DOI: 10.5061/dryad.bvq83bkhr
title: Data from: Molecular sibship reconstruction reveals a promiscuous mating system in brood parasitic little bronze-cuckoos (Chalcites minutillus)

description: In theory, emancipation from parental care is expected to favour
 promiscuous mating systems. However, in avian brood parasites monogamy is
 surprisingly widespread and it has been proposed that this may be favoured
 by factors such as low population density and territoriality.
 Correspondingly, our previous research revealed that brood parasitic
 Horsfield’s bronze-cuckoos (Chalcites basalis), which occur at low
 population densities and defend territories, are monogamous. Here, we
 contrast this study with the mating system of the congeneric little
 bronze-cuckoo (C. minutillus), an obligate brood parasite that exploits
 more concentrated hosts and is therefore likely to occur at higher
 population densities. We use single nucleotide polymorphisms to
 characterise the reproductive patterns of unsampled adults by inferring
 sibling relationships among 30 offspring. We show that 1) little
 bronze-cuckoos occurred at high densities, 2) polygamy was the most common
 mating pattern found in this study in both sexes, and 3) where multiple
 cuckoo eggs are laid in the same nest, they were unrelated. These results
 indicate that females do not defend exclusive territories and males do not
 defend multiple females (polygyny). Instead, little bronze-cuckoos appear
 to have a non-territorial, promiscuous mating system. Our results are
 consistent with theoretical predictions that polygamy is more likely to
 evolve in species that are emancipated from parental care, where there are
 plenty of available mates and where home ranges are not defended.
description: Here we provide details of tissue preparation and DNA extraction,
 a summary of all samples sequenced (Table 1) and reports from DArT on the
 SNP genotyping.
description: # Data from: Molecular sibship reconstruction reveals a promiscuous mating
 system in brood parasitic little bronze-cuckoos (*Chalcites minutillus*)
 [https://doi.org/10.5061/dryad.bvq83bkhr](https://doi.org/10.5061/dryad.bvq83bkhr) ## Description of the data and file structure The supplementary information contains a description of methods for tissue preparation and DNA extraction. The Supplementary Table 1 contains details of every sample that was analysed, including Nest ID, collector, date collected, locality, GPS location, DNA extraction ID, who extracted DNA, the date extracted, the total yield, the average fragment length the concentration to submitted to DART, Plate well, whether it failed or downshifted, identification of sex and preparation methods. Reports on SNP genotyping by DArT are also included. This dataset contains the raw Dart-seq SNP data from 30 samples of little bronze-cuckoo collected from northern Queensland, Australia from 2016-2018.  The raw Dart-seq data is in the format delivered by Diversity Arrays Technology using a high density (2.5mln reads) Chalcites DArTseq 1.0 sequencing, presented in SNP 1 Row Mapping Format: "0" = Reference allele homozygote, "1" = SNP allele homozygote, "2"= heterozygote and "-" = double null/null allele homozygote (absence of fragment with SNP in genomic representation). Cells highlighted in red indicate missing data and yellow highlights indicate individuals with very high amounts of missing data.