May 27, 2010
Egg incubation seems like a very easy business. The parent or parents simply keep the eggs warm, move them about a bit and, after a period of time, the eggs hatch. Easy!...but not so fast. Scientists have learned by various means, including placing telemetry eggs under various bird species, that incubation is an incredibly complex process, and that controlling the temperature and movements of eggs is not really that easy at all. In the case of the osprey, incubation also involves lots of teamwork, with the male taking over the duties when the female leaves the nest to feed.
This week, incubation continues at the osprey nest-this will last from 35 to 40 days-so we should expect the first egg to hatch around the middle of June. More on incubation next week!
Lisa McDonald is the Calgary Zoo's Visitor Education Specialist.
May 19, 2010
Last week we had numerous reports from concerned osprey cam watchers who were keenly observing a black plastic bag that the male osprey had brought to the nest. Sadly, plastic bags are an abundant reality in our river landscape and ospreys continue to select them to line their nests. The female appeared slightly stressed by her placement of the bag which allowed it to move in the wind and periodically covered her two eggs.
A decision was made to remove the bag before a third egg was laid. Zoo Curator Bill Dubreuil working in conjunction with the ENMAX team made short work of the removal with the female just a few wingbeats away. She returned to the nest and to incubation within moments of the bag's removal. Just one more reason for us all to reduce, reuse, recycle and rethink our consumption or perhaps participate in the next river clean up. The ospreys will lay up to 4 eggs-and they should be hatching in mid-June.
Lisa McDonald is the Calgary Zoo's Visitor Education Specialist.
May 12, 2010
Nesting materials can be brought to the nest by both birds, but typically the male brings most of the materials leaving the female to arrange them to her liking. While sticks and sod make up most of the nest, other human items are often found in the midst of construction. The ospreys will often look for plastic or other materials to line the nest to prevent the eggs from falling through cracks. (Ewins, P.J., J.R. Miller, M.E. Barkker. 1994). Starting from scratch the ospreys will take from 10-20 days to build their nest. Then egg laying will begin.
This week a black plastic garbage bag was delivered to the nest by the male. It was incorporated into the nest and shortly therefter the female laid the first egg. Unfortunately the bag continues to blow about in the breeze which appears to stress her. At times the bag has covered the egg completely. The situation is being closely monitored and we'll keep you posted.
Tanya Hope, Interpreter Coordinator at the Calgary Zoo