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

Uploaded to Wikipedia Commons by Miroslav Deml

Keepers of Poison Frogs, Mantellas, newly-transformed frogs, and other tiny amphibians face difficulties in providing their charges with a varied diet.  Wild frogs consume dozens to hundreds of invertebrate species, but captives are usually limited to fruit flies, flour beetles, pinhead crickets and springtails.  Vitamin/mineral supplements help, but dietary variety remains critical.

Throughout my career at the Bronx and Staten Island Zoos, I have relied heavily upon wild-caught invertebrates.  I recently “re-discovered” an old favorite – the various Sap or Picnic Beetles (Family Nitidulidae).  I first used Sap beetles when rearing Wood Frog metamorphs decades ago, and later fed them to Spring Peepers, Red-Eyed Treefrogs, Poison Frogs and others in zoo collections.  Many small amphibians will eagerly gobble up Sap Beetles, but Poison Frog and Mantella keepers will find them especially useful.  Sap Beetles never fail to bring an enthusiastic feeding response, and can save us some time and money while providing nutrients missing from standard foods.

Natural History

Sap Beetles are classified in the Family Nitidulidae, which contains nearly 3,000 members.  Most top out at 1/8 inch, with the largest barely reaching ¼ inch in length.  Several species, commonly known as “Picnic Beetles”, show up when sweet foods are served outdoors.  Some feed upon over-ripe fruits, corn and other crops, while others take nectar, sap, fungi and carrion. Read More »

I began working with Poison Frogs and Mantellas in zoos just as the secrets to longevity and breeding were being discovered.  Today, captive-bred animals are almost mainstream.  This is wonderful, but there is a downside – they are sometimes viewed as “simple to keep”.  But while these tiny gems can be surprisingly hardy, they will not thrive long-term if their unique nutritional requirements are not met.  Friends of mine who have broken new ground with Poison Frogs – in one case years before most zoos did – have always expended a great deal of effort on providing a varied diet.  The following information is drawn from their and my own experiences over several decades, and may also be applied to the care of many other small and newly-transformed amphibians.

General Considerations

Uploaded to Wikipedia Commons by Marcel Burkhard

Although we do not know the exact nutritional needs of any species, certain principles have become evident.  Chief among these is that a highly-varied diet is essential. Crickets alone, even if powdered with supplements, are not an adequate diet.  There are exceptions, but nearly every study of free-living amphibians reveals that a surprising range of prey species are consumed. Read More »

Poison Frogs (also known as Dart or Arrow Poison Frogs) exhibit an amazing array of colors and patterns – some so spectacular as to appear unreal. What’s more, they are active by day, exhibit complex social behaviors, and care for their tadpoles in “mammal-like” fashion…and are not at all shy about doing so. Small wonder they are among the most desirable of all amphibian pets! Once considered delicate captives, Poison Frogs are now regularly bred in captivity and may live to age 15 or beyond.

The following information can be applied to most available species, including Blue, Green and Black, Strawberry, Golden, and Phantasmal Poison Frogs. However, details vary; please write in for information concerning individual species.

Natural History

These 0.75 – 2 inch-long beauties are native to Central and South America. Identification by physical appearance alone is difficult, as some species exhibit a great many color variations. Their taxonomy is in flux, with various authorities recognizing between 180 and 300+ species. Read More »

Springtails are minute, primitive, wingless insects classified in the Order Collembola.  Over 6,000 species are found in most temperate and tropical habitats, where they figure importantly in the diets of Poison Frogs (Dendrobates, Phyllobates, Oophaga), small salamanders and newly metamorphosed amphibians of many kinds. Please see Part I of this article for information on procuring Springtails and their role in helping to save the nearly extinct Kihansi Spray Toad (Nectophrynoides asperginis). Read More »

The diets of captive Poison Frogs (Dendrobates, Phyllobates, Oophaga), Mantellas, small salamanders (i.e. Red-Backed Salamanders) and tiny, newly-transformed amphibians are usually limited to the two readily available foods of appropriate size – pinhead crickets and fruit flies.  The minute, wingless insects known as Springtails (Order Collembola) are easy to procure and rear, and offer a convenient means of increasing dietary variety for small amphibians.

Natural Diets of Smaller Amphibians

Most small terrestrial frogs and salamanders forage among leaf litter, which is invariably inhabited by thousands of species of tiny invertebrates (surprisingly, the weight of invertebrates in most habitats exceeds that of all vertebrates combined!).  It seems certain that these amphibians consume an extremely varied diet in the wild, and that typical captive diets do not meet their nutritional needs.

Aphids (1/8-inch-long green or red insects found in colonies on plant stems) are an option, but these are becoming scarce in many areas and, with their complicated life history (involving sex-switching and other unique twists), are difficult to maintain long-term.  One can also collect ants, tiny beetles and other leaf litter invertebrates (please see article below), but of these only Springtails can be easily bred in large numbers.

Problematical Captives

Some amphibians are so small that even pinhead crickets prove too large a meal.  I’ve run into this situation with Kihansi Spray Toads (Nectophrynoides asperginis), which are a mere ¾ inch long when full grown.  These toads, now likely extinct in the wild, give birth to fully formed toadlets that are so small as to be barely visible.  A steady supply of Springtails was essential to the successful rearing of these Tanzanian natives, the last of their kind on earth.  Folks breeding other tiny amphibians, such as Strawberry Poison Frogs (Oophaga pumilio), will also find Springtail colonies an invaluable resource.

Procuring Springtails

With over 6,000 species identified thus far, Springtails are common in most temperate and tropical habitats.  They usually appear as tiny white “dots” jumping about below fallen leaves.  You can start a colony by scooping them up in the leaf litter or by purchasing any of the several species available through commercial suppliers.  Most breed well in captivity and can build up enormous populations under favorable conditions – please see Part II of this article for details.

Further Reading

Whenever possible, the diets of smaller amphibians should be supplemented with wild-caught invertebrates.  Please see Collecting Leaf Litter Invertebrates for some useful techniques.

Strawberry Poison Frog image referenced from wikipedia and originally posted by Encarna Sáez Goñalons & Víctor Martínez Moll

Springtail image referenced from wikipedia and originally posted by Mvuijlst