DOI: 10.5061/dryad.54k41
title: Data from: Temporal migration pattern and mating tactics influence size-assortative mating in Rana temporaria

description: Assortative mating is a common pattern in sexually reproducing species,
 but the mechanisms leading to assortment remain poorly understood. By
 using the European common frog (Rana temporaria) as a model, we aim to
 understand the mechanisms leading to size-assortative mating in
 amphibians. With data from natural populations collected over several
 years, we first show a consistent pattern of size-assortative mating
 across our two study populations. We subsequently ask if assortative
 mating may be explained by mate availability due to temporal segregation
 of migrating individuals with specific sizes. With additional experiments
 we finally assess whether size-assortative mating is adaptive, i.e.
 influenced by mating competition among males, or by reduced fertilization
 in size-mismatched pairs. We find that size-assortative mating is in
 accordance with differences in mate availability during migration where
 larger individuals of both sexes reach breeding ponds earlier than smaller
 individuals. We observe an indiscriminate mate choice behavior of small
 males, probably due to an advantage of larger males in taking over females
 during scramble competition. The tactic of small males, to be faster and
 less discriminative than large males, may increase their chances to get
 access to females. Experimental tests indicate that the fertilization
 success is not affected by size-assortment. However, since female
 fecundity is highly correlated with body size, males preferring larger
 females should maximize their number of offspring. Therefore, we conclude
 that in this frog species mate choice is more complex than formerly
 believed.
description: data_Rana_temporaria_pairsContains raw data on pairs and singles of Rana temporaria, collected in the field at two locations. The location Fabrikschleichach (WGS 1984, 49.924 N, 10.555 E) and the location Kleiwiesen (WGS 1984, 52.328 N, 10.582 E). Given are the locations, the date and year of capture, if available the time of the day, the single ponds which were fenced to measure migrating individuals, sex, weight in g and snout-vent-length in mm of individuals; status (paired, paired inside of buckets and single individuals); SVL difference of pairs (male SVL minus female SVL) and day of capture (from the start of the migration per year).data_Rana_temporaria_migrationContains the raw data on the migration of Rana temporaria individuals in the location Fabrikschleichach (WGS 1984, 49.924 N, 10.555 E). Single ponds were fenced and individuals captured twice daily. Given are the date and year of capture, the day of capture (from the start of migration per year), the name of the ponds, sex of individual frog, weight in g and snout-vent-length in mm per individual. Additionally the status of each individual (arrived in a pair or as single).data_Rana_temporaria_fertilisation_successContains raw data of all pairs that were used for the fertilisation success experiment. All individuals are from the location Kleiwiesen (WGS 1984, 52.328 N, 10.582 E). Given are clutch ID, snout-vent-length in mm of male and female per pair, the number of eggs per clutch, the size difference of male-female in mm, the log transformed data of female size and egg number, the number of unfertilized eggs, the number of developed embryos, the proportion of fertilized eggs (number of embryos/number of eggs) and the fertilisation success in % (proportion*100).data_Rana_temporaria_mating_speedContains raw data of all trials of the mating speed experiment (n=44). Given are snout-vent-length in mm for female, small male and large male per trial; wich male was faster in grabbing the female first (Male_ampl); the size difference of female and non-amplexed male in mm; the size difference of female and male in amplexus in mm.