Poison Dart Frogs Hit the Bullseye
They're not as dangerous as their common name implies.
By Richard Revis
Published in the September 2004 issue of Reptiles magazine.
Poison dart frogs have been experiencing a recent surge in popularity because these little animals sport some of the brightest colors in nature and their diurnal habits make them ideal display animals. Their reputation as being difficult frogs to maintain is fading because captive-bred frogs are hardier than their imported predecessors and their needs are better understood.
While not suited to handling, poison dart frogs are fascinating to watch and display interesting behaviors. They even display dedicated parental care. When their environment is set up properly they can be quite long lived, perhaps into their teens. And few other animals offer the possibility of setting up beautifully landscaped terraria that can become just as interesting as the inhabitants.
Poison dart frogs are found throughout the tropics of Central and South America and live in rain forest habitats ranging from the forest floor to high up in the canopy. They are generally small animals; the largest reaches nearly 3 inches while some of the smaller species can comfortably fit on a thumbnail. What they lack in size is more than made-up for by their stunning coloration, which serve as warnings to would-be predators of these frogs' toxicity.
The family Dendrobatidae has collectively acquired the name "poison dart frogs" mainly due to the powerful toxins of one genus: Phyllobates. While all dendrobatids possess alkaloid skin toxins, only a couple Phyllobates species have earned the group its common name. Specifically, Phyllobates terribilis is used by the Choco Indians of Colombia to poison their hunting darts. The Indians rub their darts on the backs of the frogs, smearing the darts with toxins. Phyllobates terribilis has enough toxin in its skin to kill several adult humans.
Thankfully, captive-bred animals are completely harmless (ALL DART FROGS ARE NON-TOXIC WHEN CAPTIVE BRED) due to captive diets lacking something the animals consume in the wild that makes them toxic (it is not fully understood what the wild frogs seem to be eating that allows them to produce their poison).
Two Excellent Starter Species
Deciding which dart frog to begin with can be a challenge given the number of species available today. There are more breeders working with many more types than even 10 years ago. Most of the commonly available species are easy enough for beginners to keep, although larger species tend to be more forgiving if conditions are not perfect. Some species for beginners to consider would include Dendrobates auratus, D. leucomelas, D. tinctorius and D. azureus.
Dendrobates auratus (the green and black dart frog) and D. leucomelas (the yellow banded or bumblebee dart frog) are similar in regard to husbandry and compatibility. These two species are commonly recommended for beginners due to their ease of maintenance and relatively inexpensive price. Dendrobates auratus is found in Costa Rica and Panama, where numerous color forms exist. Dendrobates leucomelas is native to Venezuela, and although multiple forms are said to exist only one is common in the hobby.
Some forms of D. auratus have very striking patterns, including blue and black, green and black, and bronze and green, as well as variations within the forms. They are quiet frogs -- the male's call is a faint buzz -- and some are shy. The forms vary in size, usually ranging between 1.5 and 2 inches.
The form of D. leucomelas most common in the hobby possesses yellow or orange bands, each marked with black spots, across a black background. Another form with more yellow and finer spots, which is common in European collections, is becoming available in the U.S. Male D. leucomelas have a very pleasant loud trilling call.
Both species are easy to keep in 10 or 20 gallon terrariums and do well in small groups. A 10-gallon tank could house two or three individuals; a 20 could accommodate three to four. These frogs can get territorial, but this normally does not result in serious problems. One note of caution though: Females will prey upon each other's eggs. Also, it is not recommended to house these species together because hybrids have been known to occur.
Two Other Beginner Poison Dart Frogs
Dendrobates tinctorius and D. azureus are also suitable for beginners, although they are not as comptatible. Both are best kept as individual male/female pairs as adults as both sexes are very territorial with females being somewhat more aggressive. Although they can be kept in groups when young, as the animals mature same-sex frogs will fight. In some cases males will get along, especially if no females are present, but they rarely tolerate each other much after the age of 2 or 3. This poses a challenge to the keeper as most animals available for sale are not sexable and thus must be separated if they turn out not to be a pair. Buying a group of three or more improves the chances of getting a pair and additional animals can be either sold, traded or paired with new ones.
Although D. tinctorius and D. azureus are less compatible than D. auratus and D. leucomelas, they more than make up for it with their personality and coloration. Dendrobates tinctorius is one of the most variable dart frogs with forms displaying almost every color in the rainbow. They are large frogs with some reaching nearly 3 inches. They are bold animals that rarely hide, and they come to recognize their owners as food sources. Do not keep different forms together as they will hybridize.
Dendrobates azureus displays a vivid blue coloration with black spots. Once considered for experts only and costing several hundred dollars each, they are now within the reach of most hobbyists (although they still cost more than some other poison dart frogs). They too have very outgoing personalities and are almost always visible hopping around the terrarium. Medium to large in size, adults typically measure 2 to 2.5 inches.
Both species have relatively faint calls consisting of low buzzes. Maturity is usually reached after approximately 11Ś2 years, but growth can continue until about 3 years of age.
Captive-bred animals are always preferable to wild-caught stock. You have the advantage of knowing who bred them and how old they are, and they are less likely to harbor parasites and disease. Captive-bred animals are available directly from many good breeders across the country and can often be found at reptile expos.
Be sure to ask sellers as many questions as possible. They should be able to tell you all of the care requirements, including diet and housing as well as compatibility. A frog's price should not be the sole deciding factor; unhealthy animals might be dumped at very low prices. Another point to remember is that most dart frogs are sold as younger animals.
Due to their small size, dart frogs require small prey items. Flightless fruit flies (Drosophila) normally make up the bulk of the diet but other items such as pinhead crickets, tiny wax worms, flour beetle larvae, springtails and termites should also be offered whenever possible to add variety to the diet.
Fruit flies have a reputation as difficult, time consuming and smelly to deal with, but these frustrations may be the result of using homemade formulas and a lack of attention to cleanliness. With the widespread availability of instant formulas and disposable culturing containers, these problems are all but eliminated and culturing the flies is simple. Having a steady and reliable food source is important, as even though the frogs are small in size, their appetite is not. They can quickly devour dozens of insects a day. Froglets should always have food available to them; adults can be fed once daily.
Dust prey items with a good quality vitamin and mineral supplement. Dusting is accomplished in the typical manner: Place the insects in a container with a pinch of vitamin powder and shake it to coat them. Be sure to use a supplement that is ground to a fine-enough dust to coat tiny insects. Young, growing poison dart frogs should be supplemented daily; adults can be fed dusted food three or four times a week. Calcium is especially important for froglets as they can develop deficiencies quickly. This usually results in seizures that will eventually kill the animal if the diet is not corrected. A good calcium supplement with vitamin D3 should be alternated with the vitamin supplement three times a week for froglets and once to twice a week for adults.
Most poison dart frogs can be comfortably housed in 10 or 20 gallon tanks, the latter offering more space without taking up that much more room. This makes these animals ideal for apartment dwellers and others who may have limited space. Froglets are best housed in simple setups consisting of a moist substrate, such as damp sphagnum moss, that can be changed regularly. Hiding places can be provided by using cork curls and logs as well as coconut huts. A small water dish should always be provided and cleaned often.
Larger juveniles and adults fare better in fully planted terrariums. The creation of these habitats is a large part of the enjoyment in keeping these animals as spectacular displays can result.
Proper drainage is of paramount importance, and one of the best ways to provide this is to use a product such as Terra-Lite, a lightweight, porous clay pellet that provides excellent drainage. The next layer would be a substrate divider to keep the planting mix from sifting down into the drainage layer. A piece of fiberglass window screen can be cut to fit the dimensions of the tank for this purpose.
The final layer is the planting mix. Peat moss or mixes containing peat moss should be avoided as this material quickly breaks down to a soggy mess in as little as six months under moist terrarium conditions. A better alternative is one of the ground coir products widely available today. Coconut bedding is an ideal choice as it is very long lasting and while it is moisture retentive it also has good drainage properties. Ground tree fern fiber is an excellent addition to this product to enhance drainage even further. One word of caution about coconut bedding, though: There are many different grades available and some have high salt content left over after processing. In the closed system of the terrarium they have nowhere to go and will quickly kill the plants.
When planting the tank choose plant species carefully as many types sold through mass merchandisers and many nurseries are simply not suitable for terrarium use. One concern with store-bought plants is the risk of chemical residue from fertilizers, fungicides and pesticides. Another problem is that many species grow far too large for the typical terrarium. Larger-growing Philodendron, Spathiphyllum, Syngonium and the ubiquitous Pothos will quickly overwhelm a tank and ruin any hope for a diverse landscape. Dwarf and miniature forms or species of many of these plants are becoming available and are better choices. Otherwise, it can be frustrating to have to replace plants when they outgrow the terrarium. Frequent replacement is an antiquated approach to vivarium design and prevents the enclosure from ever reaching equilibrium as the contents are constantly disturbed. A terrarium constructed using the appropriate materials can be expected to last for years without changing out the plants or substrate, and it will easily break down waste produced by the frogs.
Pieces of driftwood such as cypress, ghostwood or cork provide climbing and hiding areas as well as add decor to the tank. Avoid woods such as grapewood, cholla or manzanita as these tend to continuously grow mold and are not suitable for a moist terrarium. Epiphytic plants such as orchids, ferns and bromeliads can be attached to the wood to add another attractive dimension to the tank.
The humidity level inside the tank should be 80 percent or higher, and the best way to achieve this is by spraying water and restricting ventilation. Too much ventilation will require more frequent spraying, however, which can flood the terrarium. If you live in a naturally humid area, spraying the terrarium may only be necessary a few times a week.
The temperature of the enclosure should be in the low to mid 70s. Stress from temperature extremes can be fatal to poison dart frogs, especially from overheating. Fluctuation of both temperature and humidity, as long as it's within the ranges given, is both normal and beneficial.
Fluorescent lighting is required as even low-wattage incandescent bulbs can quickly overheat a tank and will do little to help plant growth. Double fluorescent fixtures are still often used, although power compact fixtures are becoming more common and make excellent choices. It is a widely held myth that poison dart frogs need dimly lit enclosures to do well. However, bright light encourages lush plant growth of the plants and creates the varied type of habitat the frogs thrive within. I recommend a bright white full-spectrum bulb that helps keep the colors balanced. Plant growth tubes generally skew the color range to accent reds and blues and lack the intensity required to be used on their own.
Although this subject could easily make up an article in itself, the basics for breeding the four species discussed here is as follows.
Once the animals mature at around 1 to 11/2 years of age, breeding will usually occur as long as the animals are adequately housed. Most species do not follow any seasonal breeding cycles and will spawn throughout the year although breeding activity can be reduced or stop if temperatures are outside of the species' preferred range.
The male initiates courtship by calling to attract a female. If a female is receptive she will approach the male and begin stroking his back with her front legs. This will continue as the male leads the female around the terrarium and finally ends as the pair select a spawning site. This usually consists of a coconut hut placed atop a deli cup lid or petri dish. No water or leaves are required in the breeding "bower" for successful spawning. The frogs will continue courting in the hut as the female lays her eggs and the male fertilizes them. The male will often leave the female to continue laying while he goes out to soak in the water dish. When his bladder is full, he returns to soak the eggs and hydrate them. At this time, the female has finished her part and has left the area.
In the wild, once spawning is complete, the male will guard the clutch, occasionally moistening the eggs, until they hatch after approximately two weeks. Once they hatch the male will squat down into the writhing mass and allow one or two tadpoles to wriggle up his back. He will then carry them to a pre-selected, small, water-filled cavity, in trees or on the ground, and deposit the tadpoles to continue developing on their own. He is careful to choose a site that does not already contain other tadpoles as they are cannibalistic and will devour new arrivals. He then returns to the remaining tadpoles to repeat the process until they have all been transported to their new homes.
In the terrarium, most keepers remove the eggs when the pair has finished breeding and raise the offspring artificially. The eggs, still adhered to the deli lid or petri dish, are placed in a covered tupperware or similar container that will hold humidity and kept moist until they hatch. A small amount of water should be added to the dish or lid to prevent the eggs from drying out. Be careful to not cover them too deeply, about 1/4" or so. is fine. After hatching, the tadpoles are raised individually in 16oz or 32 oz cups as the tadpoles do not need large volumes of water.Most breeders use a tannin enriched 'Tadpole Tea' of one type or another which helps prevent any bacterial or fungal problems. We find that using one of the commercial Blackwater Extracts at ten times the aquarium dose is a quick and easy recipe that produces great results. We typically feed our tadpoles three times per week and perform water changes twice per week. Diet for tadpoles usually consists of various flake fish foods, frozen or live daphnia, bloodworms and powdered algae. Tadpole development typically takes about three months depending on water temperature. Once the tadpoles' front arms emerge they should be transferred to a larger container of water with areas to climb out in preperation for metamorphosis. Placing plant material on the land areas will help provide cover for the newly emerged froglets. It is also important to maintain a very high humidity level as the tiny froglets are very prone to drying out. As the froglets begin to emerge from the water they can be moved to the previously described enclosure for young frogs. At this time, they are usually large enough to begin feeding on fruit flies and newly hatched crickets.
Poison dart frogs have been admired for many years although it had always been assumed that their successful maintenance was beyond all but the most advanced herpetologist. Today, due to increased knowledge of proper husbandry and the availability of captive-bred animals, some of these living jewels are well suited for even beginning hobbyists. While it is important to properly house and feed these frogs, the efforts put forth by their keepers is richly rewarded in the vibrant health and fascinating behaviors witnessed in the vivarium. The low maintenance required and the hours of enjoyment provided by these fascinating animals make them an ideal choice for every herp keeper.
Richard Revis has been keeping and breeding poison dart frogs for over 10 years. He is co-owner of Black Jungle Terrarium Supply located in Greenfield, Massachusetts, where a collection of over 200 dart frogs encompassing more than 60 different types is maintained and bred. Black Jungle also sells a wide variety of terrarium-suitable plants and supplies.
Success with Froglets
Keep accommodations simple and provide adequate cover. This allows for better monitoring of feeding and health.
Only keep similarly sized animals together. Size differences can lead to stress, stunting or even death.
Provide constant access to food. Small pieces of fruit used as an attractant will keep prey insects concentrated in one area for easier monitoring.
Supplement well. A quality vitamin supplement as well as calcium with D3 should be provided to prevent deficiencies.
As animals mature, watch for signs of aggression.