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

Jess Lund awarded an R. C. Lewontin Grant from the Society for the Study of Evolution

The Society for the Study of Evolution has awarded Jess Lund an R. C. Lewontin Graduate Research Excellence Grant, which will enable her to expand her investigations into the fascinating lives of honeyguides. This grant is awarded to students early in their PhD programmes to assist them in enhancing the scope of their research. Thank you to the SSE for their generous support of our work!

read more

New paper on eggshell surface properties

Stephanie McClelland’s paper entitled “Eggshell composition and surface properties of avian brood-parasitic species compared with non-parasitic species” has been published in the journal Royal Society Open Science. This study measured structural properties of the eggshells of brood parasites and their hosts around the world. The study found that…

read more