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JuLy 20, 1907.] 
FOREST AND STREAM. 








Growth of the Alligator. 
BY RAYMOND L, DITMARS, CURATOR OF REPTILES, 
From the Eleventh Annual Report of the New York 
Zoological Society. 
For an indefinite time, many authors of 
natural history essays have insisted that tor- 
toises and crocodilians require an amazingly 
long time to attain full growth and maturity. 
These .assertions have, without doubt, been 
prompted by observations made under condi- 
tions which positively retarded the natural 
growth. of the reptiles. Unfortunately, theory 
appears to have elicited much elaboration in 
some writings. Particularly plausible assertions 
have been so frequently exploited as to be gen- 
erally quoted nowadays in the best text books. 
There is some solid foundation, however, for 
the pronounced theoretical side of the question, 
for of all reptiles, tortoises and: crocodilians 
grow at a tardy rate as compared with repre- 
sentatives of the other orders. While the aver- 
age lizard or snake attains maturity in- one or 
two years (exclusive of the hibernating season, 
if there be any), a tortoise or crocodilian may 
require five years or more, according to condi- 
tions, before reaching the stage that might be 
designated as a young adult. From that point it 
continues to increase steadily in size until it 
reaches maximum adult dimensions. The latter 
period, embracing a slower growth, may cover 
from five to ten years—possibly more; and the 
reptile continues to survive to a surprising age 
as compared with the lizards and snakes. 
The present article has been prepared with two 
objects in view. The first is to correct the 
erroneous and theoretical impressions concern- 
ing the growth of crocodilians, using as a sub- 
ject of Our observations the American alligator 
(Alligator mississippiensis). Our second object 
is to furnish information that may possibly be 
of value to experimenters in alligator culture. 
There have been numerous rumors of alligator 
farming in the interests of the leather trade, but 
it seems, those ‘attempts have always been dis- 
couraged by the idea that the slow growth of 
the reptiles would render success quite impos- 
sible. As an illustration of how efforts to start 
alligator farms have been discouraged, we may 
quote from an authority of the United States 
Fisheries Bureau, who says, in one of the Goy- 
ernment publications: “Alligators grow very 

CAROLINA 
ALLIGATOR, 
slowly.. At fifteen years of age they are only 
two feet long. A twelve-footer may be reasoni- 
ably supposed to be seventy-five years of age.” 
Our observations in the Reptile House have 
enabled us to look well into the development 
and habits of the alligator. This article is the 
result of seven years’ accumulation of notes, 
during which time, among several series of ex- 
amples, the writer has been able to gauge the 
rate of growth of the alligator from the time of 
hatching up to the twelve-foot reptile—and a 
specimen of the latter size is a giant, nowadays. 
In a period of six years, the writer has suc- 
ceeded in hatching alligator eggs, and rearing 
the young to a length of over five feet. Inas- 
much as alligators of various sizes were received 
at the Reptile House seven years ago, at the 
opening of the building, we are able to approxi- 
mately carry our records of the rate of growth 
from the young specimens hatched in the park, 
through other series that have attained much 
larger growth during the time specified. As 
will be explained later, wild crocodilians seem 
to grow much faster than those in captivity, 
notwithstanding all possible facilities and food 
abundance in the latter state. It would there- 
fore appear that the rate of growth figured in 
the following list is actually below the normal, 
rather than above it. The table in question, 
however, was compiled from actual specimens 
and the tape line, all theoretical deductions be- 
ing eliminated. 
Our observations in the Reptile House were 
made under what we consider the best possible 
conditions. Our alligator quarters are com- 
modious, giving the-reptiles ample room for 
swimming, while they are provided with banks 
floored with sand upon which the animals may 
emerge from the water. During the cold months 
of the year the water of the tanks is kept heated, 
by means of a submerged pipe, to a temperature 
varying between 90 and 95 degrees Fahrenheit, 
while the temperature, of the Reptile House 
ranges from 75 to 85 degrees F. Owing to a 
generous supply of tropical plants, the’ atmos- 
phere of the building is very moist. We find 
that if alligators are kept in water of a lower 
temperature than that mentioned during the 
cold months they feed indifferently and irregu- 
larly, even though the température of the air is 
satisfactory. They prefer to pass the greater 
port of their time in the water, consequently 
this medium, to promote normal dévelopment 
must have a high temperature. The average 
captive “pet” alligator that appears to indefinite- 
ly remain the same size, or to grow at a rate 
that would require a stupendous period -to- 
bring it to maturity, is an individual whose 
growth has been arrested by the effects of cold 
water, and an insufficient depth of that medium 
for proper exercise. 
In addition to the tepid water of the Reptile 
House tanks, the high temperature of the build- 
ing and moist atmosphere, the feeding of our 
crocodilians is a matter regulated with thorough 
system. It is highly essential that all croco- 
dilians receive plenty of bone nourishment. 
Beef and fish alone are insufficient to promote 
rapid growth, or cause the animals to attain a 
large size. Our freshly hatched crocodilians 
are first given a diet of earthworms and min- 
nows. Upon this they are kept for about two 
months, when dead mice are occasionally given 
them. As soon as they show an increase in 
size, the quantity of food is correspondingly in- 
creased. Earthworms are then excluded from 
the meni, while small rodents are given fre- 
quently, in alternation with frogs, fish and scraps 
of beet. Young rats and sparrows are soon 
added to the list. 
It’ will be realized that this food produces 
good bone development. Our medium-sized alli-: 
gators receive small hares, pigeons, and large 
fish, all of which are entire. This food supply, 
we are convinced, closely approaches the diet 
of the wild alligator. The amount of food con- 
sumed by our specimens is not nearly so great 
as might be imagined. Usually they are fed 
twice a week, and at most three times a week. 
The average wild alligator should fare fully as 
well as this. If there is a scarcity of larger 
food it may always resort to a fish diet, for the 
waters of the most of the southern bayous 
usually teem with finny creatures. 
At this point it is well to bring forward the 
answer to a query that may at once present it- 
self to the reader: How does the growth of 
captive alligators compare with that of-alliga- 
tors in a wild state? We have already explained 
that our captive examples have proven their 
ability to attain maturity in a comparatively 
brief period, in comparison with the great num- 
ber of years so generally alleged to be necessary 
in completing the process. We are moreover 
quite convinced, when considering our observa- 
tions of wild alligators and their haunts, that 
FLORIDA CROCODILE, 

