Hope Farm Winter Monitoring Results 2023-24

Today’s blog by Duerden Cormack, Monitoring Assistant, gives us the latest results of the winter bird counts at Hope Farm, Cambridgeshire.

The winter of 2023/24 has been exceptionally warm and wet with just a couple of days of freezing conditions. In fact, this has been the wettest winter we have experienced at Hope Farm since we began farming here in 2000. This has made my job of choosing suitable survey days quite challenging and on one count the rain stopped just minutes before we were due to get out into the field! Warmer, wetter winters are a predicted consequence of climate change and if winters such as this one are to become the new normal, our wildlife and farmers face some serious challenges.

To monitor our wintering birds, a team of volunteers conducted surveys on one morning in each of December, January, and February. We use a whole area count method, where the farm is divided up into different areas and each is covered by an individual or pair of surveyors. All birds using the farm are recorded, mapped, and later digitised which allows the total number of birds of each species using the farm to be calculated.

Keen surveyors on a rare, frosty morning.

This winter saw some huge counts and in total we recorded 12,664 birds of 49 species including 15 of the 16 possible Farmland Bird Index species. Table 1 shows the dramatic improvement in abundance and diversity compared to the original surveys conducted in the winter of 2000/2001 when the RSPB first took on ownership of Hope Farm. In that winter 1178 birds of 32 species were recorded including just 9 of the 16 possible Farmland Bird Index species.

Table 1: Comparison of Hope Farm winter counts for Farmland Bird Index species.

Using these counts we produce a Winter Bird Index for RSPB Hope Farm which gives a measure of the average change in the numbers of these 16 species. For 2023/2024 the Hope Farm Winter Bird Index reached 31.41 compared to the baseline of 1 in 2000/2001 (see Figure 1). Accounting for year-year variation this equates to an overall average increase of 1546% or an average year-on-year increase of 13%. This shows that our winter bird populations are resilient and are able to recover strongly after dips, such as happened between 2016/17 and 2020/21. The winter of 2023/24 produced our highest index yet, but before we reach for the champagne there are some underlying trends to consider.

Firstly, this winter saw high numbers of Woodpigeons. As other arable farmers will be well aware Woodpigeons can be a major pest species of Oilseed Rape crops by consuming leaves and buds. In the baseline winter of 2000/01, we had relatively low numbers of Woodpigeons so in years of abundance they can boost the index. Similarly, this winter we experienced high counts of Jackdaws and Rooks due to a large winter roost in the nearby woodland. As with Woodpigeons these high corvid counts contributed to the increased index this year despite them being species of lower conservation priority. Interestingly, it has been noted since at least the 1940s that although Rooks can be a pest of newly sown crops, they consume enough soil invertebrate pests to be considered a net positive contributor to the arable farm.

It wasn’t all false positive this winter though as we did have good numbers of some threatened farmland passerines. Skylarks were abundant in our cover crops before they were grazed off by sheep and we hosted a large gathering of 1000+ Starlings in the early winter (coinciding with an exceptional roost at nearby RSPB Ouse Fen). As well as this, our January and February counts of Linnet (1076 and 973 respectively) beat our previous highest count of 733, a record only set last winter, by some margin. Yellowhammers had another good year too with a high count of 591 and although 6 Corn Buntings doesn’t compare to last year’s exceptional count of 128 (link: https://community.rspb.org.uk/ourwork/b/science/posts/hope-farm-bird-monitoring-results-2022-2023), it is still 6 more than wintered here in 2000/01!

Counting Linnets.

Linnets appeared to be finding enough food in our winter bird seed mixes (funded as AB9 options in our mid-tier stewardship; £732/ha, profit £424/ha) throughout the winter which is a good sign that we’re delivering seed rich habitat for this species effectively and they are not becoming too dependent on supplementary feed. On the other hand, despite leaving an unharvested cereal headland of Spring Barley (funded as an AB10 option; £1072/ha, profit £711/ha), buntings and finches had moved on to supplementary feed by January. This might suggest that we may need to tweak our management to ensure we are providing enough bunting-palatable seeds throughout the winter or perhaps that the wider landscape is lacking seed rich habitats. Alternatively, the mild weather this winter might have increased the amount of available invertebrate food which could explain why supplementary feed wasn’t depleted as rapidly this winter as in previous years.

Overall, we had a good season here at Hope Farm and despite the rain it was enjoyable to be out surveying. Besides our indicator species, notable highlights include a Merlin hunting Skylarks, five species of wader recorded on a single survey (Snipe, Jack Snipe, Woodcock, Lapwing, and Golden Plover), and several mobile Grey Partridge coveys. As I write, Chiffchaffs have arrived in good numbers, Blackcaps have started to sing, and a Greenfinch is building a nest in the yard. All good indicators that I need to get out in the field for summer surveying!

3 of a covey of 7 Grey Partridges.

To hear more about our work on the farm please subscribe to the RSPB Farming blog page or in the meantime you can now find us on Twitter @RSPBHopeFarm for farm news, habitat management updates, and wildlife sightings.