Many Whooping Crane Eggs Does it Take to Make Another Whooping Crane
1977 and 1988 the Canadian Wildlife Service banded 134 young Whooping
cranes. By keeping track of the survival and breeding history
banded birds we are able to answer many questions, including: How
many Whooping crane eggs does it take to make another Whooping
crane egg? The answer is not as simple
as it seems!
How Many Eggs Would You Expect?
Don’t The Numbers Add Up?
It doesn't work exactly like that because of these factors:
1. Maturity: It takes about five years for the birds to reach maturity and successfully breed.
2. Weather and Habitat Conditions: Too much rain at hatching can cause young to die of pneumonia and other diseases. Drought can make the area more accessible to predators that eat the young. (Cranes roost in water so they can hear approaching predators in time to escape, but good roost spots are fewer in times of drought.)
3. Accidents, Diseases, and Predators: Collisions with power lines can kill adults and subadults during migration. Each year birds can be lost to diseases, old age, and predators.
|What are the Real Numbers?
When we take all these factors into account, we come up with the following numbers:
To Answer the Question…