What brings me to Greenland, as you will have understood, is of course the pleasure of finding myself in this extraordinary isolated site, with its incredible landscapes and atmospheres. But, what first brings me and my two colleagues… is science! And more precisely the ADACLIM research program (ADACLIM – cebc UMR 7372 (cnrs.fr)), supported by the CNRS and the University of La Rochelle, and financed by the Paul-Émile Victor Polar Institute.
Its objective: to study a colony of little auks over the long term, in order to understand how this key species in the Arctic ecosystem reacts to changes in its environment.
Question #1: How are the adults doing? what is their survival rate?
To answer this question, many birds have been adorned with colorful bands over the years, with unique color combinations:
left leg then right leg , from top to bottom, here is the Metal-Purple-Orange-Green bird: MPOG
Your mission: spend enough time each year (in this case 42 hours) on the small colony sector in question, and write down all the combinations you see. Then run mathematical models to determine the demographic parameters of the colony.
And... how old can a little auk reach?
Over 18 years old! (for example in 2020, of the 89 ringed birds that we saw, 6 had been ringed since the start of the program in 2005, when they were already adults and over 3 years old)
But... if the auks wander elsewhere in the colony, don't we risk missing them and distorting the results?
This is without taking into account the extreme fidelity of the auks, from one year to the next, to their small colony sector, and even to just a few rocks! This method therefore makes it possible to observe the (almost) totality of the birds present.
Question #2: How do chicks grow?
First step: examine the scree in search of "accessible" nests, that is to say... not too deeply hidden under the stones... For around forty nests, allow 2 to 3 half-days: there are many of them, but their nests are well hidden!
you often have to plunge your forearm under the stones, or even contort yourself, to reach the chick (here, Julie at work)
Next steps: note the hatching date (only one egg per pair), then weigh and measure (beak-leg-wing) the little balls of down every 2 days, in order to trace beautiful growth curves.
weighing only around twenty grams at hatching, the chicks then quickly gain weight (10 to 15 grams every 2 days), reaching a plateau of 110-120 grams, stage where they exchange their down for real feathers and build muscle to be able to fly: in short, 3 weeks of intensive feeding and they are already ready to take off!
Question #3: Are adults and chicks healthy?
To answer this question, take a blood sample (at the wing) and a few feathers from all the birds handled.
This makes it possible in particular to search for pollutants, first and foremost mercury. Rejected by industries in the northern hemisphere, this invisible pollutant travels on atmospheric and marine currents to the Arctic, where it rises and concentrates throughout the food chains. The little auk is one of the twenty bio-indicator species closely monitored by the international ARCTOX network (The project - A pan-Arctic network to track mercury contamination across Arctic marine food webs (cnrs.fr)).
Also collect egg shells as well as auk preys, and repeat the same analyzes in the laboratory.
and above all, once you have finished handling the beast, don't forget to release it! (Greg, here at work)
[next episode] Science again!
Come next week, we'll continue to talk about science, but with little miniaturized electronic gems this time, to answer different questions: where do little auks spend the winter? what do they eat ?where and how do they feed?