DOI: 10.5061/dryad.6hdr7src0
title: Data from: Not all who wander are lost: Prospecting and settlement of male floaters in the spotless starling

description: Floaters are non-breeding individuals that lack a territory or a breeding
 site. In many species, they can be seen visiting the territories of
 conspecifics before obtaining their own breeding site. Prospecting
 behavior is hypothesized to benefit floaters through information
 acquisition, enhanced site familiarity and dominance over other floaters.
 Here, we used detections of PIT-tagged male floaters in a population of
 spotless starlings (Sturnus unicolor). We investigated how floater
 activity varied across breeding stages and how their visits influenced
 subsequent nest site selection. We also tested whether distance,
 reproductive success, and phenotype and fate of the former owner
 influenced final settlement. We found that floater activity increased
 during the nestling-rearing period as nestling age increased. Floaters
 were more likely to breed near the area where they had been detected the
 previous year, suggesting that prospecting allows males to secure a
 foothold in their future settlement area. Although prospecting was higher
 in nests with a higher number of nestlings, neither breeding success,
 phenotype, nor provisioning rate of the last owner were related to nest
 choice, suggesting that public information is not used by males to decide
 where to settle. However, we found that floaters were more likely to breed
 in nest boxes where the previous owner had disappeared from the colony,
 suggesting that visits by male floaters in this species allow them to
 detect new vacancies. Our results suggest that prospecting might serve
 several non-mutually exclusive functions. Further studies in non-saturated
 colonies could shed light on the functional aspects of prospecting.
description: # Data from: Not all who wander are lost: Prospecting and settlement of
 male floaters in the spotless starling Dataset DOI:
 [10.5061/dryad.6hdr7src0](10.5061/dryad.6hdr7src0) ## Description of the
 data and file structure ### Dataset Overview This dataset contains the
 data required to replicate the analyses in Redondo et al. 2025. In this
 work, we used detections of passive-integrated-transponder tagged
 (PIT-tagged) male floaters in a population of spotless starlings (*Sturnus
 unicolor*) to investigate how floater activity varied across breeding
 stages and how their visits influenced subsequent nest site selection.
 Floaters were captured before breeding season began and were marked with a
 PIT-tag that allowed us to monitor their visits to nests of conspecifics
 and future settlement. We used long-term data (10 breeding seasons) on the
 intrusion behaviour and posterior nest site choice of male floaters in a
 population of spotless starlings. Our objective was two-fold: 1.
 Describing the temporal patterns of prospecting in this species by
 monitoring nest intrusions by tagged individuals and examine the cues that
 may induce birds to prospect in particular boxes. 2. Testing different
 hypotheses that have been proposed to explain prospecting (*the
 alternative reproductive hypothesis, the foothold hypothesis, the public
 information hypothesis*) ### Files and variables #### File:
 Prospecting\_at\_breeding\_stages.csv **Description:** contains the data
 related to the analyses of the factors influencing prospecting activity.
 ##### Variables * event (factor): variable for identifying the nest and
 the breeding attempt. * year (factor): year of observation. * stage
 (factor): part of the breeding cycle where the observation was taken. *
 nestlings (numeric): number of nestlings at the moment of observation. *
 cs (numeric): clutch size * bs6 (numeric): brood size when nestlings are 6
 days-old. * bs14 (numeric): brood size when nestlings are 14 days-old. *
 bs18 (numeric): brood size when nestlings are 18-days old. * brood_fledge
 (factor): binary variable. 0 = none of the nestlings fledged, 1 = at least
 one nestlings fledged. * male_floaters_sl (numeric): number of floaters
 detected visiting the nest. * dad_visits (numeric): number of times the
 male owner of the nest visited his nest-box. * mum_visits (numeric):
 number of times the female owner of the nest visited his nest-box. *
 parent_visits (numeric): sum of the visits the male and female owners
 visited their nest-box. * duration (numeric): duration of the recording in
 minutes. * wave (factor): whether the breeding attempt belonged to first
 clutches (1), reposition clutches (1.5) and second clutches (2). *
 days_since_laying (numeric): days since the first egg was laid. *
 days_since_hatching (numeric): age of the nestlings. #### File:
 Prospecting\_and\_settlement.csv **Description:** this dataset contains
 the data for the analyses aimed at determining the factors influencing
 settlement in relation to prospecting behaviour. ##### Variables * order
 (numeric): file ID. * ring (factor): identification number of each focal
 male. * nest_dummy (factor): name/number of the nest box where a focal
 male was either detected or potentially could've been detected. *
 distance (numeric): distance (in meters) between the centroid coordinates
 and the nest dummy nest. * visited (factor): whether a male was actually
 detected visiting that nest box (0 = no, 1 = yes) the year before
 breeding. * chosen (factor): whether a male was detected breeding in that
 nest box (0 = no, 1 = yes) the following year. * chosen_dummy (factor):
 whether a male was detected breeding in that nest box (N = no, Y = yes)
 the following year. * out_circle (factor): indicates whether the nest box
 was outside the median prospecting circle that was projected for each
 focal male. * year (factor): the year of observation of the prospecting
 activity. * first_brood_young_fledged (numeric): number of chicks that
 fledged from a nest during the first brood round. *
 second_brood_young_fledged (numeric): number of chicks that fledged from a
 nest during the second brood round. * annual_young_fledged (numeric):
 total number of chicks that fledged from a nest during a breeding season.
 * second_brood_succeeded (factor): whether at least one chick fledged from
 a nest during the second brood round. * body_condition (numeric): body
 condition (calculated as the residuals of weight versus size, the latter
 calculated from a PCA of tarsus, beak and wing length) of the last male
 individual known to have owned the nest box. * age (numeric): age (in
 years) of the last male individual known to have owned the nest box *
 ornamentation (numeric): Mean length (in mm) of three throat ornamental
 feathers) of the last male individual known to have owned the nest box. *
 owner_not_return (factor): whether the last individual known to have owned
 the nest box has been detected again in the colony (0 = seen again; 1 =
 not seen again). * feeding_rate (numeric): the mean number of times per
 hour a male attended their nest during the chick rearing period. NA - Not
 applicable ## Code/software ###### Language and Environment R Environment
 for Statistical Computing ###### Version R 4.0.3 ###### Packages car
 glmmTMB effects parameters effectsize performance emmeans DHARMa
 adehabitatHR sf geosphere ggdist