Many thanks to Silke Kipper, Sarah Kiefer, Michael Wei&#223;, Conny Bartsch and Silke Voigt-Heucke for enthusiastic sample collection in the field, to Janett Birkenfeld for continued assistance, to Ulla Kobalz for the beautiful gels and to Tobias Krause for moral support.

All procedures were performed in compliance with the German law for animal protection (TierSchG).
1. Preparation of Reagents and Consumables
<ol>
	<li>Prepare a 5% (w/w) Chelex-100 solution in molecular grade water. Prepare aliquots of 200 &#181;l in standard 1.5 ml reaction tubes. As the Chelex resin precipitates fast from the suspension it is necessary to re-homogenize the suspension constantly during the preparation of the aliquots. It's advisable to prepare 50 ml or more in one batch and...

<ol>
	<li>Russell, W. M. S., Burch, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+principles+of+humane+experimental+technique.">The principles of humane experimental technique.</a> , (1959).</li><li>Robertson, B. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+sexing+of+individual+kakapo,+Strigops+habroptilus+Aves,+from+feces.">Molecular sexing of individual kakapo, Strigops habroptilus Aves, from feces.</a> Mol. Ecol. 8, 1349-1350 (1999).</li><li>Yannic, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Description+of+microsatellite+markers+and+genotyping+performances+using+feathers+and+buccal+swabs+for+the+Ivory+gull+(Pagophila+eburnea).">Description of microsatellite markers and genotyping performances using feathers and buccal swabs for the Ivory gull (Pagophila eburnea).</a> Mol. Ecol. Resour. 11, 877-889 (2011).</li><li>Bello, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+genomic+DNA+from+feathers.">Isolation of genomic DNA from feathers.</a> J. Vet. Diagn. Invest. 13, 162-164 (2001).</li><li>Handel, C. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+buccal+swabs+for+sampling+DNA+from+nestling+and+adult+birds.">Use of buccal swabs for sampling DNA from nestling and adult birds.</a> Wildl. Soc. Bull. 34, 1094-1100 (2006).</li><li>Brubaker, J. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+noninvasive,+direct+real-time+PCR+method+for+sex+determination+in+multiple+avian+species.">A noninvasive, direct real-time PCR method for sex determination in multiple avian species.</a> Mol. Ecol. Resour. 11, 415-417 (2011).</li><li>Arima, H., Ohnishi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Usefulness+of+avian+buccal+cells+for+molecular+sexing.">Usefulness of avian buccal cells for molecular sexing.</a> Ornithological Science. 5, 139-143 (2006).</li><li>Seki, S. -. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+sexing+of+individual+Ryukyu+Robins+Erithacus+komadori+using+buccal+cells+as+a+non-invasive+source+of+DNA.">Molecular sexing of individual Ryukyu Robins Erithacus komadori using buccal cells as a non-invasive source of DNA.</a> Ornithological Science. 2, 135-137 (2003).</li><li>Wellbrock, A. H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Buccal+swabs+as+a+reliable+source+of+DNA+for+sexing+young+and+adult+Common+Swifts+(Apus+apus).">Buccal swabs as a reliable source of DNA for sexing young and adult Common Swifts (Apus apus).</a> J. Ornithol. 153, 991-994 (2012).</li><li>Marion, W. R., Shamis, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Annotated-Bibliography+of+Bird+Marking+Techniques.">Annotated-Bibliography of Bird Marking Techniques.</a> Bird Banding. 48, 42-61 (1977).</li><li>Scharff, C., Adam, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurogenetics+of+birdsong.">Neurogenetics of birdsong.</a> Curr. Opin. Neurobiol. , (2012).</li><li>Griffith, S. C., Buchanan, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Zebra+Finch:+the+ultimate+Australian+supermodel.">The Zebra Finch: the ultimate Australian supermodel.</a> Emu. 110, 5-12 (2010).</li><li>Fee, M. S., Scharff, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+songbird+as+a+model+for+the+generation+and+learning+of+complex+sequential+behaviors.">The songbird as a model for the generation and learning of complex sequential behaviors.</a> Ilar J. 51, 362-377 (2010).</li><li>Honarmand, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stressful+dieting:+nutritional+conditions+but+not+compensatory+growth+elevate+corticosterone+levels+in+zebra+finch+nestlings+and+fledglings.">Stressful dieting: nutritional conditions but not compensatory growth elevate corticosterone levels in zebra finch nestlings and fledglings.</a> PLoS On. 5, (1371).</li><li>Krause, E. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zebra+finch+nestlings+beg+more+under+better+nutritional+conditions.">Zebra finch nestlings beg more under better nutritional conditions.</a> Behaviour. 148, 1239-1255 (2011).</li><li>Griffiths, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+DNA+test+to+sex+most+birds.">A DNA test to sex most birds.</a> Mol. Ecol. 7, 1071-1075 (1998).</li><li>Pluthero, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+purification+of+high-activity+Taq+DNA+polymerase.">Rapid purification of high-activity Taq DNA polymerase.</a> Nucleic Acids Res. 21, 4850-4851 (1993).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Joint+Working+Group+on+Refinement.+Laboratory+birds:+refinements+in+husbandry+and+procedures.+Fifth+report+of+BVAAWF/FRAME/RSPCA/UFAW+Joint+Working+Group+on+Refinement.">Joint Working Group on Refinement. Laboratory birds: refinements in husbandry and procedures. Fifth report of BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement.</a> Lab Anim. 35, 1-163 (2001).</li></ol>

Sexing from buccal swabs using Chelex showed an extremely high success rate. Cutting hatchling's down feathers enabled differentiation between nestlings until leg banding was possible.
Chelex-DNA extraction from buccal swabs yielded enough DNA to successfully perform molecular sexing. Sex determination was 100% correct as validated by sexually dimorphic plumage. The success rate reported here is markedly higher than the rate reported by two previous studies7,9. The DNA extraction wi...

Individual recognition, sexing and genotyping are fundamental prerequisites in a variety of experimental studies. Obtaining DNA bearing material and marking subjects unambiguously (even at an early age) should have minimal impact on physiology, behavior, and survival. Whenever possible, invasive procedures should be avoided according to the RRR principle1.
Non-invasive methods are not only beneficial for the animal but also might improve the obtained data as animals are less affected by the treatments.
In birds, DNA sexing can be performed on a number of non-invasively obtainable materials as droppings2, feathers3,4 or buccal swabs3,5,9. Regardless of subject&#180;s condition and age buccal swabs are the method of choice for avian sexing, because they are easy to perform, rarely fail and handling is short.
So far, DNA from buccal swabs was either extracted with commercially available kits3,6 or time consuming standard DNA extraction protocols3,6-8. Kits are not only rather expensive, but their protocols can impose challenges for field work. Some procedural details, e.g. drying and incubation of samples, are not practical in the field. Especially in a setting where experimental protocols require sex dependent treatment from as early as a few minutes post hatching, there is urge for a quick, non-invasive, reliable and easy method to obtain results.
Across the avian taxa a considerable toolbox for marking individuals has been developed10. The wide array of available techniques accounts for the variety of research objectives, species and budgets. However, marking small nestlings has confronted researchers with additional challenges. In some species (e.g. passerines) chicks are too small to apply leg bands and require alternative methods, which do not alter parent-offspring behavior. As awareness and interest in improving animal welfare and techniques in field and laboratory studies is growing, the use of non-invasive techniques is strongly encouraged and preferred.
This protocol provides a non-invasive, quick, easily recognizable and persistent method to individually mark very young nestlings before applying leg bands is feasible. This marking method is introduced on one of the most important avian laboratory model species, the Zebra Finch (Taeniopygia guttata)11-13. The protocol complies with all of the previously published objectives for individual marking techniques10 and has been already successfully applied14,15.

<table border="0" cellpadding="0" cellspacing="0" width="702">
	<tbody>
		<tr height="75">
			<td height="75" style="height:75px;width:191px;">Whatman 3MM Chromatography paper</td>
			<td style="width:163px;">e.g. Fisher Scientific</td>
			<td style="width:269px;">No.:3030-153</td>
			<td style="width:80px;"></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:191px;">Chelex 100 Resin</td>
			<td style="width:163px;">Biorad</td>
			<td style="width:269px;">#143-2832</td>
			<td></td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:191px;">Taq polymerase</td>
			<td style="width:163px;">addgene</td>
			<td style="width:269px;">http://www.addgene.org/25712/</td>
			<td></td>
		</tr>
		<tr height="75">
			<td height="75" style="height:75px;width:191px;">leg band (Flexi number rings for birds, diameter 2,5 mm)</td>
			<td style="width:163px;">Horst Stengel &#38; Sohn</td>
			<td style="width:269px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

who is who? non-invasive methods to individually sex and mark altricial chicks

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.

Buccal swabs can be used to obtain DNA for sex determination in a variety of small birds
Samples were collected from Zebra Finches (Taeniopygia guttata, 99 individuals, age 0 days - 5 years), Canaries (Serinus canaria), Bengalese Finches (Lonchura striata), Nightingales (Luscinia megarhynchos), Great Tits (Parus major) and Blackbirds (Turdus merula) (for all other species: sample size 1-3, age unknown) (Figure 1).
<p class...

Watch this Scientific Journal Video about Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks at JoVE.com

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

This protocol provides a convenient set of methods, which enables extremely fast, easy, non-invasive, reliable and low-cost, molecular sex determination of birds and their non-invasive, quick, safe and easily recognizable marking shortly after hatching. Only limited handling of chicks is required. This convenient toolbox of methods complies entirely with the RRR-guidelines.

Many experiments require early determination of offspring's sex as well as early marking of newborns for individual recognition. According to animal ...

who-is-who-non-invasive-methods-to-individually-sex-mark-altricial

Research

JoVE Journal

Biology

18.2K Views.  Freie Universität Berlin.  Questo protocollo fornisce un insieme di metodi conveniente, che consente estremamente veloce, semplice, non invasivo, affidabile ea basso costo, determinazione del sesso molecolare degli uccelli e la loro non-invasivo, rapido, sicuro e facilmente riconoscibile marcatura poco dopo la schiusa. È necessaria solo la gestione limitata dei pulcini. Questo comodo toolbox di metodi del tutto conforme alle RRR linee guida. 