Another update about the breeding season from some of our key species! This one focusing on our cliff nesting seabirds in 2019. For those of you who might be less familiar with the reserve we have a small number of seabirds on the cliffs from Collieston all the way down to Rockend where the cliffs give way to beach.
The number of Kittiwakes nesting at Forvie has varied considerably over the years, with a steady decline in the late 1990s/early 2000s being followed by a partial recovery, since then numbers have fluctuated from year to year. This year we identified 387 nests which is a drop from last year but overall a fairly average total for this site in relation to the previous few years!
Fulmar numbers have also fluctuated widely at Forvie from one season to the next, with a breeding population of between 180 and 360 pairs in most years. The long-term trend has been for a slow decline since the late 1990s. This years census found only 56 fulmar sites the lowest total since recording began on site in 1986. The previous lowest total has been very recently in 2016 with 73 nest sites. There were higher numbers than previous years of fulmars loafing around on this cliffs not on nests so perhaps there was a chance for some late breeding attempts here to boost these numbers.
Both Guillemots and Razorbills breed at Forvie in small and relatively recently-established colonies. Both species increased steadily in numbers from the late 1990s up to 2012, and have fluctuated slightly from year to year since. 2019 seen an increase in both species over the previous year with 148 razorbills and 59 guillemots!
The Cormorant colony was first recorded at Forvie on this monitoring programme in 2002, with numbers increasing to a peak of 93 nests in 2006. Since then the population has become very variable between seasons, and the colony was abandoned altogether in 2017. 2018 seen the return of 2 nests but this season recorded no Cormorant nests in 2019. It would appear that there is an exchange of birds between local colonies each year, including one just to the north of Collieston village (personal observations of Daryl Short) so no nests this year does not mean that cormorants are not having a good year overall.
Two pairs of Shags nested at Forvie in 2019, both at the traditional nesting site on the stack at the Corbie Holes (unfortunately we don’t have any pictures of shags). This particular site has been occupied by a single pair most years since at least 2000! A second pair has been present in recent years since 2014.
Herring gulls on site have undergone an alarming decline between 2010 and 2011 (315 to 144 nests). Although the herring gull population somewhat recovered in the subsequent seasons the decline continued reaching the only 37 nests in 2019, and sharp decline from the 63 nests in 2018. Similar to Fulmars, this is the lowest breeding population recorded since surveying began in 1986, exceeding the previous low in 2016 of 45 nests. Since surveying began at Forvie in 1986, the breeding population of Herring Gulls has declined by some 95%.
For the ninth consecutive year, no Lesser Black-backed Gull nests were recorded, and no adults or immature birds were noted on the day of the survey. Although loafing birds can still occasionally be seen at Hackley Bay this species has become locally scarce in recent seasons.
One Great Black-backed Gull nest was located pictured above! We were lucky enough to see the little chicks around their nest area on top of a sea-stack, taking its place at the top, definitely an apex predator in the colony of seabirds. The numbers of GBBGs have been low at Forvie for some time, back in 2007 there were 7 nesting pairs but this year and in 2017 seen only one nest. Like with the other species the reason for the species relative scarcity in recent seasons is unclear, but there has been a distinct decline since seven nests were recorded in 2007.
All in all, the census for the seabird season provided some positive news but mostly a continuing trend of worrying news. Some of the species are holding their own, but species like fulmar and herring gull suffering further declines, peaking with their lowest nesting season yet. With the proximity of the tern colony on the south end of the reserve which overall is doing extremely well, food supply for the cliff nesting seabirds was likely not a problem as it seems to pose no issue for the terns which share much of the same food supply. When looking at these population trends like our loss of cormorants on site for example its important to take in the bigger picture. While it is a decline for cormorants at Forvie, further north along the coast might see an increase, so that bigger picture needs to be taken into account. We send all our data into JNCC as do other sites so that a full image of how the seabirds are doing can be assessed! This will help us understand how our seabirds are really doing looking into next season.