This past Sunday, we carried out our first survey for this year’s harbour seal moult when individuals spend long times ashore because they are shedding their fur. As their breeding season comes to an end, this species sheds the fur coat which usually takes time between August and September. To give colonies some time after the breeding season and not to disturb any pups, we waited until now to avoid any unnecessary disturbance. Surveys are carried out in five SAC’s around the Irish coast.
We arrived in Rosslare just about an hour before low tide as low tide is the best time to carry out surveys. I prepared the kayak and got the wet gear on. The site has quite strong currents and is very close to the opening of the bay into the ocean with strong sea states close by which made for a very exhausting trip over. However, this was well worth it as there were large numbers of seals on their haul-outs. Initial counts suggest about 20 harbour seals and over 60 grey seals. The species mainly hauled out separately though there was the odd grey seal observed amongst the harbour seal haul-out as can be seen in the photo.
When we finally made it to the small island where the seals haul out, we wanted to observe the animals for some time before going over to look for samples. So that the haul-out groups are not disturbed I lay down flat on the ground and approached animals from a flat position. I didn’t have to go too close as I managed to get the good camera with a 600 mm lens over. This allowed me to observe behaviour and also acquire really good photographs that can be used for photo-identification. As winds were strong, the sand was very high making observations a little more difficult considering I had my face pretty much under constant attack from sand. Here a photo of the group without zoom. Can you spot how many seals are in the picture?
The closest group was a small group of young grey seals that were very active. These were mostly females although a bull was observed as well. The animals were very playful and fighting each other. This is very common behaviour in grey seals and it was really great being able to observe this for such extended periods of time in the wild.
Towards the very end of the island, there was a larger group of about 60 grey seals. These were lying very close together in a large group, which is very common haul-out behaviour in grey seals. It was not possible to capture the entire group due to visibility with the sand and standing up all the way would have caused a stampede of seals. But you can get a good impression of just how close they were lying together in the below photo.
In contrast, harbour seals like their individual space and do not usually haul-out that close to one another. Individuals on this island were no exception as you can see in the photograph below.
The harbour seals were relatively quiet. Some were moving around a little, but mainly they were enjoying being lovely resting seals. One of the adults had a wound on its neck. It looked to be from a fight with another seal, either harbour or grey seal. However, no aggression involving this seal was observed and the wound was present from the moment we arrived on site. It seems like it lost some fur in the process as well, but this is not surprising considering that the moult started and it is shedding fur anyways.
From a photo-identification point of view, there were a lot of very different pelage patterns ranging from a very light seal with dark black spots to an almost black seal with light spots. For a few seals it was difficult to see the pattern in their fur coat as they were very brown and in the process of moulting. During their annual moult, the actual pattern can be hidden which makes it more difficult to identify seals. Juveniles quite often are observed with a brown coat where the pattern is difficult to see for a dry seal that is hauled out.
After observing the individuals for some time recording behaviour and taking footage for identification, it was time to disturb them and look for samples. All required licences were successfully obtained from NPWS and only a minimal time spent in the area to minimise disturbance. All seals went off into the water and we searched the area for scat and hair. It came as no surprise that there were no hair samples in the area. As it is quite an exposed site and mainly sand, all hair that harbour seals might have shed would have been blown away. However, there were a few scat samples. These were collected and labelled. They will be used as a source for genetic information of the colony.
For the remainder of the moulting season we will visit other sited around Ireland that are of importance for the species. The rocky area where seals haul out in Glengarriff makes for a good place to get hair samples. Let’s see what the next surveys will bring.