Brood parasitism: a test of the optimal acceptance threshold hypothesis (Part 1)

HAPPY 2019!

Variation in multicomponent recognition cues alters egg rejection decisions: a test of the optimal acceptance threshold hypothesis.
Philosophical Transactions of the Royal Society B

- One contribution of 18 to a theme issue ‘The co-evolutionary biology of brood parasitism: from mechanism to pattern’ -
https://royalsocietypublishing.org/toc/rstb/374/1769

AAA Science News (sciencemag.org):
http://www.sciencemag.org/news/2019/03/there-s-arms-race-going-bird-nest-scientists-are-uncovering-how-each-side-fights-back

www.mnn.com by Russell McLendon:
https://www.mnn.com/earth-matters/animals/blogs/eggs-cowbirds-mockingbirds

ABSTRACT: The optimal acceptance threshold hypothesis provides a general predictive framework for testing behavioural responses to discrimination challenges. Decision-makers should respond to a stimulus when the perceived difference between that stimulus and a comparison template surpasses an acceptance threshold. We tested how individual components of a relevant recognition cue (experimental eggs) contributed to behavioural responses of chalk-browed mockingbirds Mimus saturninus, a frequent host of the parasitic shiny cowbird Molothrus bonariensis. To do this, we recorded responses to eggs that varied with respect to two components: colour, ranging from bluer to browner than the hosts' own eggs, and spotting, either spotted like their own or unspotted. Although tests of this hypothesis typically assume that decisions are based on perceived colour dissimilarity between own and foreign eggs, we found that decisions were biased toward rejecting browner eggs. However, as predicted, hosts tolerated spotted eggs more than unspotted eggs, irrespective of colour. These results uncover how a single component of a multicomponent cue can shift a hosts’ discrimination threshold and illustrate how the optimal acceptance threshold hypothesis can be used as a framework to quantify the direction and amount of the shift (in avian perceptual units) of the response curve across relevant phenotypic ranges.This article is part of the theme issue ‘The co-evolutionary biology of brood parasitism: from mechanism to pattern’.
Related video:
https://www.youtube.com/watch?time_continue=41&v=R7l4aSQ4e7I
https://youtu.be/_CIfIVVTRmI (Part 1)
https://youtu.be/DzcHYuvHAGg (Part 2)
https://youtu.be/8n9ZpSscoys (Part 3)
https://youtu.be/qsJ0JIZOfCM (Part 4)
https://youtu.be/XwvUIpujvqc (Part 5)
https://youtu.be/TIOoCp-D0HU (Part 6)
https://youtu.be/hJQ70-OUDc0 (Part 7)
https://youtu.be/noNaWigPB2A (Part 8)

Photos and Videos:
Analía V. López
#broodparasitism - #cowbird

Music:
Is that you or are you you - Chris Zabriskie
(https://www.youtube.com/watch?v=ed8N141l9FQ)
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Видео Brood parasitism: a test of the optimal acceptance threshold hypothesis (Part 1) канала Analía V. López