That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Click: Captive Care of the Ball or Royal Python, Python regius – Part 1, to read the first part of this article. Or, click:  The Natural History of the Ball Python, Python regius: Ball Pythons in the Wild to read about the natural history of Ball Pythons.

Feeding

Most ball pythons take readily to pre-killed mice and small rats, with hatchlings usually being large enough to handle a “fuzzy” mouse.  In the wild, ball pythons do not feed when nighttime temperatures become cool (January-February in some areas), during much of the breeding season, and while incubating eggs.  They are well adapted to long fasts, and frequently go off-feed in captivity.  This can occur even in captive-hatched animals, tuned, perhaps, to an internally-controlled cycle, and is rarely a cause for concern.

Individuals that go off feed regularly should be fed once weekly during those times when they do accept food, as should hatchlings and young animals.  Regularly-feeding adults do fine with a meal each 10-14 days.

Leaving a food animal in the terrarium overnight may induce reluctant feeders to eat.  Particularly stubborn animals may sometimes be tempted by switching food animal species…Mongolian gerbils are a particular favorite, but sometimes a weaning rat does the trick.   Of course, you may then be saddled with the responsibility of always providing that favored food item, so think carefully before offering anything too exotic.  “Scenting” a mouse by rubbing it with a with a favored food item is a well-known technique for tricking fussy snakes into eating.

Captive Longevity

A ball python kept at the Philadelphia zoo died at age 47.6 years, and holds, as far as I know, the longevity record for captive snakes.  Another was reported to have survived until age 51, but the record is unpublished.  A number of specimens have lived well into their 30’s.

Handling

Ball pythons are fairly mellow in disposition, but even long term captives will bite if provoked.  Their habit of coiling into a ball, while interesting, is a defense response – please do not harass yours into exhibiting this behavior.  As with all snakes, the head should not be placed in the vicinity of one’s face.

Breeding

Only snakes in good body weight should be used for breeding purposes.  Success will be more likely if the male and female are housed separately outside of the breeding season.

Ball pythons should be subjected to a semi-natural temperature and light cycle prior to and during the breeding season.  In October or November, nighttime temperatures should be allowed to fall to 68-72 F, and a night (dark) period of 12-14 hours should be established.  Daytime temperatures should remain as usual.  Feeding should be discontinued 1 month prior to turning down the temperatures, to allow for digestion of the last meal.

One month after the cooling period has begun, the female should be placed in the male’s cage for 1-3 day periods each week.  This process should continue for 6 weeks or so, after which temperatures and the day/night cycle should be returned to normal.

Gravid females will usually not feed.  Eggs may be expected from 2 weeks to 2 months after the reintroductions have been discontinued, depending upon when copulation had occurred.

The Rosemond Gifford Zoo ball python information sheet is posted at:

http://www.rosamondgiffordzoo.org/animals/Reptiles/BallPython.pdf

Please see The Natural History of Axolotls and The Captive Care of Axolotls for further information on this fascinating captives.  Today I’ll finish up with a note on reproduction.

Inducing Reproduction

Adult axolotls are sexually dimorphic, with females being of a heavier build and having shorter and broader heads than males.  The cloaca of the male is noticeably swollen during the breeding season, and gravid females become very plump.

The natural change in day length and room temperature in temperate regions is often enough to stimulate reproduction.  Animals under my care in NY respond to natural variations in room temperature (they are housed in a cool basement) and possibly day-length (light enters through a ground level window).  Females generally lay from January through March, sometimes into April, at water temperatures of 55-60 F.

A sudden increase of water volume and a drop in water temperature seems to stimulate breeding even outside of the normal breeding season. Be careful, however, that females actually lay their eggs when artificial methods such as this are utilized. Retained eggs are a great concern among many captive amphibians, although I have not run into such with axolotls.

The Eggs

Please see the Natural History of Axolotls for details on courtship and mating.  Females have been observed to pick up several spermatophores during the night, although it is not clear all are from one or several males.  Eggs are attached to water plants or any other substrate within the tank. Plastic plants make ideal deposition sites (from a pet-keepers point of view!) as they are easily removed from the aquarium.

Axolotls are ravenous consumers of their own eggs, and few will survive if the adults are left in the same tank. At temperatures of 55 to 60°F, the eggs will hatch within two to three weeks. I generally provide them with mild aeration, just enough to keep the eggs slightly moving. Eggs deposited on plants and on floating objects seem to have a higher hatch rate than do those laid along the bottom of the aquarium, so be sure to provide suitable sites for your females.

Caring for Axolotl Larvae

The larvae lie motionless for a day or so after hatching, after which they become veritable eating machines.  They are best raised in a bare-bottomed plastic or glass aquarium.  Mild aeration via the return from a corner or sponge filter should be provided.  The young require daily feedings and very frequent water changes – after having raised 160 to adulthood at one point, I can vouch for this as being a labor-intensive but ultimately rewarding task.

I’ve found light plastic terrariums or sweater boxes that can be easily dumped and filled to be the method of choice when rearing large numbers of salamanders.  I’ve also used plastic wading pools, but unless you can arrange a way to drain and re-fill easily, these can be a bit un-wieldy to work with.  The extra room they provide does, however cut down on cannibalism.  Please see Captive Care of the Mexican Axolotl (Physical Environment, Feeding) for tips on setting up enclosures and feeding axolotl larvae.

The IUCN’s recommended conservation strategy for this species, as well as historical and natural history information, is posted at:

http://www.iucnredlist.org/details/1095

I’ve come across several of the 11 unique snake species known as sand boas, and have had the good fortune of working with breeding groups of an Asian and African species. Following are some remarks drawn from my notes and conversations with colleagues.

Indian Sand Boa

The Indian sand boa (2 possible subspecies) ranges widely through India and Pakistan.  Those I have kept have reproduced without a winter cooling period (this likely varies among the various populations).  It is a good deal larger than the more popularly kept Kenyan sand boa, sometimes reaching 40 inches in length.  Unfortunately, this impressive burrower is not commonly kept in the USA.

Courtship

Males in breeding condition go off feed and actively search for females.    During courtship, the male attempts to unearth the female’s tail (she is generally below the sand when found) with his head.   His spurs stand out slightly from the body and are rubbed along the female’s back.  Copulation seems a quite awkward affair, with the male burrowing below the female and flipping more or less unto his back.

The Young

The young are born alive after a 4 month gestation period.  They are larger than those of related species, averaging 10-11.5 inches in length.  A bit of umbilical cord usually remains attached for a few days, after which time it dries up and falls off.

The young shed within 2 weeks of being born, after which most accept pink mice.  In common with other members of the genus, young Indian sand boas likely prey heavily upon small lizards in the wild.  “Scenting” pinkies with a lizard may encourage reluctant feeders.

East African Sand Boa (Kenyan and Egyptian)

The East African sand boa is frequently classified as two separate subspecies, the Egyptian and Kenyan, with the Kenyan being the more brightly colored race.  However, taxonomists disagree on this point, with some considering the entire species’ name invalid (please see reference below).

Their reproductive mode parallels that of the Indian sand boa, but breeding is more likely if they are subjected to a winter cooling period (70F ambient, with a warmer basking site and a drop in temperature to 65F at night).

Mating usually takes place in June-August, and the young, 4-18 in number, are born in October-December.  They are 5-8 inches in length at birth, and reach sexual maturity at approximately 2 years of age (at which time they are approximately 16 inches long).

Sand boa taxonomy is currently in flux; you can review the species currently accepted by the American Museum of Natural History at:

http://www.jcvi.org/reptiles/search.php?submit=Search&genus=Eryx

The bizarre Surinam toad needs little introduction to amphibian enthusiasts…their unique strategy of brooding the eggs below the skin of the female’s back has rendered the species quite well-known. Yet, when I received a group of adults in 1986, I found that little had been published on their husbandry, and the last recorded captive breeding seemed to have occurred in the 1950’s.

Courtship and Fertilization of the Eggs
One female was in breeding condition, as evidenced by the circular, swollen ring about her cloaca and the dark brood patch on her back. Several males were giving forth their metallic, clicking breeding calls, so I chose the most robust of the group and placed him with the female.

Surinam toads swim in a series of circular loops, from the bottom to the top of the aquarium, when in amplexus, and will rarely be successful in fertilizing the eggs unless provided with a tank of at least 48 inches in depth. As the pair reaches the top of their loop, the female lays an egg, which is (on the next loop) fertilized and manipulated by the male onto her back’s spongy brood patch.

My Observations of Amplexus and Birth
Amplexus in the frogs I observed lasted for nearly 3 days, which I have subsequently found is the norm. The pair “shivered” in unison on many occasions, but I was not able to see the “bobbing” motions described by others. The photo accompanying this article shows what might be the first captive breeding (this while I was working at the Bronx Zoo) in many years. Within 24 hours of this photo, the skin on the female’s back swelled and completely covered the eggs.

After egg-laying, I removed the male. The female fed as usual. I did not offer blackworms, as these voracious little beasts burrowed into the soft skin of her brood patch at one point…talk about a horrid sight (I was able to wash them away easily)!

The young began to pop their heads out (the sight of 74 pointed little heads protruding from their mother’s back was yet another vision not for the squeamish!) in 100 days, and swam off on their own within a day or so. They averaged ½ to ¾ inches long, and fed readily upon chopped blackworms, brine shrimp and guppy fry. Sexual maturity was reached in 3 years.

Amazing Healing Abilities
The females back appeared “healed” within 24 hours of giving birth, but remained roughened in appearance for several weeks. Amphibians are increasingly being found to produce compounds of great medicinal value…I wouldn’t be surprised if the incredible skin trauma undergone by female Surinam toads is somehow tempered by a chemical that could be of use to people.

A wonderful video of baby Surinam toads emerging from their mother’s back is posted below:

Baby Surinam Toads emerging from their mother’s back

The success that hobbyists have had in establishing breeding populations of so many species of poison frogs is truly astonishing, and has served a greater purpose in removing the financial incentive to collect them from the wild.

Unfortunately, the extraordinary parental care supplied by many poison frogs is difficult to observe in captivity, and the most effective way of rearing the tadpoles is to remove them from their parents’ terrarium. I was most fortunate to have had the opportunity to observe the breeding behavior of wild strawberry poison frogs in Tortuguero, Costa Rica, and in a large zoo exhibit.

Finding and Feeding the Tadpoles
Strawberry poison frog tadpoles, which are moved by the female frog to individual water-filled bromeliad stems, exhibit what has been termed “begging behavior” when their mother visits their pools. When the female lowers her vent into the water, the tadpole moves against her, stiffens, and vibrates. This stimulates the female to release 1-5 unfertilized eggs, which comprise the tadpole’s sole diet.

She visits and feeds each of her offspring, every other day or so, for the 43-52 days that they remain in the tadpole stage…no wonder these tiny moms eat so much! When one considers the complexity of the frog’s rainforest environment, especially as compared to the size of the frog, the female’s ability to locate each tadpole borders on the unbelievable.

Additional Behaviors
Outstanding herpetologist Elke Zimmermann (in “Breeding Terrarium Animals, 1986. TFH: Neptune City, NJ) has even observed females to dip their heads into bromeliad pools before laying, and notes that disturbances from other than the mother frog sends the tadpole into retreat. Field research in Panama indicates that female strawberry poison frogs consistently avoid feeding other than their own progeny.

I was able to observe parental care only in huge exhibits and the wild, but please write in if you would like to try at home…it’s well worth the effort.

We now know that Chirixalus eiffingeri, a treefrog endemic to Taiwan, also communicates with and feeds its tadpoles. The abstract of an article documenting this behavior is posted at:
http://www.ingentaconnect.com/content/brill/beh/2000/00000137/00000001/art00009?crawler=true