Major study of nest camera data confirms principal predators of waders

Working for Waders contributed data to a major review of nest camera studies which has just been published in the international journal, Ibis. The Working for Waders data were from our Nest Camera Project, which has run since 2022, in which we loan cameras to interested land managers who are keen to find out the fate of wader nests on their land.

The Ibis study, led by the BTO and the University of East Anglia, analysed data from 2,088 nests including 1,062 of waders, that had been collected from across Great Britain between 2003 and 2023. Out of the total sample of nests, 609 (29%) predation events were recorded. Focusing on the wader nests showed that 356, or 34%, were predated.

The principal predators of wader eggs were badgers (42%) and foxes (23%), with hedgehogs significant on some islands and surprisingly few cases of corvids taking eggs (4%). The pre-eminence of mammals – and badgers in particular – in the wader sample may not come as a surprise to some, but actually this represents a slight change in the rank order of things as foxes traditionally have been the main robber of wader eggs. This is an important advance and presumably reflects the increase in badger numbers across the country: for example, a survey by Scottish Badgers recently estimated a 4-8% increase in the number of 1 km squares in Scotland containing at least one main sett, and that 39% of all squares now showed signs of some kind of badger activity.

The Ibis study offers the most comprehensive and up to date overview of the rates of egg and chick predation in Great Britain, and of the predators responsible, but how does it help wader conservation? Well, it shows that the concerns of many practitioners regarding badger predation are supported by the science which is important to recognise. It also shows once again that, for waders in particular, predation management is absolutely crucial in the restoration of wader populations. We know from several quality studies and practitioner experience that low breeding success – most often due to predation on eggs and chicks – is what is currently holding back wader populations, and the Ibis study adds a little more detail to that picture. In most cases, it is likely to prove judicious to focus attention on managing mammalian predation and less on avian, especially where resources are scarce. This may need to include some kind of fencing if badgers are prevalent as lethal interventions are not an option.

Interestingly, another paper out recently suggested that badger predation at the study farm in question was strongly influenced by weather. Only when temperatures dropped below 10 °C for around seven days did badger predation of lapwing eggs occur, and only when below about 4 °C did it become a significant issue. This raises the possibility of using the weather forecast to help predict when protective measures might be necessary in some cases…

The Working for Waders Nest Camera Project will run again next year and if you would like to take part, please get in touch. As the Ibis paper shows, the information collected can be illuminating and important.