Thursday, March 22, 2018

Avian Detectives Discover Vikings Dreamed on the Feathers of Giant Eagle Owls


Ancient Origins


Those legendary sea warriors who dominated the oceanic territories of the northern hemisphere between the 8th and 12th century, the Viking’s, rested their sea-weary heads on luxury pillows stuffed with “Eagle-owl feathers” says Jørgen Rosvold, a postdoctoral fellow in the Department of Archaeology and Cultural History at the Norwegian University of Science and Technology (NTNU) University Museum.

 According to an article in phys.org, Rosvold has a rare skill set that makes him one of only “a few experts in Norway” who can identify birds only by making observations of feathers. After examining a “pillow that was found in a Viking grave” he isolated a tiny fragment of a feather from Europe's largest owl and finally confirmed what many archaeologists have suspected, that “Vikings valued feathers as an important resource."


Eurasian Eagle Owl (Bubo bubo) in San Francisco Zoo (CC BY-SA 3.0)

Although Rosvold’s team nailed it this time, there are endless variables in their relatively diverse scientific discipline: “Some feathers are just too similar to be certain what species it comes from. You might be able to say whether a feather comes from a game bird or a sparrow, but not always much beyond that,” Rosvold told reporters. To increase the probability of successfully identifying bird species from feather samples, the NTNU University Museum Down Project (Dunprosjektet) has built up a large collection of feather matter, and if researchers can first determine which family a feather belonged to, it can then be compared with samples in the Down Project collection.

Among the pointers, or signatures, feather analysts look for when attempting to identify bird species are found in the “down,” at the smallest branches of a feather, known as “barbules.” It was the “size, shape and colour” of the barbules that provided the clue which enabled Rosvold to identify the “Eagle-owl feathers,” according to the phys.org report. Rosvold also said that “pigmentation in feathers from early Viking times, around 800 AD… indicates game birds,” recognizable by the “rings around their barbules” while duck feathers have distinctive “triangular growths.”


Miniscule barbules, the smallest branches of a feather, are examined under a microscope to identify the kind of bird. Here are two different birds. At bottom left is a rock ptarmigan, a type of game bird with rings around its barbules. At bottom right is a mallard with triangular growths at the ends of its barbules. Credit: Jørgen Rosvold, NTNU University Museum

 Rosvold told reporters that the second phase of this project is going to study, “Norwegian grave discoveries from the Nordic Iron Age, including the Oseberg grave, to find out which birds the feathers come from” and also to find out when eider farmers first built nesting boxes to gather duck down. According to Rosvold the relationship between man and duck “goes way back in time” and his researchers have found feather samples that date as far back as the late Germanic Iron (or Merovingian) Age, from around 570 and through the Viking era.


An approximately one centimeter long well-preserved fragment of a bird feather found in a grave dating back to the Viking Age. Even after many hundreds of years, it is possible to see the colors and that this is a crow feather. (Image: Jørgen Rosvold, NTNU Unversity Museum, Trondheim)

Rosvold’s Viking pillow feather discovery is the next link in a chain of high end archaeological discoveries in this field. Early in 2016 another ancient feather set the paleontological world on fire. Discovered in Myanmar and dating back to the Middle Cretaceous, about 99 million years ago, a piece of amber contained “a part of a small and feathery tail,” according to an article in The Guardian. Based on a number of observations, including “several features of the feathers,” the scientists argued that this “tail did not belong to an ancient bird, but rather to a dinosaur known as a coelurosaur. This amber entombed feather was the first “official” piece of a dinosaur ever to have been found trapped in amber, the first unofficial one reaching pop cultural fame in the Jurassic Park franchise.

And as if this wasn’t enough in the world of feathers for one year, in November 2016, nature.com reported that Chinese scientists discovered a near-complete fossil of “the oldest feathered bird-like dinosaur.” Although this discovery brought with it a wave of skeptics, dating established “that such feathered animals were present on Earth at least 150 million years ago.” According to Mark Norell, curator of vertebrate palaeontology at the American Museum of Natural History in New York, “these four-winged dinosaurs also had feathers on their feet and wing-like attachments on the arms and legs. But they could probably only glide, as their plumage was insufficient for powered flight.”


The holotype of Microraptor gui, the four-winged dinosaur.This shows the preserved feathers (white arrow) and the 'halo' around the specimen where they appear to be absent (black arrows). (CC BY 2.5)

Returning to the Norwegian discovery of the Eagle-owl feathers in the Viking’s pillow, to gain a greater understanding of how ancient Nordic cultures interacted with Eagles, archaeologists might consider studying The Tomb of the Eagles, a Neolithic chambered tomb located on a cliff edge at Isbister on South Ronaldsay in Orkney, Scotland. This unique ancient burial chamber contained over “16,000 human bones… as well as 725 bones from predominantly White-tailed Sea Eagles (Haliaeetus albicilla). These eagles died c. 2450–2050 BC, and although almost all organic matter has now rotted away, maybe Jørgen Rosvold and his team of feathery sleuths at (NTNU) University Museum could find fragments of ancient Sea-Eagle feathers buried deep beneath the meters of compacted bird excrement which has solidified like cement.

And remember, to archaeologists in Norway or Scotland, this compacted avian excreta is comparative to Chinese amber in the organic treasures it has been found to contain.

Top image: This microscopic image shows what bird feathers and bone fragments look like close up. Branching off the feathers are thin hairs. (CC BY 4.0)

By Ashley Cowie

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