21/4/2023

Curlew nest protection: what works and what doesn’t work? A view from the New Forest

By Mike Short, Head of Predation Control Studies

After two consecutive years of intensive curlew nest monitoring in the New Forest, it’s now clear that foxes pose the greatest threat to curlew nest survival in our study area. Of the 41 curlew nests monitored with cameras in 2021 and 2022, 25 failed due to predation, and 17 of these were attributed to foxes.

But that’s not to say that lawful control of other species – like carrion crows – isn’t important, for they have also been recorded predating nests, and in other regions where fox densities are much lower, nest predation by stoats could be the biggest threat.

Fox flushing curlewIn the New Forest, our nest camera research shows that foxes are the principal predator of curlew nests.

Protecting curlew nests in lowland heath: challenges and solutions

Our nest sample size is rather small, but with a fast-declining breeding curlew population (circa 33 breeding pairs recorded in 2022), and an expansive area of lowland heath in which to search for nests, it’s the best we could muster. However, it seems our results are fairly representative of the situation in other lowland curlew breeding areas, where foxes are usually reported as the principal predator of curlew nests. 

For example, in one recent published study in Breckland, East Anglia, between 2019 and 2021, up to 80 pairs of curlews were studied annually across eight different sites. Over this three-year period, 136 nests were monitored, and 84 nests failed.

Of these, predation accounted for 86% of nest failures. Nest cameras weren’t used to identify predators in this study, but temperature loggers in nests showed that most predation events occurred at night, and foxes were assumed to have been the main culprit. Here, the authors suggest that electric fencing could help improve nest survival by preventing mammalian predators – principally foxes – from predating nests at night.

In the New Forest, the use of electric fencing to protect curlew nests is not a viable option, and likely never will be. In this complex landscape, finding nests is extremely time-consuming. The birds breed on ‘open access’ lowland heath and wet mires, where commoners graze cattle and ponies.

Fences of any description are the virtual antithesis of commoner rights, and on one private land-holding where the gamekeeper urgently wanted to use a temporary electric fence to protect a vulnerable curlew nest, Natural England made his request so problematic that the fencing route can be off-putting.

Fox in thermal scopeIntensive fox culling at night has led to greatly improved curlew and lapwing nest survival.

Lawful culling essential to reduce fox predation on curlew nests in New Forest

As it stands, in the New Forest, the only viable way of reducing fox predation pressure on curlew nests is by lawful culling, both prior to and during the critical incubation phase. Our curlew nest camera studies show that of the 17 nests predated by foxes, 11 were lost during the third week of May, which coincides with increasing fox prey-food demands as cubs are reared and when most first or early-second clutches are likely to be hatching.

For foxes, the extra cheeping noise that’s emitted from hatching curlew eggs can give their location away, so it’s a precarious time, and vital that fox predation pressure has been adequately supressed prior to this critical stage of the nesting period.

Alongside our curlew nest monitoring work, we have been collecting predator culling records from wildlife managers across the New Forest National Park. The area involved now includes over 33,000 ha of predator-managed land, with detailed records on fox culling effort and bag data provided by shoot tenants, gamekeepers, and Forestry England personnel.

One objective of this important research is to determine what level of fox culling effort is required to improve curlew nest survival and ultimately, productivity. Although in its infancy, it’s already revealing what level of fox culling effort improves nest survival, and what doesn’t.

For example, during the 2022 curlew breeding season, on one management unit, 7 out of 9 monitored curlew nests hatched. One nest was destroyed by crows after the adults mysteriously disappeared, and the other nest was lost to a domestic dog – our first documented dog incident in two years of wader nest camera monitoring. To say this represents impressive nest survival is an understatement, but it took a great deal of hard work.

Between 1 April and the end of May, the small team involved put in over 200 hours of dedicated fox management work, and fox sighting rates had more than halved by the third week in May, indicating greatly reduced predation pressure.

The result was at least 24 curlew chicks leaving their nest-cups but sadly, many of these perished, so understanding why chick survival in the New Forest is so poor, despite first-class legal predation management occurring right through the breeding and fledging period, is our next curlew research priority.

Although it’s just a few years old, contrary to the conclusions of the RSPB’s controversial Curlew Trial Management Project, the GWCT’s curlew and predation research in the New Forest is showing that targeted culling of foxes (and carrion crows) greatly improves curlew (and lapwing) nest survival, which is the first-step towards generating more wild-born curlew in their natural breeding areas.

Where electric fencing is not a viable management option, or where finding curlew nests is too problematic, this is what many breeding curlew populations desperately need:commitment by skilled and motivated wildlife managers prepared to go the extra mile for the birds they’re trying to protect.

Given the now large numbers of people involved – and new Defra funding for curlew recovery projects in the English lowlands – regional populations could stabilise and grow if the most site-appropriate predation management actions are implemented immediately.

But time is running out; these long-lived birds urgently need new recruits. Head-starting curlew chicks only buys time, and is pointless unless breeding site managers address the fundamental current problems of poor nest and chick survival. The GWCT plays an active role in UK curlew conservation efforts through its research, advisory, training and policy work, and with the Curlew Recovery Partnership.

However, through discussions with those who work on the ground to conserve breeding curlew on a day-to-day basis, there is clearly rising concern there has been rather a lot of curlew-talking over the past few years, but insufficient action: lots of curlew monitoring, but not enough protection. If curlew are to hang on in the English lowlands, then it’s imperative that wildlife managers act now to improve the breeding success of these magnificent birds.

Please help us to understand what’s fuelling Britain’s foxes

Your donations will help us understand the regional population structure of foxes, their impact on breeding waders, and how to manage their populations most effectively.

Comments

Curlews and predators

at 19:17 on 25/04/2023 by Trevor Macdonald

Excellent report - coincides with Telegraph releasing RSPB contract for someone to cull foxes and use it"bait" cages ( Larsen traps to you and I ) to control crows in Northern Ireland - at a contract price of £96000 over 4 years. Finally their stance is out in the open and vindicates all those scientific organisations like yourselves, BTO etc who have maintained that effective and planned predator control benefits ground nesting birds success rates enormously

Fox culling

at 18:00 on 25/04/2023 by Ken Freshwater

Thank you for a very business-like report. Every success for the continuation of preventative fox culling. I hear that even RSPB are doing it but trying to publicise as little as possible. Spotted a pair of Lapwings in lowland Angus this afternoon which is always a treat and all too uncommon.

Curlew appeal

at 17:28 on 25/04/2023 by Anne Garton-Jones

Good luck with your work

Can grazing aid post-fledging survival?

at 16:50 on 25/04/2023 by Jamie Buxton-Gould

Could chick survival be increased if chicks have access to areas of low, open sward with bare patches where invertebrate prey is rich? I know in Scotland on the Kinveachy Estate, keepers told me that restoring cattle grazing on the grassland that had become long and tussocky greatly increased waders like Lapwing and Curlew - they then had record counts.

foxes

at 15:47 on 25/04/2023 by Barrie Ronald Payne

I have found that most of the fox problems seem to come on the fringes of towns and the population of foxes is ever increasing due to the fact fast food chains and some people feeding a non stop food supply, This in turn is pushing foxes out to find new territory. I shot seventy four in 2021 and in 2022 you would think I had never shot a fox

Curlew

at 15:45 on 25/04/2023 by Chris Lock

It is a pity that electric fences cannot be used in the forest, as with the hordes of people and dogs who roam the forest it would be impractical. Thus fox culling is the only way.

Electric fence protection of Curlew nests

at 12:08 on 25/04/2023 by Stuart Rogers

I am a member of a group of farmers who want to protect Curlew nesting sites and on the whole we think this can be done by electric fences in our area. I have heard that a 20m x 20m fence is big enough but am concerned nests might be disturbed in setting them up so close. Is there any recommendations as to how big an area should be and how many wires? Any other suggestions would be appreciated too.

Curlew article

at 10:57 on 24/04/2023 by Donal Beagan

Hi Guys, Great article, well done. I fully agree with everything you have said. I have worked on a small breeding Curlew population in Ireland for the past number of years and know first hand the efforts required. The main one bing, intense fox control. At the beginning With only 3-4 breeding pairs in my area it made margins even tighter and with only a handful of chicks reaching fledgling stage and flying off it can be a an extremely tough task. Having a fair idea that fox were the main culprit we have really upped our game with regard to fox control in the past 3-4 years and I am encouraged to hear once again in another study that they are the main perpetrators for predation. That being said, our Curlew population is so low here that we feel they need a boost and that the only way around this is to headstart for a period of time in an effort to boost our population. And meanwhile continuing to carry out extensive predation management with and emphasis on fox control. I was just curious to know what your views would be on this? Mine are that our population needs the boost and that the best possible way to do so is headstart nests that occur in unsuitable environs. Thank you for sharing your hard work and I hope to hear your thoughts on the current situation here.

Make a comment