Dendrobates tinctorius Robertus
Dendrobates tinctorius Robertus are medium, yellow, light blue, dark blue, and black frogs who are typically quite confident in captivity. Like the other tinctorius frogs, Robertus are diurnal so they will be awake during the day so you can watch them eat and hop around. Introduced fairly recently, with the first import likely being in 2013, Robertus is a newcomer in the dart frog hobby, and Jungle Jewel Exotics was among the first have Robertus into Canada!
Quick Stats:
Minimum Enclosure: 45cmX45cmX45cm (18”X18”X18”)
Heat: 18°C-27°C (65°F-80°F)
Humidity: 70-100%
Food: Juveniles D. melanogaster, Adults D. hydei, isopods, springtails.
Lifespan: 10-15 years, occasionally over 20
Description
Dendrobates tinctorius Robertus dart frogs can be variable in both color and markings. They seem to be yellow on their base level, displaying the color on their heads and sides, and occasionally on their backs. This yellow fades into powder blue, which can cause color mixing and present as a mild green color. From powder blue the color can fade further into a dark cobalt. On top of this rainbow there are splotches, spots, and stripes of black. The yellow and blues can mix higher or lower on the frog’s body, giving each individual multiple layers of unique coloration. Robertus are medium tinctorius frogs. Large females measure in at about 64mm (2.5 inches), with males being slightly smaller. Females often appear rounder or “chunkier” than males. Usually the male’s toe pads are wider and the arch in the back is less defined than the female’s. All Robertus share the common hunchback pose and bulldog stance the tinctorius species is known for.
Distribution and Natural Habitat of Dendrobates tinctorius Robertus
Tinctorius Robertus are native to Southern Suriname however their exact location has been kept from the public. These frogs can be found living near streams in the subtropical jungles interspersed across the region. Tinctorius is considered by the IUCN Red List as “Least Concerned” as of 2010, but Robertus frogs are under constant threat of deadly virus, agriculture and logging and human collection. There are few Robertus specimens in captivity, but they are breeding actively.
Behavior
Like all tinctorius, the Robertus frogs are diurnal meaning they are awake during the day. They are terrestrial and live in the understory of the jungles they inhabit. In the wild they are constantly foraging for small insects, invertebrates and arthropods in the leaf litter. Some of the plants in the jungles contain various alkaloids and toxins, the micro fauna eat these plants and in turn get eaten by the frogs. This causes a downstream effect and these amazing frogs have evolved to harness the toxins as a means of self-defence. A combination of their striking colors and the toxins stored in their glands help ward off potential predators. In captivity the tinctorius do not contain any of these toxins due to the diet provided to them. They don’t have access to the food they would be eating in the wild. Robertus live near streams and can be found soaking in shallow ponds or right on the edge of slow moving water. While being frogs they are not very good swimmers and great care should be taken when making a suitable vivarium for them to live in. Once mature, the males will boldly perch on a rock or log and call out to attract females. The tinctorius call is barely audible, and is a quiet buzzing sound. When a female selects a male, she will caress and gently pet his back to tell him she is ready to mate. The male will then hop away to a nice quiet place, with the female close behind. For most tinctorius the adult females are quite aggressive to each other and will wrestle and chase away opponents. In the wild the loser can just hop away to live another day, however in captivity this isn’t an option.
Life in the Vivarium
Like all dart frogs, Robertus require a humidity range of 70-100%. They can survive for brief intervals at 50% humidity if clean water is provided for them to soak in. You can place a bromeliad or small shallow dish of water in the enclosure or add a pond feature to achieve this. Remember, tinctorius Robertus cannot swim well, so ensure that the water source is shallow and easy to get out of. The water level should be no higher than the smallest frog can sit in with his head and upper torso out.
Robertus thrive at temperatures near 21°C (70°F) but can survive a range of 18°C-27°C (65°F-80°F). Never exceed 29°C (85°F) as this can be fatal to the frogs. Generally a heat source such as a pad or light is not needed on a dart frog vivarium, apart from any lighting for plants. Do not rely on sunshine from a window, because the sun through the glass will heat up to extremely unsafe temperatures very quickly. Keep note of any air conditioning or heaters used in your home as well, as they may affect the temperature in your frog cage.
It is possible to house a single tinctorius Robertus in a 10 gallon aquarium, but we recommend that you use a minimum 45cmX45cmX45cm (18”X18”X18”) enclosure – bigger is always better. This size vivarium is suitable to house 2-3 adult Robertus.
As juveniles you can house several Robertus together, however as they mature you will need to remove all but one female once you notice the first signs of aggression. Sometimes the males will exhibit aggressive behaviors to each other while defending their territory. If it appears to be stressful you may be required to remove the passive males. This is less common than female aggression, so it may be possible to house multiple males with a single female. The size of the vivarium provided and the individual personalities of each animal will dictate how many frogs you can keep in an enclosure. Because of the female on female aggressive behaviour over mating rights it is common for most hobbyists to house only a pair or trio of two males and one female.
It is common for a healthy tinctorius Robertus to live between 10-20+ years in a vivarium. Please consider this before deciding to take them home to your family. As with most amphibians they are considered a “hands off” pet similar to a fish. Due to their delicate and permeable skin, it is not advised to handle your frogs. The chemicals, oils and debris on your hands could prove fatal to your dart frog pet when it is absorbed through their skin. It is recommended that you wear powder free rubber gloves if you are required to handle your dart frogs. In an emergency, such as an escape from the enclosure, try to capture them as fast as possible (bare hands will do… if needed) as they will try to hide quickly, and unfortunately this will become fatal very rapidly.
Tinctorius Robertus require small live prey to hunt. This is easily achieved by providing them with flightless or wingless fruit flies. Baby and juvenile Robertus will eat Drosophila melanogaster fruit flies, and the adults will hunt for Drosophila hydei. But the flies on their own are a poor nutritional source. We recommend “dusting” your fruit flies with a high quality vitamin and mineral supplement. We use and recommend Dendrocare all in one vitamin/mineral supplement. You can combine and use other supplements available to you, however please ensure you research what ratio or frequency you can supply vitamins as some can be lethal in high dosages.
It is very common to build a bioactive vivarium for your dart frogs. This is achieved by introducing isopods and springtails into the environment. These little land crustaceans (no they are not insects!) will eat the decaying and decomposing bio matter as well as any excess feces in the vivarium. Some of these micro fauna will be eaten by your dart frog, as a little snack.
As with all our frogs, we do not recommend that you house multiple species or morphs together. Please supply each group with a vivarium to call their own.
Breeding Dendrobates tinctorius Robertus in Captivity
If you have provided all the necessary parameters to keep your tinctorius Robertus happy and healthy, they are fairly easy to breed in a vivarium. This makes them a popular choice for many dart frog enthusiasts. Eggs will be laid on a smooth clean leaf surface in a secluded location. Many hobbyists will place a petri dish under a coconut hut to give the frogs a nice quiet place to lay their eggs. The adult male should return frequently to his eggs to keep them moist and clean. Tinctorius Robertus eggs are clear and gelatinous, making them excellent to watch develop into tadpoles. The eggs take approximately 10-14 days to fully develop, at which point they will hatch and the adults will return to give the tadpoles a piggyback ride to a shallow pond. The tadpoles will take approximately 60-80 days to fully metamorphosis into colorful little froglets.
Final Notes
Dendrobates tinctorius Robertus are a fairly new acquisition to the dart frog hobby. Their absolutely unique yellow, blue, and sometimes green color combined with their contrastive black markings makes them a must for the collector, but, like the rest of tinctorius, they are fairly easy to keep and thus great for the beginner as well.
