Plovers, camera, action!

Each year, from March onwards, ringed plovers gather on our coast to set up their breeding territories and battle the odds to try and raise the next generation of plover chicks. While these little shorebirds are incredibly tenacious, they face many threats along the way. Every season they face bad weather and tides which can destroy their nest while also contending with disturbance from people using the beach for recreation, as well as trying to avoid the attention of hungry predators. Unfortunately, ringed plover eggs and chicks are small enough to be on the menu for most of our predator species in the UK, and each year we lose more of our nests to predation than any other cause.

Most of the time, when a nesting attempt gets predated, it happens at the egg stage before the chicks have hatched, which takes about 25 days of incubation from the parent birds. Therefore, if we can get more of the eggs to survive until hatching then that’s half of the battle!

A well camouflaged plover nest

Ringed plovers make their nests on the ground, laying their eggs out in the open directly on the sand or shingle of the beach and relying on their excellent camouflage to keep them safe. The incubating adults are constantly on the lookout for danger, and if they see a threat they discretely scuttle away from the eggs so that they don’t draw attention to them. This means that it is possible to place a wire mesh structure over the nest to keep larger predators off the eggs without causing too much disruption to the adult birds. The mesh size of these nest cages is specially selected so that it is small enough that it keeps out predators like crows, foxes and cats, but large enough that the adult plovers can come and go as they please.

There is lots of evidence to show that these cages work excellently to boost the hatching success of ringed plovers and other species across the world, and since we started using nest cages over the past two breeding seasons, we have had similarly positive results. However, one big concern about using these cages is that they may potentially be making the adult birds themselves more at risk to predators while they are sitting on the eggs. While the adult plovers will always try to walk on and off the nest on foot to draw as little notice to the nest location as possible, if they get really scared or caught off guard by a dangerous predator they will fly directly from the nest as fast as they can to escape. In these situations, the plovers can get confused and trapped inside the cage in their rush to escape, which could make them easier to catch, and there has unfortunately been grizzly evidence of this happening at other ringed plover breeding sites in the country. While losing eggs and chicks is never good, it is so much worse for the ringed plover population if we are losing breeding age adults.

One of our nest cages at Lynemouth

After talking with other beach nesting bird projects across the UK, we decided that we needed to have more evidence to determine if our cages are actually having a positive effect or not on the plover population. The problem we faced was finding a way to see what was happening at our plover nest sites even when we weren’t there, and so our plover-cam project was born! By using motion-triggered cameras we were able to capture footage of any creatures that came close to the plover nests, some with cages protecting them and some without, and from this we have been able to build up a picture of how other species have been reacting to our nest protection measures as well as getting a wonderful insight into the lives of the plovers that we haven’t seen before.

A trail cam set up on a caged nest

Our cameras were able to record activity 24 hours a day, with infra-red imaging giving us a glimpse into the lives of the nocturnal creatures on the coast, and by the end of the season we had been capturing footage over an incredible total of 5665 hours! This is where the work of our dedicated Plover-cam volunteers was vital in making this project work, as there is no way we would have been able to go through anything close to the amount of footage we had ourselves. Through the magic of the internet, our dedicated team were able to work their way through the stacks of video files at home, recording any exciting behaviour and interesting sightings of predators and other more benign creatures.

A fox visiting one of our nesting sites at Beadnell

A curious hare being seen off by the adult plover

What we found from the footage was that the top three most common predators caught on camera at our sites were all corvids (crows, rooks and jackdaws), these accounted for a massive 78% of all potential predators. This number is huge considering the big range of species that would happily make a meal of a plover egg, and it gives us evidence to support our assumption that corvids are the biggest problem facing the plovers when it comes to egg loss. We also had regular sightings of gulls and foxes around our plover nests, but none of the footage showed them trying to take plover eggs. This was really encouraging, as these two species are known to be voracious egg-eaters at other sites around the country, and shows us how predator behaviour can vary greatly from one place to another, making our site-specific observations even more useful to us.

The top three predator species are all corvids

A jackdaw taking an egg from an uncaged nest

Arguably, what we didn’t see in our video footage has been more important to us that what we did see, in that we saw no instances of predators trying to take adult plovers from within the cages. We also didn’t see any corvids successfully get into the cages through our larger “escape” doorways that we added to help the plovers get out faster if they were panicked (despite lots of footage of frustrated crows trying!). This is a great result and means that we can feel more confident using our nest cages for the next season. However, it is important that we keep on watching for any worrying predator activity with our plover-cams, as predator populations and behaviour can change dramatically year on year.

A crow failing to get inside a nest cage through the escape holes

This means that we are hoping for even more footage from more nest sites next season, so our plover-cam volunteer team will be back and looking for new recruits to help keep our nesting ringed plovers safe! Anyone is welcome to get involved and it doesn’t matter if you are a complete beginner when it comes to spotting wildlife, as we give everyone full training in the spring before we start, all you need is a computer or device that has internet access. If you would like some more information about getting involved in the project or if you have any other questions, feel free to get in touch through our website or social media pages.