Weaned pups and grown-up fights

Once again we are approaching the end of our photo-ID effort at the study sites. Following last year’s pattern, the mood at the haulout sites in Orkney has considerably changed over the last couple of weeks. Most of the pups have been weaned which means the females are free to go foraging before they start moulting.

Pup suckling at one of the haulout sites in Orkney

Pup making the most of the fat-rich milk before weaning time arrives

The haulout sites are now filled with the newly weaned pups, some of which are not quite over the fact that the good days of suckling the fat-rich milk are over. If the opportunity shows, they will try to get some extra feeds from the few females that are still suckling their pups. Despite their best efforts, they tend to get discouraged fairly quickly either by the females or by the pups holding the right to suckle. In the video below you can see a female coming to shore followed by three pups, two of which are just wanting that extra feed. However, they quickly realize that’s not going to happen and go back into the water.

On some occasions females seem to tolerate the presence of a second pup and might allow it to rest near by,  but again, that doesn’t last long if the pup attempts to get too close. That’s exactly what seems to occur in the next video, also captured in Orkney. This female came onshore with two pups and started suckling one (assumed to be hers) while tolerating the presence of a second one of similar size. However she quickly snapped that pup to presumably stop it from approaching any further.

To better understand whether this phenomenon is down to just a few pups or is more widespread, we do try to get pictures of the pups as well as the adults. Because pups are born with their adult coat, they already have a characteristic and unique pelage pattern. By identifying pups we can attempt to estimate how long are pups seen in association with their mothers, how long does the lactation period last and whether pups will suckle from different females.

Female Or098 with her pup on 14th July 2017. This wee guy has a wishbone mark on his left cheek!

Or098’s pup on its own on 16h July 2017. The same wishbone mark can be seen in the pelage pattern on his left cheek.

As pupping season comes to an end, preparations for mating and moult season are well underway. Some of the bigger males have been seen more regularly at the haulout sites in Orkney and have offered all kinds of displays. These go from simple grunting exchanges with other males in the distance, to fast swimming along the haulout sites, throwing seaweed around, as well as proper physical fights. In the next video we captured two harbour seal males fighting; the younger one (smaller) had been warming up by doing the seaweed throwing as well as grunting, and got even crossed with an unfortunate pup that was at the wrong place at the wrong time. Luckily it was all just a big scare and the pup managed to haulout and recover from the unwanted fight. However, the young male kept on challenging a much bigger male, until they started to fight. After a resting period, they both took it back into the water, where full body flips and jumps were seen from the distance. After that, they both rested on land, like nothing had happened.

While the adult males are busy maintaining territories and fighting with other males, some of the younger seals are well into their annual moult, while other adults are just starting it off. The first seals to moult are those with the oldest coat, which will be the pups born last year, as well as the very young seals that also moulted early last year. The old hair is brown and in patches, but the new coat showing underneath displays gorgeous and distinctive black and white patterns. The moult period is an itchy one, and seals can be seen scratching themselves as the old coat gets slowly replaced by the new one. Is in this time of the year when seals spend a higher proportion of time hauled out onshore rather than in the water. The moult is an expensive period in terms of energy, as warm blood is circulated very close to the skin to help the new hair grow quickly. To avoid losing energy by getting cold in the water, seals spent much more time onshore.

Adult harbour seal starting to show signs of the annual moult

Moulting male harbour seal; all the old brown hair will fall and be replaced by the new coat

This young female is already showing her new coat around the head and shoulders

 

Haulout-site neighbors

For the last three weeks I have been a very busy bee in Orkney, hence the delay on updating the blog! The pupping season is advancing with giant steps, pups are getting bigger every day, some others have already been weaned and adults are showing the first signs of the annual moult!

The weather has mostly been on our side with overcast and slightly breezy days, which make photo-ID a much easier job. However, we’ve had our share of sunny and calm days, which make photo-ID a tricky business as the seals look all hazy through the lens and the pelage patterns are really difficult to identify. And there is always the risk of unwanted midges company! Very wet and windy days also pose a challenge as it’s hard to keep the equipment dry and safe.

Sunny and calm day in Orkney = photoID with 10,000 midges.

A couple of weeks ago I spotted a grey and a harbour seal having a nice rest on a hot and sunny day, both with a telemetry tag on. The grey seal was tagged as part of a separate SMRU project, which is collecting data for the Met Office. Grey seals are often seen sharing the same haulout sites as harbour seals, although haulout sites of only grey or harbour seals are also the norm. In Orkney, all the of the monitored haulout sites where we collect photoID data are mainly harbour seal haulouts, but grey seals are also found in smaller numbers. In Loch Dunvegan (Isle of Skye), where Andy collects photoID data, it’s very rare to have grey seals sharing the same skerries, but sometimes there is the odd grey seal that shows up.

 

Grey and harbour seal tag buddies on a hazy day

Grey seal with a telemetry tag on one of the monitored haulout sites in Orkney

Grey and harbour seals have different haulout behaviours. While grey seals seem to be ok hauling out very close to each other, harbour seals prefer to keep a larger personal space around them. If another harbour seal or a grey seal comes too close, they start grunting and moving one of their foreflippers to keep the approaching seal away. Harbour seals will rather get back into the water and find a quieter space than staying too close to a curious grey seal!

Harbour seal looking rather unhappy with an approaching grey seal…

Two grey seals having a snooze at a haulout site in Orkney with harbour seal neighbours

In general grey seals will haulout and rest, but in some occasions some other action can be seen. Sometimes younger grey seals will curiously approach harbour seal pups, or simply stir the tranquility of the haulout by walking through the grey seal haulout, starting a sequence of loud and characteristic grey seal hauling. Last month, as I was taking pictures in Widewall Bay, in South Ronaldsay, I filmed a couple of grey seals playing-fighting at one of the haulouts. In my limited experience with grey seal behavior it looked like a male grey seal playing with a female and making a rather poor attempt at mating.

Despite our main interest being harbour seals, one cannot miss the other wildlife sharing the haulout sites, starting with the many species of birds that can be regularly seen. Black-backed gulls and great skuas patrol the haulout sites in search of a free meal. At the start of the pupping season large groups of greylag geese can be seen at or flying past the haulout sites, generally in a rather noisy way! Oyster catchers and curlews add to the sound track, very often giving away my hiding spot to the seals. At one of the study sites, which sits below a cliff, the seals are accompanied by the constant chatter from fulmars nesting nearby. Redshanks and ringed plovers can be seen on the sandy and pebble shores close to the water, and herring gulls can be often seen walking around the seaweed covered rocks by the water. It turns out they like to eat sea stars!

Ringed plover at one of the haulout sites

Herring gull eating on a sea star

As the summer advances, larger groups of arctic terns are making an appearance at two the the monitored haulout sites, the larger being in Widewall Bay. A couple of weeks ago there was such a large group of them that they frequently photo-bombed my photo-ID effort. I don’t think the seals were very happy with such noisy neighbours!

Arctic terns photo-bombing my attempts to photoID a harbour seal mum pup pair in Widewall Bay

But it’s not all birds among the neighbours… there are also some more infrequent visitors. Last week we had a surprise visit from an otter! She was seen swimming past the haulout site and ended up coming up on shore to undergo a good clean up. She then had a quick rest before going back to the water. I was lucky enough to be close by without being spotted and the digiscope system we use to get photoID data did the rest… check the picture and video below.

Otter spotted near one of the haulout sites in Burray

And finally, another marine mammal that can make an appearance is the killer whale. Killer whales are natural predators to seals, and are regularly seen around Shetland, Orkney and the north coast during this time of the year. I have personally never seen them nearby the haulout sites we monitor, but have seen them in other areas around mainland. Public sightings report them frequently in the Pentland Firth between Orkney and mainland, but also in the waters around Birsay. While going for a walk along Rerwick Head, at the north side of mainland, we were lucky enough to bump into a group of 5 killer whales that were swimming very close by the shore. After the initial excitement we managed to capture them passing by, see the video below. The group seemed to be composed by 1 male and 4 females or juveniles, the male having the very tall and straight dorsal fin. I seemed to recognize one of the females as Mousa, a female killer whale that is regularly seen in Shetland and Orkney waters. This female is also included in the catalogue of killer whales from Iceland (with ID number IS086). Like Mousa, some other individuals repeatedly move between Iceland and Scotland. These whales appear to feed on the Icelandic summer-spawning herring stock in the winter, and then move outside the summer distribution range of this herring stock (check more details on this published paper on the matter). More information on the Icelandic orcas can be found in their website and in their Facebook page

 

Half way

The end of June marked the half way point on our photo-identification effort during this year’s pupping season. At least at the monitored haulout sites in Orkney, all females seem to have given birth, as I cannot observe obviously pregnant females anymore. For what Craig tells me, he is still observing a few pregnant females in Kintyre ready to give birth. After all, he was the last one to observe the first pup this year. As for Isle of Skye, Andy has been going our regularly with the boatmen from Dunvegan Castle when the weather has permitted, and has had really good days counting around 130 seals hauled out and 34 pups seen! At the haulout sites in Orkney, numbers are much lower, with around 40 adult seals and 20 pups seen on average at the main pupping site.

Several mum-pup pairs in Orkney, well camouflaged!

With all the new pups around, the haulout sites are busy places. Pups seems to have their own agenda, going into the water quite often and consequently dragging mum behind. When not suckling or sleeping they are curious individuals and will explore their surroundings and neighbors. Other pups seem to be ok with other little ones approaching, unless they are getting too close to their food provider. Some adults tolerate pups that just get close to have a nice spot to rest, but will get rather annoyed with with pups that approach too close, especially if they are after suckling from females other then their mothers. Yesterday I came across a mum pup pair that hauled out right next to another two pups on their own. One of them came closer to inspect, until he got too close and got a grunt from the female (see photograph below).

Lonely pup (back) staring at another pup suckling

Pup climbing over his mum soon after hauling out

After suckling, some pups go straight onto having a nice nap, while others like to move and play around for a bit, like this one:

At this time in the pupping season, it is normal to observe pups on their own. Female harbour seals will go on short foraging trips during this time, and come back shortly after to suckle their pup. While this is normal for seals, it makes photo-ID life a little bit more complicated as it becomes a bit more difficult to link pups and adult females. Patience is definitely a key element. Sometimes pups left on their own will fall asleep totally unaware of what the tide is doing. When they fall asleep while the tide goes down they then wake up rather far away from the water, as it happened to this pup:

Lonely pup waking up rather far away from the water’s edge!

On a couple of occasions I have witnessed female harbour seals accompanied by two different pups. While twin births are rather rare in seals, fostering is a more frequent event. Sometimes inexperienced mums which might have had their first pup will get confused at a second pup approaching and will allow it to suckle. If a pup gets abandoned to somehow separated from its mum, it will try to suckle from other females. In both occasions, one of the pups seemed to be of smaller size and weight than the other one, which makes me think it was an abandoned pup not feeding as much as needed. In both cases the female seemed to be snappy at times with the second pup and at the end left into the water with just the bigger pup. Having to suckle a second pup is likely to have a detrimental effect on the survival probability of both pups, as resources have to be split and they might not put enough weight before getting weaned. At the same time, it might also have a negative effect on the female’s fitness condition at the end of the pupping season, potentially having had to use more energy resources than anticipated and potentially compromising her fitness for the next steps in her yearly cycle.

Female harbour seal with two pups. The one on the right was obviously much smaller than the other one. Both pups managed to suckle from this female.

A different female harbour seal with two pups again. After suckling the pup on the left, the female ended up swimming away with the pup on the right, which looked bigger.

Blog entry written by Mònica

 

Pups make an appearance in Kintyre at last

Patience is definitely a necessary virtue here in Kintyre, as pupping appears to start a good few weeks after everywhere else that we are surveying. However, I have finally spotted our first pups of the season here in Kintyre. I photographed two different mum and pup pairs on the 26 June at a site known as Island Muller, just north of Campbeltown. Last year, the first pup was observed on 23 June – so it is no surprise that I would have to wait a bit longer than the rest of the teams to see some pups.

First mum pup pair spotted in Kintyre!

This was the same seal photographed on 23 June 2017 – looking pretty large and evidently ready to pop:

Same female before giving birth and looking rather big

And here is the second mum-pup pair seen in Kintyre:

Count of mum-pup pairs goes up to two! about time…

The Island Muller site is interesting because a number of seals often haul out on skerries in the northern part of the small bay as the tide is going out, and then transfer over to a more extensive network of skerries in the southern part of the bay once the tide is sufficiently low for these to be exposed. This is great because it gives me two opportunities to photograph some of the seals. This is particularly useful if any of those hauled out on the northern skerries are in a position where I cannot photograph the sides of their heads or if they are being super lazy and not moving at all.

There have been a good number of obviously pregnant seals at the Muller Island site so I am looking forward to seeing more pups appearing over the next week or so.

Another of the soon-to-be mums at Kintyre

Written by Craig.

Busy haulouts

We use a digiscope system to photograph seals from the distance to avoid disturbing them

Pupping season is well underway in Orkney. Over the last few days, the number of both seals and pups has increased at the main haulouts, with less and less pregnant looking females and more tiny pups disturbing the quiet and peace of the haulout sites. Breeding season is a critical time in the life cycle of harbour seals, and so it is for us. One of the main objectives of the current project is to collect data on birth rates for harbour seals in areas where numbers of harbour seals are declining (such as Orkney) and in areas where the numbers have been stable or increasing (such as the West coast). During this time, we focus our effort at haulout sites that we know are used for pupping, and we try to visit them on a daily basis, weather permitting. So far, the weather in Orkney has allowed for almost daily visits to the selected haulout sites.

A count sheet and a waterproof notebook are essentials to our photo-identification data collection

When collecting data, we photograph as many seals as possible, ideally taking photographs from both sides of the head. If we see any obvious signs of pregnancy we will take notes to later on link those to specific photographs taken. The same goes if we can see a pup with a seal, but maybe we cannot manage to photograph the pup properly because it is hiding behind mum.

 

 

The first pups were seen in Orkney last week, with the first one being born to one of the females we tagged earlier in April. Just a few days later, another of the seals we tagged in that trip gave birth to her pup. She was seen at the haulout for a few days with a massive belly and looking rather uncomfortable. She is female Or085, known from our catalogue from last year. This female had spent the last few weeks, since she was tagged on 30th of April 2016, traveling and foraging around Scapa Flow, before returning to Burray to pup.

Female Or085 looking very pregnant a couple of days before giving birth

Movements of female Or085 during the weeks previous to having her pup

Or085 with her two day old pup

Or085’s new pup having a snooze after feeding

Births are a fairly quick business in harbour seals. When close to giving birth, seals can be observed changing position frequently, rather than resting still for long periods. Contractions can be observed and normally the birth will not be far from that point in time. Studies in Atlantic harbour seals near Newfoundland showed that the mean time from the onset of obvious contractions to birth was 3.5 minutes, with a minimum of 38 seconds and a maximum of 21 minutes (Lawson and Renouf 1985). That study also showed how newborn pups were very active, immediately trying to crawl and touch nearby objects. New mums can be seen making many nose-to-nose contacts.

Yesterday I missed the birth of two pups right in front on my eyes. The fact that the haulout-site is located in a rocky and weedy shore does not help, as I do not have full view of all the hiding places. When I arrived at the haulout I distinguished a seal with remaining of blood in her genital area as well as the face and flippers. After a while I distinguished a tiny pup behind her, who must just have been born.

Female harbour seal with a newly born pup hiding behind

Another seal kept moving further away from the water’s edge, and finally settled in a spot among the seaweed covered rocks. I photographed this seal the day before, when I noted she was massively pregnant. A while after, I saw there was more movement and suddenly a little head showed up! By then the female was busy checking on the pup while moving in circles to force the placenta out, check the video below! It did not take long for a group of great black-backed gulls to show up and take an opportunity to take advantage of the placenta. The pup was actively moving around, and the female kept on checking on it, while scaring off the group of seagulls. By the end of my watch the pup was suckling, and as the tide came in mum and pup went into the water. I will keep my eyes peeled today to see if I can photograph the pair again.

Female with a rather large belly resting photographed on 19th June 2017

The same female with her tiny new pup on 20th June 2017!

 

Post written by Mònica

New 2017 pups!

Pupping season has officially started in our Orkney and Isle of Skye study sites! Both Andy and myself saw the first pups during the weekend. Craig is patiently waiting to see the first one while monitoring the pregnant females at selected haulout sites along the Kintyre coast.

Harbour seals at Dunvegan this last week.  (Photo credit: Andy Law – SMRU)

Pups have a lanugo coat (white fur) while inside mum which they will shed before birth, so that when they are born pups already have their dark spotted adult coat. The pup seen in Loch Dunvegan seems to have a bit of white fur remaining, which can happen. Hopefully it’s only that and not a sign of having been born a bit too early. The pup, which had been seen by the boatmen at Dunvegan Castle for a couple of days before Andy saw it, cannot be more than a few days old, as the umbilical cord is still visible.

New pup in Loch Dunvegan with umbilical cord still visible (Photo credit: Andy Law – SMRU)

In Orkney, the first female seen with a pup was actually one of the seals we tagged last April. She is female Or021 in our catalogue and she was already a recapture from 2016. Last year she was not seen with an obvious pregnancy or with a pup, but this year the story is obviously different.

Female Or021 having a rest on wednesday 7th June with a fairly big pregnant belly

Female Or021 with her new pup, seen on friday 9th June!

I photographed Or021 last Wednesday, without a pup yet but with a big belly instead, and then saw her with her new pup on Friday and missing the extra belly. Checking on the seals on an almost daily basis allows us to estimate birth dates with a smaller error than if we only went once a week for example. In this case,  we know the pup was born sometime around Thursday 8th June (plus minus one day). On Sunday I went out and saw her again at the same haulout with her pup, who was suckling while she was taking a rest.

Female Or021 and her pup seen on Sunday 11th June

Or021’s pup having a short rest after suckling.

The second pup showed up during the weekend, as I checked the main pupping site in Burray. I could not see the pup to start with, just an adult seal checking on what looked like a wet dark rock hiding among the seaweed. That was no rock but a newborn pup! I must have just missed the birth, as the placenta could still be seen next to mum. Mum and pup made a lot of nose to nose contact while I was there. This female, which is Or148 in our catalogue, is a rather young looking female, based on her size compared to other adults. Last summer we photographed her, but never pregnant or with a pup, so this could well be her first pup. Female harbour seals reach sexual maturity around age 4, meaning they can start having pups around age 5. We will keep monitoring this and other females at the haulouts during the pupping season. By the look of it, things are about the get noisy and hectic at the haulouts!

Female Or148 seen looking rather pregnant last Friday 9th June

Female Or148 with a brand newborn pup on Sunday 11th June. The placenta can be seen next to the seal

Lots of nose to nose check ups between mum Or148 and her new pup

Written by Mònica

Familiar faces in Orkney

The second year of photo-identification collection has officially started in all three study sites, with Andy going out on the boat seal trips at Dunvegan Castle, Craig having settled in beautiful Kintyre coast and myself checking on the seal haulouts in Orkney. The first taste of photoID in Orkney was during our trip earlier in April to capture and release harbour seals in order to collect individual data on health condition as well as to deploy telemetry tags.

Harbour seals are so well camouflaged against the rocky shore! There are ~15 seals in this picture, can you see them?

During the first day out taking pictures we came across a group of 17 seals hauled out in Burray. I managed to photograph around 14 of those but had to give up on a few that were so comfortably sleeping that would not move at all to give me a view of the pelage pattern in their head. Once back in the office I checked the pictures and realized that I already had 13 of those seals in the catalogue of seals from last summer!

For example we saw Or146, a male harbour seal already photographed in 2016, who actually was seen fighting with another male last summer, as seen in the second video in this blog entry from last year.

Or146, a male harbour seal, seen on 16th April 2017

Or146 seen on 21st May 2016

We also spotted a known female, Or020, who we captured and released last year and then subsequently photographed during the pupping season. Last summer she had a pup, and by the looks of it she is likely to be pregnant again.

Or020, a female seen on 8th July 2016 with her pup to her right

Or020 seen on 16th April 2017

We also saw a couple of younger seals, which sometimes prove a bit more difficult to identify if their spot pattern in the pelage is not so well defined. However, that was not the case for this little female, Or105, already photographed last summer.

Or105 seen on the 10th June 2016

Or105 seen again on 16th April 2017!

We have not seen pups yet, but the first one cannot be far away from being born as the haulouts fill with pregnant females. Last week I photographed Or045, a known female from last summer, who had a pup last year and is currently very pregnant, as you can see in the photograph below.

Or045 looking very pregnant on 9th of June 2016

Or045 with her pup in 2016 (picture taken on 20th June 2016)

Or045 looking very pregnant this year (picture taken on 5th June 2017)

Information such as this will be recorded on an annual basis for all known and new females that enter the catalogue, and will help build up a database of information on which females were seen each year and whether they were seen with a pup or not. We will use such data to estimate birth rates in the different study sites. We can then compare those birth rates in study sites of contrasting population trajectories (e.g. study sites where the number of harbour seals have been declining or where they have been stable or increasing), which on its own will be very interesting given the very different population trajectories at different study sites (e.g. Orkney versus Isle of Skye). These birth rates together with survival rates that we will also estimate from the photo-ID data, can inform a population model for harbour seals. This model, which simulates what happens in a population over time, can be tweaked around with different scenarios of birth and mortality rates to understand which scenarios might be representative of the different population trajectories.

Meanwhile we will be going out to take pictures on a daily basis when the weather allows, counting the days until the first pup shows up… That day can’t be far given the activity in some of the females bellies! Check this wriggly pup in the video below:

Checking on Orkney seals…

Following our trip to Isle of Skye I had a couple of weeks of office based work, which allowed me to catch up with some of last year’s photoID data but mainly to finish organizing the upcoming photo-identification season at the project study sites in Dunvegan (Isle of Skye), Kintyre (West coast) and Burray and South Ronaldsay in Orkney. Once protocols, equipment and logistics had been organized it was almost time to head up to Orkney for our second trip in this study area to capture and release harbour seals in order to collect individual data, as we did last year. Like the 2016 trip and the recent Isle of Skye trip, the objective was to capture a number of harbour seals and collect individual data regarding their body condition and health, as well as to deploy telemetry tags on a sample of the adults. This information, collected annually and in different areas of contrasting harbour seal population trajectories, will help us get a better picture of what may be behind the decline in harbour seal numbers in the north and east coast of Scotland and in the Northern Isles, compared to the stable and in some areas increasing numbers of harbour seals in the west coast and Outer Hebrides.

Happy to be back in beautiful Orkney!

In mid-April we headed up to Orkney, aiming to finish the work within a couple of weeks. Despite having a rather summer-like weather at the start, things turned around very quickly and we were suddenly in proper autumn and winter weather for a good week and a half. We had snow, hail, and wind. And more wind, lots of it, which made working outdoors and in the water rather challenging. The team found extra energy where we thought we did not have it and we were out at every opportunity we had, working double tides if needed.

Phoenix the house cat was rather interested in our work

From summer to winter in 24 hours!

 

 

 

 

 

 

 

Getting snowed down… in April!

We were not the only ones disliking the weather though. Not surprisingly, the seals did not enjoy the heavy winds and chose not to use most of the haulouts where they normally would regularly come ashore to rest and decided instead to stay in the water, use haulouts out of our reach or only use those more sheltered. In addition to our limited ability to work given the bad weather conditions, most of the seals we captured in the first couple of weeks were mostly males, similar to what happened during our trip to Isle of Skye. This could have been caused by a segregation in the use of haulouts between the two sexes or maybe just by being unlucky and getting more males caught then females. Despite the challenging conditions our female scoreboard slowly started to fill up. A couple of calm and sunny days allowed us to travel further away to check on other haulouts around Scapa Flow, and we successfully caught another few harbour seals.

Good weather = exploring Scapa Flow coast line

 

Finally some calm conditions!

Overall, we captured and released around 20 harbour seals of different sexes and age classes and deployed telemetry tags on eight of the adult females. The tags, which are small and lightweight, are glued to the back of the head of the seals and will provide with detailed information on their location, movements and diving behaviour until they fall out sometime close to the start of the annual moult in late July and August.

SMRU GSM-GPS telemetry tags being tested before being deployed on seals

Despite tagging a very small proportion of the total population, the data we obtain from the telemetry tags are useful and interesting in many ways. For example, the location of the seals will inform and guide the photo-identification effort during the pupping season. Also, by looking at where and how often tagged seals use certain haulouts where the photo-identification data are collected, we can understand how representative our selected study sites (and the results coming out of those) are of the total population of harbour seals in Orkney. The telemetry data can also inform us about potential foraging areas, where we can get fish samples from to look at the prey availability and quality.

One of the adult harbour seal females tagged in 2017 in Orkney

The telemetry tags have been reporting back frequently and, similar to last year’s deployments, showing a variety of movements among the seals. The figure below shows the tracks of all 8 adult female harbour seals. For now most of the females have stayed within Scapa Flow or just south of it off Hoy and South Ronaldsay, but one female has taken a trip north to Shapinsay and from there she has been doing longer trips off the NW coast of Orkney mainland. For me I will keep a close eye on the whereabouts of these females, especially as we are approaching the peak in the pupping season in about three weeks’ time. Hopefully I will get to see some of them with their pups while I take pictures, and we can compare my observations with the results from the pregnancy tests conducted during the captures as part of the data collection on individual health status.

Movements from the tagged adult harbour seal females between the end of April and the end of May 2017

I almost forgot! We had an unexpected visit while we were up in Orkney, with a group of three fin whales showing up in Scapa Flow. The good weather conditions and the unusual sight filled up the roads between Burray and Kirkwall with curious observers. What a treat!

One of the three fin whales sighted in Scapa Flow in April

Massive blow from one of the fin whales, easy to see from far away

Blog post written by Mònica

First trip of 2017!

Dunvegan Castle

It has been a long time but we are back to update on the Harbour Seal Decline Project! We spent most of the autumn and winter processing all the data that were collected during 2016 (keep tuned for updates on that!). After months of office based work we were out again on our first fieldwork trip of 2017. In this first trip we headed up to Isle of Skye in early March, with the objective of capturing and releasing harbour seals to obtain individual data on their health and condition as well as deploying telemetry tags. The sites chosen to capture seals are located in Loch Dunvegan, and include the skerries where later on in the summer Andy will be collecting photo-identification data of the seals in collaboration with the Dunvegan Castle seal boat trips. These haulouts in Isle of Skye represent our study area where numbers of harbour seals have been stable or increasing, compared to haulouts located in our other study area in Orkney, where numbers have been declining by 75% since around the year 2000.

Loch Dunvegan from Dunvegan Castle boat slip

After a long day on the road we arrived to Dunvegan Castle where we met with some of the staff who very kindly showed us how to access the boat slip. The sight of around 100 seals hauled out right opposite to the boat slip was a nice welcome. However, the weather did not want to play the game and we had a good share of rain, wind and hail, with temperatures below 5 degrees for a good week. Given these conditions we started by checking out the more sheltered skerries close to Dunvegan Castle. During the first catching attempts we kept on  capturing adult males, but not a single female, suggesting different haulouts might be used differently depending on age and sex.

Sheltered skerry in Loch Dunvegan

To try and have a better idea of haulout composition, we took a road trip with the scope and the camera . The photographs confirmed that the haulouts we were targeting were dominated by males. We then learned that the boatmen in Dunvegan had named one of the skerries as ‘male island’… no surprise there! This segregation between haulout sites is known to occur in harbour seals, as other studies have shown (see for example the study by Thompson 1998 on harbour seals in Loch Fleet, Moray Firth, or the one by Harkonen and Harding 2001 in Norway.)

Seals taking a rest in Loch Dunvegan

Beautiful view of snowy Cuillins

In the current study we are mostly interested in adult female harbour seals, as information on their survival and birth rates will be compared between sites of contrasting population trajectories. With the hope of encountering a higher proportion of females we waited for a window of good weather and traveled to haulouts closer to Skinidin and Colbost. Luckily for us those haulouts had a better male to female ratio.

After the slow start we finally started to get more females, and deployed 8 GSM-GPS telemetry tags on adult females. These are the same type of tags that were deployed last year in Orkney, and will inform us about the movements and diving behaviour of the seals, as well as their whereabouts during the pupping season. The combination of snowy days and a last day of pure sunshine and calm seas left us with incredible views of The Cuillins. Since the tags were deployed we have been receiving regular updates on the seals’ location and movements. Below are maps with the movements of some of the tagged seals, showing individual differences in the extent of the movements as well as the areas visited by each of them.

Movements of seals tagged in Loch Dunvegan in April 2017

Track from female harbour seal with tag #507

Track from female harbour seal with tag #497

Track from female harbour seal with tag #211

Harbour seal with telemetry tag

The tags, which are glued to the back of the seal behind the head will stay on until they fall during the moult sometime in late July or August. During the pupping season they will inform us on the seals’ whereabouts, and hopefully the seals decide to stay around Loch Dunvegan for Andy to check on them and (hopefully) on their pups. Keep tuned for updates on these Skye seals and on our other trip to Orkney!

Harbour seal and a heron

End of 2016 fieldwork!

That’s it, after weeks of taking photographs, counting seals and looking for mum-pup pairs, 2016 fieldwork season has reached the end! The weather has unfortunately kept me indoors on my last day, and with that finish 80 days of going out on the field since the end of March, over 200 visits to haul out sites and more than 11,000 photographs taken in Orkney! Craig has also finished the season in Kintyre, and Andy will go out to check on the seals at Loch Dunvegan this upcoming weekend for the last time this year.

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I cannot believe fieldwork is over!

It has been a very intense but rewarding season. I have enjoyed spending so many hours out in the field observing the seals, and generated tons of (hopefully) great data. The good weather also helped, allowing me to go out almost everyday, missing on just a few very rainy days.

Some of the telemetry tags that were deployed back in April are still attached to the seals and sending information on their location, movements and diving behavior. The rest have stopped transmitting likely because they have fallen out with the seals’ undergoing their annual moult, as expected.

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Male with telemetry tag #260 in Burray on July 24th 2016

One of the seals that still has the tag on is a male with tag number 260 (see picture above), which I have lately seen hanging around at one of the haulout sites in Burray. He was initially tagged on March 14th 2016 in Widewall Bay and since then he has been moving within and out of Scapa Flow, spending a lot of time between Flotta and Burray.

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Movements of a male harbour seal with telemetry tag #260 between 14th March and 28th July 2016

When I took the previous photograph, this male had just come out of the water to haulout. After a while though, as the tide came up, he was not there anymore, and I couldn’t figure out where he had moved to. As I took my eyes from the camera and looked towards the water I spotted him silently checking on me, just a few meters away! I do sometimes wonder who is the one checking on who here…

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Male with telemetry tag checking on me!

The haulout sites will continue with their activity after I leave, with the last few pups being weaned, mating season already started and all seals except this year’s pups undergoing their annual moult. A few days ago I captured on video two males getting into a fight once again. The smaller of the two seals initially approached the bigger one just to exchange some growling, the bigger male not being too worried. Despite his much smaller size though, the youngest of the males ended up taking up the fight, to my surprise and, I think, the opponent’s!

Ahead of me there are a good few months of data processing and analysis. All those pictures that have been taken need to be graded for quality and then each seal needs to be identified in order to build a catalogue of seals in each area. These catalogues will be used when we come back in the following summers, to construct a sighting history for each identified seal, allowing us to look at the fate of each individual over time and estimate their survival rate. The pictures and observations taken this year will also allow us to know which females were seen with and without a pup, which will be used to estimate fecundity rates in each area.

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Two harbour seal pups resting

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Harbour seal pup taking a nap

Observing the seals has been great fun, and I have also enjoyed spending all these weeks in Orkney, what an amazing place! I am happy to have met and talked to so many people during my time here, and I am very grateful to the many land-owners that have allowed me to drive through and park in their properties at all times and days of the week in order to get to the haul out sites.

For now it’s a goodbye to Orkney and the seals, although I will be seeing them in photographs over the next few months. Keep tuned to this blog as I will update with news on how we are getting on in the upcoming months. Few fun seal pics to finish off!

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Big male yawning and stretching…

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Balancing seal

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Seal pup suckling, look how big he is getting!

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Seal sticking its tongue out!

Written by Monica