Black grouse counts in 2007

In the spring of 2007, we surveyed leks in the North Pennines as part of our black grouse recovery project. The results showed an 18% increase in numbers since 2006. We estimate the population to be close to 1,200 males, exceeding our 2010 Biodiversity Action Plan (BAP) target of 1,000 males. We are also making progress towards our other 2006 BAP target of expanding the range from 43 to 48 occupied 10x10 kilometre squares. We recorded black grouse displaying in the spring on the southern fringe of their range in the Yorkshire Dales in 10x10 kilometre squares where they had been absent in the 2006 survey.

On our long-term study sites, we found a total of 80 greyhens, but only 23% had broods, at an average of 0.3 chicks per hen. This breeding success is the lowest since 1996 (see Figure 1) and was caused by prolonged wet weather in June coinciding with the peak hatch. This is a setback, as productivity was lower than the 1.2 chicks per hen required to maintain population stability.

Figure 1. Black grouse breeding success in northern England between 1996 and 2007. The horizontal line at 1.2 indicates the estimated level of productivity required to maintain a stable population.