Chattanooga, Tenn. (May 18, 2009) - Another fascinating aspect of penguin life is on display at the Tennessee Aquarium as a pair of macaronis have produced the first eggs inside Penguins' Rock. The first eggs were laid in the nest built by "Paulie" and "Chaos" a little more than six weeks after the nesting materials were given to the birds.
The first egg was broken by the parents almost immediately, a process that is perfectly normal for this species. "Macaroni penguins on exhibit or in the wild lay two eggs," said Amy Graves, the Aquarium's senior aviculturist. "The first egg is 50 to 60 percent smaller than the second egg and is usually kicked out of the nest or crushed by the parents. The female will lay a second egg anywhere from four to six days after the first egg is kicked out."
The first egg was laid by this couple one week ago. The second egg was discovered by keepers this past Thursday, five days after the first. "They are very protective of that egg and each other right now," said Loribeth Aldrich, a Tennessee Aquarium aviculturist. "Even while one bird is lying on the nest, they are preening each other and supporting each other. The way they are acting is very sweet."
Paulie and Chaos may be first-time parents if the egg they are protecting is fertile, but right now that cannot be determined. So penguin keepers are observing the egg and the behavior of this pair closely. Both parents take turns incubating the egg with Paulie appearing to rule the roost. Over the weekend, Paulie was clocked spending over six hours on the egg at a time with Chaos nearby. From time to time the parent lying on the nest will raise up to carefully rotate the egg using its feet and beak. The only other movement is to change shifts to eat or defend the nest. "Both birds will chase other birds off," said Aldrich. "They are protecting that egg and keeping the other birds very far away."
It will be some time before anyone knows whether or not this egg is viable. The incubation time for macaroni eggs is anywhere from 33 to 39 days. "Today marks day number five since the day the second egg was laid, so we have a long way to go," said Graves.
If the egg is fertile, the chick will have to hatch without any parental help. This process, called pipping, can take 24 to 48 hours to complete. After that, the chick's struggles continue explained Dave Collins, the Aquarium's curator of forests. "Newborn chicks must overcome high infant mortality rates and have diligent parents. Paulie and Chaos would be first-time parents, so hopefully their instincts will be strong enough to raise a chick successfully," said Collins.
A penguin chick is dependent upon the parents for warmth during the first two weeks of life. "After about 14 or 15 days, a chick will be able to maintain its own body temperature," said Aldrich. "Then a chick can be left alone in the nest and both parents can go off to feed and bring back food to the chick."
Penguin chicks go through three different types of plumage before they are able to take their first swim. They hatch with a very soft, downy set of feathers which are replaced by juvenile feathers. It takes 60 to 75 days for a baby penguin to grow their adult feathers depending upon the species. "Those are the waterproof ones, the nice black and white feathers you see on the adult penguins," said Graves.
Right now there are three other penguin pairs that seem to have very strong bonds and are being watched closely. One other pair of macaronis, "Hercules" and "Sweet Pea", have been diligently building their nest and have been observed laying on that nest for long periods of time. And gentoo pairs, "Biscuit" and "Blue" and "Poncho" and "Peep" have shown strong bonding and nesting behaviors.
For now Paulie and Chaos are the only ones with an egg. But according to the penguin keepers, that's enough to raise the excitement level at the Tennessee Aquarium this summer. "If all goes well, Paulie could be a dad around Father's Day," said Aldrich.
Egg incubation: Macaroni – 33-39 days. Gentoo – 36-41 days
Both penguin species lay two eggs approximately four days apart. Penguin chicks hatch without help from parents. It usually takes 24-48 hours for a chick to fully hatch.
Both penguins share in parental responsibilities by taking turns on the nest keeping the chick warm and regurgitating food as needed. Parents sit on the chick for approximately 15 days until the chick is able to maintain its own body heat. Chicks remain at or around nest until fledging. Penguins fledge (or become independent from parents) between 65-75 days.
Watch the penguins on the Tennessee Aquarium’s live webcam.