Arctic Life/Arctic Animals/Birds

From Arctic Bioscan Wiki
Artic birds canadian goose.png

Birds are an integral part of Artic and a voice of nature. They are part of the fragile ecosystem that needs to be preserved for future generations. Given that the Canadian Arctic is undergoing substantial economic and social changes (e.g. natural resources exploitation and tourism) it remains to be seen on how these factors will affect birds population [1].

In the sections below, you will find information on most representative species in the Canadian Arctic. Will cover cool facts, adaptations to the harsh environmental conditions, migration patterns, reproduction specifics, evolution, etc.

Northern Birds

Birds are vertebrates that belong to the Class Aves, within the Phylum Chordata. You may be familiar with arctic species such as the snowy owl or Canada goose. However, around eighty other species of birds can be found in the Arctic! There are forty-one species of freshwater birds in the Arctic. Two of these species, the phalaropes, spin around in circles on the water's surface to create a vortex that helps capture their food.

Biology

Birds are extremely interesting and unique animals. If you would like to learn about the biology of birds, please browse the topics below.

Historical periods

The Cretaceous
Historical preriods birds.jpg

Most early bird groups disappeared during the mass extinction at the end of the Cretaceous period, but a few survived, and along with a hypothesized second major bird radiation near the Cretaceous/Tertiary boundary, are the ancestors of modern birds. Some hypothesized survivors of the Cretaceous/Tertiary extinction, present in the Arctic region today include:

  • Order Gaviformes – Loons
  • Order Gruiformes – Cranes, Rails, Coots, and Gallinules
  • Order Charadriiformes, Family Scolopacidae – Sandpipers
The Tertiary
Ice coverage of Canada during the Pleistocene epoch

Most of the Orders of birds that we see today first appeared in the Tertiary period, 65 to 2 million years ago. Many of these are represented in the Arctic today, including:

  • Order Anseriformes – Ducks, Geese, and Swans
  • Order Charadriiformes – Family Laridae (Gulls and Terns)
  • Order Falconiformes – Falcons, Hawks, Eagles, and Osprey
  • Order Passeriformes – Perching Songbirds
The Quaternary

The Quaternary is the historical period in which we now live. It has thus far been a period of great climatic change and intense glaciation. Early in this period, over half of the approximately 21,000 bird species then present died out, leaving us with the 9,500 or so alive today. In the Pleistocene, repeated glaciation, sometimes covering half of the North American continent, caused rapid changes in weather patterns and sea levels. Great dispersals of many bird species occurred, as did widespread extinction.

Controversies

Many ornithologists today disagree on exactly how the Class Aves evolved, and even when the first bird appeared. Fossil evidence from Texas may have pushed back the origin of the first birds by 50 million years, but the jury is still out. Also, new fossils from Mongolia are being uncovered at a rapid pace, so in ten years our understanding of avian evolution may be completely different from that which exists now!

The ability to sequence DNA has enabled us to look more closely at the relationships between organisms, but it has also created problems. For example, how much of a genetic difference is required for two organisms to be considered separate species? Or separate families? Estimates have been proposed, but an agreement is rare. In 1988, Charles Sibley and Jon Ahlquist, two U.S. scientists, proposed a new classification of Class Aves based on DNA-DNA hybridization. Nearly a decade later, their classification is still turning ornithology on its ear!

References

  1. Mallory, ML (2006). "A review of the Northern Ecosystem Initiative in Arctic Canada: Facilitating Arctic ecosystem research through traditional and novel approaches". Environmental monitoring and assessment. 113 (1–3): 19–29.