Final Whooping Crane Field Notes: May 21, 1998
To: Journey North
From: Brian Johns
Another sunny day in Wood Buffalo with no rain in sight. I have discovered 47 Whooping Crane nests so far. This is good, but not quite as good as the record 51 nests that were known from last year. I have also seen a few additional pairs of cranes on their territories but it looks like they are not going to nest this year.
One of the nests has already disappeared. This sometimes happens during incubation when the eggs are lost to predators. I do not know what happened in this case, but in the past we have discovered that both Northern Ravens and Black Bears have taken eggs from the nests.
If the eggs are taken shortly after they have been laid, the adult cranes may make a new nest and lay more eggs. But, if this happens late in the incubation period the adults will usually not waste their energy to build another nest and lay more eggs.
The reason for this is that there would not be enough time left in the summer for the adults to raise their young. Once the 2 eggs are laid it takes about 30 days of incubation, which is a duty shared by both parents, before the eggs begin to hatch. From hatching time it takes another 80 days before the young begin to fly. By this time it is mid to late August and the summer is almost over. The end of August and the month of September is used to develop the young birds' flight capabilities so that they can migrate the 3800 kilometres to Texas.
The family groups usually begin leaving the nesting grounds in late September and early October. They may spend several days or weeks in Saskatchewan feeding on waste grain in agricultural fields. By the end of October they will be gone from Canada for another year.
Have a great summer and be sure to check back next season to find out how the cranes made out during the rest of the summer nesting season in Wood Buffalo.
Canadian Wildlife Service
Final Field Notes From The Great Plains
To: Journey North
Have A Nice Summer--See You Next Year!