Molecular sibship reconstruction reveals a promiscuous mating system in brood parasitic little bronze-cuckoos (Chalcites minutillus)

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 i..., 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., , # 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...