How it's made: The Davoren Lab Feather Processing Protocol!

Author: Mica Athayde

Ever wonder about the ways we spend our working hours when we’re not in the field? Curious about the details that don’t make it into our publications?  Read on for the story behind some of the methods in this recent paper out of the Davoren Lab: Spatiotemporal and isotopic niche overlap among Atlantic puffins, razorbills, and common murres during the non-breeding season in the Northwest Atlantic 

Part I: The science doesn’t stop in the winter! 

We start our scientific journey during the field season in Newfoundland, when we collect samples which we then bring back to the lab in Winnipeg at the end of the summer. For example, we have collected head, body, and wing (secondary) feathers from 3 alcids (Common Murres, Razorbills, and Atlantic Puffins) over a few years, with the goal of using them for stable isotope analysis. Stable isotope analysis is measuring the stable isotope ratios of certain elements in the body tissues of an animal. Measurements of the stable isotope ratios in these feathers can provide information on a bird’s diet, movement, and health when the feather was grown. Since these species molt and regrow feathers during the winter, when they are away from the colony, out at sea, and far more inaccessible, stable isotope analysis of these feathers is one of the best ways to learn about that part of their lives. However, to get from a feather sample to a stable isotope ratio, we must do a lot of work in the lab! A very important step is washing the feathers, as this removes dirt and oils that would contaminate the samples and ruin the measurements. To learn which feather washing methods to use, we received some guidance from other researchers, but there were still many details to figure out as we began this lab work.   

Photo: Scott Morrison

Photo: Mica Athayde

Photo: Scott Morrison

Part II: In the lab and on the screen 

The first step in switching from field work to lab work is organizing your samples. There were hundreds of feather samples from several different years, and it’s not necessary to use every sample for one project, nor is it efficient. We ended up using feathers from 20 different birds for each year and alcid species. With 3 different types of feathers from 3 different alcids and 4 years of data, this worked out to be about 720 individual samples to be processed! With so many samples it’s important to keep track of what’s what, so labelling meticulously as feathers are moved from the envelopes used in the field to glass vials is a must – and just happens to eat up some time too! Our excel spreadsheets were sprawling, and our vial count seemed endless, but we persevered and made it to the next stage. 

The next step in going forward is washing the feathers so we can process them further. Using Sodium Hydroxide (NaOH) and water was recommended, but how exactly does one wash a feather? We added the solution to the vial with the feathers then shook it around for a bit, basically like a miniature washing machine! After that you drain out the liquid and try to keep the feathers in. We ended up trying a couple different ways to not lose the feathers and came up with the idea of treating them like rice – rinsing the rice then draining the water out and holding your hand to the pot – only we were using feathers and the vial cap instead of rice and our hand. We also found that using less liquid worked better for keeping all our feathers in; less really can be more! 

Photo: Mica Athayde

After getting our method down when washing the head feathers, it was time to move on to washing the body feathers. These look very similar, so we expected washing them to be much the same, but subtle differences in the feathers’ size and structure lead to surprising changes in washing methods! Because the body feathers are bigger, there was a need for more liquid to cover them and wash them thoroughly, but they also stuck to the vials more, so pouring the liquid out was no problem at all! 

Photo: Mica Athayde

When moving to the secondary feathers (from the wing) we found a new challenge, and some uplifting evidence that our methods were working. Secondary feathers are thicker, but the individual barbs on the feather would easily come apart because they were clipped from a larger feather. This meant going back to our rice method to not lose any little feather bits! The secondary feathers also made it clear that our washing was successful; some of the feathers had physical dirt on them so we could see more clearly the feathers becoming clean after multiple washes. This wasn’t something that was obvious with the other feather types, so being able to see the process working before sending the feathers off for stable isotope analysis was reassuring. Also, we could have confidence that we wouldn’t have to do it all over again!

At the end of all this, we had 720 freshly washed feather samples ready for the next step towards isotope measurement and a brand-new feather washing protocol with all the little tips and tricks we learned! Our science may start in the field, but it continues into a lab year-round, and not even a global pandemic can stop us! Though we did have to change how we interacted, and we all learned new ways to keep safe, the science never stops.

If you are interested in our final protocol, don’t hesitate to reach out!  This working document is passed among lab members for many additional projects and many more feathers.