The author and journalist Simon Barnes once observed that in nature conservation, the light at the end of the tunnel often turns out to be an approaching train. These words, wrought from the sort of wry humour that’s a necessity in this line of work, were brought to mind this week following the abrupt conclusion to the breeding season at the Forvie ternery.

After the avian ‘flu debacle of 2023, we entered into the 2024 season with a degree of trepidation, lest the situation should repeat itself. After all, one duff season every now and then isn’t the end of the world for Forvie’s seabirds, but when you pile failure on top of failure, things start to get rather more urgent. In the event, though, not a single case of avian ‘flu was recorded throughout the entire 2024 breeding season. What a relief – and surely some cause for optimism?

Well, to some extent yes. In the final analysis, the numbers will show that with the exception of Black-headed Gull, all our key breeding species actually increased in number from 2023 to 2024, despite the horror-show the previous year. The early part of the season was very encouraging, with all species laying good numbers of eggs and enjoying a high level of hatching success. But the breeding season here is a long haul, and it’s not until the young have actually fledged that we can judge the success (or otherwise) of the season as a whole. And despite the promising start, it was late in the piece that we began to notice some very worrying signs. Here, perhaps, was Mr. Barnes’ approaching train.

As has often been the case in recent years, the early-nesting species – namely Black-headed Gull and Sandwich Tern – had a good solid season, and ended up producing satisfactory, if unexceptional, numbers of fledged young. Neither species seemed to have too much trouble keeping their chicks fed, and the mortality rate at the chick stage was very low (notwithstanding the dreadful weather throughout much of June and early July). However, the smaller species – Arctic, Common and Little Terns – appeared to find life much more difficult.

In the case of Little Tern, we already knew that predation was a problem, with the adult birds having moved their chicks outwith the protective electric fence (excuse me while I face-palm myself). But perhaps more worrying, in the bigger scheme of things, was the situation emerging among the Arctic and Common Terns.

As we’ve explained before, Forvie’s Arctic and Common Terns are dealt with collectively when carrying out the annual nest-census, as their eggs and chicks are so similar in appearance. The proportion of one species to the other in the colony is then determined by means of feeding-counts, i.e. counting the adult birds arriving at the colony carrying fish for their chicks. Usually, the tricky thing about these counts is separating your Common Tern from your Arctic Tern as they rapidly fly past you. This year, however, the problem was not so much identifying each individual bird (this is, in fact, straightforward enough with experience), but rather ascertaining whether the bird in question was actually carrying a food item. Basically, it appeared that most of the fish being brought back to the colony were pitifully small.

In mid-July the breeding colonies of the various species all began to wind down and clear out. This is a perfectly normal process at this stage of the season. But this year, something felt different. Firstly, the scale and speed of the clear-out were remarkable: we went from practically a full-strength ternery to almost complete abandonment within less than two weeks. Secondly – and even more startlingly – the estuary and beach were also devoid of birds. Something was clearly amiss.

In an ‘ordinary’ season (for if there is such a thing), when the birds clear out of their respective breeding colonies, they relocate to the adjacent beach and estuary. Here they join forces with birds from other colonies which are passing through the area on migration. In recent years it’s not been by any means unusual to count upwards of 4,000 Arctic Terns alone in South Forvie in late summer, with thousands more Black-headed Gulls, Sandwich Terns and others alongside them. It’s one of North-east Scotland’s genuine wildlife spectacles, and over the years many happy hours have been spent trawling through the great flocks to pick out a Roseate or Black Tern, or watching the aerobatic antics of the Arctic Skuas working over the flocks and hoping to steal somebody’s catch.

But this year, nothing. Just an empty beach and an empty estuary. The whole place feels like a ghost town. Danny used the word ‘eerie’ to describe the silence and emptiness of South Forvie this week, and I am inclined to agree with him.

In trying to rationalise what we were seeing, we started to piece together the information we had, plus snippets from other observers. Chatting to a knowledgeable angler on the Ythan, he remarked upon the paucity of Sea Trout this season both here and on the nearby Ugie Estuary, citing the lack of ‘bait fish’ (Sand-eels and the like) as a reason for the poor showing. Meanwhile, other seabird biologists had noted a similar lack of oily fish being brought in during the second half of the season, with all kinds of weird and wonderful items being substituted (including prawns, flatfish and even insects). It appeared that the change had happened suddenly and abruptly, as if the food supply had been switched off overnight. In the fullness of time, with the completion of the season’s monitoring work at seabird colonies throughout the North Sea, the full picture will be revealed.

At this stage, speculation is rife, but it appears that high sea temperatures in the North Sea have effectively caused the food chain to collapse. Water temperatures affect the distribution and abundance of plankton, which in turn affect the small fish (most notably Sand-eels), which in turn affect the higher predators – whether terns, trout or marine mammals. What we don’t know is whether this is a temporary blip, or a sign of things to come.

It’s easy to think of climate change as something that may-or-may-not have some sort of vague effect upon everyday life. Sure, some faraway places might get flooded, or other places burnt up by wildfires, or Polar Bears might have to swim further between ice floes, or whatever. To many ordinary folk, these things might seem abstract and irrelevant. Ultimately, though, the impacts of a changing climate will affect all and sundry. Rachel Carson famously wrote of a silent spring, with regard to the effects of agricultural chemicals in the 20th Century. But the thought of a silent summer along our coasts, as a result of climate change in the 21st Century, is similarly heartbreaking.

In summary, then, the 2024 seabird season appears to have been a case of out of the frying pan and into the fire. Having recovered from the carnage of avian ‘flu in 2023, we now find ourselves in the situation I had been dreading for the past seventeen summers, with the collapse of our seabirds’ food supply. What remains to be seen is whether the events of recent weeks are an anomaly, or turn out to be the new normal.

Fingers crossed, already, for 2025!