Page 552 - Hand rearing birds second

552 Hand-Rearing Birds

Record Keeping

Detailed hand‐rearing records are kept to ensure the ability to repeat successes, share data, or track
changes that lead to success. Specific information about their location, parents’ identification, age,
reason for removal, and condition of chick at time of removal is recorded. Care is taken to either
place a band on, or mark with nontoxic colored felt pens, all chicks for identification purposes.
Detailed feed and weight records should be kept. Target amounts to feed are entered along with the
frequency of feedings, which are determined from past successes. The actual amounts fed are
recorded, tallied, and compared to the target. Chicks are weighed every morning before their first
feeding. Decisions related to target amounts to feed are based on whether weight gains or losses are
in the normal range.

Incubation of Eggs

Artificial incubation is used if the parents have a history of failure to hatch eggs or if there are
conditions within their enclosures that would make it difficult to rear young. Incubation
parameters have been determined based on past successes of closely related species. Incubation
periods have been difficult to establish in cavity‐nesters, as it disturbs the parents to have
someone investigate the nest, and there are very few that have been set up with cameras for
monitoring.
All of the successfully reared hornbill species and the Kookaburra were artificially incubated at
99.0 °F (37.2 °C) at 56–62% relative humidity (RH). The smaller eggs of the other kingfisher spe-
cies, all the rollers, and bee‐eaters were incubated at 99.5 °F (37.5 °C) at 50–66% RH. These RH
settings are the starting point for incubation, but the percentage of egg weight loss is monitored for
most eggs and the humidity adjusted accordingly. If eggs are not losing enough weight, the humid-
ity is lowered, and conversely if they are losing too much weight, the humidity is raised. The earlier
these changes are made, the more effective they will be. Several small adjustments early in incuba-
tion are safer to the developing embryo than one drastic change later in incubation. Decreasing or
increasing the surface area of water within the incubator will change the humidity. For example, if
an egg loses only 9%, water pans with a smaller surface area would replace the original pans in an
attempt to lower the RH by 6–7%. RH should not be raised or lowered drastically; aim for less than
10% each week.
Eggs are weighed twice a week during incubation. One method used to calculate egg weight loss
is the following formula:

SE I
D
S

where S = set weight, E = end weight, D = # days incubated since set weight, and I = incubation
period. Set weight is the weight of the egg when it is pulled from the nest. End weight is the weight
of the egg on any given day of artificial incubation. This formula allows the egg weight loss to be
calculated even if the fresh egg weight was not obtained, and may be used at any point during
incubation to determine the trend of the egg weight loss. For example: if an egg is removed from