Equipped with a tiny body (mostly around 100 g), elegant plumage, graceful movement, excellent directional sensation, they can make the longest journey in this planet solely on their own wisdom and power.
When the Arctic weather becomes too harsh, they do not simply go down a little to south but they fly all the way down and reach the Antarctic ocean. They are real extreme migrators!
According to a research by C. Egevang et al (PNAS 2010;107(5):2078-81), their flight statistics was like below:
- Average distance of a round-trip: 70,900 km
- Average daily distance (northbound): 520 km
- Average daily distance (southbound): 330 km
Isn’t this amazing?
The authors of the reference applied geolocators on 70 arctic terns but retrieved only 11 from which the data mentioned above were drawn. The first author, Dr. Carsten Egevang expressed his wish for a future research where he could follow-up the rest of the individuals carrying the unretrieved geolocators; however, I could not find any further articles for this matter. Specifically he pointed out that the terns took two routes during southbound migration, of which reason is unclear. He proposed two hypotheses: 1) the terns might have been affected by the wind system so that each individual may choose a different route each year depending on the wind condition or 2) the route may be genetically encoded or learned by an individual so that the same tern would take the same route each year. Unfortunatley, nobody seemed to succeed in securing the fund to follow-up those terns in 2010.
Unlike other sea birds, arctic terns rarely float on the open ocean. Rather, they rest on the ground or an iceberg. Rest of the time they usually stay in the air.
Their main diet consists of various fishes. Species of fishes they choose differ depending on the studied regions.
Their longest survival record has been recorded as 34 years (J. J. Hatch. Bird-Banding. 1974;45:269–70). In the article, the banded individual (#35.325864) was trapped its nest on Petit Manan Island, Maine, USA on June 19, 1970. Although the bird had broken bill, he/she was in excellent condition and weighed 119 g. The author (Jeremy J. Hatch, 1937-2015) initially could not find the banding record; however, he eventually tracked it down and reported that the bird was banded on Green Island by Arnold E. Davis, along with other 48 young terns, on July 24, 1936. The author cited three articles about longevity records of arctic terns, which were 23, 27, and 28 years. The bird bearing the band number 35.325864 was rebanded and released. And the author expected the record he reported would be beaten by another one in near future. But it seems the 34-year record still holds the number one position.
I unexpectedly encountered arctic terns for the first time in Latrabjarg, Iceland. I and my husband planned a northern summer trip covering Iceland, Longyearbyen, Tromso, and Oslo for a month in 2019. We started from Iceland. We landed in Reykjavik and first headed to Latrabjarg, a kind of a starting point of our trip. Anyway, the road to Latrabjarg was terribly foggy, the road was curvy and narrow, and sheeps were constantly popping out from both sides of the road. The driving made us extremely nervous. We even had to pass a car in which the driver was mentally exhausted and gave up on driving in the middle of the road. We finally made it to the Hotel Latrabjarg and exhaled a sigh of relief. Applause to my husband, the best driver! The weather was not kind and we had to mostly stay indoor. Nevertheless, we had a morning walk the next day and had the luck (?) of receiving hostile attacks of arctic terns. We were walking on the normal passage for humans but suddenly two terns started attacking us with violent clicking sound, which ironically sounded very charming to me. It turned out the field alongside the road was dominated by many terns. So we had to leave as soon as possible. Although my eyeballs were almost pulled out or pierced by the terns, it was a uniquely, attractive moment!
In the introduction section for arctic tern in birdsoftheworld.org, there is a paragraph reasoning whey there are not enough research data of inland arctic studies. The author describes like this “The notable absence of inland arctic studies is chiefly attributable to the wide dispersion of the species and thus the difficulties of assembling adequate samples, but the ferocity with which the Arctic Tern defends its nest could be a contributing factor.” Yeah, I totally agree!
I recorded the attack with iphone and managed to take a few shots with DSLR camera. The iphone footage lasts only 45 seconds but the whole watch time is several hours, if I count. I made a video and uploaded on Youtube. I am the most avid watcher of my channel.
I admire this tiny bird. No doubt that they are the true experts in the field of aviation business. Bravo, arctic terns, my heros!