Studying Derbyshire's wading birds species
PUBLISHED: 00:00 11 July 2019
The clever tactics employed by woodcock, plovers and lapwings to survive on Derbyshire's moorland
When I started bird photography in the early 1980s I worked almost exclusively from a small canvas hide at the nest. However, with larger lenses, digital cameras and a desire for more dramatic images, nowadays very few of us, including myself, work in this way. I am sure that this is not necessarily a bad thing but there is a downside.
Whenever I spent time in a hide watching, for example, a golden plover I would take extensive notes about the bird's behaviour. I then used these notes to fill in nest record cards for the BTO's (British Trust for Ornithology) nest record scheme. This programme has been running for 75 years and in that period it has received over 1.25 million records of 232 British species. In many ways this is one of the most, if not the most, important natural history recording schemes in Britain. The analysed data helps scientists to say with confidence exactly what is happening to our breeding birds and how they are succeeding in the modern world, particularly with regard to climate change.
Another aspect of photographing birds from the nest that I really miss is the recording of breeding behaviour. I would regularly spend periods of 12 hours at a time watching the same nest for days. This extensive viewing allowed me an intimate and privileged view into the home life of many breeding birds. It also allowed me to compare similar species, such as the waders that breed in Derbyshire.
Wading birds lay four large well-camouflaged eggs that are usually exposed to the sky and are therefore very vulnerable to predators. The main defence against predators such as crows or foxes is to sit tight. In some cases, such as in that of the woodcock, the incubating female bird (only the female incubates in this species) is incredibly well camouflaged. I have walked up to nests when I know exactly where they are and still have been amazed that I needed a while before my eye locked onto the incubating female. She has one simple but subtle strategy to help - she will push her long beak into the leaf litter making her even harder to pick out. However, she does have a serious disadvantage over other waders - she is entirely on her own. What this means is that she does not have a male to help her share incubation or provide an early warning system. This is the main reason why she relies on her camouflage so much and sits tight even if the predator, or human, is incredibly close, only exploding from the nest at the last moment.
In contrast, the golden plover, the most beautiful of Derbyshire's moorland waders, work their nest as a pair. Both birds share incubation. This means that the off-nest bird can feed for longer without having to worry about exposed eggs. It also means that he or she, when not incubating, can be an early warning system. If they see a predator approaching they will call so the incubating bird is aware, and if the predator gets too close, particularly a ground-based one, they can run, crouching, away from the nest. However, this system in not infallible because the feeding bird may be nowhere near the nest when a predator approaches. If this happens the incubating bird may not be aware there is a predator until it is close. She/he will now adopt a typical wader strategy - feigning injury. The incubating bird runs from the nest with its tail spread out and wings drooping, hoping it looks like an injured bird. The idea is neat, and often works. The predator is distracted and runs, following what it thinks, is an easy meal.
Injury feigning is practised at its highest level by another of Derbyshire's breeding waders, the ringed plover. Like golden plovers, they lay four camouflaged eggs in a shallow scrape in the open. If a predator gets too close, particularly if the eggs are near hatching or have hatched, both birds will work really hard to entice the fox or stoat away. The initial run is like the golden plover's, tail spread, wings held out and head down, and is often referred to as the rat run. When the predator's attention has been caught, and perhaps if it looks as if it might not follow, the plovers use their wings more, often lifting one up, almost like a wave. Occasionally they lift both wings up and try to lure the predator further away with shuffling wings and a spread tail. With luck a combination of these tactics is enough to get the fox or stoat well away from the eggs or chicks, then the plovers remarkably recover from their life-threatening injuries.
Not all of our waders use this elaborate distraction display. Lapwings tend to nest in colonies and any predator is usually spotted when at quite a distance. Then every incubating bird takes to the air and may even mob the predator by flying at it, calling all the time and hopefully driving it away.
Returning to the nest is a tricky time. The birds never know when they may be watched. Certainly they will check, and if they see a crow or raven around simply won't return until it has gone. However, when they do make their way back to the nest it is via a very circuitous route, never directly back to the eggs. They continually stop and pretend to feed to deceive any possible watcher.
Generally, waders are not faring well in Derbyshire, in particular snipe, lapwing and curlew. There is hope for the future though and in an upcoming article I will be looking into a modern and exciting conservation scheme that is attempting to help these fantastic wading birds recover in our county.