Wednesday, 23 April 2014

Antler Growth

From Fay Rowantree at Wild Highland Tours:

What is horn and what is antler?

Antlers differ from horns in that they are shed and reproduced annually. Antlers are made of bone while horns are made of keratin, the same material as your fingernails. Horns are a thin sheath grown over a portion of the skull while antlers are completely separate to the skull, held on only by a small section nourished by vitamins and minerals with the ability to start and stop growth. Horns grow continuously while antlers grow for around 128 days. Antlers are the fastest growing tissue in the animal kingdom growing at up to 2.5 cms per day and can be grown only by Cervidae. Horns are grown by cattle, goats, sheep and antelope.

How an antler grows

Antlerogenesis is the term that describes the annual physiological production of antlers. It is regulated by a series of interconnected processes. Antler growth is primarily regulated by testosterone levels. The testosterone levels in a stag’s body are regulated by photo-period, or length of daylight, and length of daylight is regulated by the seasons that occur from the tilting and rotation of the Earth. Because of all of this, the antler growing process lasts only 128 days and cannot be extended or expanded.

When first born in the spring time, a stag calf or buck fawn has small indentions and hair swirls on the frontal bone of his skull. Before being a year old the buck or stag is affected by increased testosterone levels which help to produce small, flat platforms called pedicles. Pedicles provide the structural base for the foundation of future antler development in all male deer. At approximately ten months of age and in good conditions, the young male’s testosterone level increases enough to produce his first set of antlers. By the next autumn, the young stags will be about eighteen months of age and referred to by deer managers as “knobbers”.  Under ideal conditions and with good genetics, his first antlers can have more than two points but most only have two spikes. 

As antler growth begins, the underlying pedicle gives rise to new antler material, which at this point is a semi-firm tissue composed of approximately 80% protein. This growing material is cartilage-like and full of blood vessels. The nutrient-rich transporting blood vessels rise up through the pedicle as well as form the soft lining around the outside of the growing antler. The tiny little blood vessels and protective hairs are what we refer to as velvet when a buck or stag is actively growing antlers. Blood vessel density and capacity is what “feeds” the growing antlers. A healthy male produces and maintains a high volume of blood vessels and draws heavily on nutrients during this period. The velvet is also full of a dense network of microscopic nerves. The nerves make the velvet covered antlers sensitive and help to protect the soft growing tissue against damage. The nerves may also make the stag aware of how his antlers are shaped, which will be useful when stripping the velvet and sparring with competing stags. The visible grooves on the base and beams of hardened antlers are the impressions left by the blood vessels as it grew in velvet. The scab that forms over the wound left by the cast antler heals and becomes covered with fine, thin hairs. The fine-haired skin forms the beginnings that will nourish and protect the growing antlers for the next four months.

Many thanks to Fay for the article and top photo.
Wild Highland Tours' website is here, and you can follow them of FaceBook here.
Wild Highland Tours is the only wildlife company based on the Ardnamurchan peninsula.

Tuesday, 22 April 2014

A Warm Easter

Dawn this morning, looking across Kilchoan Bay from above the Ardnamurchan campsite at Bogha Caol Aird.

The temperature yesterday hit 20C on the warmest April day we've had since we started keeping records.  We couldn't have had better weather for the Easter weekend.

Grasshopper Warbler

This is, or may be, a grasshopper warbler.  We saw it in the next-door plot, in amongst the brambles, but identified it - tentatively - as a grasshopper warbler by its song.  This is an exciting find, partly because the only other time we've heard it was in the Raptor's garden, and partly because, according to the RSPB, the population of this little bird is in steep decline, so it's on their 'Red List', and Ardnamurchan is outside its normal range.

More details about it on the BBC site, here.

Monday, 21 April 2014

New Kilchoan B&B Opens

A new Bed & Breakfast has opened in Pier Road, Kilchoan - and there's something very special about it.

The premises is Skipper's Cottage, built originally by Ardnamurchan Estate to house the skipper of the Estate launch.  In the centre of the village, with views across the Sound of Mull and close proximity to the CalMac ferry terminal, it's ideally placed both for the passing trade and for those who want to enjoy West Ardnamurchan at a more leisurely pace.

There are two rooms available.  This one, with double bed, is called Lady Butterfly, the other has twin beds and has been named Sea Eagle.  Both have sea views, and come with complimentary tea and coffee facilities, hairdryer, and wi fi.

What's so special about this new venture is that it's run by a young Italian couple, Lara Ferrarotti and Filippo Perratone, who have lived on West Ardnamurchan for long enough to fall in love with it and become determined to stay - even though they've seen it through the wettest winter ever.  Their passion for the place is reflected in the invitation on the first page of their website: "We are a young couple determined to offer you the opportunity to truly taste the unique West Ardnamurchan experience, made of astonishing views, strong gales and a very friendly community."

Lara and Filippo's B&B has just opened.  Their website is here.

Last Night's Skies

For those of us who were up in the early hours of this morning in response to two aurora alerts but who saw nothing in the northern skies, there were a couple of compensations.  The brightly-lit ship in Kilchoan Bay, its lights reflected in the still waters, was the Forth Jouster.  We're also coming up to the maximum of the Lyrid meteor display, so there was something going on in the skies, if not an aurora.

The Forth Jouster sailed out of the bay at half past seven this morning, just as the Tobermory ferry was coming across.  The day has dawned misty but with the promise of fine weather.  Yesterday's maximum temperature was a glorious 18C, and we're hoping for more of the same today.

The best site for local aurora activity is here.
Details of where to see the Lyrids, here.