DOI: 10.5061/dryad.g79cnp5xx
title: Data from: Costly conspicuousness reveals benefits of sexual dimorphism in brood parasitic diederik cuckoos

description: The existence of adult sexual dimorphism is typically explained as a
 consequence of sexual selection, yet coevolutionary drivers of sexual
 dimorphism frequently remain untested. Here, I investigate the role of
 sexual dimorphism in host-parasite interactions of the brood parasitic
 diederik cuckoo, Chrysococcyx caprius. Female diederik cuckoos are more
 cryptic in appearance and pose a threat to the clutch, while male diederik
 cuckoos are conspicuous and not a direct threat. Specifically, I examine
 whether sexual dimorphism in diederik cuckoos provokes threat-level
 sensitive responses in Southern red bishop, Euplectes orix, hosts. I use
 experimentally simulated nest intrusions to test whether hosts have the
 capacity to differentially (i) detect, and/or (ii) discriminate between,
 male and female diederik cuckoos, relative to harmless controls. Overall,
 I found no evidence that diederik cuckoos differ in detectability, since
 both sexes are comparable to controls in the probability and speed of host
 detection. Furthermore, neither male nor female hosts discriminate between
 sexually dimorphic diederik cuckoos when engaging in frontline nest
 defences. However, hosts that witnessed a male diederik cuckoo during the
 trial were more likely to reject odd eggs. Moreover, experimental eggs
 were significantly more likely to be rejected when female bishops observed
 a male compared to a female diederik cuckoo. While the cryptic appearance
 of female diederik cuckoos does not reduce detection by hosts, it does
 provide the benefit of anonymity given the egg rejection costs of
 conspicuous male-like appearance in the nest vicinity. These findings have
 implications for the evolution and maintenance of sexual dimorphism across
 the Cuculidae, and highlight the value of testing assumptions about the
 ecological drivers of sexual dimorphism.
description: This dataset was collected during an experiment in an ecological
 context. Behavioural data were extracted from videos. Please see main
 article for full details.
description: # Data from: Costly conspicuousness reveals benefits of sexual dimorphism
 in brood parasitic diederik cuckoos
 [https://doi.org/10.5061/dryad.g79cnp5xx](https://doi.org/10.5061/dryad.g79cnp5xx) ## Description of the data and file structure * "nest": unique identifier for experimental nest. * "treat": experimental treatment group – 'Male'= male diederik cuckoo model, - 'Female'= female diederik cuckoo model, 'Bulbul' = dark-capped bulbul control model. * "SRBsex": host sex – 'MALE', 'FEMALE'. * "lat_frame": timestamp host enter nest vicinity. * "lat_close": timestamp host approach model &lt; ~40cm. * "lat_strike": timestamp physical contact with model. * "strike_YN": binomial attack 'Y'=1, did not attack 'N'=0. * "first_record": day 1 nest check outcome in text format – 'Accept'=experimental egg present, 'Rejected'=experimental egg no longer inside the nest, 'Predated'= signs of depredation, 'NA'=no data point recorded on this day. * "2nd_record": day 3 nest check outcome in text format – 'Accept'=experimental egg present, 'Rejected'=experimental egg no longer inside the nest, 'Predated'=nest signs of depredation, 'NA'=no data recorded on this day. * "egg24": day 1 nest check outcome in binomial numeric format – 'Accept'=1, - 'Rejected'=0, 'NA'=no data recorded or depredated on this day. * "egg72": day 3 nest check outcome in binomial numeric format – 'Accept'=1, 'Rejected'=0, 'NA'=no data recorded or depredated on this day. * "lat_frame_s": numeric format, interval in seconds between beginning of trial and host enter nest vicinity. * "lat_close_s": numeric format, interval in seconds between beginning of trial and host approach model &lt; ~40cm. * "lat_strike_s": numeric format, interval in seconds between beginning of trial and host physical contact with model. * "lag_detect_window": numeric format, interval in seconds between host enter nest vicinity and approach model. ## NOTES * For numeric interval in seconds data, '300 s' = host did not engage in defined behaviour before the end of the 5 minute trial. * Please see the methods section of "Costly conspicuousness reveals benefits of sexual dimorphism in brood parasitic diederik cuckoos" for further details on data structure. ## Code/Software Code to run analyses in R see Zenodo: "Code_for_CostlyConspicuousness2024_DRYAD"