Bird blood behaves differently to mammalian blood, and most extraction protocols are not written with that difference in mind.

Avian red blood cells are nucleated, unlike mammalian red blood cells, which means a small blood sample carries a disproportionately large amount of DNA. Researchers at the Allan Wilson Centre, University of Auckland, tested prepGEM Universal across four common avian blood storage methods: FTA cards, ethanol, frozen whole blood, and Queen's lysis buffer, on species ranging from chickens and petrels to black stilts and swamp hens.

Every single sample, across every storage method, amplified successfully for both molecular sexing and DNA barcoding, and four of the resulting sequences came back at sequencing quality scores above 90 percent. FTA cards and Queen's lysis buffer produced the highest yields, with every storage method comfortably clearing the minimum DNA concentration the same kit's protocol specifies for mammalian blood.

That is not a small sample size problem to work around. It is what nucleated red blood cells are supposed to do, and it means avian researchers can work with smaller blood volumes, lower-stress sampling for the bird, and fewer repeat collections than a mammalian-calibrated protocol would assume.

If your lab is running avian genotyping, sexing, or barcoding work and still treating bird blood like mammalian blood, the storage method may be costing you more DNA than the extraction step ever will.