Costly conspicuousness reveals benefits of sexual dimorphism in brood parasitic diederik cuckoos

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 ..., This dataset was collected during an experiment in an ecological context. Behavioural data were extracted from videos. Please see main article for full details., , # 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 < ~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 –...,