Partridge Count Scheme

Partridge & Biometrics

JOIN THE PCS

The country’s wild grey partridges need more land managers, especially those with only a few grey partridges, to join the Partridge Count Scheme. Find out more at gwct.org.uk/pcs.

Partridge Count Scheme

Effective partridge-friendly management helps support partridge populations and advances recovery. © Kalina Georgieva

KEY FINDINGS

More than 6,600 grey partridge pairs were recorded in 2020.

National productivity, recorded as

Young-to-Old ratio, increased by 24% to 2.6 young birds per adult.

National autumn density averaged 20.2 birds per 100ha, an increase of 7% from 2019.

Neville Kingdon Julie Ewald

The results of the 2020 spring and autumn grey partridge counts from the PCS are summarised in Table 1. A total of 530 spring counts were received, 6% (31) fewer counts than for spring 2019. Although disappointing it is not wholly unexpected, with delays in counting due to the wet start to the year, followed by the Covid-19 lockdown that prevented access to count areas for those not living on-site.

Despite this, PCS participants were still able to count 6,654 grey partridge pairs over an area of 171,900 hectares (ha) (424,800 acres). This was a 10% decline from the 7,406 pairs recorded in 2019, due mainly to the decline in the area counted. Average pair density across all PCS sites nationally remained stable at four pairs per 100ha (250 acres), but eastern England, Midlands and Scotland recorded regional declines of 13-19% from their 2019 densities.

The long-term trend in spring pair density on long-term sites (those participating before 1999) remained stable at an average of 5.7 pairs per 100ha (see Figure 1). This analysis adjusted for site turnover and missing counts, as not all sites managed to return counts in every year. Meanwhile, ‘new’ sites recorded a 7% decline in pair density, with an average of 3.4 pairs per 100ha.

In autumn 2020, 500 counts were received, an encouraging increase from the 476 of 2019 (see Table 1), especially as it is the first rise in autumn counts returned

Figure 1 40

Trends in the grey partridge spring pair density, controlling for variation in different count areas

Long-term sites

New sites

ACKNOWLEDGEMENTS

We are extremely grateful to GCUSA for its ongoing support of our grey partridge work.

Spring grey partridge pairs per 100 hectares (95% CL)

35

30

25

20

15

10

5

TABLE 1

Grey partridge counts

Densities of grey partridge pairs in spring and autumn 2019 and 2020, from contributors to our Partridge Count Scheme

Number of sites Spring pair density Number of sites Young-to-old ratio Autumn density (spring) (pairs per 100ha) (autumn) (autumn) (birds per 100ha)

Region 2019 2020 2019 2020 Change (%) 2019 2020 2019 2020 2019 2020 Change (%)

South 81 79 1.5 2.4 60 74 84 1.8 2.3 8.8 12.5 42 East 175 151 5.3 5.2 -2 129 145 2.1 2.4 25.5 19.9 -22 Midlands 103 92 2.6 3.1 19 87 84 1.8 2.2 11.7 14.7 26 Wales 2 2 1.5 1.5 0 2 2 0 1.5 0 7.3 730* North 123 127 6.0 5.1 -15 113 117 2.2 3.0 28.4 34.0 20 Scotland 76 79 2.7 2.4 -11 70 68 2.2 2.9 10.9 14.2 30 N Ireland 1 0 9.9 0 - 1 0 0.8 - 22.0 - Overall 561 530 4.1 4.0 -2 476 500 2.1 2.6 18.8 20.2 7

* Small sample size. The number of sites includes all that returned information, including zero bird counts. The young-to-old ratio is calculated where at least one adult grey partridge was counted. Autumn density was calculated from sites that reported the area counted.

for over a decade and looks to have been due to the expectations of it being a good partridge year. Indeed, the number of grey partridges recorded nationally was 26,163, a 36% increase (over 6,900 birds) from 2019. This was from a total area counted covering 161,600ha, 5,200ha more than in 2019. Eastern England continued to report the greatest share of national grey partridges, with 11,889 birds recorded (45%), and northern England saw 6,594 birds (25%). Sadly, with the retirement of our one remaining participant site in Northern Ireland, that was re-establishing a sustainable population of wild grey partridges, we no longer have insight into partridge numbers from across the Irish Sea.

UK productivity, measured by the average Young-to-Old ratio (YtO), increased from 2.1 in 2019 to 2.6 in 2020 (+24%); this was one of the highest national YtO ratios in the past 10 years. This is positive news and raises expectations of an increased potential for breeding pairs in spring 2021, although regionally Wales did not achieve the YtO threshold level of 1.6 necessary to cover adult losses into next year.

The average national autumn density was 20.2 birds per 100ha, an increase of 7% from 2019. Southern England saw a 42% increase to 12.5 birds per 100ha, but other than Wales it still remains the region recording the lowest autumn density. The Midlands and Scotland reported increases (26% and 30% respectively) each with over 14 birds per 100ha. Grey partridge densities in northern England also saw a large increase (20%) to achieve the highest regional autumn density of 34 birds per 100ha. Although eastern England recorded a density decline (-22%) it still recorded the second-highest regional density with 19.9 birds per 100ha.

The 2020 partridge counts witnessed the full gamut of conditions and consequences of the spring and summer weather. Many sites benefited from local conditions and their habitats provided them with one of their best years for grey partridge chicks in a long while. But for others the conditions were just too much, and they lost all their broods, the combined effect of poor crop and habitat germination, lack of chickfood insects and even flooding from heavy downpours onto parched ground. Retaining as many birds as possible through to spring, and ensuring partridge-friendly management for 2021, is the best way to address this.

The Partridge Count Scheme is our primary method of collecting information about grey partridge numbers across the country. It relies on the continued interest and enthusiasm of farmers, gamekeepers and land managers to count their ground. We encourage all readers who have wild grey partridges on their land to join. When it comes to grey partridge conservation and recovery –‘Every one Counts’. Go to gwct.org.uk/pcs to find out more. BACKGROUND

Partridge counts can offer valuable insight into how well your partridges breed, survive and benefit from your habitat and management provision throughout the year. Each count (spring and autumn) is easy to carry out and helps assess the previous six months without the need for continual monitoring. How to count:

Spring: Ensure winter coveys have broken up and breeding pairs have formed – typically in February and March. Record all pairs and any single birds.

Autumn: Wait until most of the harvest has finished – ideally between mid-August and mid-September. Record adult males, adult females and young birds in each covey separately. Don’t assume a covey is two adults and some young.

Use a high 4WD to cover more area in less time. Drive each field perimeter and then criss-cross using tramlines to minimise crop damage. Binoculars help when examining each pair or covey. www.gwct.org.uk/pcs.