnal and are very well adapted to their amphibious lifestyle, their eyes, ears and nostrils are high up on their head so that they can use all of their senses without exposing too much of their body when swimming. They have special muscles in their nostrils and ears to prevent water from entering and the eyes have a third, clear eyelid called the nictitating membrane to allow for seeing underwater. They are also in possession of a large tail which is used to store fat and steer themselves through the water, they have a streamlined torpedo-shaped body, webbed hind feet and a double-layered fur with outer guard hairs for waterproofing and a dense underfur for warmth.
Beavers are highly social animals, living in family groups, in and around freshwater. They are a very important part of the aquatic environment and are known as “keystone species” because of their benefits to other species and the habitats they create.
Beavers love water they feel safe in the aquatic environment. Any sign of danger, they will slap their tail and disappear under water. They can swim at an amazing 2.1 metres per second and can stay underwater for 15 minutes! Their main predators are land based mammals such as the Brown Bear (Ursus arctos), Wolf (Canis lupus), Lynx (Lynx lynx), Wolverine (Gulo gulo) and the Fox (Vulpes vulpes). In Scotland, most of these are now extinct, but retreating to the water for safety is instinctive when they feel threaten.
Beavers are vegetarian (they do not eat fish). Their huge incisors (two front teeth) and molars are used to chew vegetable matter. They have been recorded to eat 80 species of tree and nearly 150 species of herbaceous and aquatic plants. Beavers do not eat conifers, but the leaves, bark and cambium layer of deciduous trees. Their favourite food is aspen, willow, birch and water lily. As a result their diet is highly seasonal, in spring and summer the diet is dominated by terrestrial and aquatic herbaceous plants while in autumn and winter their food is
mainly bark from trees.
Beavers are famous for felling trees. The reason they like to fell trees is not only for building material, but also for food, so that they can access parts of the tree that are normally out of reach. The record diameter for a beaver felled tree is 106cm! They fell trees near the water's edge and towards the water so they can float them easily to their lodge or dam.
Importantly the felled tree is not dead. Willow branches will re-root & the stumps of the felled trees coppice well. This extends the life of the tree and the new shoots provide new habitats and food for many other species.
Beavers sometimes build dams to control the water level of a particular area. Running water stimulates them and they will build a dam where the sound of water is the loudest. Dams are constructed out of sticks and are made watertight with mud.
Beavers may also extend their loch or create new lochs so that they can access new food sources in safety - beavers are hard-wired to stay in water away from predators.
Beavers live in lodges which are constructed in a similar way to dams (sticks and mud). Beavers build two types of lodge; bank lodge and brook lodge. Bank lodges are dug into the embankment of a river or a loch whereas brook lodges are built upwards, are conical in shape and often surrounded by water. The lodges have a series of tunnels and chambers with the entrance underwater and protected by sticks. Lodges can be built within 20 days. Imagine building your house that quickly!
Beavers are “keystone species”. This means they are very important and essential to the environment. There are endless reasons why beavers are so important to ecosystems, but the main reason is that they promote biodiversity by encouraging many species of plants, invertebrates and mammals to thrive. They also create wetland habitats, standing deadwood, aquatic deadwood and filter the water. The ponds they establish create new opportunities for all
sorts of aquatic plants, which in turn are food for aquatic and terrestrial invertebrates, in some studies the number of dragonfly species has trebled. This attracts fish and amphibians, which in turn will attract otters, ospreys, white-tailed eagles, and so the list goes on.
Beavers also open up forest canopies creating enough natural disturbance to promote regeneration and allow understory plants to flourish. Beavers really are eco-system engineers!
The pine marten is a carnivore, meaning that they have sharp teeth and claws to help them hunt and catch other animals. The pine marten belongs to the family “mustelidae” and has a scent gland underneath its tail which it uses to mark its territory. It also marks its territory using a scent gland on its stomach and by leaving scats (droppings) on raised areas around its territory. Male pine martens are called “dogs” and females are known as “bitches”.
The Pine Marten Den
Pine marten’s live in a den, where they will use old bird’s nests, trunks of rotten trees, rocky crevices and old buildings. They are called Pine martens because they used to be found only in mature coniferous forests like the Caledonian Pine Forest. However, they are adaptable creatures and can be found many different areas including the mixed woodlands around Aigas.
The Pine Marten Diet
The pine marten will eat a wide selection of foods. Much of its diet consists of small mammals, especially field voles, but they will also eat small birds, frogs, beetles and worms. Birds eggs are often taken and in the summer and autumn, berries, nuts and fungi make up an important part of their diet.
The Pine Marten Family
Pine martens are not as sociable as badgers and spend most of their time living alone or in pairs. The young are born in the spring and are called kits. They usually have 1-3 kits and these are blind when they are born. The male does not take any part in rearing the kits, all the care is undertaken by the female. The young are fully independent by the time they are 6 months old and leave home to establish their own territories. The pine marten is not as territorial as the badger and the territories of several animals often overlap.
The pine marten was widespread across Britain until 1800 when its numbers began to decline. The population had reached its lowest numbers by the beginning of the 1900s. One reason for this decline was the loss of their woodland habitat. The pine martens were also hunted for their fur and many were trapped or poisoned. With growing numbers of cars on our roads, more and
more were run over. Today, you only really find pine martens in the north and west of Scotland but their range is growing! The pine marten is now protected by the law and it is illegal to deliberately kill them. This is good news for the pine marten as this, as well as an increase in forest cover, is helping their numbers to increase!
The badger is a medium-sized land mammal. It is a carnivore like the fox and the wildcat. Carnivores are especially adapted to eat meat – they have very sharp teeth for biting and tearing and often have sharp claws for catching and holding prey. The badger belongs to the family “mustelidae” – this is the weasel family and members of this family are called mustelids. Other members of this family are weasels, stoats, pine martens, polecats and otters. The main features of this family are that they have 5-toed feet with claws and a big scent gland at the base of their tails. Smell is very important to them and the scent glands are used to mark territories and sometimes even other animals. Male badgers are called “boars” whilst females are called “sows”.
The Badger Sett
A group of badgers is called a cete (from the French word for city – cite) and the badgers house is called a sett. The sett is a hole under ground which usually has several entrances. Some setts have been in use for decades or perhaps even centuries. They usually have several chambers including a sleeping chamber or bedroom. Grass and bracken is often collected in order to provide bedding. The badger keeps the sett extremely clean with regular cleaning sessions and piles of old bedding can often be found outside the entrance to active setts.
The Badger Diet
Although badgers are carnivores they have an omnivorous diet and flattened molars for grinding vegetation — this means that they will eat almost anything! Earthworms are their main food source, but they also eat beetles, fruit and berries, small mammals, slugs and bulbs. They spend as much as 10 hours every day foraging for their food over an area as big as 50 hectares – this is the equivalent of about 70 football pitches! They often follow the same routes every night giving rise to well-trodden “badger paths”.
The Badger Family
Badgers are social animals—they like company! They usually breed once a year and have a litter of 1 to 3 cubs. The cubs are born in March and stay safely underground for the first 7-8 weeks. After this time their mother starts to bring the cubs above ground for lessons on how to find food! The cubs are completely independent by the time they reach 4 months of age but may stay with the family for 2 years or more.
Badgers have been in the UK for many thousands of years and have been hunted throughout this time. They were hunted mainly for their fur which was used to make clothes, sporrans and shaving brushes, but they have also been hunted for sport. Badgers would be dug out of their setts and captured so that they could be forced to fight against dogs. Both of these practices still occur in some places and they have resulted in many badgers being killed. In addition, thousands of badgers are killed every year on our roads. As people have learnt more about wildlife and conservation, persecution of badgers has reduced. Gates in fences and tunnels under roads have also helped to reduce badger deaths on roads. At this time, the badger population is doing well with approximately 350,000 badgers in the UK. Although this seems like a large number, because they are mostly nocturnal, very few people have actually seen badgers.
The red squirrel is a small arboreal rodent that belongs to the family ‘Sciuridae.’ They have sharp, curved claws and strong hind legs to help them climb and jump between trees and they also have the ability to swim. It is the only squirrel that is native to the United Kingdom, but its range has become restricted over the years. It can be found in North Scotland and it is a frequent visitor to Aigas.
The Red Squirrel Drey
The red squirrel inhabits both coniferous forests and broadleaf woodlands, but they are better adapted to live in pine forests. They build nests (dreys) out of twigs in the fork of branches or close to the tree trunk. Dreys are 25-30cm in diameter and are lined with moss, leaves, grass or bark. They are often built high up in the tree canopy, usually about 6m or more above the ground.
The Red Squirrel Diet
Their diet consists of fungi, berries, nuts, bird eggs and sometimes even small birds! However, their favourite food is pine cone seeds, especially Scots Pine, but they also eat Larch and Spruce cones. They bite off each flake of a cone to obtain the seeds underneath. You can often find evidence of gnawed pine cones along a forest floor.
Red squirrels do no hibernate, but they do gain extra weight over the autumn and store food in preparation for the winter months.
The Red Squirrel Family
Red squirrels are solitary animals, but they do come together to mate during February and March and sometimes later on in the year during June and July. The young are born after 45-48 days and are known as kits. The female usually has between 2-3 kits, but litters up to 6 individuals have been known. The female is extremely territorial over her brood and brings them up alone. For the first 3 weeks the kits are blind and hairless, but after 7 weeks they begin to leave the drey and by 8-10 weeks they are weaned.
Red Squirrels first arrived in the British Isles over 10,000 years ago. In more recent times their population has declined because of deforestation, the introduction of the grey squirrel and disease (squirrel poxvirus). There are approximately 120,000 individuals in the United Kingdom, with 85% of population found in Scotland. They can also be found on a few sites in England and Wales. Over the years many conservation groups have set up programmes to protect the red squirrel.