Seals on Rona

So, the weather has officially turned chilly. It also shows a mischievous streak, springing heavy (hail) showers on us with unwanted repetitiveness. This makes our lives a tad more difficult for many reasons: it is certainly not as easy to see the seals in the rain, particularly rain blowing in from the north-east as it has been recently; neither Cammy nor the cameras we use to record behaviour are particularly fond of the rain; conducting photo surveys in the rain is not possible, and furthermore manual dexterity is substantially reduced in the cold making what you may think of as easy tasks a real challenge, such as holding a pencil. Nevertheless, we are persevering using the two powers that we Brits fall back on in times of adversity: moaning (as demonstrated by this blog) and tea. Indeed, our feelings towards the weather are shared by one of the seals…

It was sad to see one of the earliest pupping females leave today: Monachs L. As in previous years, she’d been an adventurous soul, choosing to clamber up a small mountain (in seal-terms), miles from the access point (in seal-terms) to give birth to her pup. After 3 amorous males caught her on her way back to the sea (that we saw), she left her now rotund pup and successfully re-traced her flops back down the slope and eventually down the rock gully back to the sea. Charlotte wishes her a very happy, fish-filled year away from Rona.

Although we promised a pic update of Des, there’s been so much bad weather, we haven’t a decent one, so watch this space. Mum and pup are doing fine tho’.

More inspiration – a potential plot for the next Indiana Jones film: “Indiana Jones and the Grey Box of Doom”. The ‘grey box’ is a food storage facility outside of our hut, approximately 3m x2m. Kelly called It the grey box of doom/death because, like the island’s gulls, it has a taste for blood. To date, in the battle of wo/man vs. box, wo/man is winning. In fact Amelia and Luke vanquished the box last night, with Galaxy chocolate bars and popcorn as their reward.

Yesterday we explored the rocky west coast of the peninsula here – known as Sgeildighe. Rona is mostly composed of a type of rock called gneiss, which has formed vast cliffs and caves around the island. The edge of Sgeildighe is an impressive cave that penetrates into the heart of Rona, if you follow the cave up its entire passage, you emerge in the ‘blow hole’, where a number of our study females like to hang out. At low tide we were able to enter the opening at sea level. It was wet and slippery and bright pink. Large male seals lurked all around. The cave is pink because it’s covered in pristine Corralina algae,exposed at low water and the seals watched us curiously while we explored and took photographs (while also sheltering from the rain!).

So far this field season the photo-ID tools wielded brilliantly by Amelia have identified over 130 individuals who have been photographed previously. Of these, approximately seventy are from our study catalogue of named females that Paddy can recognise by eye, without the aid of the computer. By using the computer programme to help us to match photos we have almost doubled the number of “recaptures”. This is a powerful tool to allow us to look at the history and movements of animals that we hadn’t “known” previously. Great news!

Updates: Look at Des – he’s getting fatter by the day. Also scarf colour number 3 has been reached! Some heavy work days lie ahead, we’re keeping our fingers crossed for reasonable weather. Well, you can but hope…

Luke writes:

The breeding season here has finally peaked, and we are seeing a drop in the rate of births on the colony. Nevertheless, there are still a few births every day, and we’ve been trying our best to record them. It is amazing to see how quickly the pups adapt once they’re born. They can be pecked quite viciously by gulls looking for a quick meal, but most can look after themselves! The mothers will also staunchly defend their newborns, and we’ve seen what can happen to the gulls if they are not fast enough…a few have broken wings. The pups seem to race to see how much weight they can gain before weaning. This weight gain is astonishing, with pups averaging around 15kgs when they’re born and anything up to 55kgs when they’re weaned around 18 days later. The mothers then return to sea, leaving the fat little ‘weaners’ on their own. We’re beginning to see the first of these weaners, who will hang around the colony for a few weeks before heading to sea themselves. Amelia pictured one of the first weaners yesterday.

Des and mum are right up the slope near the top of the hill, and looking good. Another pic will follow soon.

A note from Charlotte: Happy Anniversary to her mum and dad, Helen and Peter. Hope you go out to celebrate somewhere nice.

The weather has been chillier today, with strong NE winds finding their way past most layers of clothing.

There are a few mountaineering mums perched on the upper part of the Leathad slope now. One of these is just below the hide with a new pup. We’re in the process of checking if she’s new to the catalogue and will keep a running update on her and her pup’s progress (the pup is sooo fluffy it’s being called Des).

More thoughts (spawned by long hours in the hide) on seal types (with no reference to any manufacturers of any products sounding similar). You may want to play this game at home:

IMBEseal – like its human counterpart, not the sharpest tool in the shed; FRAMEseal – gets the blame for others’ misdeeds; sealIAC – has a very special diet; WINDOWseal – just a pain; BLASTOseal – drifts around aimlessly until it settles somewhere and then things develop

All well, with in my case a little antibiotic help, and although the rainbows are back, hail has also appeared…

As predicted, the weather has taken a turn for the worse over the past couple of days (typical), meaning that Cammy tests have taken a bit of a hit. Not deterred, we ventured to the hides in the rain yesterday and were pleased to have a productive day on ‘BirthWatch’, recording 3 more births. The similarly exciting ‘GullWatch’ is providing some useful observations too, with our noticing that many individuals sit in vantage points around the colony until the scent of birth wafts their way. Then what can only be described as pandemonium ensues, with gulls hustling amongst each other for scraps of umbilical cord or placenta whilst often dodging protective lunges from new mothers, who are extremely protective of their pups and probably dazzled by swathes of grey and white. It appears that the large adult greater black-backed gulls get “first pickings” of the placenta shortly after it has been delivered (or at least noticed), with juveniles fighting over leftovers later on. Evidence of a “pecking order” me thinks… We have a number of other birds on the island, including the graceful northern fulmar (see picture), rock pipits, kestrels and merlins. Recent arrivals also include colourful migratory redwings, winter visitors from Iceland.

Hopefully this turn of the weather will prove fruitful for our somewhat lacking water supply, both of our wells are pretty low. Don’t worry, we collect rainwater outside the hut so if worse comes to worst we can drink this (and there’s always beer of course). The rainwater, however, may have an “essence d’uric acid”, courtesy of the murmuration of starlings that tend to hold important meetings on the hut roof – generally first thing in the morning.

Also, the rainbows have disappeared. We are quite alarmed by this, but are leaving food-gifts outside of the hut for the Leprechauns as a peace offering in the hope that they will sort this out for us.

Today marks our half way point. Here’s to an equally enjoyable second half.

In a previous blog we told you that we think the seals breeding on Rona have different ‘personalities’, and today we thought that we’d talk about noted differences between some of our girls. Take Jolene (can you spot the ‘JL’ on her?), a female we’ve seen here in many seasons – she’s a “feisty lady” and can be aggressive towards other seals when she wants to be, but is a good mum usually. This can’t be said for Femsneck, who has a habit of abandoning her pups, or Sigma who has been known to steal pups to raise alongside her own! Other females such as O8 seem to be pretty good mums year on year, but occasionally have a blip – last year she abandoned her pup before weaning. Other females seem to relish motherhood and can be very socially attentive, for example 15-4 often plays with her pups which can be fun to watch.

Grey seals are ‘capital breeders’ meaning that they breed and feed at different times. This means that Rona mums usually stay with their pups from birth to weaning (approximately 3 weeks) without leaving them to go to sea and forage. Breeding therefore requires a large energetic investment from females – a 200kg mother can lose 80kgs raising a pup. Therefore differences in how females use their energy reserves become very interesting. Investigating ‘personality’ differences (like we do with ‘Cammy’- see Luke and I at the office below!) can help us to view variations in energy expenditure from an interesting perspective: for example, do mums such as 15-4 who are more socially active with their pups transfer their energy (or fat reserves) less efficiently than others, who may do the minimum required to raise their pups to a viable weaning weight? Exciting ideas!..

We managed to record more births today, adding to our collection nicely. These videos will be really useful later on for assessing the impact that gulls in the colony might have on newborn pups (they seem to have a taste for blood, you see).

Today has been poor for rainbows (only 3) which is sad, but on the plus side it was lovely and sunny with very little wind- we could almost have been somewhere in the Caribbean! Pina Colada anyone? Of course, we’re now expecting a hurricane tomorrow as we have planned to do Cammy tests out amongst the seals… (I’m renowned for my optimism you know…).

Yesterday a plane flew over the island – this is the first aircraft we’ve seen here, and it wasn’t just any old plane, it was our colleagues from theSea Mammal Research Unit – Callan Duck and Chris Morris. They are photographing grey seal colonies to help estimate how many grey seals there are in Scottish waters. Over the years it has been found that the number of grey seals has been increasing in Scotland. However, the situation in North Rona is different, as the population here is declining. Therefore, linking the findings of the aerial surveys and our work is particularly important, as any discoveries we make could help us to understand factors influencing changes in colony size and structure. For example, does the decline in number of animals breeding at North Rona lead to a shorter breeding season?

Over the past few days we have extended our photo identification surveys to the north of the island. We were surprised on our first visit to “the north” to find a strange grey seal ecotype: the “croco-seal”. These animals are very similar in appearance to our familiar greys, but have a habit of submerging in the deep pools found at this end of the island, waiting to surprise naïve researchers. One such seal, shown here, almost had us in the pool with her, so severe was our reaction to her unexpected emergence to breathe! From adventuring around the island for these photo surveys, we have continued to identify a lot of old faces – seals that return to North Rona to breed. We found Banana up north – she hadn’t been seen in the south for a few years.

We have also been continuing with our “Cammy” tests and have now managed to successfully test 6 individuals, and are having much better luck with pot-holes- good progress!

Other miscellaneous points of interest: rainbow count now somewhere in the millions; scarf colour number 2 has been reached; rum is running worryingly low (as is water…come on rain!); Amelia is STILL obsessed with ‘Bananagrams’ and has been playing by herself recently, and we have just discovered how to take panoramic views of the island using Charlotte’s camera.

Ladies, gentlemen and children….introducing CAMMY, son of ROCKY! We’ve already mentioned in our blogs that we know individual seals at our colony, and indeed, that we have known several of them for many years. Over this time, we have realised from our observations that contrary to popular belief, grey seals are not just grey blobs that eat fish. Indeed they seem to have distinct ‘personalities’, just as we see elsewhere. For example, some animals are naturally more “relaxed” than others no matter what whilst others seem “bolder” or “more aggressive”. We test this in the colony by recording different individuals’ responses to a mildly alarming sound stimulus – a wolf call. This is delivered by our specially designed RCV (remote controlled vehicle), aka ‘Cammy’. We have started conducting these “Cammy tests” this week and have managed to successfully test two animals (even if Cammy did take a couple of tumbles down some hidden pot holes…!). Charlotte and Luke showed great determination on the first test day, waiting outside in seemingly endless rain showers for a Cammy-friendly break. Points for effort?

In other news, we have objectively observed that there are an unusual amount of rainbows (even of the double variety: what does it mean?!) on North Rona. We have determined that this can mean one of two things: either this is a magical isle where dreams can come true, or alternatively an indication of what can only be described as variable weather conditions. We favour the former and are now simultaneously on the look-out for leprechauns and pots of gold at the bottom of the rainbows in our study area, as well as births.

Finally, Amelia has become obsessed with ‘Bananagrams’- a favourite evening past-time. Friends and relatives, you should be worried. Is “Ai” really a word? Also, Luke found a carrot today that he truly believes is shaped like a seal. Make of this what you wish…

We saw lots of births yesterday – the season is definitely picking up. Three of the known animals pupped yesterday – one of them did a great job of diverting the gulls away from the newborn pup. After giving birth, she moved a metre or two into a pool where she delivered the placenta. Moving back to the pup, it was left to an adult GBB to find the placenta and heave it (it weighs about 2-3 kgs) into the shallows where about 15 other gulls descended on it, all away from the pup and mum.

Luke and Amelia take time out to explore the interior of St Ronan’s cell in the village ruins.

Since we last blogged the science has been kicking up a gear! We’ve been on “Birth Watch” which involves long days of sitting in the hides and watching our girls to see who’s likely to pup. So far we’ve managed to film 3 live births, however it seems that the seals know how to time their births inconveniently and many give birth when we leave the hide! Quite a few old favourite mums have shown up already including: O8, Boobies, FFN, Parsley, Dancer, SM and Alien and not all have pupped yet so hopefully we’ll capture a couple of their births.

Today we went catching to weigh and measure seals in the colony. We do this so that the weights of this year’s pups can be compared to those of previous years, giving an indication of how this breeding season compares to others. In doing this we soon discovered that pups are neither small nor cuddly!!

One evening Paddy gave us a a brief history of Rona, including the story of St Ronan. St Ronan came to the island with his 2 sisters. However, after he made a comment about his sister’s “fine legs” one day, the happy trio were separated. One sister decided that relocating alone to nearby Sula Sgeir was a sensible idea under the circumstances. Later we went to find St Ronan’s “cell” in the village ruins. Having survived 1400 years of gale force winds, we were impressed by it’s sturdiness (but not about having to crawl into it!).

Next time we will be reintroducing….. Rocky IV!