Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Abstract

Many experiments require early determination of offspring's sex as well as early marking of newborns for individual recognition. According to animal welfare guidelines, non-invasive techniques should be preferred whenever applicable. In our group, we work on different species of song birds in the lab and in the field, and we successfully apply non-invasive methods to sex and individually mark chicks. This paper presents a comprehensive non-invasive tool-box. Sexing birds prior to the expression of secondary sexual traits requires the collection of DNA-bearing material for PCR. We established a quick and easy method to sex birds of any age (post hatching) by extracting DNA from buccal swabs. Results can be obtained within 3 hours. For individual marking chick's down feathers are trimmed in specific patterns allowing fast identification within the hatching order. This set of methods is easily applicable in a standard equipped lab and especially suitable for working in the field as no special equipment is required for sampling and storage. Handling of chicks is minimized and marking and sexing techniques are non-invasive thereby supporting the RRR-principle of animal welfare guidelines.

Calbindin expression in developing striatum of zebra finches and its relation to the formation of area X

“…We modified an existing sexing protocol by using saliva samples from nestling zebra finches (Adam et al,2010). DNA was extracted using the CHelex‐method and sexing polymerase chain reaction (PCR) was conducted using 19 μl of genomic DNA as template.…”

A novel method to optimise the utility of underused moulted plumulaceous feather samples for genetic analysis in bird conservation

“…This not only provides evidence in support of using non-invasive sampling methods for genetic analyses, in particular when applied to endangered species, but also highlights the utility of biological material kept in non-optimal conditions, may previously have been discounted (Rawlence et al 2009;Vili et al 2013). Data collected in this manner is informative for species identification, presence/absence detection, population structure and phylogenetic analyses of rare and elusive species (Bonin et al 2004;Marucco et al 2011;Adam et al 2014), all of which are key questions in conservation research.…”

Sex‐specific prey partitioning in breeding piscivorous birds examined via a novel, noninvasive approach

“…Whilst the majority of pellets collected could be reliably sexed, 160 pellets did not produce a result in PCR and 22 samples, initially classified as male pellets, were excluded from the analysis. This high number of inconclusive samples could be caused by different reasons: Whilst buccal swabs are successfully used for molecular sexing (e.g., Adam, Scharff, & Honarmand, ; Handel, Pajot, Talbot, & Sage, ), the reliability of pellets as a source for bird DNA remains to be further assessed. The DNA fragments amplified with the selected primers are comparably long (459 and 652 bp) for samples exposed to digestive processes (King et al., ).…”

“…Breeding 2 Morel, 1996) or introduce correction factors for affected hard parts (Boström, Östman, Bergenius, & Lunneryd, 2012;Veldkamp, 1995a Adam, Scharff, & Honarmand, 2014;Handel, Pajot, Talbot, & Sage, 2006), the reliability of pellets as a source for bird DNA remains to be further assessed. The DNA fragments amplified with the selected primers are comparably long (459 and 652 bp) for samples exposed to digestive processes (King et al, 2008).…”