Nest Camouflage in Nightjars & Other Birds

Introduction

Fiery-necked Nightjar

A Fiery-necked Nightjar brooding two chicks among leaf litter in Zambia.

Nesting nightjars (and other ground-nesting birds such as plovers and coursers) are a particularly neat system for studying the evolution of camouflage in the wild: they don’t build any kind of nest structure but just lay their eggs directly on the natural background, which means they depend completely on the appearance of their eggs or their own bodies for concealment. It’s also important that nests by definition are in a fixed location – so you know the bird has chosen that spot rather than happening to have landed there after being disturbed. At our study site in Zambia we have several species of nightjar, plover and courser breed out in the open in the baking heat of the late dry season. They need to make sure that their eggs (and themselves) are protected not only from predators but also dangerously high temperatures out in the sun at midday.

Jolyon and Jared

Jolyon Troscianko and Jared Wilson-Aggarwal in the field in Zambia, photographing an incubating Fiery-necked Nightjar using a UV-sensitive camera.

We’ve been studying nightjars, coursers and plovers in the field in Zambia since 2011. These birds are currently the focus of Dr Nick Horrocks‘s work on thermal ecology. They were previously the focus of a BBSRC-funded research project in collaboration with the Sensory Ecology Group Exeter University, co-led by Exeter’s Dr Martin Stevens and carried out by Dr Jolyon Troscianko and Jared Wilson-Aggarwal. Please read more about our work on the ProjectNightjar website, help us with our research by posing as a predator in an online computer game and exerting some natural selection on ever-evolving populations of virtual eggs, have a look at the photo galleries below of real nightjars and coursers in the field, and join nearly half a million others in watching this very short video that our funders, the BBSRC, made using our film footage from Zambia:

Publications

  • Stevens, M., Troscianko, J., Wilson-Aggarwal, J.K. & Spottiswoode, C.N. 2017 Improvement of individual camouflage through background choice in ground-nesting birds. Nature Ecology & Evolution 1: 1325-1333. Read on journal website [Open Access]
  • Troscianko, J. Wilson-Aggarwal, J., Griffiths, D., Spottiswoode, C.N. & Stevens, M. (2017) Relative advantages of dichromatic and trichromatic color vision in camouflage breaking. Behavioral Ecology 28: 556-564. Read on journal website [Open Access]
  • Troscianko, J., Wilson-Aggarwal, J., Spottiswoode, C.N. & Stevens, M. (2016) Nest covering in plovers: how modifying the visual environment influences egg camouflage. Ecology and Evolution doi: 10.1002/ece3.2494 Read on journal website [Open Access]
  • Wilson-Aggarwal, J., Troscianko, J., Stevens, M. & Spottiswoode, C.N. (2016) Escape distance in ground-nesting birds differs with level of individual camouflage. American Naturalist 188: 231–239. Read on journal website [Open Access]
  • Troscianko, J., Wilson-Aggarwal, J., Stevens, M. & Spottiswoode, C.N. (2016) Camouflage directly predicts the survival probability of ground-nesting birds. Scientific Reports 6: 19966. Read on journal website [Open Access]

Nightjar Photo Gallery

Coursers Photo Gallery

News

Dr Gabriel Jamie gives a talk on mimicry in parasitic finches at the African BirdFair

Dr Gabriel Jamie gave a talk on mimicry in the parasitic finches of Africa at Birdlife South Africa’s Virtual African Birdfair. Please also see Dr Jessica van der Wal’s talk on our sister research project on honeyguide-human mutualism (more information at www.AfricanHoneyguides.com) and many other great research talks by our colleagues at the FitzPatrick Institute of African Ornithology. Also visit the amazing line-up of other talks at the Virtual African BirdFair, including a talk on bird art by the brilliant Faansie Peacock who has generously allowed us to use his illustrations in several of our scientific publications. Thank you BirdLife South Africa!

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Mairenn Attwood submits her MPhil thesis

Congratulations to Mairenn Attwood for successfully submitting her MPhil thesis at the University of Cambridge, entitled ‘Angry birds: does it pay a cuckoo to parasitise a highly aggressive host?’. In it, Mairenn asks whether high levels of aggression by fork-tailed drongos affect hawk mimicry by the African cuckoo, and whether it pays cuckoos to specialise on such aggressive hosts. An amazing feat of field experimental work in Zambia (in collaboration with Jess Lund), analysis and writing in just one year of research – well done Mairenn!

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Front cover of Trends in Ecology and Evolution

Dr Gabriel Jamie and Dr Joana Meier’s paper on the persistence of polymorphisms across species radiations is on the front cover of the September issue of Trends in Ecology and Evolution. The cover image provides a specific example of the trans-species polymorphisms that the paper explores. Here, a polymorphism in shell chirality that recurs across multiple species of Amphidromus snails . Photos by Menno & Jan Schilthuizen. You can read the full article here: https://tinyurl.com/ycgdw4lu

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