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.