Wood Buffalo’s Whooping Crane Aerial Survey

by Sharon Irwin, Resource Management Officer, Wood Buffalo National Park, Canada

Since the discovery of nesting Whooping Cranes in Wood Buffalo National Park (WBNP), the Canadian Wildlife Service (CWS) and WBNP have conducted aerial surveys to monitor the population. Aerial survey techniques involves flying a combination of circular flights and transects over known nesting territories and similar looking marshes likely to contain breeding Whooping Cranes. These aerial surveys account for nearly 100% of the breeding Whooping Cranes each year.

In August 2014 CWS staff were unavailable to lead the fledgling survey so I became the Survey Lead and Navigator. The pilot, Mark Rayner, WBNP staff Queenie Gray, Jane Peterson, Amy Lusk and I spent 4 days flying over the Wood Buffalo nesting area in an attempt to locate the whoopers and their chicks.

Eurocopter EC120 Colibri used during Wood Buffalo Whooping Crane arial survey. L-R: Queenie Gray, Amy Lusk, Sharon Irwin and pilot Mark Rayner.
Eurocopter EC120 Colibri used during Wood Buffalo Whooping Crane survey. L-R: Queenie Gray, Amy Lusk, Sharon Irwin and pilot Mark Rayner.

Breeding pair surveys are done in mid to late May over 4-5 days with a crew of 2-3 made up of Parks Canada staff and Canadian Wildlife Service biologists.  Breeding pairs normally use the same territory each year to build their nest and raise their chicks. Knowing where the cranes nest helps make locating the adults and juveniles a bit more successful.

whooping crane aerial survey
GPS connected to a laptop computer with a mapping program called ArcPad.

A Eurocopter EC120 Colibri has been the preferred aircraft for the last couple of years.  It has an enclosed tail rotor which makes it quieter than other helicopters of its size. The helicopter flies at an altitude of about 1,000 to 1,200 feet above ground level (AGL).  The person in the front seat next to the pilot is the navigator.  They use a GPS connected to a laptop computer with a mapping program called ArcPad.

The program allows us to have multiple layers showing at any time our map. We usually have the rivers and ponds showing as well as last year’s nesting locations.  The map has an icon to show where we are flying and draws a trail showing where we have been.  Blocks are flown with transects that are one kilometer apart in the areas where Whooping crane nests have been found in the past.  If the team thinks that a pair of Whooping Cranes may have been missed, we go to the location of the nest from previous years and fly a spiral working out from the nest. The other personnel on the helicopter are observers and collect data as a backup on a GPS, another laptop and in a notebook.

whooping crane aerial survey
Queenie takes GPS points and notes in the backseat of the helicopter.

Each evening after the survey the staff spends a few hours sorting out the data and trying to figure out which pairs of Whooping Cranes have and have not been found for an area.  Frequently a return flight is required to go back to an area to find a missing pair. It really depends on the light conditions, on how easy it is to spot a Whooping Crane.  Sometimes we can see them from a couple of kilometers away and other times we just can’t find them.

The fledgling survey is done in between the end of July and mid-August.  Fledglings are birds that have reached an age where they can fly. The technique for this survey is very similar to the breeding pair survey.  The nest locations are known so we can fly right to the nest.  It may be more efficient in areas where the cranes are more spread out to use the spiraling technique to locate the family group.  In areas where the nests are close together, it seems easier to use the transect method.  In some cases we end up using both techniques.  If the Whooping Cranes have not been successful in raising a chick they may still be in their territory or they could be kilometers away.  Unless they are banded birds, it is almost impossible to figure out which nest a pair used.  If a pair does have a chick, they are generally found fairly close to their nest.

Both the Nest Survey and the Fledgling Survey are part of the world-class restoration plan that has made the Whooping Crane an international success story and symbol of species recovery and conservation. By counting the number of fledgling chicks, Parks Canada, Canadian Wildlife Service, US Fish and Wildlife Service, and others gain important insights into the health of the world’s last remaining natural nesting flock that contribute greatly to our ongoing stewardship of these magnificent birds.

A record number of 164 Whooping Cranes were counted incubating their eggs in 82 nests during the annual survey in June 2014.  This number surpasses a previous record of 76 nests in spring 2011.  These endangered birds all nest in and around WBNP, Canada. The mission of the survey was to determine how many chicks had hatched and survived to become fledglings since the nest counts were made in June.

WBNP officials reported that a total of 202 whoopers were counted, including the fledgling and nesting pairs.  The 32 fledglings were found in 30 family groups: 28 families with one chick and two families with two chicks. In addition to the family groups, the surveyors observed 6 groups of three whooping cranes, 43 groups of two, and 6 individual cranes.

***** FOTWW’s mission is to help preserve and protect the Aransas/Wood Buffalo
population of wild whooping cranes and their habitat. *****

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