EcoInformatics International

Wood Buffalo National Park

First aerial photos of bisons (1931)

Jean Thie - Ecoinformatics International

Since the early 1920's the Royal Canadian Air Force (RCAF) was flying aerial reconnaisance photo mission in selected areas of Canada. In 1930 and 1931 parts of Wood Buffallo National Park were covered by the RCAF with their "flying canoes". A series of unique aerial photos taken on February 24, 1931, show a number of bison herds in their typical winter habitat.

This page provides an overview of some of these early images of bisons and compares the 1931 habitat with the present situation. The source of the aerial photos is the National Air Photo Library in Ottawa. The large time lapse - almost 90 years- with todays high resolution satellite images provides an surprising insight in the environmental changes in the National Park's ecosystems.

two small groups of bison from higher altitude

1931, discovering the first bison herd from higher altitude

A landcape overview - bisons in their winter habitat; blue arrow

first aerial encounter with a herd of bisons

Taking a closer look

abundance of bison trails in the snow

Image 1: Bison Habitat -Take the challenge: Locate the bison photos on this 2007 satellite image.

It is not easy, and without the actual flight line maps from the National Air Photo Library, it becomes an 'ecosystem puzzel' wich provides an interesting perspective of bison habitat and landscapes. Click on the image for higher resolution. Solution link below.

Link to the solution here. On the solution image: The red arrows point to the locations and indicate the flight direction, the light blue marks the bison herds. Only the first, second and 4th image could be located. More recent satellite images are available, some show impacts of recent wildland fires.

Image 2: Reconstructing the 1931 oblique aerial photos with Google Earth.

The unique tilting feature of Google Earth Pro enables an interesting time lapse experience. The actual air photo is outlined on the satellite image. The bison herd (red arrows) on the air photo are within the red circle on the satellite image. The similarity of the two landscapes, after almot 90 years,is striking.

Image 3: Time Lapse Bison Landscape in Wood Buffalo National Park 1931 and 2018. What are the changes? The 1931 winter images shows clearly the shadows of the bisons, the shape of the treed landforms and more subtly the abundance of bison tracks in the deep snow. The 2018 image shows the same area with a higher resolution. It is surpising to see so little change in the vegetation cover after almost 90 years.

Image 4: Winter-fall comparison, white winter habitat and fall vegetation colours

Fortunately small parts of Wood Buffalo National Park are or have been covered by some amazing high quality winter images, providing a different perspective of its ecosystems. This winter image was taken on January 18 2020. It shows the abundance of bison tracks that are also so distinct on the 1931 aerial photos.The fall image is from 16 september 2015. The images can be viewed at a scale that individual bisons should be detectable. Is there a relationship between the bison tracks and the vegetation cover? To test that possibility an overlay of the two images is provided below as image 5.

Image 5: Winter-fall overlay showing bison tracks on fall vegetation cover.

On this overlay the winter bison tracks are still visible as shaded pattern through the partially transparent fall image.

Some Royal Canadian Airforce Historical Northern Surveys Photos

Ready for a long misson in Canada's North

A typical RCAF "flying canoe" used for the early aerial surveys

RCAF winter landing area Slave River near Fort Smith

Fort Smith around 1931

References

Milne Alex J., 1983. "Pioneer Survey Flights in Northern Manitoba and Saskatchewan", Canadian Aviation Historical Society Journal 21, no. 4 (1983).
Shaw S. Bernard, 2001."Photographing Canada from Flying Canoes" ISBN 1-894263-42-1, Published by GSPH -General Store Publishing House, Canada.

Jean Thie, EcoInformatics International Inc. - Ottawa, Ontario and Wakefield, Quebec, Canada