Yesterday, our team went out to another photo-ID survey of harbour seals in the Galway Bay Complex SAC. We had to be extra careful not to cause any disturbance. On our last survey in March, we found a dead premature pup in that area. While this provided an excellent opportunity for genetic sampling of this colony, it was also a cause for concern. Thus, with pupping so close, we did not want to cause any stress on this month’s survey. We were approaching the colony at a low angle and stayed a good distance away, hiding in the grass across the water. Using our 600mm lens, this still provided good photographs that we can manually match to previous encounters to identify individuals. At the same time, the seals took no notice of us. A few of them took their heads up in our direction upon making our way to the site. However, we kept a low profile and we slowly approaching so that they did not appear stressed and very soon lost interest.
First off, we noticed a juvenile grey seal female among the group. Grey seals do frequent this area and we commonly observe 1-3 grey seals around on our harbour seal surveys and scouting trips. Soon after our arrival, this juvenile left the area.
We stayed in our little hiding spot for a few hours observing the seals. This allows getting an idea of their behaviour at the site and offers the opportunity to get photographs from different sited per individual if these turn around. A group of seals to the left of the colony was hauling out very close together as you can see in the picture here. This can make it challenging to obtain photographs suitable for identification of all animals. Luckily, we managed to get at least one suitable aspect of all these individuals. A so called-aspect is an area of the seal that can be used to match it to a previous encounter. We use the following areas: head, neck, chest, flank and abdomen (i.e. the ventral side).
It was a particularly sunny day considering this is Galway and we only had one little shower throughout the survey. Do you know the feeling when being out in the sun for a bit and you just get tired for no reason? Well, we do. From what we observed, the seals seemed particularly lazy and tired as well and were yawning more than we would usually observe. (Side note: this is just us making a funny observation with no scientific evidence). Here is a few of them yawners for you, because who doesn’t love to look at those pictures? :)
The survey site is located at the channel in Tawin and there is an area, where the currents meet just in front of the haul-out area. The two seals in the front of the lower picture above (one of them the yawner), are juvenile harbour seals. They took full advantage of these currents earlier on. The juveniles were displaying very playful behaviour swimming at full speed at jumping around where these currents meet. They were doing this solitary using the currents one after the other and showing off some good moves including playful behaviour such as porpoising and torpedoing. For anyone who is interested, a nice description of some playful behaviours can be found in these old but valuable studies by Wilson (1974) and Renouf & Lawson (1986). Some more up to date analysis of harbour seal behaviour - and specifically of adult males - can be found in this thesis by Nicholson (2000).
One of the adult seals was also seen swimming around for a little while before hauling out, albeit without the playful behaviour. As it found its spot within the colony, we noticed that it was wounded within its head area (see image below). We did not notice any sign of this when it first hauled out and did not observe aggressive behaviour between this seal and another individual. Upon closer inspection, it appears that this might be a small wound and just became apparent when the fur dried and the bloody area stood out. There does not seem to be any loose or missing skin. Keeping in mind that the species’ breeding season is underway, intraspecific aggressive behaviour may occur and we will keep monitoring this in addition to interspecific behaviour with grey seals in the area.
Overall, this was a successful trip with 24 harbour seals hauled out towards the end of the survey and one grey seal that left the area. We obtained photographs for identification from 20 of these. The remaining four seals were on an island further off and were too far away for suitable photographs. Now it's time for matching, we'll keep you posted :)