For Red Grouse the combination of a late cold Spring left hens in poor condition when nesting, not least by the near total failure of cotton grass which is a major source of spring protein for grouse. The exceptionally warm dry Summer that followed reduced the insect population on which new grouse chicks feed. The result has been a dramatic drop in grouse population on the high uplands.
Grouse remains an entirely wild bird, neither reared nor released commercially, and ultimately reliant on nature being kind to grow numbers. There is a limit to the extent to which moor owners are able to manage habitat to increase numbers of red grouse, which remains on the BoCC4 Amber list.
There is a strong likelihood that the weather has affected the Black Grouse population, which until 2018 had been showing steady growth. The Black Grouse seem willing to feed on lower ground on this moor, so we are hoping the dramatic fall in red grouse won’t be as marked in the Black Grouse population – we’ll know better next Spring.
A group of Durham Wildlife Trust young volunteers visited in May and July to count what birds they could see in designated spots.
Two years don’t show any trend, but that does not mean the results aren’t dramatic.
What of other birds on the moor? How have those populations fared?
It is clear that the weather pattern for 2018 has been very different from 2017, both in temperature and the amount of rain. The upland temperatures, and volume of rain is always (or always feels) lower and higher respectively than is recorded in the nearest town along the River Wear below. Our two charts here show that it was generally both colder (January) and hotter (June/July) in 2018, and that the sustained rainfall was significantly greater in 2018 too.
It would have been surprising if this didn’t impact on the birdlife population, certainly on the higher upland moors. We anticipated that our annual monitoring project, in its second year, would provide evidence of the scale of the impact made by such a marked year of weather extremes.
What we see clearly from comparing 2017 to 2018 is a significant change in both the range of birds and the numbers of those identified year on year.
First, good news for the Curlew and Lapwing populations which seem to have been unaffected by the year’s weather, with an extended wet Spring probably suiting their nesting and feeding requirements. For the same reason we shouldn't be surprised that the Graylag Goose made an appearance.
Most striking from the monitoring report is the number of larger predator birds that are added to the list this year. Buzzards, Kestrels and even a Peregrine Falcon all make an appearance. That may be because the weather has made them have to range further, or spend more time in the day, in search of prey, which in turn may have increased the competition for food for regular residents such as the short-eared owl.
The increase in predators may also have resulted in fewer gulls, sensitive to the potential of being someone else’s dinner. While this is a natural order of things, the deterrence factor of birds of prey is well recognised.
The absence of the stock dove suggests perhaps that they’d been dinner for predators already.
The lack of crane fly larvae, which will most certainly have impacted on the number of Black Grouse for 2019, may also be a reason for an apparent absence of the lazy and opportunistic jackdaw that no doubt found an easy source of food somewhere else.
The value of our small monitoring project with Durham Wildlife Trust and the Young Volunteers will gain significance as we add information year on year. For the current Young Volunteers it has been an exceptional couple of years in being able to see the dramatic impact of weather the birdlife of our wild uplands.
For now the moor waits to see how the year ahead will fare. Despite the conservation management efforts on our uplands, we are at the mercy of the weather as to what happens next. Until next year and our third round of birdlife monitoring, who can tell?