Woodcock – Scolopax rusticola
In depth studies, advanced technology on the satellite tracking side and a clearer understanding of these amazing migratory birds have given Woodcock publicity and attention. The ‘amber-listed’ woodcock as a bird of conservation concern in Britain has led to these studies and concentration on their flight patterns and migratory habits.
Tracking the woodcock
Game and Wildlife Conservation Trust (GWCT) are running a Woodcock tracking programme and the results have been insightful. The birds are tracked by minute satellite transmitters that weigh around 9.5g which are mounted on the lower back using an elasticated leg-loop harness. Each transmitter will send a signal containing identity for 10 hours in every 58 hour period for as long as battery is sufficiently charged. The signal is then received and relayed by earth orbiting satellites, some tracking data however has been hinder due to low batteries and birds simply ‘disappearing’ from radar due to hiding, dying and being blown off course….the results are mixed. According to the GWCT while in Britain the numbers of woodcock are down and have declined overall, the figures remain steady in Scotland.
In collecting the data, the technicians have uncovered several problems, namely the fact that the tags are solar powered batteries so depend solely on the sun which is not reliable enough. Short day length and low sun intensity in the winter months in Northern Europe mean a low solar power. Gloomy wet weather also affects the transmitting of the tags with droplets and moisture disrupting the data. The woodcock also will hide in the day if it is cold and wet.
An insight to woodcock migration
Woodcock have shown through this tracking data, that they make large movements throughout the course of the winter, (not just in the autumn) and show that they are faithful in returning to a familiar site, time and time again. ‘Amy’ a tagged woodcock illustrated this perfectly with flights from the UK to the Netherlands, Kiev, Belarus, Moscow and returning by way of Lithuania, repeatedly visiting the same areas to breed. With 6400km covered, the woodcock demonstrate their extreme hardiness, intelligence and determination to breed and live; the average lifespan for the woodcock is 4 years. In autumn and into December and January, Britain and Ireland see a large influx of migrant woodcock, escaping the freezing weather of Northern Europe and spending the winter with us.
The migration patterns of woodcock are fascinating. With long, fast flights covering distances in a day of 600-1100 km (375-690 miles) and then stops typically lasting between 7-15 days, the birds will loyally target their sites and show great fidelity in their breeding areas. The threat to these areas is varied yet vital to the results of woodcock migration. Climate change, deforestation, marsh drainage, continued heavy hunting in Northern Europe of these birds and intensive farming are all having some say in woodcock numbers and breeding sites.
With bird watchers being recruited to count and watch woodcock, numerous sites have been collated all over the UK, including Scotland, Durham, Northumberland, Hampshire and Wiltshire. Sonographs are created based on the call recordings from each bird to equate the pattern of both the male and female. The results show that Scotland is a stronghold for roding (courting) woodcock while in southern England, where there is more densely populated woodland, there are more clustered areas of breeding woodcock. Either way, these incredible migratory birds are present, although the Woodcock are amber listed as a concern for their conservation, they do continue to breed and thrive.
The woodcocks’ habitat
The woodcocks’ preferred breeding habitat is more deciduous, mixed woodland areas where there are more varied types of tree stands, brambles, holly and hazels but equally with grasslands for feeding nearby. Housing and improved grasslands seem to put the birds off, likewise the taller wooded areas especially conifer/spruce settings seem to show low numbers of breeding. Picky perhaps, but woodcock are explicit in their needs and find the exact spot they have used before. Essentially the numbers are steady but the woodcock is changing in how they cluster and where they are tending to gather.
The woodcock is an elusive wader adapted for life in woodland and fields, with a diet of invertebrates, earthworms, worms etc. They probe the soil with their long, pointed bills so can not withstand long periods of permanent frost. Grasslands and arable fields are more preferable as breeding sites with more soil invertebrates present and yet they need the mixed woodland to provide cover from avian predators. With their cryptic plumage giving them some camouflage amidst woodland in daytime and their large eyes placed high on the sides of the head to give them 360° vision for detecting potential dangers, the woodcock are well placed once they find the ideal breeding site. It’s amazing how the woodcock remember different sites and return faithfully year on year.
Protecting the woodcock
The very fact that a huge amount of research and tracking of woodcock is happening is testament to their bravery and incredible performance as a migratory bird. Diminutive in size, weighing only 346 grams or less, the fact that they survive these distances and can fly for such hours at such speeds encourages us to protect this species and learn more about how we can help them. With careful land management in both United Kingdom and across Europe, taking into account their landing sites and keeping shooting restricted (many shoots request they aren’t shot at all), woodcock will continue to flourish both here and abroad.
The GWCT continue to ring woodcock with the aim to ring 200 each winter in order to obtain progressive information on their survival and wintering site fidelity. They aim to collect detailed tracks for a sample size of at least 30 spring migrations and 20 return autumn journeys which will all go towards enhancing our understanding and answers of woodcock; the larger and more accurate the data sets will give the detail to make the best decisions.
Find out more
If you would like to see the details of the tracking of these adventurous birds and all the other tagged woodcock, where they have been to and where they are right now - visit http://www.woodcockwatch.com/.