Page 236 - Hand rearing birds second

224 Hand-Rearing Birds

areas), size of the air cell, and whether there is embryo movement. It is good practice to candle eggs
weekly, and after 2 weeks of candling it is often possible to determine the hatching day of the egg.
Candling is done on the blunt end of the egg at first, and as the embryo further develops candling
can also be done on the pointed end. Care must be taken to prevent cooling the egg during can-
dling, or burning with the light source. Each egg must be handled carefully and slowly, as any
sudden movements or jarring can affect the viability of the embryo. There are numerous commer-
cial brands of candlers available; however, a LED flashlight is an ideal substitution; with a bright
white light and minimal heat discharged, it can work just as well as a candler.

Hatching
Once the chick has internally pipped (pierced through the air cell), it is taken off the rollers and
placed in a container with paper toweling; this container is still kept in the incubator; however, the
turning has now stopped.
Once the chick has externally pipped/starred (pierced through the egg shell) the egg is removed
from the egg incubator and placed into a hatcher, where the humidity is set at 60%, and the tem-
perature is lowered slightly to 96.1 °F/35.6 °C. A higher humidity ensures the membrane does not
dry and stick to the chick inhibiting the hatching process or blocking the nares. The hatching
process takes 48–50 hours, African Penguin chicks hatch out of their shell in an anti‐clockwise
direction, and are positioned with their head under their right flipper and beak facing up toward
the shell. A hatching egg should be checked on frequently to ensure the chick is still correctly posi-
tioned. If the chick has not shown progress after 50 hours has lapsed, an assisted hatch must be
considered as the chick may be now fatigued or possibly malpositioned. By using the candler to
shine into the external pip site, an evaluation can be made of the problem.
There are several reasons why a chick may not hatch successfully on its own, which is why it is
so critical to monitor the pip to hatch interval carefully. If a chick has made internal pip but has
failed to progress for over 12–15 hours, is well beyond expected incubation period, or if a chick has
rotated inside the egg without further chipping such that the bill is no longer visible at the pip hole,
this is a good indicator that something is wrong. However, the most common hatching difficulty
for penguin chicks is malpositioning of the chick inside the egg. This may or may not be accompa-
nied by unabsorbed yolk and/or residual albumen. Once a chick is determined to be having hatch-
ing difficulty, the egg should be removed for assistance.
When performing an assisted hatch, care should be taken not to introduce bacteria to the chick.
Hands should be washed and gloved and all instruments sterilized. The pip should be examined
and an evaluation of the problem should be made before beginning to assist the chick to hatch. The
egg should be candled to assess vascularization and pip location (above or below the air cell), and
a small flashlight can be used to look inside the pipped hole to look for unabsorbed yolk, residual
albumen, or other problems. Once these steps are completed, carefully hold the egg in one hand
and slowly peel away small portions of the shell from the pip site with sterile forceps. This must be
performed under a heat lamp to keep the egg warm.
After the pip area has been further exposed, the membrane should be moistened with warm
sterile water on a swab to check for active vessels. If no vessels are present, the membrane can be
peeled back to expose the chick. Be sure that the membrane does not stick to the nares and occlude
breathing. Efforts should be made to expose the head first. In extreme cases, it may be necessary to
manipulate the head out from under the flipper. If the membranes are active, they will bleed when
disturbed. Try another section of the egg to avoid active blood vessels. Throughout this process,
monitor the chick’s temperature; it may be necessary to place the chick back in the incubator to
warm up before continuing the assisted hatch.