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Is it necessary to return captive dolphins to the very place
they were
captured? It is often desirable, perhaps, but not always necessary. The
readapted captive male dolphins cannot be expected to rejoin their original
family pod. Even if they had not been captured, they probably would not remain
with their pod because male dolphins at maturity normally find or form their
own pods, sometimes bachelor pods, with groups of females and their offspnng,
or both males and females traveling together. We also sornetimes find singular
dolphins who have either chosen to be alone or were ostracized from their
pod.
So it's a mistake to think that we must return dolphins to the very
place
they were first captured. In fact, if the water in which they were captured
had become polluted or poisoned during their absence or if fish they normally
ate were no longer plentiful, we would not want to return them there. A search
of the literature indicates that there is no empirical scientific documentation
to substantiate the claim that dolphins must be returned to the exact spot of
capture.
Dolphins are quite adaptable and can readily accommodate themselves to
a new
home range if it is similar to the site where they were captured -
similar in terms of tides, currents, extremes of water temperature, food supply
and potential predators.
Our team will arrange for capturing enough local prey fish for them to
practice catching and eating. Water quality tests of the region have also been
conducted and are available.
One of the most important functions in rehabilitabng Buck and Luther
is to
maintain a proper feeding regimen. The main objective is for them to maintain
proper body weight by foraging and eating only live fish. This is a gradual
process which may be viewed in four phases:
1. Encouraging the dolphins to eat with their heads underwater and
the
introducton of live fish.
2. Eliminating interaction with the feeder by varying feeding times
and
locations.
3. Dolphins eating only live fish.
4. And once again becoming opportunistic foragers.
In Phase 1, all activities are done from a regular feeding station,
both live
and dead fish to be offered only when the dolphins' heads are underwater. We
continue feeding them dead fish but include live ones just to acquaint them,
tossing the fish randomly at short distances, gradually increasing the distance
and discouraging the dolphins from feeding with their heads out of water.
In Phase 2, we gradually wean the dolphins from their usual feeding regimen by
tossing both dead and live fish from different locations and at different
times. By now we are behind a blind to keep the dolphins from seeing us. We
don't want them to associate feeding with the feeder.
We always toss live fish toward the center of the pen so the dolphins have a
better chance to catch the fish before it escapes through the fence.
Sornetimes it is necessary, initally, to trim the fins of the fish so that the
fish will not escape.
Feeding becomes more random and uncertain. We now toss dead and live fish
from behind a blind at all hours, including early morning and after dark. In
the water we have a hydrophone so that we can rnonitor the dolphins' use of
sonar in finding fish, especially live fish. We can compare audio recordings
of confirmed catches during the day with night feedings.
We increase the number of feeding sessions, decreasing the quantity of fish
per session. Short, quick feeding sessions from varied locations and at all
hours will discourage the dolphins from searching for the feeder.
In Phase 3, which is to reach and maintain a diet of only live fish, we must
first make sure we can provide enough live fish for the dolphins. We need a
good source of fish species indigenous to the release site. We analyze these
for nutritional value and, in figuring the dolphins' total diet, allow for the
energy used in chasing live fish.
While continuing to feed the dolphins at various times and from various
places, we now increase the proportion of live fish. When the dolphins are
eating mostly live fish, we introduce them in groups of 10 or 15, creating a
"school" of fish, which adds realism and forces the dolphins to select the prey
they will chase down.
Finally, in Phase 4, we eliminate the human element from feeding and encourage
the dolphins to forage on their own. We constantly introduce live fish into
the pen and keep track of the dolphins' rate of consumption, finally replacing
dead fish in their diet with live indigenous fish such as mullet. When the
dolphins are ready to venture out of the pen they make it very clear to those
who can read their body language.
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