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Young animals come into rehabilitation for various
reasons. They may be orphaned, abandoned, injured in a fall from
the nest, blown out of the nest during a storm, kidnapped by well-meaning
people who believe they are in need of rescue, etc.
Newly hatched reptiles and amphibians are independent from birth
and receive no parental care.
Some precocial birds are semi-dependent. They may be self-feeding
almost immediately, but the parent or parents protect them, keep
them warm and teach them. Other precocial avian species are more
dependent; they are able to pick up food that the parents bring
to them. Precocial mammals (e.g. deer) are dependent upon their
mothers for milk, protection and learning.
Species that are born without fur or feathers are completely dependent
upon their parent(s) for food, protection and warmth, as they cannot
regulate their body temperatures. For these animals, a significant
period of time without the warmth of the mother and/or conspecifics,
and the shelter of nest or den will cause them to become chilled
and weakened when temperatures are cool. If they have fallen from
the nest in warm weather and have no protection from the sun, they
may also become overheated and dehydrated.
The animals may have heavy ectoparasite loads, and some animals
have insect bites, or maggots where flies have laid eggs on them.
Examination
Thorough physical examination is very important. Beginning at the
top of the head and working down towards the feet, check head, ears,
nostrils/nares, mouth, anus/vent, skin, etc. The animal should be
examined for ectoparasites, endoparasites, injuries and bites from
insects or domestic or wild animals. The animal should be weighed,
and its weight compared to that of wild conspecifics.
Stabilization
An animal that is hypothermic must be warmed; an animal that is
hyperthermic must be cooled. Any life-threatening injury (e.g. bleeding,
shock, convulsions, hypothermia, hyperthermia) must be attended
immediately.
When the animal's temperature is normal, it should be rehydrated
with Lactated Ringers solution. If the animal is conscious and able
to swallow, this should be administered orally. If it is very weak,
it should be administered by feeding tube. Severely dehydrated mammals
may require I.V. fluids or subcutaneous fluids (special training
is required to administer fluids other than by mouth to birds and
reptiles). When the animal is rehydrated to the degree where it
has urinated (or, in the case of a bird, produced a dropping with
urine), any necessary medications may be administered.
Food
If the animal is severely dehydrated, it will require extra fluids
for three days to allow the kidneys to recover, even if urine is
copious. If it is emaciated, food must be introduced to the rehydration
solution very gradually (5% per feeding). The food must reflect
the natural diet (e.g. milk replacer for mammals, predigested insects
for insect eaters, predigested fish for fish eaters, pre-digested
meat for birds of prey, etc.). However, if the animal is only somewhat
dehydrated or thin, dilute foods can be offered.
Environment
Most neonates will require a 'nest' and warmth. A heating pad (on
the low setting) placed under one half of the cage will provide
warmth while offering the animal opportunity to move away from the
heat if it so desires (be sure that the animal cannot chew the cord
or become entangled). The pad should be securely wrapped in a towel,
with the bedding (e.g. towels, blankets) laid over it. All bedding
used for young animals should be in good condition so that they
do not become entangled in threads, ravels or holes.
Cleaning
The animal should be immediately cleansed of food, feces, urine,
etc. to prevent bacterial growth, skin irritation or pasting of
the vent/anus. Bedding and nesting materials should be changed each
time the animal urinates or defecates.
Specific and reliable information on the care of wildlife in rehabilitation
is not readily available on the Internet. There are a number of
rehabilitation manuals published in North America. Most are not
peer reviewed and information may range from poor to reliable.
A list of rehabilitation manuals can be viewed at http://www.wildliferehabtoday.com/
Common problems
- Precocial birds imprint upon their parents within the first
few days of hatching, and if they do not have conspecifics, they
may become imprinted on the rehabilitator or another species.
It is in the best interest of the bird to locate a conspecific
nest mate or foster parent of the same species.
Ground feeding birds may ingest parasite eggs and larvae from
feces or foods contaminated with feces of other animals. Ground
feeding birds may also ingest herbicides, pesticides and spilled
chemicals.
Water or shore birds may become entangled in fishing line, hooks
and lines or marine debris. Water and shore birds may be contaminated
with oil. Some species are particularly susceptible to aspergillosis.
- Altricial birds may become entangled in nesting material (e.g.
string, fishing line, etc.).
Some species are predated [or preyed upon] by other birds, and
may be dropped to the ground; they may also fall from the nest
if the nest is jostled or dislodged during a storm. As a result,
the bird may have internal injuries or injuries of the legs, wings,
spine or head. Some birds are jostled from the nest by the activity
of nest mates.
Some birds may be evicted from the nest by the parent(s); these
birds may be evicted because they are diseased and a threat to
their siblings, or because they have a birth defect. Because birds
can fall from the nest accidentally, it should not be assumed
that they are diseased or defective. Even when they have been
evicted by the parent(s) because of a high parasite load or a
disease, these problems can often be treated by a rehabilitator.
Common parasites of altricial birds include coccidia, capillaria,
trichomonas gallinae, gape worm and roundworm. Many species, particularly
doves and pigeons, are affected by candida (yeast). Young birds
(as well as weak or old birds) are susceptible to infectious diseases,
including pox and a number of other viruses (e.g., West Nile virus).
Passerines and other orders are frequently exposed to pesticides.
Young birds, regardless of species, are often given water and
food by rescuers. Because most rescuers are unfamiliar with feeding
methods and appropriate foods, the birds may have aspiration pneumonia
and/or be full of food they cannot digest (e.g., bread, seed,
grass, etc.).
Young birds of any species may be victims of animal attack (usually
cat attack). Birds that have been injured by a cat must receive
appropriate antibiotics if they are to survive.
Food
Diets and feeding intervals are species-specific; information can
be found in the nutrition section of Wildlife Care. Every effort
should be made to supply the bird with foods it would eat in nature
at its particular life stage. Diets must be supplemented with calcium
carbonate and vitamins.
An altricial bird that does not gape vigorously is likely to be
dehydrated and/or ill. The bird should defecate after it has been
fed; if it does not, it may require more food (or fluid, if dehydrated).
Passerines and many others produce fecal sacs - an encapsulated
dropping that contains rich brown feces and white urates. Fecal
sacs are firm and similar to gelatin. If the bird does not produce
a fecal sac or if the droppings are loose and runny, it is possible
that it has received too much food. Fecal sacs/droppings should
be removed from nests and bedding should be replaced. Many species
do not produce fecal sacs, but their droppings, if normal, contain
brown or dark green feces and white urates.
Environment
Birds should be provided with nests similar to those that would
house them in nature.
Housing for precocial birds should include suitable substrate and
have appropriate bedding and a heat source. Some water birds swim
relatively soon after hatching; in nature, they are warmed after
swimming by a parent. In the rehabilitation setting, these youngsters
should have supervised swims, and water should be removed from the
enclosure at other times. They must have a source of heat so that
they can dry and warm. Brooder lamps are especially good for these
species.
Young altricial birds must be nested so that their bodies are supported
and their feet can develop normally. They should be allowed to rest
on their bellies, with their weight distributed over their feet.
Nests may be placed in temperature and humidity controlled incubators.
Development
Development and maturation of precocial birds is species-specific.
Altricial birds are ready to leave the nest when their flight feathers
have opened; prior to fledging, they will begin to perch on the
edge of the nest, and in nature, some species would begin to perch
on branches, often returning to the nest to rest or sleep. Most
birds continue to receive parental attention for weeks or longer
after they have left the nest. The parents continue to feed them
as they learn to forage and fly. Many species remain with their
flocks for their lifetime, while solitary species (e.g., hummingbirds)
disperse when they are self-feeding.
Because rehabilitators are not able to take the birds into the
wild to teach them everything they must know, fledging dates published
in texts should not be used to determine when an individual is to
be released. In the wild, the bird would have the guidance, protection
and care of its parent(s) for weeks, months or, in some cases, years.
In the rehabilitation setting, these steps towards independence
must occur while the animal is confined to an enclosure for its
safety.
Precocial mammals are born with their eyes open, are furred or
haired and able to regulate their body temperatures, and are able
to stand and move about soon after birth or within a day or two
of birth (e.g., deer, mountain goats, zebras, etc.).
Marsupials (e.g. opossums, kangaroos, etc.) are embryonic and move
from the birth canal to the mother's pouch, where they continue
to develop.
Monotremes (e.g. platypus) hatch from eggs.
Many other species are born naked or lightly furred, with eyes
closed and ears furled shut.
Regardless of state of development after birth, all mammals are
nursed, protected and taught by their mothers. Some stay with their
mothers only until they are self-feeding, some stay with their mothers
for the first winter, and some stay with family groups for their
lifetime.
Common Problems
Fawns and some other precocial mammals are not able stand immediately
after birth. Their mothers move away from them so as not to attract
predators, returning to nurse them and keeping watch from a distance.
Often, people who come across precocial neonates believe them to
be orphaned or abandoned. They may pick them up and attempt to raise
them or deliver them to a rehabilitation center. These animals should
be returned to their place of origin and reunited with their mothers.
Rabbits also return to the nest only to feed their young, and people
assume the neonates are orphaned or abandoned. If the rabbits have
not yet been 'rescued', and there is some concern as to the mother's
fate, have the would-be rescuers place long pieces of straw, grass
or dental floss across the nest in a 'tic tac toe' pattern. If the
pattern has been disturbed by the following day, it is likely that
the mother is tending her young. Young rabbits are weaned while
they are still quite small in size, and people often assume they
are too young to be out on their own. A cottontail rabbit that is
the size of a softball or larger is usually weaned and independent.
Some young mammals (e.g., squirrels) may become entangled in nesting
materials, and their tails or limbs may become intertwined. Many
small mammals (e.g. rabbits) are dragged from their nests by wild
or domestic animals, and may be seriously injured. Lawnmower injuries
are not uncommon. Species that use tree nests or high roosts (e.g.
squirrels, bats) may be injured as a result of a fall.
Young mammals often suffer from exposure and may have pneumonia.
Young mammals that have been orphaned, abandoned or lost (as opposed
to 'kidnapped' healthy animals) may not be found for some time.
These animals are often infested with ectoparasites and maggots
and are dehydrated and emaciated.
Many mammals are given food, milk or water by rescuers, and may
be suffering from aspiration pneumonia or digestive upsets. Young
mammals must be stimulated to urinate and defecate. If a rescuer
has had the animal for any length of time, he or she may not have
stimulated the animal, and the animal may be suffering from urinary
and/or fecal retention, which can be life-threatening.
Parasites are species-specific, but often include ticks, mites,
fleas, roundworm and tapeworm. Diseases are also species-specific,
but can include parvovirus, distemper, rabies, etc.
Food
Milk replacers are discussed in the Nutrition section of Wildlife
Care. A milk replacer should be similar in composition to the milk
of the species.
Nursing bouts should mimic natural patterns as much as possible.
Very young animals require night feedings as well as regular feedings
throughout the day.
Some species may nurse their young only a few times a day (e.g.
rabbits), while others nurse far more frequently. Because even the
best milk replacers are dissimilar to 'natural' milks, it may be
necessary to feed the youngster different amounts and densities
than would occur in nature. The fluid requirement must be met, as
must the protein requirement. Many species (especially carnivores)
require a replacer that contains the amino acid taurine.
Some problems that can occur when milk replacers are not well digested
or tolerated include bloat, constipation and diarrhea. The animal's
feces may be pale, indicating that it is not digesting nutrients
well. Often, feces improve within a few days as the animal adjusts.
If not, a different replacer must be found, as the animal is not
receiving required nutrients. Some species (e.g. deer, raccoons)
tolerate goats' milk far better than cows' milk.
Many species should be 'blind fed', without seeing the caregiver
(e.g., moose, elk, deer, bears).
Environment
Altricial neonates sleep when they are not eating, and thus require
only enough room to hold them and their bedding. Litters should
be housed together, and single animals should be placed with conspecifics
if they are healthy and of similar age. Large mammals (e.g. deer,
elk, moose, etc.) can be bedded in an enclosure that protects them
from the elements. Smaller species can be bedded in pet carriers,
cages, etc. Small mammals are often comforted if they can sleep
with a piece of fleece, fur or a soft stuffed toy. Odors are of
great importance to mammals, so do not use perfumed laundry products.
Bedding materials should, if possible, have been in previous contact
with healthy conspecifics.
Development
Development and ages of weaning and independence are species-specific.
Weaning can be a slow process; natural foods should be introduced,
but the animal will not receive much benefit from them at first
and will require supplemental feedings.
As the animal begins to self-feed (and drink), it should be weighed
daily if possible to ensure its weight continues to fall within
normal range. As it begins to show interest in food and becomes
more active, it should be graduated to an enclosure that allows
exploration, and exercise appropriate to the species (e.g., climbing,
swimming for aquatic species, burrowing, etc.). There should be
dirt available to the animal at all times-for eating, stashing,
burrowing, dust bathing, etc. Mammals must be capable of all activities
normal to the species before release. They must be familiar with
their natural foods, forage or hunt proficiently, be acclimated
to the outdoors and must be eating the foods available at the season
of release.
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