Thanks to volunteer Phil for his report and photos
Every Spring since 2015 I have been involved with a team of volunteers who regular monitor our breeding lapwings. For me this involves a weekly visit in-depth survey of the main areas of the reserve where lapwings like to nest and feed. This starts in mid-March and runs through to mid-June. Unfortunately, the strange events of 2020 have caused this activity to be largely cancelled. To fill the gap I decided to write about it instead.
The aim is to work out how many pairs have nested and then to count how many fledged lapwing juveniles they have produced. The initial aim is for a productivity rate of 0.7 fledged birds per pair per year which is calculated to be the rate needed to maintain the population at its current level.
Clearly higher productivity rates are desirable as breeding lapwings have been in serious decline in the UK for some time and the species is on the red list of the highest conservation concern. Studies have shown that the main contributor to this has been various changing in farming practices to do with changing grassland into arable fields, sowing crops in the autumn, and more drainage removing too much of the damp meadows where lapwings and their young find food. The declines have been most marked in the South of England. An interesting article on the RSPB website describes these problems in more detail.
https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/lapwing/population-trends/
The population of breeding lapwings in the Arun Valley and surrounding area is so low that it cannot sustain predation losses now. This means that improving breeding success requires a lot of effort to maintain a good habitat and protect this from predators. Regular visitors to Pulborough Brooks will have seen temporary electric fences erected in recent years in an attempt to keep foxes away from the nests and the growing chicks. These require considerable effort to erect and maintain each year and it is hoped that eventually funds might be secured for a permanent fence, such as the one at RSPB Rainham Marshes in Essex which has seen sustained lapwing breeding success for several years. For the first 3 years the electric fence seemed to be successful especially in 2018 where the productivity rate was 2. Unfortunately, in 2019 it seems that a predator, probably a fox or maybe a badger managed to get inside the fence after most of the chicks hatched, and consequently the success rate crashed below the target level.
It is important to keep sufficiently wet areas of the reserve as the spring progresses and the land dries out. At Pulborough it is sometimes necessary to pump water from the ditches to keep open pools with soft muddy margins. In 2020 this issue may have been a major challenge during the sunniest Spring on record and I am unaware whether our wardens have been able to do this.
In late summer and early autumn mowing takes place to ensure that there is a good short sward for the next spring where lapwings can scrape out their remarkably open nests, which are just a simple depression in the ground lined with soft plant material. Lapwings curiously adopt an open nesting strategy, relying on their feisty nature to spot and chase away potential predators as they approach. This relies on good sight lines so it is important for the vegetation to remain short until the chicks have hatched. This photo shows a lapwing sitting on a nest on one of the islands in West Mead pool – a regular choice for a nest site that can be easily seen from the nearby hide.
Lapwing nesting on West Meas Island
Once chicks are hatched the growing grass and rush becomes useful for hiding when danger approaches.
The monitoring process normally starts with looking for signs of birds pairing up which involves loopy display flights and “venting” where the male displays on the ground. He dips his chest, lifts his rear wing feathers and show the orange vent under his tail to a nearby female. Males will also scrape depressions by rubbing their breasts on soft ground to create a depression for a nest to be established. Sometimes we see birds mating as they don’t hide away to do this. Typically this is a very brief affair
Eventually we will see birds sitting on nests usually with a partner on lookout duty nearby. Mostly the female does the incubating but sometimes she will move away, and the male takes over for a while. At this point we can establish how many pairs are attempting to breed on the site, one half of the main data being sought.
Once found nest sites are plotted on a map and then closely monitored over the next few weeks as best we can, bearing in mind that most of our observations are done from a distance to avoid disturbing the birds. Sometimes our wardens will check out the nests on the ground as discreetly as they can to confirm the position and that the nest is still viable.
Lapwings usually have a clutch of 4 eggs and the hope is that all will hatch after an approximately 4 week incubation. Once hatched the tiny chicks are “precocial” meaning that they can walk around and feed for themselves so the parents escort them to the damp pool margins where they can find soft invertebrates to eat.
Lapwing chick at Winpenny
From this point our focus moves to checking the pool margins for the presence of chicks. Usually the family group will not move away unless the pool dries out. Listening for distinctive alarm calls from the adults is usually helpful to confirm the presence of chicks.
Monitoring the pool margins can become more and more difficult as the grasses and rushes grow and provide more opportunities for the chicks to stay out of sight, but with different volunteers observing on different days there are usually enough opportunities to work out how many chicks are surviving.
Eventually we will see juvenile birds fly and at this point they count towards the measure of breeding productivity. These are rather like a drab version of the adult, with an undeveloped crest and a dark brown colour instead of the typical black, dark green and iridescent colours of the adults. They also display pale edges to the wing feathers.
Lapwing juvenile
Sadly, I was only able to do one monitoring session in mid-March before the closure of the reserve, so I am in the dark about how well our breeding lapwings have done this year. It seems impossible that we will be able to work out the number of breeding pairs and all we can hope for is to spot some juvenile lapwings.