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Grebes 173

Avoiding­Captivity-related­Problems
Great care should be taken to avoid captivity‐related issues that can compromise a grebe’s chance
for wild release. Although these issues are less common in chicks than adults, foot and hock lesions
may occur when skin is abraded on hard substrates or when the skin dies due to pressure between
a hard surface and a bony prominence, such as at toe joints. These lesions can become contami-
nated and infected, and may progress to infection of the underlying bone or joint. Prevention of
these captivity‐related problems is far superior to treatment. Grebes unable to remain in water
during their rehabilitation due to injury or contamination may benefit from applying preventative
foot wraps or keel protectors, or being kept in a soft‐sided, net‐bottom cage. See Goodman et al.
(2016) for examples of appropriate nonaquatic housing for diving birds. That being said, grebes
that are waterproof and thermoregulating should be housed in water, as prolonged dry housing
inevitably causes severe problems.
Grebes, even as young chicks, maintain their waterproofing by preening their feathers to regu-
larly organize the fine structure of each feather’s barbules and barbicels to create a barrier imper-
meable to water. Preening also distributes oil from the uropygial gland that keeps the feathers
supple and helps maintain the integrity of the feather structure. The loss of waterproofing can
adversely impact every aspect of a grebe’s rehabilitation. Compromised waterproofing is a com-
mon result of becoming soiled by food or feces in a captive setting that fails to meet their needs.
Loss of waterproofing can also be present due to an injury sustained in the wild where there is an
exposed wound and feather damage, or it can occur when feathers have been exposed to contami-
nants such as oil before the bird has come into care. When waterproofing is lost, diving birds not
only lose the ability to control their buoyancy but also have no protection from the wet and cold,
and will eventually succumb to hypothermia.
Birds suffering from a loss of waterproofing will need repeated, carefully controlled sessions in
clean water to preen and restore their feather condition. During this time, rehabilitators should
take care that the bird never becomes chilled, and carefully monitor improvements to feather con-
dition. Grebes that are heavily contaminated may need to be washed or rinsed if unable to water-
proof themselves within a small number of days. Debilitated patients may lack the ability or energy
to preen, so their feather condition should be carefully and constantly monitored. It is critical that
the water in pools used to house waterbirds is kept scrupulously clean at all times.

Diets

Since each species of grebe has evolved adaptions for catching and eating their prey, as well as
adaptations to specific hunting environments, it is important to become familiar with the natural
history of any grebe species in care. There are many commonalities among grebe species. In gen-
eral, similar diet and rehabilitative care may be applied to all grebes. As a rule, the size and the
shape of the bill reflect the types of prey the particular species eats. These bill characteristics
should be taken into consideration when choosing foods. Grebes swallow their food whole, so take
care to ensure that offered foods are not too large for the bird’s mouth. That being said, Pied‐billed
Grebe chicks have been photographed swallowing surprisingly large crayfish whole.
It can be difficult to replicate the wide variety of foods that a grebe would consume in the wild,
but best efforts should be made to present the patient with foods that are as similar as possible to
what they naturally would find and consume. Grebes primarily eat fish, plus insects and other
invertebrates, and therefore this is the diet they need in captivity.