Otterly fascinating

Yes, that cheesy pun in the title was completely necessary.

Today started off well in that I spotted a Golden Plover Pluvialis apricaria in the field behind my house whilst I was having a half-hearted attempt at finding a white-winger amongst the Herring Gulls Larus argentatus and Lesser Black-backs Larus fuscus that had gathered to feed. When I first panned past it I was completely stumped as to what it was and even considered Jay for a second. Beautiful bird and a brilliant patch tick for my inland Edinburgh patch!

I went out later on from about 16:30 until 18:00. My main aim in this time was tracking of mammals. I’ve become engrossed in mammals recently. Not sure exactly why, but I’ve been liking all sorts of IUCN Specialist Group pages on Facebook, scrolling through numerous trip reports from all over the place, and looking at buying myself a trail camera.

Before I get into the mammal stuff, I was on top of Agassiz Rock on patch where I picked up that Tawny Owl Strix aluco pellet that I showed you in my last blog post. I was hoping for another one so I could look at more dentition of whatever small mammals the owl had caught, but there were no new pellets visible. I did find a small crack in the rock where pellets had clearly accumulated though, with bones and the general matrix of the pellets sitting there, making some nice new substrate for colonisation by plants!

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Owl pellet creating new substrate

Here’s a selection of other tracks and signs found while wading up the Braid Burn…

Now, on to the main attraction. As you will have guessed from the title, this means Otters, Lutra lutra. I have known for a while that Otters are present on my patch. I’ve seen one in the dark from my bedroom window and fairly frequently find signs of their presence. Plus they occasionally get press coverage and the rangers like people knowing that an animal as enigmatic and exciting as an Otter is living on this reserve in a city as busy as Edinburgh.

I decided to focus today on Otter tracking for that last reason I mentioned, they are enigmatic and exciting. However they are also a species that I don’t see a lot of and would like to learn more about. I also chose to focus on Otters today as I recently found some very fresh spraint on the Braid Burn, and funnily enough it appeared to have been placed quite purposefully on a bag of dog s**t that someone had carefully and clearly very thoughtfully placed on a rock. Either that or it’s just coincidence that the Otter has decided to place it on the bag. I’ve found a possible sign of Otters marking territory against Red Fox Vulpes vulpes in Findhorn Bay so perhaps this is a somewhat similar case?

Anyway, I passed that spraint today and actually collected it and will be taking apart later to try and see what the local Otters are eating.

I continued wading upstream from this piece of spraint to see if there were any more bits for me to see and possibly collect. Here’s a map showing where I found each of the 5 spraint sites.

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I had thought that I’d be able to find information on the usual intervals along a watercourse that Otters spraint at, but found nothing. I’m thinking that maybe it depends on the watercourse. The close togetherness of the spraint on the Braid Burn may be due to the likelihood of other Otters discovering the area, or because it’s easier to cover the area in markers since it’s not such a big area, or because of how busy the area is (people/dog-wise)… I dunno. On the other hand, perhaps I’ve not looked hard enough for this information! I did find a couple of good sources of information on Otters; one is a little more information heavy than the other.

Anyway, from that map you can quite clearly see they are pretty evenly spaced apart (except the last two) and the pictures below give you an idea of where the spraints are being placed…

To put it simply, on rocks. I have a feeling this is actually because most of the large logs have been washed downstream by all the rain we had towards the start of the year, but I might see if there’s a running theme of my patch Otters only placing spraints on rocks.

You’ll maybe notice I have only shown 4 photos above, despite saying there were 5 spraint sites. The fifth one is actually in a spot that I’m not going to disclose because I suspect the Otters may sometimes use it as a place to lie up during the day, called a holt or a couch. I’ll maybe place my trail camera there when I get it!

Now for some dissecting of stuff that actually smells pretty surprisingly nice! I mean, it’s not the best smell but it’s not unpleasant. I’ve heard it described as smelling like jasmine tea!


 

Right, well that took a wee while to take it apart and get the bigger bits out, but I’ve managed, with perhaps slightly less signs of diet as I’d hoped. But there are still things to learn! (also, if you’re exposed to a concentrated enough amount of spraint, it begins to smell not so nice, more fishy)

For starters, here’s the spraint being broken up in some hot, disinfectant-filled water…

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Otter spraint water

Well, what did I find?

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One thing I was slightly expecting was for there to be a lot of frog bones in the fresh spraint, considering the recent spawnathon that has been under way in ponds across the country. This was the case (I think)!

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Suspected frog bone fragments

Above, from left to right:

  1. No idea
  2. Maybe the ball joints at the top of the femur?
  3. 4. 5. Think these are parts of the tibiofibula

This wee exercise taught me that frogs have tibiofibulas as opposed to a tibia and a fibula. This makes sense as it gives frogs a far better anatomy for jumping. Toads have it as well. I wonder if newts do… It would appear not.

Next up, the usual food of Lutra lutra, fish!

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Bits from Otter spraint

From top left to bottom right:

  1. Fish rib, this is the only part here that I’m pretty certain is from a fish.
  2. I think this and number 3 might be scales, but they feel very bony and hard, as opposed to slightly flexible and thin…
  3. See number 2…
  4. 5.6.7. I really have no idea what these bits are. Maybe 4 and 7 are parts of scales, after having a look with the hand lens. The hand lens has revealed that 5 and 6 are actually a bit more interesting though…

If you look at the pic below you’ll see that there are small circular things coming from this piece of bone (or cartilage or something else?). It almost looks like peas bursting from a pod.

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Anyone know?

Could this be part of a jaw? The only fish I’m aware of living in my general area are Brown Trout Salmo trutta, Stone Loach Barbatula barbatula and maybe Minnow Phoxinus phoxinus. Not sure whether that helps with ID but now you know how little I know about fish!

I have no idea what this is, so if anyone thinks they know, do tell!

The other bits and pieces are really just fragments of bone and things that I have no chance of identifying.

Anyway, I hope that wasn’t too boring. Hopefully, when I have my trail camera, I’ll be able to supplement all of this with pictures of the Otter(s?) Lutra lutra that live on my patch! And there’s always the possibility of getting Pine Marten Martes martes when I’m up in Aberdeen…

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Pine Marten caught on trail camera on my campus
Otterly fascinating

Keeping Busy

This time of my life appears to be full of things needing done or in the process of being done. It’s great, I’m loving it! So many brilliant opportunities and just fun, exciting stuff that I have going on. However, between writing articles and application forms, and replying to emails, and volunteering, and birding/botanising/being a naturalist… I do sometimes find myself lacking things to do. And I mean besides tidying my room and taking the bin bags out…

Nevertheless, I always find some wee project that I can do to fill the time. Going back to chores for a second, I did a little bit of helping around the garden for my mum recently. Gardening is my favourite “chore” as it’s one of the few in which I’m outside, and for that reason I don’t really see it as a chore.

I realised how good gardening could be last year, when I saw my first Tree Bumblebee, Bombus hypnorum, on a Cotoneaster. A good spot since they are only just spreading into this part of the UK!

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Typical, dodgy iPhone-bumblebee shot

More recently, I was shearing off the edges of a Lawson Cypress that we have in the garden (I want mum to replace it with a Rowan or something) and then went on to trim the top of a hedge, and finally mum told me to go and cut the raspberry plants from last year so they were shorter.

As I was doing this, I realised that they would be quite good for weaving as a small fence for around my pond to keep all the litter and leaves out that have been blown across the field (and also to dissuade a certain small child from throwing large rocks in it). It worked well!

I was also cleaning out the leaves from my pond when I noticed little bivalves in amongst the leaves, which turned out to be an Orbshell Cockle species; Musculium lacustre.

My most recent wee spare-time project was dissecting a Tawny Owl, Strix aluco, pellet that I found on top of Agassiz Rock on my patch. Here’s my post in the Wildlife Tracks and Signs group on Facebook…

Tawny Owl, Strix aluco, pellet. Agassiz Rock, Edinburgh, Scotland. 22 Mar 2016

Owl pellets can be great for finding out what small mammals you have present in your area. My first time “pelleting” was unfortunately done on what I thought was a Tawny Owl, Strix aluco, pellet but turned out it was a misidentified Red Fox, Vulpes vulpes, scat.

I have learnt since then and this one is definitely a Tawny Owl pellet. I gave “pelleting” a go again and it has yielded results! I followed this guide made by the Royal Society for the Protection of Birds (RSPB):https://www.rspb.org.uk/Images/Owlpellets_tcm9-133500.pdf

The jaw bone that I found in the pellet keyed out as being from a Field Vole, Microtus agrestis. I did know they were present in the area but you never know, I might’ve found a Water Shrew, Neomys fodiens, which has been reported as possible in the area.

I suspect I’ll be looking for more owl pellets now that I know where to look, and I suggest you try it too!

So the end message here is, there’s always something to do! Whether it’s for your own learning, for conservation, for advancing your career, whatever. There’s always something to do.

Last thing: before typing up this post, I pestered the council about the loss of wetland habitat on my local patch, and asked them whether anything would be done. So there’s another thing to do; pester people! Speaking of which, I need to call about the high turbidity (there’s a word for you to Google) of the burn running through our campus. It’s as a result of the work of the Aberdeen Peripheral Route and can’t be good for the ecosystem involved at all.

Keeping Busy

Back to Buteo

The past couple of days have been ideal raptor weather, with some staggering, almost unbearable highs of 13 degrees C! Plus nice clear, blue skies and now that I’m looking, there was a light southerly breeze. Not ideal conditions for the Merlin Falco columbarius that I spotted buzzing a Buzzard, just a few minutes after Geoff Morgan had said “weather now perfect for a good raptor… Merlin N maybe or dare I hope for a Red Kite….” I also had 1 Peregrine, 3 Buzzard, 2 Kestrel and 1 Sparrowhawk.

Just perfect timing! It was the 3rd bird I looked at after 2 Buzzards. Now, speaking of the good old double buteo, I’ve had plenty sightings of those recently too.

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Kestrel – Falco tinnunculus

The first Buzzard I’ll have a go at ageing will be this one that I photographed today soaring over the field, and saw displaying over Blackford Hill yesterday. Awesome watching them go into that full stoop then slight pull-up, then into a stoop again.

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The first thing that is obvious is that this bird is missing a couple of primaries (P6+7?) and if you read my previous post on Buzzards, you’ll know that there’s a local Buzzard that I knew which was missing primaries. Is this common in Buzzards? Something I’ll keep an eye out for.

Right, from what I already know, this is an adult as it has a fairly parallel/straight wing-shape, with the nice dark trailing edge and the square-shaped tail. Easy enough, however, I want to take this a little further.

With all those features so clear, I reckon that rules out 2CY as then it would show some plumage details that would say juvenile, such as a slight lack in the dark trailing edge. This means it’s either 3CY or 4CY+.

I’ve read here, on Geoff’s blog, that adults tend to have longer inner primaries. That may explain the missing primaries as this bird could be moulting into it’s 4CY, with those average length inner primaries having just fallen out. Confusing stuff this moulting…

Next Buzzard…

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I reckon I’d go for straight up 4CY+ bird on this one. All the adult features are there pretty clearly…

Here’s that same bird being mobbed by a posse of Carrion Crows.

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Last thing on Buzzards, these two (and another) were all submitted to ButeoMorph, and it seems I’m currently responsible for 4 out of 5 ButeoMorph reports from Scotland! Come on, we’ve got to do better than that, plus it’s easy and will no doubt produce interesting results at the end of the study!

 

I’ll finish off with a quick round-up of how my Braids n’ Blackford Patchwork Challenge is going. Since I’ve been back in Edinburgh, I’ve added 15 species.These include:

  • 2 falcons, Peregrine and Merlin, both 2 pointers
  • Pied Wagtail, Meadow Pipit, Skylark, Pink-footed Goose all vismigged whilst looking for Ospreys
  • And wee things like Long-tailed Tit, Treecreeper and Tawny Owl

Speaking of Tawny Owl, I managed to find a pellet whilst scrambing about on the rocks in the quarry. Soon to be dissected!

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Back to Buteo

Gull Counts

Just a short post because I feel like typing.

On Thursday I decided to do my second complete BirdTrack list of the month on patch. I headed out at about 3 and got back about 5:30 after a reasonably successful count. Highlights of Collared Dove, Stock Dove, Buzzard, and just the lovely appreciation of common birds such as Goldcrests in a Yew, and a Treecreeper actually settling down to roost in a hole it had made in the bark of one of the Coast Redwoods Sequoiadendron sempervirens in the arboretum on campus.

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Chaffinch Fringilla coelebs

One number that particularly stood out on that list (and my first list of the month) was the number of gulls flying over. The gulls I was counting were ones heading back to roost nearer the coast after feeding inland. Mostly Herring Gulls but with a few Common Gulls passing over in wee groups, plus the occasional Black-headed and a single Lesser Black-backed.

I was intrigued as to how many gulls were really flying over, so on Friday I decided to go to the back of my campus where there’s some slightly higher ground, and just count all the gulls that were heading over Craibstone, Brimmond Hill and the south side of Dyce.

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I actually missed the start of the movement as I was finishing off my last bit of work for this term. However, I was there in time to see a huge number of gulls heading east. The largest group of Herring Gulls I counted in one view was 54, and 33 for Common Gull.

My end total was 531 Herring Gulls, 64 Common Gulls and Black-headed Gulls. Quite a number! I’ll maybe head out earlier some time in the next week to see how many I can count from when they begin moving. Perhaps doing the count from a higher vantage point (Brimmond Hill) in clearer weather (not raining) with my scope would be better. Plus I might be able to see where all these birds are coming from. Hm, future mini-project in the making I think.

This spot of skywatching also resulted in a Patchwork Challenge tick in the form of 3 drake Mallards that were flushed from some of the wetland that has been accidentally created by the construction of the Aberdeen Western Peripheral Route.

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Before starting on the gulls I spotted 3 of the pairs of Oystercatchers nesting on the various buildings around campus. Speaking of Oystercatchers, I’m helping out with a survey of urban nesting Oystercatchers in Aberdeen this year, which is nice! Getting designated a nice big area to cycle about and plot them on a map.

That’s the end of this wee post. Just felt the need to blog.

 

Gull Counts

Birding returns to BirdingWithGus

It’s been a wee while as all my typing has been focused on handing in work! (birding more towards end, but you might as well read the other stuff, eh?)

Therefore, this is just a quick catch-up from the past while. To start off with we’ll head back a few weeks to Tyrebagger Forest where I was meeting the North East Scotland project officer for Saving Scotland’s Red Squirrels. Steve took a wee group of us around Tyrebagger, West Woods and across to Kirkhill Forest where there were various hair traps already in situ.

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Hair trap for squirrels

The idea here is that a squirrel (or Pine Marten) will climb up (or down) the tree to grab a snack. When they open the lid of the feeder their head/neck will rub on a sticky bit of plastic, depositing hair for us to send away to be DNA tested so as to work out whether we’ve got Reds or Greys (or, again, Pine Marten). I’ll keep you updated as to what’s going on with this project. I think we have to check the traps every couple weeks… I should probably find out… And then send away the sticky plastic bits from each month for each trap.

Just a wee note here, possible Pine Marten Martes martes tracks in West Woods. They were about the right size but not very clear so I’d rather not say these are marten tracks.

Next up, Elrick Hill, where I was removing gorse 2 weeks ago. This may seem an odd thing to do as gorse is native and provides habitat and all that good stuff, but the habitat that the gorse was taking over is quite a unique habitat this close to Aberdeen (gorse also fixes nitrogen but I’ve forgotten why this is a bad thing). The majority of Elrick is covered in Heather Calluna vulgaris, Cross-leaved Heath Erica tetralix, and Blaeberry Vaccinum mytillus. Within this heath are Rowans Sorbus aucuparia and Scots Pine Pinus sylvestris dotted around with a few Silver Birch Betula pendula. This is a great habitat that the rangers want to conserve, but it’s quite difficult given some of the other species that are taking over: Rhododendron, Lodgepole Pine, Bracken, Gorse, spruces… seems everything is against them! Good thing there’s a group of us that help with the removal of such plants that can completely dominate an area.

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Apparently there’s a few Red Grouse Lagopus lagopus about

Next, more voluntary! Thinking about it now, if I was even paid minimum wage for each hour of voluntary I do, I’d probably be able to afford a new camera so you guys aren’t subject to my wee compact camera that has pieces of leaf inside the lens!

Anyway, yeah, Sands of Forvie NNR where I was helping with putting up the tern fencing. This is fencing that goes around the ternery there so as to keep out Foxes, dogs, people, Badgers, etc. so there’s actually 2 fences that go up. One is a general sort of netting fence and the other is just two slightly electrified lines to add some extra dissuasion.

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Suspected Peregrine Falco peregrinus kill site

In total they have 900 metres of fencing to put up so I think we helped a fair bit when we pitched up half way through the day after letting the other volunteers start the job for us. We actually finished pretty much just in time as the snow became very, very heavy and cold and grim. A good day of work though.

The Little Terns Sternula albifrons tend to nest on the rocks to the left of the pic below, although the rangers were saying that, being Little Terns, they’ll nest on the rocks outside the fence and below the waterline. Nevertheless their ternery is growing in size, with Sandwich Tern Sterna sandvicensis Arctic Tern Sterna paradisaea being the only ones that have plateaued to a breeding population that isn’t increasing. I’ll be back once they’ve all returned and started breeding as I’m told it’s quite the spectacle!

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Getting back to botany stuff, briefly, I doubt that I’m going to be finding many flowers out until I head back down to Edinburgh as the snow hasn’t really stopped yet, with the occasional layer being added every few days. Although I did get my first Bumblebee of the year at the window on a particularly sunny day, and my first spring migrant in the form of a Lesser Black-backed Gull Larus fuscus (quite a dark one) on my walk to Lidl!

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Returning to that Mountain Hare Lepus timidus skull that I picked up ages ago; it looks great and smells not so bad now! Plus I cleaned my mates Roe Deer Capreolus capreolus skull that he picked up at Forvie. I didn’t really want it because its nose had been snapped off so the incisors were missing.

Right, here comes the return of birding to birdingwithgus.wordpress.com! A nice thing to watch has been the various pairs of Oystercatchers Haematopus ostralegus that have returned to campus and been feeding in fields all around, but one pair in particular have been feeding behind my halls so I get great views from my window. At one point I noticed a crow was pestering one of the pair and the other one came in and said, “I’ve got your back,” so to speak.

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Over the weekend I took a break from work and decided to venture out into the local area, as I almost always do. This was very, very productive in terms of raptors as I had, in total, 2 Buzzards Buteo buteo, 3 Sparrowhawks and the last raptor species comes with a wee story because it was a lifer… In fact, due to the status of this species I reckon I’ll skip the story as it might give away details of where it was, not that I think any of my readers are the sorts who would cause harm to a Goshawk (!) but I’d rather not risk the information getting into the wrong hands. But Goshawk, what an awesome bird! Think I had two displaying over the trees beyond me, couldn’t quite tell, so I had to run through in wellies so as to get these two rather blurry shots of my first Goshawk Accipter gentilis (male).

I always think that the scientific name for this bird is so ironic as they really aren’t very gentle at all. As a gamekeeper (boo, hiss) once told me, “You always know it’s a Goshawk kill because of all the feathers everywhere, absolutely everywhere.” I suspect I may have found the site of a Gos kill in the area I saw this one/these two and there were feathers absolutely everywhere, but that really just deepens my interest in this perfectly adapted predator.

Here’s a better pic of the Goshawk’s smaller cousin, Accipter nisus, and the two Buzzards that were enjoying the warm thermals that we’ve been lacking so much recently.

Finally, to finish off, I’d like to commend Birdtrack on the terrific job they’ve done with the recent update. I decided to update the app on my phone today as I feel I’m not keeping to my resolution to do more recording, and after one session of sitting at my window just counting whatever went by, I found myself not wanting to stop! Anyway, highlights from 15mins at my window were…

  • 106 Herring Gull, 18 Common Gull, 1 Lesser Black-backed Gull (the Lidl bird?) all heading inland
  • 10 Fieldfare, 2 Yellowhammer, 2 Stock Dove, 2 Collared Dove and a Grey Heron (Patchwork Challenge 2016 tick!) all flying high over the campus
  • 2 Great Spotted Woodpecker, 1 Jay, 1 Buzzard and 1 Sparrowhawk all travelling around on the campus

Speaking of Patchwork Challenge, I can recommend the monthly podcasts! I was listening to the March podcast whilst typing this up!

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Typical hybrid, with the dark flanks and undertail coverts. Maybe a 2nd or 3rd generation hybrid considering how dark it is in these areas. Notice the flecks on the lens of my camera.
Birding returns to BirdingWithGus