R Evens1, N Beenaerts², N Witters³ and TJ Artois1

Centre for Environmental Sciences, Research Group 1Zoology: Biodiversity & Toxicology, ²Environmental biology, ³Environmental economics. Hasselt University - Campus Diepenbeek, Agoralaan, Gebouw D, BE-3590 Diepenbeek, Belgium

Scan this QR-code to download an animated CartoDB-map and experience the foraging behaviour of these nightjars.

If the rate increases by 0.1°C/min foraging time is reduced by - more or less - 10 minutes.

During the egg stage, foraging time of breeding females is 10 minutes significantly longer at sundown.

Do Nightjars visit takea ay restaurants?

•EuropeanNightjars Caprimulgus europaeus are crepuscular birds that feed on nocturnal insects and breed in semi-natural habitats, closely associated to sandy soils.

•Resulting from dramatic population declines since the 19th century nightjars were added to AnnexIoftheEUBirdsDirective.

•Recent studies, using radio telemetry, indicated that most European Nightjars forage in specific habitats outside their breeding sites (Figure a).

•We now combine information on the foraging ecology of 60 nightjars tracked with radio-tags and 30 others tracked using 2g GPS-loggers in three populations in Flanders (Belgium).

• 2g nano GPS-logger• 4 minute sampling rate (3-6 nights)• 30 nightjars tracked (2014-2016)

View on the back of a bird:GPS-loggers deployed as backpacks

GPS backpacks

•They forage up to 7km from their breeding areas and feed in extensively grazed farmlands and wet meadows surrounded by hedge rows and trees (Figure b).•Here, they always find more food compared

to the breeding areas.•Some individuals undertake quick foraging

trips during dusk and dawn.While others remain in foraging areas throughout the night (Figure c).•Nesting birds regulate their foraging time

based on environmental temperature and time of departure (Figure d & e).

Foraging behaviour of nightjars mapped using GPS-loggers

Using new GPS-technology we now know where nightjars forage, why they do so and how they get there. This detailed information on habitat use can be implemented by policy makers to protect foraging habitats and improve the conservation efficacy of nightjars.

Yes! Nightjars put many efforts in finding the best insect-takeaway.

A B CHABITAT COMPOSITION | breeding (orange), foraging (green), sleeping (grey) and unsuitable (black)

FORAGING FLIGHTS | flight tracks between foraging and beeding areas (one colour = one individual)

FORAGING BEHAVIOUR | Simulations of the same GPS-tracks can inform us about foraging behaviour.

Conclusion

D

E