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Herons, Egrets, and Bitterns 283

Housing plans should allow for four main stages of thermoregulatory support:
Stage one: 100 °F (37.8 °C) with 40–50% humidity environment for initial stabilization of hypo-
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thermic birds of all ages, and housing for hatchlings and young nestlings.
Stage two: 85 °F (30 °C) environment for fledglings in early stages of feather growth.
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Stage three: 70–75 °F (21–24 °C) environment (ambient indoor temperature) for fledglings that
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are developing feather growth throughout their backs, axillary regions, sides, hocks, and chests.
Stage four: Variable outdoor ambient environment for fledglings that have contour feathers cov-
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ering their backs, axillary regions, sides, hocks, and chests.
Caging in the first three stages should have heating pads and heat lamps available as accessories
that can be added and removed as needed to create transitional stages of thermal support within
the basic stages. At every transition point, birds should be monitored closely to ensure that they are
comfortable in their new heat environment. Cloacal temperatures should be taken daily while
birds are housed in stage one and stage two environments. When moved to stage three, birds
should be provided with a heating pad or heat lamp in one corner of the cage for the first day, and
they should have their temperatures checked daily for the first 2 days in the new environment, or
every day until stable. Behavior changes such as anorexia, hunching, and sitting quietly are all
indicators of possible thermoregulatory distress. Any bird that exhibits these signs or has a body
temperature below 102 °F (39 °C) should be regressed one step and reevaluated for progress in
24–48 hours.
After birds have demonstrated consistent thermoregulatory ability over 2–3 days at stage three,
daily temperature checks can be discontinued, and thermoregulatory progress can be monitored
visually on the basis of behavior changes. Warm birds will be alert, active, vocal, and self‐feeding.
Before young birds are moved to variable outdoor ambient environments, they should have con-
tour feather growth covering their axillary areas and backs. The axillae are the last part to become
covered, and this is necessary to protect birds from ambient temperatures below 65 °F (18.3 °C).
Birds raised in climates where it remains warm at night may be able to be housed outdoors without
thermal support at younger ages.
At no point in time will young birds’ abdomens become fully feathered. A fringe of powder down
feathers will grow underneath coverts at the perimeters of the abdomen, but this area remains bare
through adulthood.

­ Housing

Whenever possible, young herons and egrets should be housed together in groups matched by
developmental age and species. They are gregarious in hatchling and nestling stages and will be
especially well‐supported to develop self‐feeding habits if housed in a casually competitive caging
environment. Cages should be monitored for aggressive competition, and aggressive individuals
should be moved in with birds of like demeanor.
For birds at the first stage of thermoregulatory support, appropriate housing may consist of an
Animal Intensive Care Unit (Lyon Technologies). This is a clear acrylic box with a sliding front
door and hinged roof (Figure 17.1). Its side‐mounted electric powered heating unit is adjusted by
an exterior control panel. It also has a removable water trough that keeps the environment hydrated
and an automatic alarm that sounds if the temperature diverges from the level that has been set.
Such incubators can be set to 100 °F (37.8 °C). Interior measurements of such units are typically
24 × 12 × 12 in. (61 × 30 × 30 cm).