Category Archives: birds

Trail cameras

There is a lot of wildlife on Ardnamurchan. It is one of the reasons I returned here time and again … and came back more permanently in 2018.

Some of the wildlife is obvious.

Siskin (male)

Siskin (male)

The never-ending parties of tits, siskins and finches on the bird feeders.

A white tailed eagle effortlessly gliding along the scarp slope of Beinn Bhuidhe.

The stag ghosting away in your peripheral vision as you drive back late along the B8007. Did you really see it at all?

An otter rolling amongst the bladder wrack exposed at low tide as it searches for crabs.

Otter, Loch Sunart, Glenborrodale, October 2018

Otter, Loch Sunart, Glenborrodale, October 2018

But most of the wildlife you never see because it is about when you’re not.

Either the wildlife makes itself scarce when we’re blundering about … or because it’s the middle of the night.

Smile, you’re on candid camera

But with a bit of technology, some patience, a bit of trial and error and a little luck you can see what you’re missing.

Trail cameras (also know as trailcams or camera traps) are movement-activated cameras that record still images or short videos any time of the day or night. During daylight hours they record colour images. At night they use infra-red LED lighting and record in black and white.

I’m using camera traps to detect the wildlife I don’t see because I’m chainsawing out the rhododendron and making a mighty ruckus.

And I’m using them in the vain hope that they’ll help identify the gaps the undesirable wildlife get through to eat the native flowers and trees I’m planting in the newly rhododendron-free areas ūüôĀ

Red deer hind scouting out a rhododendron-cleared area for newly planted trees

There are dozens of makes to choose from at prices ranging from ¬£25 to at least 20 times that, depending upon the features required. The more expensive models have 4G or wifi built in (and I’ve no experience of these).

Optically – at least from the technical specifications provided by the manufacturers – trail cameras above ¬£150-175 don’t improve very much. Less expensive models tend to offer lower resolution and longer trigger times (I’ll discuss the significance of both of these shortly).

It’s worth noting that none of these ‘hobbyist’ camera traps are going to produce stills or video to compete with the sort of stuff you see on Seven planets, One world¬†1.

However, they can produce perfectly acceptable results.

Roe deer buck

I’ve used the Browning Recon Force Advantage and Browning Spec Ops Advantage¬†cameras.

Yes … the names are totally ridiculous ūüėČ

I felt like I should spend the weekends disguised as a bush, or at least be wearing a camouflage hat and jacket, when I ordered them over the phone 2.

Resolution

Both these trail camera models deliver still images of 4 – 20 MP (megapixels).

This is nothing like as good as it sounds I’m afraid. This is because the larger images are¬†interpolated when they’re scaled up – effectively adding pixels as the image is expanded.

I’ve only tested the still camera function during daylight and can see no significant quality differences between 4 MP and much larger images.

Do not expect images comparable to your digital SLR … they’re not even vaguely close.

Video is better being up to 60fps 1920 x 1080p HD 3. This is perfectly acceptable and I usually use them at 30fps to save SD card space.

Less expensive models usually offer lower video resolution and/or a lower frame rate. Both reduce the quality of the resulting video, though perhaps not so much it actually matters.

Lights, camera, action

Well, lights, battery life and action.

To work at night the camera needs to illuminate whatever it has picked up using the motion-sensitive sensor. It does this using infra-red LEDs. The two cameras (embarrassingly) named above use different types of LEDs.

The Recon Force Advantage has ‘low glow’ IR LEDs. These are visible to the human eye and they are certainly visible to animals (as I regularly capture video of them reacting adversely to the light).

Badger – note the surprise when this¬†poorly-sighted fellow sees the ‘low-glow’ LEDs

The Spec Ops Advantage has ‘no glow’ IR LEDs. These are essentially invisible to humans 4, but are effective over a shorter range (~70% the distance of the low glow LEDs).

The other significant feature to look for in a trail camera is the trigger speed i.e. the time it takes from detecting motion to capturing video (or a still  image).

0.4 seconds might not sound very long, but a small animal – like a stoat – moving fast across the field of view will feature for a further half second on the video before you get 10 – 20 seconds of just herbage waving in the breeze.

Mouse … one of several hundred I have videos of ūüôĀ

Both cameras use eight AA batteries. Unfortunately, not just any old AA batteries. You’re strongly recommended to use lithium AA batteries which are appreciably more expensive 5.

Why lithium? You need batteries capable of delivering high current – at least 2500mAh – and they often need to work at low temperatures. Standard rechargeables or Duracell simply cannot do this.

I get 9-12 months use out of a set of lithium batteries in a well-placed camera (i.e. not too many false triggering events) set to take short videos, about 50% of which are recorded at night. So, although the batteries are not inexpensive, they also last well.

I’m also dabbling with building a solar-powered rechargeable battery pack, though this will only be suitable for areas which receive full sunlight at least some of the time. It will make it less portable, but might be worthwhile for a really good location (or a very remote one).

Irrespective of the technical details of the camera trap, the biggest influence I’ve seen on actually capturing useful and usable images is due to the positioning of the camera.

Location, location, location

Firstly, things to avoid …

  • Glare from the sun. Try and position the camera facing north. Or at least somewhere in the arc between north-east and north-west. Not an issue at night of course, but why compromise daytime images beings spoilt by glare and dazzle? 6
  • Herbage moving close to the lens. This will repeatedly trigger the camera during windy weather. There’s only one thing less interesting than screening 89 short videos containing the same small branch being blown intermittently in and out of the field of view.
  • Mounting the camera on something that moves. This almost always ensures lots of false triggering. Even 8-10″ tree trunks sway perceptibly in strong wind. A fencepost is good, as is a tree-stump 7.
  • Mice. This is what’s less interesting. That infuriating branch I just mentioned is insignificant when compared with a couple of hundred ten second videos of mice scurrying around in the foreground ūüôĀ

Red deer stag and glare from poorly positioned camera

Obvious places to try …

  • Game trails. Large animals usually leave a track or trail, particularly if the ground is soft. I usually point the camera along the trail to get a head-on (or tail-on!) video, rather than a fleeting glimpse as they cross the field of view.
  • Paths. Many animals will follow man-made tracks rather than making their own way through the undergrowth. This is where I’ve had most success in filming a wide range of wildlife – from badgers to woodcock.

Roe deer hind on manmade ‘path’ hacked through the bracken

  • Bait. I’ve not tried this but you’ll see many camera traps set up pointing at bait of some sort. Some people use an egg, others use cat food or – for pine martens – a digestive biscuit with jam.
  • A waterhole. Don’t expect hippos and gazelle, but you might well get an otter or animals coming to drink. I don’t have anywhere really suitable so can’t comment on how effective this is.

The camera should almost always be mounted 30-60cm above the ground. Most trail cameras have a small screen you can use to check the positioning. If the camera is only 30cm from the ground this can be tricky to view 8.

Try to position the camera vertical and avoid too much sky in the field of view. The former makes the resulting videos/photos look a bit better quality and the latter avoids lots of ‘blown out’ highlights in the images.

Trail camera firmly strapped to the lower trunk of a tree

The great thing about these cameras is they’re pretty much ‘set and forget’. You can leave them for a week or a month. You certainly don’t need to check them on a daily basis. They just sit there, quietly grabbing images when triggered.

SD cards

Camera on game trail

All of the images are recorded onto full-size SD cards. I only use 16 or 32 Gb cards and have only ever run out of space when I setup the camera incorrectly and recorded very long video clips.

With 16 or 32 Gb SD cards now costing only ¬£6-8 it’s easy to carry spares and swap them with the SD card in the camera. I’ve also built a portable, battery powered, Raspberry Pi Zero backup device which copies the card in situ. However, this gets press-ganged into other roles and, frankly, it’s faster to just swap cards over.

Absence of evidence is not evidence of absence

The two most obvious signs that badgers are in an area are their extensive latrines and their corpses at the side of the road ūüôĀ The badger (above) was the first I’d seen on Ardnamurchan and I had no reason to suspect they were there.

The camera never lies.

Pine marten, Ardnamurchan, May 2018

In contrast, it’s not uncommon to see pine martens lolloping across the road and their scats (faeces) are often left in prominent places 9.

Pine marten scat

Of course, the ‘biggy’ in terms of mammals on Ardnamurchan, is the Scottish wildcat. Although this area was designated as a wildcat ‘haven’ about 5 years ago, things have gone a little quiet since then.

Scottish Wildcat Action are now concentrating on Morvern which, although not far away, is across Loch Sunart and likely forms an isolated population.

Nevertheless, over the next year or so I’ll continue to leave at least one or two trail cameras well away from areas of human disturbance in the hope of capturing one on video.


 

Walk : Acharacle to Laga

In 2005 the Land Reform (Scotland) Act came into force. This wonderful piece of legislation gives everyone rights of access over land and inland water throughout Scotland.

These rights are sometimes referred to as ‘freedom to roam’ or¬†‘right to roam’.

There are specific exclusions e.g. fields with growing crops, gardens (!), and there is a requirement to behave responsibly. All very reasonable.

Without this legislation, walking would often be restricted to rights of way such as footpaths and bridlepaths, often long-established.

And Ardnamurchan has relatively few of these.

Coast to coast

The settlements on Ardnamurchan are situated on the periphery of the peninsula. The sheltered moorings at Salen, Glenborrodale bay with its castle and Kilchoan on the southern shoreline. Sanna, the hamlets of Kilmory and Ockle on the north coast, and Acharacle at the mouth of Loch Shiel.

Ardnamurchan peninsula

These places are still linked by tracks across the relatively barren hinterland. On the north shore of Loch Sunart the winding B8007 presumably follows a historic cart track and, before then, a route used by farmers going to and from Ardgour.

However, along the north coast and linking the north and south coasts, a number of tracks remain. These provide relatively unchallenging walking over some beautiful empty hills and moors, often offering stunning views across the peninsula.

One of my favourites is the track from Acharacle to Glenborrodale.

Kentra Moss

Recent forestry activity at the Glenborrodale end of the track has made access more difficult (more on this later) and left an ugly scar on the landscape.

I therefore recommend walking north to south (starting from Acharacle) and deviating from the Glenborrodale track to instead finish at Laga.

Acharacle and Kentra Moss

The easiest point to start from is Acharacle Primary School (NM 67448 68069). This is a short walk north along the A861 from the bustling metropolis of Acharacle.

Don’t let the the ‘A’ prefix on the road number mislead you. Parts of it are single track.

Acharacle, Arivegaig and Kentra Moss

There’s a small parking area just west of the school, with a gate leading to the track to Arevigaig that winds through the Bealach Clach an Aighe 1.

Kentra Moss

You emerge from the scrubby mixed birch woodland onto the south eastern edge of Kentra Moss. This, together with Claish Moss on the southern shore of Loch Shiel, is one of the rare ‘eccentric’ mires in the UK. This habitat is characterised by oceanic blanket bog, rich in mosses, sphagnum, cross-leaved heath and bogbean.

Stick to the track. This amount of sphagnum doesn’t flourish without very large amounts of water. The raised bog isn’t safe to walk on, and would be damaged if you did.

Kentra Moss … very wet everywhere

Kentra Moss is a great place for dragonflies and insectivorous plants, neither of which I’m much good at identifying. During the summer months the bird life is good, with a number of different breeding waders.

A couple of hundred metres after the track bears west you come to a junction with a concrete bridge over one of the many burns that drains the bog. Turn left here (bearing south) on a recently upgraded track leading up away from Kentra Moss into the low hills.

Kentra Moss – track junction looking north

To see more of Kentra Moss there’s also a circular walk that follows the track on to Arivegaig.

Waterworks

There is a new water purification plant up the hill above Kentra Moss. The track goes past a large agricultural-looking building and a water tank with a fabulous view across Kentra Bay to Eigg and Rum before abruptly petering out at a gate held closed with a rusty chain.

View across Kentra Bay to Eigg and Rum.

The track changes from reasonably well-graded crushed rock to a more typical gnarly mountain track, largely suitable for a good 4WD vehicle, an Argo ATV, a mountain bike (and fit rider) or Vibram-soled boots.

Here, and increasingly on the route south, the track offers the ‘path of least’ resistance to water, so it’s not unusual to be walking up a shallow stream.

There’s plenty of evidence of the previous glaciation of the region, with rocks bearing characteristic linear scarring where glaciers have advanced or retreated.

Glacier was ‘ere

The track climbs gently before cresting the ridge and dropping to a sturdy wooden bridge over the Allt Beithe (Birch stream).

Bridge over Allt Beithe

After crossing the stream the track gets smaller and wetter, climbing across the hill in a south-easterly direction towards Beinn Laga.

As the track approaches Loch Laga the land levels out and it gets very wet underfoot. The water just stands around waiting to overtop your boots, rather than conveniently running away downhill.

But the view opens out to the south and east, particularly if you climb a little way above the track (but don’t leave a cairn to spoil the landscape for others). It feels remote but isn’t really.

The Sunart hills

On a poor day, with heavy cloud and squally showers, the views are less good, or potentially non-existent. However, don’t forget to scan the surrounding ridges for eagles – I’ve often seen them here, particularly when the weather is less than favourable.

Loch Laga

Loch Laga lies in the boggy ground between Meall nan Each and Ben Laga, east of the Fiddler’s Slab (Leac an Fhidhleir). There’s a small corrugated fishing hut at Loch Laga and I assume the fishing is controlled by the Ardnamurchan Estate, though I’ve not been able to confirm this.

Approaching Loch Laga.

It’s an exposed spot and it’s not unusual for the loch to be covered in short, white-capped waves. This is a good place to see both red and black throated divers. I wouldn’t be surprised if at least one of them bred on the small rocky island in the Loch.

Loch Laga

As the track skirts the west shore of the loch it is indistinct in places and heavily eroded in others, with the latter likely due to over-enthusiastic (or ambitious) access with an Argo on the peaty soil.

The track rises gently, curving in a more westerly direction. About half a mile after the fishing hut there’s a small cairn in the heather on the left side of the track (NM636632).

This marks the junction with a smaller track leading to Laga.

Cairn do

From the Acharacle to Glenborrodale track, this spur off to Laga is almost invisible. Perhaps this is one of the few times when a cairn is useful. Approaching from the west there’s a tendency to turn south too soon and the ground is very rough and boggy. Not recommended.

After a hundred metres or so the track rises on a rocky spur leading south. Underfoot the going is good except for a few extensively boggy areas. None of these offer too much of a problem if you’re willing to skirt around them and take a ‘leap of faith’ (from one semi-dry tussock to another) a few times.

Track to Laga

The track descends very gently towards Laga. With every step the views across Morvern, the Isle of Carna and Loch Sunart increase and improve.

Keep an eye on the rocky ridge of Ben Laga to your east. This is a good place to see eagles, though the prevailing wind tends to need to be south-westerly or westerly.

From outside in – Laga Farm native woodland

The descent steepens and a deer fence appears to the west. This marks the boundary of the Laga Farm native woodland development.

The end is nigh

In a fold in the hillside a heavy angled gate appears in the deer fence which enables you to cross into the land enclosed by the Laga Farm fencing.

From inside out – open moorland to the east of the Laga Farm native woodland enclosed area

Within metres the difference is striking.

Inside the protective deer fence there are trees growing all over the place. Inevitably some of these will have been planted, but many of the birches, rowan etc will be self-seeded.

In contrast, outside the fence, the moorland is barren with barely a tree in sight. The only exceptions are those growing in inaccessible clefts on the steepest slopes, or in the ravines through which the streams tumble.

This is compelling evidence that there are too many deer.

Laga Farm native woodland, looking south across Loch Sunart to Morvern

The next kilometre or so are increasingly steep and increasingly wooded. It’s lovely now and it’s getting better year after year as the trees mature.

The gravelly and rocky path still offers the¬†‘path of least resistance’ to water which, in turn, provides miniature pools for dragonflies to lay eggs, like this golden-ringed dragonfly.

Finally the track levels out and you reach a gate through the deer fencing which brings you out onto the B8007.

Turn left for the fleshpots of Salen and all points east, turn right for civilisation, Glenborrodale and Kilchoan.

Loch Sunart, near Laga

It’s worth noting that parking at Laga is very restricted. The road is single track and the passing places are heavily used for, er, passing. Don’t park in them! Laga Bay is also the base for Mowi in this part of the loch and some gateways are used for lorries turning. Finally, Laga is the base for Ardnamurchan Charters¬†(ferry to Mull, Carna and wildlife trips) and their parking area should not be used.

Alternative ending

Rather than turn south at the cairned turn (NM636632) shortly after Loch Laga you can keep on the main track to Glenborrodale. The route turns more westerly and eventually turns south into Glen Borrodale. The going underfoot is much like the first half of the route, with some spectacularly wet and soggy bits.

The route crosses a couple of good-sized burns and bridges ensure your already soaked footwear doesn’t get any wetter ūüėČ

Bridge over the Allt something or other

As the route bears south into Glen Borrodale there are a number of deer fences to negotiate. This area has recently been clear-felled and it is a rather barren and unattractive landscape. The track improves and so do the height of the deer fences.

If you are lucky the gates will be unlocked. If you’re unlucky you will have to scale the 8 foot fences. In several visits over the last couple of years I’ve been lucky about 50% of the time.

Trees were here … but won’t be again for a long time

So much for the¬†‘right to roam’.

This is a well-established route between Glenborrodale and Acharacle and is in many of the guidebooks to the area.

The deer fences 2 are to protect the thousands of young (native thankfully) trees planted in the felled and adjacent areas of moorland. At my last visit these were only 30 – 60 cm tall, so there’s some way to go before the forestry-induced scarring is hidden again.

The track finally descends through the Glenborrodale woodchip plant and emerges on the B8007.

There are more places to park near Glenborrodale but the deforested landscape, locked gates and less impressive views make the Laga end to the walk preferable in my opinion.

Loch Laga

The Acharacle – Laga walk is about 6 miles. The alternative ending in Glenborrodale is probably a mile or so longer.

The route and going underfoot is easy to moderate but remember to wear appropriate footwear and take waterproofs. This near to the Atlantic the weather can change – and often does – in minutes.


 

The birds of Ardnamurchan

Blue tit

Ardnamurchan has excellent birdwatching. In a relatively small area it has a variety of habitats – mountain, moorland, all types of woodland, raised bog, coast, sea and freshwater lochs, machair and just about everything in between.

Bird Watching magazine published are article on birdwatching on Ardnamurchan¬†in 2013 calling it Scotland’s Hidden Gem.

I’m an amateur, but enthusiastic, birdwatcher. Like many birdwatchers I try and keep a running¬†list 1 of what I see locally (my patch) and on my travels.

I’m not a twitcher. I don’t chase rarities, I don’t keep monthly, annual or geographic records. I’m hopeless at discriminating between most of the Phylloscopus¬†(leaf) warblers (and gulls 2). I do however have a vague idea of the – very extensive – list of UK birds I have never seen and enjoy reducing the number when I have the chance.

It’s always good to know what¬†might be seen in a particular area i.e. what has been seen before and is therefore likely to turn up again.

Or that’s there all the time if I was only a bit more observant ūüėČ

The BTO open mapping bird atlas data

Fortunately, thanks to thousands of volunteers and the British Trust for Ornithology, there are outstanding records of overwintering and breeding birds for the entire country. This dataset now contains ~1.4 million records covering ~450 species between 1968 and 2011. It is updated every couple of decades.

This data is at 10 km resolution (i.e. was a bird present / breeding in a particular 10 km square?). More recent surveys have been conducted at much higher resolution (based upon 2 km tetrads) and now include ~20 million records covering 99.9% of the country.

Until recently this data was only available in book form, but the 10km resolution data is now freely available online. For any species you can view a map of the UK showing if and where it is present in the winter, and whether it possibly, probably or definitely breeds here in the summer.

BTO bird atlas mapping

Inevitably, the maps are rather low resolution. You can just about see Ardnamurchan, but it’s not obvious. The BTO also offer a variety of other ways to view the data, such as providing lists of birds by¬†searchable map reference or postcode.

Local lists of local birds

Not only can you query the dataset interactively, you can also download the bird distribution data as compressed ZIP format comma-separated variable (CSV) text files. Uncompressed the files total about 125Mb. The largest is the geographic and temporal distribution data which runs to ~1.5 million lines. Don’t try opening it in Excel (which is probably the default for this file type on your computer) as it can’t cope with more than ~1 million rows 3.

A wet spring weekend seemed like the ideal opportunity to generate an Ardnamurchan-specific bird list. CSV files are trivial to manipulate using a simple scripting language such as perl or python. What could possibly go wrong?

10 km resolution

Of those 1.5 million records, only a subset are relevant to Ardnamurchan. The rest of the country we can safely ignore.

The first challenge is to determine which 10 km squares overlay the ~30 km x ~10 km Ardnamurchan peninsula. The BTO uses the same grid overlay used by the Ordnance Survey and the latter provide a very useful tile locator map. If you select the relevant 100 km square (NM) you are taken to a more detailed view showing the individual labelled 10 km squares.

Ardnamurchan 10 km map squares

Ardnamurchan 10 km map squares

The numbering of these squares represent the first digits of the Eastings and Northings coordinates of the grid reference. For example, Acharacle primary school is at NM 674 681 and is in the top right hand (north west) corner of NM66.

NM47, 57, 67, 46, 56, 66 covers Ardnamurchan in its entirety 4, together with bits of Muck, Moidart and a small wedge of Morvern. That’ll do.

Big(ish) data

For the moment the only two data files that are of relevance are the lookup table of species (species_lookup.csv) and their distribution (distributions.csv).

species_lookup.csv has four fields, the unique species code (an integer 5, the common and scientific name(s) and an indication whether it is a distinct species or an aggregate 6.

distributions.csv has eight fields including the survey period, season, species (the id number only), 10 km reference square and whether breeding was possible, probable or confirmed. I’ve ignored the additional fields for the moment. With ~1.5 million lines in the file there are multiple records for each 10 km square and for each species.

Siskin (male)

Siskin (male)

For example, there are 2082 records for the six 10 km squares covering Ardnamurchan and 9290 records for the Barn Owl (Tyto alba) covering the entire country.

Of these, only seven intersect. The Barn Owl is present in five squares during the winter, but breeding is only suspected or known in NM67 and NM56.

This doesn’t really qualify as ‘big data’ but untangling it is too much to handle with just a pen and paper 7. Instead, it’s a trivial exercise to spend a wet afternoon (when I couldn’t do any beekeeping) writing some perl scripts to extract the relevant records for presentation.

Data mangling and untangling

The historical information in the BTO Bird Atlas data is of less interest to me (at the moment at least 8). I’m interested in the most recent reports from the winter and breeding season records … these are the birds I (and visitors to Ardnamurchan) are most likely to see now.

Maclean’s Nose … a good spot for white-tailed and golden eagles

Following the usual cycle of code, debug, coffee, code, debug, coffee pizza I had something that just about worked.

A total of 143 species overwinter, breed or both on Ardnamurchan. Of these, 26 (mostly overseas migrants like the cuckoo and willow warbler) are absent in winter. In contrast, 34 species are either absent in the summer or do not breed on Ardnamurchan.

Unsurprisingly considering the limited land area present in NM47 and NM57, these 10 km squares have the smallest number of summer or winter species:

  • NM47 – winter 59, breeding 56
  • NM57 – winter 49, breeding 48
  • NM67 – winter 83, breeding 89
  • NM46 – winter 66, breeding 89
  • NM56 – winter 77, breeding 81
  • NM66 – winter 103, breeding 90

It’s worth noting here that presence alone in the summer is¬†not recorded for any species on Ardnamurchan. Just because a particular species does not breed does not mean there is no chance of seeing it 9. For example, I’ve¬†regularly¬†seen gannets in Loch Sunart though they don’t breed on the peninsula.¬†

Data presentation

Having sliced and diced the BTO data it now needed to be presented in a readable format.

Rather than just present a ‘flat’ list of birds it seemed logical to include links to relevant information online. For example, to the BTO Bird Atlas maps of the entire UK for the winter and breeding season distributions and to the BTO Bird Facts data.

This turned out to be a little bit more complicated than it should have been. The BTO appear to use two different numbering schemes.

Species in the BTO Bird Atlas use a taxonomically-organised sequentially-numbered list of UK species. I’ve mentioned the red throated diver (#1) and Blue-crowned Parakeet (#1663) previously. In contrast, the Bird Facts pages are referenced using the 5 digit EURING code used by bird ringers. The EURING code for the Red throated diver is 00020 10.

Initial attempts to find the Blue-crowned Parakeet on the EURING list failed which highlighted a second problem 11. The scientific names (the only sort of names used) on the EURNG lists are sometimes different from the BTO lists. This happens when birds are reclassified. On the BTO the Blue-crowned Parakeet is Thectocercus acuticaudatus whereas EURING lists it as¬†Aratinga acuticaudata. D’oh!

Entirely the wrong time of the year to see Blue-crowned parakeets …

I cross-referenced the two lists automagically using a short perl script and then manually corrected the dozen or so species from Ardnamurchan that disagreed between BTO and EURING systems 12.

Inevitably this manual bodge will break things in the future …

A picture is worth a thousand words

One of the problems with the BTO Bird Atlas maps is that the Ardnamurchan peninsula is rather difficult to see. I therefore created a series of small 3×2 gridded icons representing the six NM-prefixed squares that cover the peninsula. I used one icon for the winter distribution and one for the breeding distribution (with probability indicated by different sized ‘blobs’, just as they are on the BTO Bird Atlas maps). For example:

This icon    represents a species that is recorded in all but NM57 in winter.

This icon    indicates a species which possibly breeds in NM46, probably breeds in NM66 and NM67 and that breeding has been confirmed in NM56 and NM57.

There are ~132 different distributions of birds in the winter and breeding seasons. Rather than draw any of the icons by hand I used ImageMagick to create them automagically, called from a perl script that read the underlying data directly from the distributions.csv file.

I also added a notes column, but this has yet to be populated.

The finished list of Ardnamurchan birds in the most recent BTO census is linked from the menu above, or directly from here (and is also available in PDF format). It will be updated as and when new BTO census data is released.


Notes

  1. It should be noted that for security reasons the breeding distribution of some rare birds is deliberately listed (by the BTO) at lower resolution.
  2. There’s a second minor problem with the BTO Bird Atlas maps. They are displayed via a server which separates the delivery of the map from the menus that control the data displayed or its appearance. This means I could either link directly to the maps (and have no menus) or to link to the default map for a species and subsequently select the desired map (which has to be done interactively).¬†The default map is the most recent breeding distribution, so this is linked from the ‘summer’ icons. Until I find a way to access the winter distributions¬†and menus I’ve left the ‘winter’ icons linked directly to the relevant map alone.
  3. The Blue-crowned Parakeet (Thectocercus acuticaudatus) is a small green South American parrot with a blue head. They inhabit Neotropical savanna-like habitats, woodland and forest margins from eastern Columbia to northern Argentina. Not Ardnamurchan ūüėČ

Blue-crowned Parakeet