DOI: 10.5061/dryad.n2z34tn4m
title: Data from: Serenade of a Whimbrel: Understanding the function of display behaviour in a sub-Arctic territorial wader

description: Animal sounds contain important information used in intra- and
 inter-species communication. For species exhibiting elaborate and
 energetically expensive signals such as aerial displays accompanied by a
 call, the nature of the message being transmitted is honest and usually
 reflects individual fitness. Display events that combine flight and calls
 and are executed during the breeding season have traditionally been
 associated with two main functions: repelling rivals and/or attracting
 mates. In waders, the distinction between the two could not only rely on
 the timing of the breeding season at which displays occur but also on the
 frequency at which displays occur in relation to local breeding density.
 Here, we investigated the function of display behaviour in the Icelandic
 Whimbrel throughout the breeding season and along a breeding density
 gradient. We used a site-based approach in the southern lowland plain in
 Iceland where Whimbrel breeding density and display frequency were
 recorded for two years. Although whimbrels showed display behaviour
 throughout the entire season, display frequency was higher at low
 densities during pre-incubation but similar at different densities during
 incubation and post-incubation. Our results indicate that this behaviour
 is context-dependent and pluripotent, supporting the importance of mate
 attraction at low conspecific density during pre-incubation, while other
 functions such as resource defense may be important throughout the
 breeding season.
description: # Data from: Serenade of a Whimbrel: Understanding the function of display
 behaviour in a sub-Arctic territorial wader
 [https://doi.org/10.5061/dryad.n2z34tn4m](https://doi.org/10.5061/dryad.n2z34tn4m) ## Description of the data and file structure Data was collected at 6 study sites where Whimbrel counts and acoustic point counts were carried out. Whimbrel counts: the number of adult Whimbrel were recorded every time a site was visited. Counts were performed along dirt tracks by driving slowly - always the same route- using binoculars, and carefully noting the location of the birds to avoid double counting. These counts were later used to calculate breeding density during the incubation period. Acoustic point counts: we selected 3 to 5 fixed points within each site. On each point, the number of Whimbrel aerial displays were counted for three minutes. This data was used to obtain the frequency of displays per point. ### Files and variables #### File: Data\_Serenade\_of\_a\_Whimbrel.csv **Description:**  ##### Variables The first row contains the variable's names: * year: Sampling year, 2020 or 2021 * site: Site name (six different sites in total) * point: fixed point-count ID. A total of 3 to 5 fixed-points per site where the acoustic surveys took place. * breeding_density: Whimbrel breeding density for the incubation period (Mean of the maximum three counts of Whimbrel pairs recorded during incubation, divided by the area of the site in km2). * breeding_period: pre-incubation, incubation, and post-incubation. * displays: frequency of displays per point. ## Code/software The software used for this analysis is R. The packages used were lmer4 for models and performance for model validation.