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We don’t usually think of frogs as complicated creatures. Your average frog is expected to be born as a tadpole the size and shape of an uncomfortably-large sperm, grow limbs, leap out of the water to catch bugs, sing to attract a mate, and eventually lay another clutch of eggs, birthing yet more tadpoles into the world. If anything, frogs in modern internet culture have become symbols of blissful ignorance and simplicity, idolized as the poster children of the phrase “no thoughts, head empty.”
Yet, many frogs have much more going on under the hood than your average person would give them credit for, and one frog in particular exemplifies this. This bite-sized amphibian, no larger than a postage stamp, not only lives in one of the most fascinating habitats on Earth, but defies many of our most basic assumptions about how frogs are supposed to behave. They are complex romantics, discerning audiophiles, skillful planners, and doting parents, all wrapped up in the most adorable tiny package you’ve ever seen. Consider: the Golden Rocket Frog. Anomaloglossus beebei.
The golden rocket frog is a close relative of the famous(ly deadly) poison dart frogs. They are incredibly tiny, reaching a maximum length of just 19 mm (0.75 inches), or the diameter of a US penny. Females in the species range in color from high vis safety vest yellow to Starburst orange, while males are a much duller brown with flecks of other dark colors designed to provide camouflage. During mating season, males will flush an even darker, more saturated brown (much like a college kid on spring break in Cancun).
We are pretty accustomed to seeing different genders of the same species have different physical appearances, but golden rocket frog coloration actually poses a mystery to scientists. Bright, obvious colors like those on a female golden rocket frog generally mean that an animal is unpleasant to eat (think poison dart frog), but golden rocket frogs don't contain any toxins (and, I assume, taste delicious, like a lemon Fruit Gusher). Some non-toxic species will evolve bright colors to try to trick predators into thinking they’re poisonous (known as Mullerian mimicry). This only works when the species in question shares its territory with a similar-looking toxic species, though, and golden rocket frogs do not.
The best remaining theory is that golden rocket frog coloration is a form of sexual selection, a process by which traits develop not to confer a survival advantage, but to make a creature look sexier to a potential mate. The standard biology class example of sexual selection is the tail on a male peacock, which eligible bachelors use to entice a female to mate with them over a rival that may have a shorter, less-impressive tail (and they say size doesn't matter). If the gold on a female golden rocket frog results from sexual selection, however, it’s a really weird instance of it, because the typical color roles are reversed. In this species, the dull-colored males of the species sing in order to attract the bright yellow females, and this suggests that these animals have a much more complicated courtship system than anyone expects out of a frog (a system which is an active area of research).
Tiny Homesteaders
Golden rocket frogs live exclusively at elevations above 450 meters (about 1500 feet) on three mountains in Guyana, with the most well-known populations dwelling in a 600 hectare (1500 acre) area of Kaieteur Tepui, one of Guyana's tabletop mountains. The mountain is home to Kaieteur Falls, the world’s largest single-drop waterfall. At a height of 226 meters (741 feet), this waterfall is four times higher than Niagara Falls (so do not try to go over it in a barrel). Kaieteur Tepui is part of the much larger Guiana Shield, a two-billion-year-old geologic formation that encompasses all of Guyana, French Guiana, and Suriname, as well as parts of Venezuela, Colombia, and Brazil. The shield contains 18% of the world’s tropical forest-stored carbon and is home to over 4,000 animal species, 40% of which are found nowhere else. Within the tepui, golden rocket frogs prefer tropical savannas and glades with little tree cover, only rarely inhabiting forests.
1500 acres might seem like ample space for a frog the size of a cough drop, but golden rocket frogs have some picky real estate preferences. Golden rocket frogs live exclusively on giant tank bromeliads of the species Brocchinia micrantha. These tremendous plants can grow to be up to eight meters (26 feet) tall, and have a rosette shape, with long leaves sprouting atop one another in a swirling pattern like the top of a pineapple. In the case of Brocchinia micrantha and other tank bromeliads, rain and waterfall mist collects in the gaps between leaves, creating small pools called phytotelmata. While small, these phytotelmata are colonized by microorganisms such as green algae and invertebrates like insect larvae and crustaceans, creating tiny ecosystems. It turns out that phytotelmata also make excellent homes for golden rocket frogs, each one like a cozy studio apartment with an in-ground swimming pool. The frogs spend their entire lives on their host bromeliads, hunting, hiding, and raising their offspring all on the same plant.
Golden rocket frogs are predators, but you wouldn’t call them particularly ambitious ones. As opposed to chasing down prey, the frogs simply sit and wait to strike and gobble up whatever lunch happens to stop by. Their diet includes a variety of arthropods such as spiders, ants, midges, and flies, though their largest food source comes courtesy of the phytotelmata they hang out in. The standing water of a phytotelmata draws mosquitoes, who lay their eggs in the pools. The mosquito wrigglers (yeah, that’s the actual name for a baby mosquito) grow within the pools, pupate, and then emerge on the water’s surface as adults. As they emerge, however, the mosquitoes become temporarily vulnerable to attack, as their wings must first dry out to allow them to fly. In this helpless state, the golden rocket frogs have no problem picking the blood-suckers off before they have a chance to escape (literal spawn camping—these frogs would love Call of Duty).
Yet, this hunter becomes the hunted just as often. Being small and lacking passive defenses like poison, golden rocket frogs often find themselves preyed upon by larger species, especially snakes of the family Colubridae or grapsid crabs, which also sometimes inhabit phytotelmata. Here, the bromeliads once more become vital to the frogs’ survival. Upon noticing a predator’s approach, a golden rocket frog will wedge itself in between the leaves of its host bromeliad, making itself as difficult for a predator to access as possible. If hiding and wedging fails, the frogs will make like a opossum (and me when I need to make a phone call) and play dead. While it might seem counterintuitive to flop over while being chased by a predator, death feigning (known as “tonic immobility” by science nerds) occasionally comes in handy when a prey animal has no other options. Some predatory species will only consume live prey, and as such they will leave a seemingly-dead frog alone.
Fabulous Fathers
Golden rocket frogs have no defined mating season, and can be found getting it on just about any time of year (that’s one drawback to living in a plant pool—no privacy). Females choose their male partners based on the quality of their calls, and they can be exceptionally picky. Calling actually functions as a decent metric for the fitness of a potential mate, as it costs a lot of energy: a golden rocket frog that calls regularly burns 25 times more energy than a frog at rest. As such, competition for mates revolves around endurance; females can distinguish between calls that are only a few milliseconds apart, and prefer males who have longer calls with more pulses. To understand this, imagine going on a date where your partner decides whether you get to go home with them based on how long of a jazz run you can sing. Research has shown that male rocket frogs with longer calls actually make better fathers, and a higher percentage of their offspring survive to adulthood. This is the only known instance of a frog’s call advertising the quality of parenting it can provide.
For male golden rocket frogs, parenting is a big deal. Once a female has chosen a mate, she lays one to five eggs in a phytotelma between the lower leaves of her bromeliad, and the male assists in caring for them. After these eggs hatch, the tadpoles need to move from the phytotelma they were born in to ones higher up in the plant, where they will have protection from predators and sufficient room to grow. The tadpoles are somewhat lacking in the terrestrial mobility department, though, so it is up to their fathers to carry them. In a daring act of parenting, a male golden rocket frog will load his tadpoles onto his back one by one and give them a piggyback ride further up the plant. Once his tadpoles are safely in their new home, the father will stay close by, protecting his young with all of the fury a frog the size of Hershey Kiss can muster.
Much like how human parents scope out neighborhoods based on the quality of
school districts, golden rocket frogs don’t choose any old puddle to dump their offspring into. Researchers have found that successful golden rocket frog fathers prefer nursery pools with beneficial features for their offspring. One such beneficial feature is a lack of goop. In addition to showcasing the golden rocket frog’s species-wide disdain for the beauty products of Gwyneth Paltrow, mucilaginous, goopy substances in phytotelmata often contain microorganisms which consume oxygen in the water, making it harder for the tadpoles to breathe. This goop can also introduce viscous chemicals to a phytotelma, making swimming more difficult for the tadpoles. Male golden rocket frogs plan their entire lives out around seeking out high-quality nursery pools, establishing territories around them which they defend viciously, especially from rival frogs.
In addition to being absolutely adorable, this good fatherhood strikes researchers as an incredible cognitive feat. Golden rocket frogs seem to be able to identify areas of a bromeliad that would make good nurseries and understand that such areas should be protected for the benefit of their offspring in the future. Scientists believe future planning to be an advanced form of cognition, but yet, this frog with a brain smaller than a jelly bean can do this just fine, without any of the advanced brain physiology found in a great ape or bird.
Protecting the Golden Rocket Frog
The International Union for the Conservation of Nature (IUCN) lists golden rocket frogs as Endangered, with their population on the decline. The biggest threat facing golden rocket frogs is the disappearance of the tropical savanna environments where they live. Over the last two centuries, trees and other woody plants have invaded these savannas, changing them into forests. This change can spell disaster for golden rocket frogs, as fallen leaves from tree canopies often clog the phytotelmata that they need to raise their offspring. While the frogs are common within their tropical savanna homes, very few of them manage to survive in forests.
This encroachment of trees on grasslands isn’t unique to Kaieteur, and I have even written about it previously in the context of the zacatuche. Over the course of the last 200 years, savannas around the world have shrunk considerably, especially in South America and Africa. This process has occurred not due to any single cause, but as a result of a multitude of human-derived changes interacting with one another. One factor is the increase in the concentration of atmospheric carbon dioxide due to the Climate Crisis. Without getting too deep into the weeds of plant photosynthesis (pun intended), woody plants often use a form of photosynthesis that is more effective at converting carbon dioxide into sugar than the form used by many savanna plants. As such, these woody plants grow more quickly than native savanna species in the high-carbon atmosphere that has been ushered in by human industry, allowing them to take over.
Another significant driver of savanna encroachment is the interruption of the fire cycle by humans. While we tend to think of wildfires as negative, destructive forces that only YOU can prevent, they actually play a critical role in maintaining many ecosystems. Healthy savannas experience wildfires on a regular basis. These burns return nutrients to the soil, facilitating the growth of new plants, and also kill tree saplings which otherwise might overrun the savanna. Humans often prevent these fires, though, allowing tree saplings to grow unchecked. Most obviously, humans extinguish fires directly to protect property or infrastructure, but other less-direct methods can also stymie healthy burns. Roads or other paved surfaces can act as fire breaks, restricting the areas that flames can burn, while overgrazing by livestock can reduce the availability of aboveground kindling and make a savanna unable to sustain a fire.
The Kaieteur National Park where most golden rocket frogs live is also threatened by human resource extraction. While deemed a protected nature reserve, Kaieteur National Park has long been known to contain valuable mineral deposits, and people will often mine for gold and diamonds there. These artisanal miners often use a method called alluvial mining, in which they tear up stream beds and sift through the sediment to find flecks of valuable minerals. This process floods rivers with sediment that can block out light, leading to the death of aquatic plants, and clog the gills of fish. The mining process also tends to leave behind pits of stagnant, polluted water in which mosquitoes breed, increasing the spread of mosquito-borne illnesses. Currently, the gold mining in Kaieteur National Park occurs at a lower elevation than where golden rocket frogs live, but if allowed to continue it may spread higher up the tepui, threatening them directly.
As of right now, the golden rocket frog’s habitat lies inside of an area protected and managed by the Guyana Protected Areas Commission. Yet, we can protect this species and many other savanna-dwelling species by spreading knowledge of proper savanna management. While conservationists agree that regular wildfires can benefit savanna ecosystems, many people still see fire in a negative light. By spreading a correct understanding of fire’s role in some ecosystems, we can protect savannas from encroachment and prevent the much more cataclysmic burns that often result from excessive fire suppression. By pressuring governments and corporations to cease the production of greenhouse gasses, we can slow the rate of climate change and potentially stave off its worst effects, saving endangered species and humans alike. To learn more about how grasslands and savannas affect the lives of humans and animals, consider checking out the International Year of Rangelands and Pastoralists (IYRP), a UN initiative to highlight the importance of these habitats worldwide.
Golden rocket frogs defy some of our most basic expectations about how an amphibian should behave, from their choice of habitat to how they raise their young. These critters have mastered just about the tiniest niche you could possibly imagine, but that niche is fragile and in danger due to human behavior. Golden rocket frogs don’t pollinate flowers or disperse seeds or build dams that hold an entire ecosystem together, but they do have the capacity to teach us so much about amphibian behavior, and I think that's worth saving. The next time you see someone on the internet belittling frogs for their perceived lack of brains, remember to stick up the for the little guy.
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Thanks to Kevin Schafer for some of the excellent photography in this article. You can see more of his excellent photography at http://kevinschafer.com/.
Sources and More Information:
Amazon Conservation Team (2021). “THE GUIANA SHIELD: ONE OF THE LAST WILD PLACES ON EARTH”.
Bourne (2001). “Color pattern, predator avoidance, and foraging behavior in golden rocket frog Colostethus beebei”. Herpetological Review
Editors of the Encyclopedia Britannica, (2024). “Bromeliacaea”. Encyclopedia Britannica.
IUCN SSC Amphibian Specialist Group. (2019) “Anomaloglossus beebei”. The IUCN Red List of Threatened Species 2019
Kaieteur Protected Areas Trust Guyana (2024). “Kaieteur National Park”.
Kok, Philippe (2024). Personal Communication.
Streiff, L (2019). “Female golden rocket frogs know a good father when they hear him”. Mongabay.
Tumulty, James (2024). Personal Communication.
University of Jyväskylä (2023). “Research investigates reproductive resource defense in golden rocket frogs”. Phys.org
Consider Nature is written and published by Stephen Goralski. Editors for this article included Benjamin Gamble, Jesse Cristoforo, and Oli Platt. Our web designer is Oli Platt. Olmungandr, the Consider Nature logo, was made by Maxwell Schumacher.
Man, I sure did post an article about how cool male frogs are on International Women's Day, huh? That was a choice. Go send this article to a woman or you're a misogynist.