Lapwing, green plover or peewit, Vanellus vanellus
If you're going to perpetuate your genes through time, you need to arrange things so the next generation doesn't get eaten, because that ends your gene line. To do that, you need to ensure you arrange things so any potential predator has difficulty finding the next generation, at least before they've managed to breed.
I appreciate these concepts are difficult for creationists to grasp, but a paper out today shows the importance of catering for the perception of potential prey on your offspring, if you want then to survive and breed.
It concerns the siting of lapwing nests and eggs.
The northern lapwing, Vanellus vanellus, green plover or peewit (from their call), is a ground-nesting bird, which, until about 40 years ago was common in my part of Oxfordshire, UK. They formed vast flocks in the Autumn that would put on impressive displays as twilight approached, as they twisted and turned in flight (hence their name, lapwing) giving the flock a twinkling appearance as they exposed their white underwings, then twisted to hide them, confusing any potential predator such as peregrine falcons. Since then, they have been in rapid decline, probably due to habitat destruction and change in agricultural land management, and these vast flocks are no more. Although they nest in the open, I can testify to how difficult their nests are to find, having spent literally hours, quartering fields looking for them. Now a study led by George R. A. Hancock of Exeter University has shown just how cleverly lapwing nests are hidden in plain view, exploiting the visual perception of potential predators. Their research is explained in an Exeter University press release:
Ground-nesting birds called lapwings use the shape of their nests and surroundings to hide from predators, new research shows.The team have published their observations, open access in the journal Ecology and Evolution:
Many ground-nesting species are in decline due to changes in land management and high populations of predators, such as foxes and crows. Conservation projects can fail because too many eggs and chicks are eaten.
The new study, led by the University of Exeter, assessed the visibility of lapwing nests in terms of cover (also called “occlusion”) and camouflage using models that simulate the vision and viewing angles of various predators.
The findings showed that despite nesting in open fields, lapwings can hide their eggs by using small variations in the terrain, making them invisible to ground predators such as foxes from anything more than around 1.5 metres away.
Hancock collaborated with the Game and Wildlife Conservation Trust (GWCT) and used smart phone 3D scanners to measure the shape and height of lapwing nests and their surroundings.Like children playing hide and seek, lapwings use cover to complement their camouflage. If a nest is properly concealed in this way, it doesn’t matter how good a predator’s vision is – they simply won’t be able to see it until they are nearly on top of it.
Nests and eggs are also camouflaged – blending in with their surroundings by matching their backgrounds colour and pattern – but it appears this is a secondary defence.
George R. A. Hancock, lead author
Centre for Ecology and Conservation
Exeter University, Penryn Campus, Cornwall, UK.
He also used specialised cameras to measure camouflage from the perspective of the lapwing’s predators (foxes, crows and raptors), which can see ultraviolet light.
Lapwing populations have more than halved since the 1970s.Lapwings tended to choose uneven ground for their nests. They selected slightly elevated positions, reducing risk of flooding and allowing them to see predators – without being so high as to stand out to predators.
Habitat variation appears to be crucial for allowing lapwings choice in where to nest. The growth of intensive agriculture has left ground-nesting birds with poorer choices of where to nest. Grazed fields provide good habitat, as long as they’re not overstocked with too many grazing animals.
Recent technology is allowing us to better measure how animals see and view the world. Tilled fields can provide really good camouflage for eggs which match the bare earth and can be concealed by the rough geometry, but might be problematic for chicks which are more exposed.
George R. A. Hancock
The findings could help inform conservation efforts for this declining species, which is an iconic part of farmland in the UK and beyond.
By providing habitats that compliment lapwing camouflage, Hancock said conservation managers could use “nature’s toolkit” – in addition to direct predator control – to help lapwings breed successfully.
AbstractCreationists might like to note how selection pressure has produced behaviour in the lapwing which gives their offspring the best chance of being overlooked by a predator and so surviving to pass that trait on to the next generation, and how the TOE provides the simplest explanation for this observed phenomenon.
The nests of ground-nesting birds rely heavily on camouflage for their survival, and predation risk, often linked to ecological changes from human activity, is a major source of mortality. Numerous ground-nesting bird populations are in decline, so understanding the effects of camouflage on their nesting behavior is relevant to their conservation concerns. Habitat three-dimensional (3D) geometry, together with predator visual abilities, viewing distance, and viewing angle, determine whether a nest is either visible, occluded, or too far away to detect. While this link is intuitive, few studies have investigated how fine-scale geometry is likely to help defend nests from different predator guilds. We quantified nest visibility based on 3D occlusion, camouflage, and predator visual modeling in northern lapwings, Vanellus vanellus, on different land management regimes. Lapwings selected local backgrounds that had a higher 3D complexity at a spatial scale greater than their entire clutches compared to local control sites. Importantly, our findings show that habitat geometry—rather than predator visual acuity—restricts nest visibility for terrestrial predators and that their field habitats, perceived by humans as open, are functionally closed with respect to a terrestrial predator searching for nests on the ground. Taken together with lapwings' careful nest site selection, our findings highlight the importance of considering habitat geometry for understanding the evolutionary ecology and management of conservation sites for ground-nesting birds.
Figure 1.
Framework for 3D analyses of ground-nesting bird nests. Example images are from an agri-environment scheme site (left-blue) and spring-cereal arable site (right-yellow). (a) Photograph nests with color-calibrated Sony camera. (b) Create 3D scans of nests with ASUS phone and upload the point cloud into Matterport scenes for standardization and reformatting. (c) Import and label point clouds in ImageJ. (d) Run nest 3D energy and visibility transect analysis scripts.
Figure 2.
3D scan energy at different spatial scales relative to clutch size: x1/8, x1/4, x1/2, x1, x2, x4. The left-hand side shows the original height map and associated regions of interest (ROIs): clutch, nest, and background. More elevated (positive) regions are shown as lighter, while less elevated regions are shown as darker. The right-hand images show the separated spatial scales with the position of the clutch marked by a black arrow. The individual eggs are most visible at x1/4 scale, the depression of the scrape at x1/1 scale, and the nest elevation at x4/1 scale.Hancock, G. R. A., Grayshon, L., Burrell, R., Cuthill, I., Hoodless, A., & Troscianko, J. (2023).
Habitat geometry rather than visual acuity limits the visibility of a ground-nesting bird's clutch to terrestrial predators.
Ecology and Evolution, 13, e10471. https://doi.org/10.1002/ece3.10471
Copyright: © 2023 The authors.
Published by John Wiley & Sons, Inc. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
To assume that this was intelligently designed would be to assume that the designer was so stupid as to design the predators to find lapwing nests then designed the lapwing to prevent the predators doing what they were designed to do - the classic evolutionary arms race that betrays the unintelligent nature of evolution by natural selection and refutes any intelligence being involved.
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