DOI: 10.5061/dryad.83bk3j9qq
title: Density-dependent individual variation in male attractiveness in a wild field cricket

description: Social environments modify a male’s ability to attract females and thus
 affect its fitness. Theory implies that an individual’s fitness should
 trade-off with its ability to cope with competition. Individuals are
 expected to solve this trade-off differently: some males should be more
 attractive at low but others instead at high density. This prediction has
 rarely been tested in the wild. We used an automated RFID-surveillance
 system to quantify for each hour of the day, over 30 days (i.e. almost the
 entire adult lifespan of our model organism), whether a male had attracted
 a female in its burrow. The data were collected across a range of
 naturally varying local densities in wild field crickets, G.campestris. We
 also estimated whether the shape of the relationship between
 attractiveness and density was under selection. At the population level,
 attractiveness increased from low to intermediate density, suggesting an
 Allee effect. Attractiveness subsequently declined at higher densities,
 for example, because of detrimental effects of increased competition.
 Opposite to expectations, males that were more attractive under low
 densities were also more attractive under higher densities. However, the
 increase in attractiveness with density varied among males, suggesting
 that Allee effects were individual-specific. Finally, selection was not
 acting on density-dependent attractiveness but males that lived longer
 acquired more mating partners. Our study reveals that social environments
 shape attractiveness in wild male insects, and imply the occurrence of
 individual-specific Allee effect that may be evolvable.
description: The data is collected by using automated RIFD-surveillance
 system. Data is processed so that for all individuals, one location data
 point was extracted for each hour.
description: <b>Explanation for
 the variables in the provided data sets:</b>
 Main data
 Fitness = binary trait for whether a male was with a
 female in its focal burrow during the focal hour (1 = yes, 0 = no). Thus,
 this variable represents attractiveness. Age = age
 for each focal male as days after molting to maturation.
 Age_2 = squared age. Max_ages = number of
 days each focal male was alive as adult. Max_ages_2 =
 squared Max_age. Distance_wall = distance of each
 burrow (in centimeters) from the edge of the study area.
 Tag = identity of each male. Datez = date
 since 201505-08, i.e. since the first maturation in a population was
 confirmed. Burrow = identity of each
 burrow. Hours = identity of each hour (i.e. 24
 hours). Max_100NEW max_700NEW = maximum experienced
 density of other males for each focal male within 100 – 700 centimeter
 distance from the focal burrow. max_100NEW_2
 max_700NEW_2 = squared Max_100NEW - max_700NEW.
 d100NEW d700NEW = hourly density of other males for each male
 for each focal hour within 100 – 700 centimeter distance from the focal
 burrow the focal male was occupying. d100NEW_2 – d700NEW_2 = squared
 d100NEW_2 – d700NEW_2. Selection gradient
 data: relative_unique_females = relative
 amount of unique females confronted in the same focal burrow throughout
 the data collection period for each focal male.
 Intercept_stand = standardized BLUP for the intercept of the
 reaction norm. Linear_stand = standardized BLUP for
 the linear slope of the reaction norm.
 Quadratic_stand = standardized BLUP for the nonlinear slope of
 the reaction norm. Survival_stand = standardized
 number of days alive after molting to maturation. Tag = identity of each focal
 male.