Osprey monitoring

Last night the ranger team went out with artist and member of the Scottish Raptor Study Group Keith Brockie to help tag osprey chicks near Lochan Oisinneach Mor. 

This beautiful area provides perfect habitat for ospreys, which breed successfully in wooded landscapes with access to freshwater lochs and rivers. Typically ospreys will build a large, dense nest of sticks high in the tops of Scots Pine or other coniferous trees (although some use artificial platforms and even electricity pylons). They typically lay a clutch of three eggs from mid-April to mid-May, with young birds fledging between mid-July and August. 

In the past, ospreys bred throughout the British Isles, but were persecuted to extinction by the early 20^th century. Following successful reintroduction at Loch Garten, Scotland has become a stronghold for a new osprey population and there are around 40 pairs of osprey in Perthshire. A possible sighting of new chicks at the nest near Lochan Oisinneach Mor brought us out to assist with the challenging task of ringing the birds, to help with ongoing monitoring of the osprey population and its breeding success. This monitoring is vital in order to secure their well-being in the longer term and results of surveys carried out by the Scottish Raptor Study Group inform conservation planning and policy at a local, regional and national level.

Reaching the nest, or eeyrie, in order to ring chicks involves some spectacular rope-work and is only permissible with a Schedule 1 licence. Thin string is thrown high into the tree, with the aid of a stone to carry it up and over a suitably sturdy branch and back to the ground. The string is then used to winch up a climbing rope. This secured, the climber ascends using mechanical jumars to reach the top of the rope, then free climbs up to the nest, arranging the rope for the return abseil down. Keith performed these tricky manoeuvres with the swiftness of an acrobat, avoiding rusty old nails stuck into the tree trunk by collectors aiming to illegally take eggs from the nest site and the razor wire set up to deter the collectors. 

However, on reaching the nest site there had been no sign of an adult bird. Ospreys are typically monogamous and highly faithful to their partners and their nest. Usually the female would be guarding the chicks, so her absence and the lack of sounds or signs of droppings indicated that there were no chicks after all. Having checked, Keith confirmed the nest was empty. Nearby, we found several osprey feathers and a broken osprey eggshell, but there was no sign of the egg having been fertilised. It was not certain what had happened and why the nest had been abandoned. Nests may fail because of adverse weather or inexperienced birds breeding for the first time as well as through disturbance. Perhaps the ospreys would try again here or close by.

We decided to visit another nearby nest. Here we found a female circling as we approached, calling and alarming to the chicks, who would have been lying flat in the nest. It wasn’t possible to climb the very old and rotten tree to reach the eeyrie, so we watched for a while, and then retreated some distance to let the ospreys settle down in peace, whilst we surveyed the nest with a telescope. We were delighted to see two, large, very healthy-looking chicks in the nest, stretching their wings and being fed by the female bird. They will soon fledge and eventually become independent enough to soar high above lochs and rivers, perfecting the art of fishing through plummeting dives underwater.

Alpines and sunshine

As the mercury soared in Perthshire, we decided to get up into the cooler hills to search for alpine flowers on the top of Beinn a’ Ghlo – designated a Special Area of Conservation and a Site of Special Scientific Interest for its rare flora and fauna. This hill habitat includes alpine and boreal heathland, the best examples of which, in the UK, are found in the Scottish highlands. 

Taking our time, we shuffled from Glen Tilt up Braigh Coire Chruinn-bhalgain ("the upland of the corrie of the round lumps") heads down and necks exposed to the sun as we examined the ground flora. Amongst the scratchy heather and a feathery, spongy and scaly mix of mosses and lichens, we found a rich carpet of bright flowers such as tormentil, milkwort, buttercup and heath bedstraw, and some beautiful specimens seen usually at higher altitudes.

If you're out on the hill, look out for these tiny but stunning plants, which survive extremes of Scottish weather to display their vibrant colours in the summer!

Mountain pansy (Viola lutea)

Common cow-wheat (Melampyrum pratense)

(Further down Glen tilt, the rare flower Small cow-wheat grows in two protected sites - it appears in only 19 sites in the whole of the UK!)

Small cow-wheat (Melampyrum sylvaticum) 

Dwarf cornell (Cornus suecica)

Alpine azalea (Kalmia procumbens)

Alpine clubmoss (Diphasiastrum alpinum)

Busy Beavers

If you go down to Mill Dam today…you’re in for a beaver surprise!

Regular visitors will have seen fallen trees, lying forlornly next to jagged, bright orange stumps, cut to a sharp 45 degree angle. Look more closely and you can see numerous teeth marks, where (in particular) alder and downy birch trees have been comprehensively gnawed by newly resident beavers!

These architecturally-minded rodents moved into Mill Dam in the autumn of 2013 and the signs of their activity are visible all around the loch. Experts in engineering, beavers fell the trees not only for construction of their burrows, dams and lodges, but also to munch on juicy bark (they enjoy the cambium layer between the outer bark and heartwood), which is central to their vegetarian diet.

A feeding area, with stripped twigs and bark

It’s amazing to see the hard work of these native animals as they make themselves at home! As a keystone species, beavers have a big impact on the survival and abundance of other members of the ecological community in which they live. Whilst the initial impacts of beavers' endeavours may seem drastic, as they coppice and dam wetland areas, the results of their labours can be hugely beneficial for other wildlife and wetland systems as they regulate water flow and improve water quality. Otters, water shrews, water voles, birds, invertebrates such as dragonflies and fish are just some of the species which may be helped by the presence of beavers. 

Beavers are crepuscular, so the best time to catch a glimpse of them is at dawn or dusk. We’re keeping a close eye on beaver activity at Mill Dam and feeding the results of our monitoring into the Tayside Beaver Study Group monitoring programme. As time goes on it will be interesting to see whether the beavers are here to stay!

Ranger Events 2014

Our events programme is now out for 2014. There are some new events and some old favourites. Have a look at www.athollestatesrangerservice.co.uk/ranger_events.cfm and start thinking ahead to the light evenings and warm sunshine.

Sleep Through Christmas?

For some of you, sleeping through Christmas might seem like an attractive option. Bats should be sleeping just now but the mild weather has wakened them and many have been spotted both in twilight and during the day. The warm weather triggers them to wake up and go and hunt for food. Bats can cope with waking up so long as there is some food available, there are quite a few moths still flying so hopefully they can have a feed and sleep again when it gets colder.

Pipistrelle bat - all our bats are small, but this is the smallest

Really cold weather can also wake them because although there body is in a deep-state of metabolic slow-down, an alarm goes off if their body temperature drops too low. They will then wake up and try and find somewhere warmer.
All our British bats are small and have a high surface area to volume ratio which means they lose heat very easily. Hibernation is the only way to survive through a cold winter.

They will also wake up once every 3 weeks or so to drink, as they lose a lot of water while hibernating
Other British animals that hibernate include dormice, hedgehogs, frogs, toads and lizards.

Our Wildlife is Ready for Winter

The hills have had their second full carpetting of snow here after a wild stormy day on Wednesday with proper blizzards. If you want to come out to the hills now, full winter gear is recommended - ice-axe, crampons and winter boots. Many of the tracks are icy - so you need to take care on bikes too.

 

White hills on Thursday morning from the estate office

However, the wildlife is ready. Our red deer have grown their thick winter coats, with hollow, duvet-like hairs and the mountain hares have moulted to their winter coat. This white coat is perfect camouflage for conditions like we have now, but it's a disaster if we have a mild winter. When there's no snow, their white coat makes them obvious for miles around, and a hungry golden eagle can follow them very easily, before swooping down and helping themselves to a good meal. Winter is a hungry time for eagles and mountain hares can be an important part of their diet. If they can't find hares, they often survive on carrion.

Too obvious when there's no snow!

Ptarmigan (Mountain grouse) and some stoats also go white in winter for camouflage.

WILD WEATHER

Winter suddenly seems to have arrived in Blair Atholl. Torrential rain, hugely swollen rivers and snow on the hills added to the long dark evenings have definitely made it feel like winter is upon us.

River Tilt in spate

 

The Witches Rock - not such a good place for swimming today! The river is running behind it too.

Up until now the wildlife has had an easy autumn with mild weather and an abundant autumn harvest to feed up on to prepare for winter. This week hedgehogs, bats and amphibians will be heading into hibernation. Our red squirrels have been stashing food furiously over the last few weeks, so that on bad days like we are having just now they can stay warm and cosy in their dreys for most of the day.
The red deer have pretty much finished rutting, but the stags will be exhausted and need to feed up frantically before the winter gets really bad.

Swollen rivers can be very dangerous for any hillwalkers or trekkers out in the heart of the Cairngorms where there are no bridges. Red deer and other animals can also get swept away. The rivers here do rise and fall very quickly.

The River Tilt at Marble Lodge. See how quickly the water levels rise.

Cold, wet and windy weather is the most testing for the animals and birds that stay here in the winter. They can cope well with very cold, crisp weather, and snow is not too bad so long as it's not very deep. But cold, rainy or sleety days are worst because the wet penetrates down to the skin and get the creatures really cold. The only way they can combat this is to eat a lot to keep up their energy levels, but if there's not enough food around then it get very bad. We shall soon see what the winter has in store this year.