The Coqui Frog (Eleutherodactylus coqui)

Originally published in The Manitoban, 2011

             

This week I have been bitten by fire ants, termites and a cactus. Now I've got all that out of the way, I hope to spend the rest of my stay in glorious Puerto Rico in perfect harmony with nature. I would especially like to harmonize with the common coqui frog, Eleutherodactylus coqui. They have a very pretty song.

            

While I have not yet seen one, they are the first thing I heard when I set foot on this fascinating island. Male coquis start singing as soon as the sun begins to set, currently around 6pm, and they continue singing until the sun comes up around 6:30am. Males sing to advertise to females and announce their territory to other males.

            

Named onomatopoeically for their song (ko-kee, ko-kee), the coqui belongs to the genus Eleutherodactylus, a long Greek name lending itself to over 600 species, meaning “free toes”. This refers to the fact that members of this genus do not have webbed feet, but have individual and unattached toes with large pads adapted for climbing. As you might guess, coqui frogs are arboreal, climbing trees as the sun sets to hunt insects until dawn, at which time they retreat to their hide-outs for the day. Just like teenagers and goths.

            

Coqui frogs are very small, ranging from 15 to 80mm in length. In fact, coqui means “little frog”. Unlike most frogs, fertilization is internal and coquis do not lay their eggs in water but terrestrially in moist areas. The young develop within the egg over a period of about 17 to 26 days and hatch as miniature adults with very small tails that disappear shortly after hatching. The tadpole stage occurs within the egg so there is no free-living larval stage as in most frogs. There are also developmental differences; some of the stages that free-living tadpoles pass through are absent in the coquis.

           

Coquis reproduce year-round but the majority of breeding takes place during the rainy season from about September to December. Male coquis guard the eggs and remain at the nest for the first few days after their eggs hatch, but by that time, the females are long gone. Females usually lay between four and six clutches of anywhere from 16 to 41 eggs per clutch – with a schedule like that, it's no wonder she doesn't stick around!

            

For the taxonomically inclined, coquis belong to the order Anura and family Leptodactylidae. In Puerto Rico there are 17 species of coqui frog; however, only two of them actually have the 'ko-kee' song for which they are named. Three species of coqui, web-footed, mottled and golden, are believed to be extinct. The golden coqui, E. jasperi, is (was?) the only member of the family Leptodactylidae that gives birth to live young.

            

Common coquis are found on St. Croix, St. John and St. Thomas, U.S. Virgin Islands, Dominican Republic, Vieques, and Florida. They are considered an invasive species in Hawaii, where efforts to eradicate the little guys are under way. The common coqui is doing quite well on the island of Puerto Rico, and Puerto Ricans like it that way – the coqui symbol is used by many local businesses and institutions and is advertised as a source of local pride.

            

In fact, in my tireless efforts to bring you only the most well-informed articles, I drove all the way to Rincon to check out an Oktoberfest (yeah, I know, right?) celebration sponsored by one of Puerto Rico's two local breweries, Old Harbor Brewery based in San Juan, so that I could sample their Coqui Lager. Coquis are great, but I liked the pale ale better. At that point, I didn't know what animal that ale was named after, but there is a Puerto Rican boa that's endangered, so stay tuned next week for the low down on that lovely creature.

              

The Puerto Rican Parrot (Amazona vittata)

Originally published in The Manitoban, 2012

The Puerto Rican Parrot (Amazona vittata) is the only endemic parrot species in Puerto Rico. The Taino Indians referred to this parrot as Higuaca or Iguaca (the "h" is silent), and so shall I throughout this article.

Higuaca are about 12 inches long. They are emerald green with blue primary feathers, a white eye ring, red forehead and a short, blunt tail. The Hispaniolan Parrot (Amazona ventralis), an introduced species, are often mistaken for Higuaca.

            

Higuaca reach sexual maturity between three to five years of age and form long-lasting pair bonds. Pairs remain together year round, breeding once a year during the dry season (February to June). Females incubate the eggs while males forage for themselves as well as for the incubating female. Both parents feed the chicks. Once fledged, the young (two to four on average) remain with the parents for several months or even into the next breeding season.

            

Higuaca are primarily frugivorous (fruit eaters) and live in the old-growth rainforests of Puerto Rico. Unfortunately very little rainforest remains, as most of it has been cut down to make way for agriculture. Yes that's right folks, that old beast habitat loss through deforestation (via massive human population increase) is back to haunt us again in this, the last Puerto Rican edition of Zoological Investigations.

            

Higuaca are one of the most endangered birds in the world today. Back in the 1400s, the Higuaca population was estimated at anywhere from 100 000 to one million (based on field observations). Spanish colonization in the 1600s led to massive human population increases and  deforestation. This drastically diminished the amount of suitable habitat and Higuaca numbers were reportedly declining as early as 1836.

            

By 1900, the human population on the island was about 1 million. About 76% of the forest had been converted to agriculture and less than 1% of the old-growth forest remained. In 1937 the Higuaca population was estimated at only 2000 individuals and could only be found in the Luquillo Mountains, the last suitable habitat available to these beautiful parrots. Rigorous population estimates were carried out in the mid-1950s (200 birds) and in the late-1960s the estimate was reduced to 14! Imagine trying to find a date (let alone start a family) with only 13 people to choose from, roughly 50% of which were the wrong sex for procreation. Ouch, hey?

            

Finally, in 1967 the Higuaca were declared endangered and in 1968 the Puerto Rican Parrot Recovery Plan was initiated. This was a joint effort of the Puerto Rico Department of Environmental and Natural Resources (DNR), the Caribbean National Forest and International Institute of Tropical Forestry (USFS), the United States Fish and Wildlife Service (USFWS) Puerto Rican Parrot Field Office and the National Biological Service. A captive breeding program was set up in 1987 and by 1989, the wild population had increased from 14 to 47 birds. Great news, right? Well, it's tough love in the jungle and in the same year, Hurricane Hugo wiped out about 50% of the slowly recovering population.

            

If I might detour away from habitat loss for a paragraph, Higuaca are also threatened by the introduction of exotic parrots such as parakeets and other species of amazon parrot. This includes birds that were introduced into the wild on a large scale in the past ("Hey, parrots are cool, let's get more!"), as well as by pet owners who release domesticated birds into the wild (never, ever do that!). These birds compete (and often out-compete endemic species) for food and precious, scarce habitat. Higuaca have also been (and may still be) killed by collectors and farmers to prevent crop damage. They have also been caught for sale in the pet industry (never, ever buy wild-caught animals!).

            

Ongoing genetic research uses DNA fingerprinting to improve the parrots' genetic diversity. This is done by mating genetically distinct pairs to reduce inbreeding depression (reduced biological fitness as a consequence of breeding between closely related individuals). This is both difficult and important for species that have gone through severe  bottlenecks in which the population has become drastically reduced. This is an extremely important method used in reintroduction programs, often with great success. Yet for the Higuaca, another factor comes into play - “behavioural compatibility”. 

As I pointed out in the example of choosing a procreation partner from the last 6 or 7 humans on earth, Higuaca will not mate just because you throw them in a cage with a genetically distinct bird of the opposite sex. They have to actually like each other. Sucks for science, bonus for freedom of choice.

            

Currently, there are two captive breeding programs in Puerto Rico (Luquillo and Rio Abajo) that focus on maintaining a healthy, viable captive population and successfully reintroducing captive bred birds into the wild. The goal is to establish two free-living wild populations that will be stable at about 500 individuals each.

            

So, with all the thrill and bustle dedicated to the fight to save a beautiful, gregarious and intelligent animal such as the Puerto Rican Parrot, I think the Higuaca have a decent chance. Yet, I would like to point out that it does not always go so well for what we think of as ugly, useless, irritating, un-cuddly and/or anti-social species. I think it is important to remember that we are the most successful species currently inhabiting this planet and we are making life very, very difficult for most of the species we share this very limited space with. I think we should view ourselves as stewards of this environment and strive to repair the damages we have done to all of the species we have negatively impacted, not simply the pretty and cute ones we feel we can relate to! I am now done preaching. Stay tuned for more Z.I. coming to a Manitoban near you in January, 2012.

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For more on the Puerto Rican Parrot research, status, and conservation plans, see Brock and White (1992; http://www.pnas.org/content/89/23/11121.full.pdf) as well as the Puerto Rican Parrot Population Viability Analysis and Recommendations (IUCN; http://www.cbsg.org/cbsg/workshopreports/23/puerto_rican_parrot_pva_final_report_1989.pdf).

Photo courtesy of Mike Morel

Photo courtesy of Mike Morel

Dinocampus coccinellae

Originally published in The Manitoban, 2011

Ah, time to go back to school. If you're anything like me you've probably bought a bunch of new pens and stationary you don't really need and have resolved to read your textbooks and class notes every day, maybe even get up extra early before classes to do something physically healthy. Soon enough though, as the first 2011 semester kicks into high gear, most of us are bound to feel as exhausted as though the life were being sucked right out of us. That's why I have chosen to begin the first fall issue of The Manitoban by telling you about the parasitic wasp Dinocampus coccinellae.

D. coccinellae is found throughout Eurasia and North America and parasitizes numerous species of lady beetles (your friendly, aphid-eating, garden variety “lady bug”). Females mate with males as infrequently as possible. A queen will store the sperm from a single mating for up to one year, using this sperm to fertilize eggs and produce sterile female workers which she uses to build her colony. When the sperm begins to run out, fertile males and females are produced and these disperse to form new colonies. 

Thus, males are rarer than females, although they are produced every once in awhile so they can disperse, mate, and contribute to the genetic diversity of the species via sexual reproduction.

The wasps preferentially parasitize female lady beetles and do so by injecting an egg directly into the beetle's body cavity. Once the egg hatches, the larva eats the lady beetle's own eggs in order to nourish itself and eliminate competition for nutrients. Once the eggs have all been eaten, the larva begins to eat it's lady beetle host's surrounding body tissue, including her reproductive structures.

After about 20 days the larva is ready to emerge. This is achieved by chewing a hole through the lady beetle's body. Then, the larva is ready to spin a coccoon inside which it will metamorphose into an adult wasp. The larva spins its coccoon within the hind limbs of the lady beetle, who is paralyzed, still alive and probably very miserable.

Currently unidentified venoms secreted by the wasp larva are believed to be responsible for the next stage in this ghastly business. The lady beetle, paralyzed with a wasp coccoon under her body, is now also a victim of behavioural modification courtesy of the wasp—the beetle begins to twitch and grasp erratically. This behaviour, along with the familiar red and black colouration of the lady beetle, serves to ward off predators, thus protecting the developing larva.

Many species of parasitic wasps lay eggs in a variety of host species; however, most of these lead to the death of the host. Not so with D. coccinellae, although I bet the lady beetles wish they were dead. After the adult wasp emerges from its coccoon, the effects of paralysis wear off, as does the behavioural control exerted by the larva. Approximately 25% of parasitized lady beetles survive this process and presumably amble off to continue their regular lady beetle duties, albeit with gored reproductive organs and a pretty wicked hole in the undercarriage.

Yet leaving the host alive is not without costs of its own. After all, nothing in life is truly free, right? Researchers at Laboratoire Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (CNRS/IRD/Université Montpellier) and the Université de Montréal were able to show that while wasp larvae guarded by lady beetles are less likely to experience predation, they also lay fewer eggs (Maure et al. 2011). The developing larvae lose resources by keeping the lady beetle alive, resulting in the observed reduction in fecundity of the adult wasps. Maure et al. (2011) showed that while larvae without lady beetle protection are more likely to experience predation, those that survive lay more eggs on average than wasps with a lady beetle bodyguard.

So when the term hits full swing remember—you don't have it half as bad as the spotted lady beetle does!

African Crested Rat

Originally published in The Manitoban August 17, 2011

I hereby nominate the African crested rat, Lophiomys imhausi, for entry into the Baddest-Ass Mammals In the World Hall of Fame. 

Here's why: when these reckless rodents are faced with a ravenous predator ready to rip them to shreds for breakfast they don't even care. They just stand there daring anyone to mess with them. And for good reason—you totally might die if you try eating a crested rat. They are really poisonous!

Crested rats actively seek out Acokanthera schimperi trees, the so-called poison arrow trees traditionally used by certain African tribes for lacing spears and arrows with deadly, elephant-killing poison. The rats chew the bark of the poison arrow tree and lather the poison-rich spit over a specific region of their body. This organic poison contains a compound called ouabain, which inhibits the sodium/potassium pumps embedded in the cell's plasma membrane. 

The sodium pump maintains the electric resting potential of a cell and is essential to normal physiological function. Ouabain is a cardiac glycoside, increasing the force of heart contractions and cardiac output. Left unchecked, ouabain causes death by heart attack.

It is not yet known how the African crested rat is itself able to resist the normally deadly effects of the poison it has usurped for its own defensive purposes. The rats have enlarged salivary glands and stomachs, which may help to process, dilute and detoxify the poison. 

In the medical world, ouabain has been used in small doses to stimulate weak hearts to contract and beat more strongly. Ongoing research exploring the resistance of the rats to A. schimperi's toxic effects may someday be used to treat humans suffering from heart-related illnesses and to better understand the effects and potential uses of other cardiac glycosides.

The African crested rat, native to northeastern Africa, is the only known mammal on earth which actively seeks out and acquires toxins from a plant for use in its own physical defense. Further, the crested rat advertises its borrowed toxicity by performing a specialized display behaviour when confronted by potential predators.

When exposed to a threat, the rat will hold its ground and expose specialized hairs along its flanks by parting the grey fur that normally covers all of its body, revealing a patch of hairs surrounded by strikingly black and white striped fur. These specialized hairs are highly modified and unique to the African crested rat. 

When viewed under a microscope, it can be seen that the hair shafts contain numerous perforations throughout their length, creating a wicking effect which draws the toxin into and along the full length of the hairs. This allows for maximum retention of the deadly poison-laden spit the crested rats coat these hairs with after chewing the poison arrow tree bark. No other animal is believed to possess hairs of this type.

Other taxa, both vertebrate and invertebrate, have shown comparable poison-stealing behaviours. Some sea slugs steal the poisonous stinging cells of cnidarians, which I wrote about in an article on nudibranchs back in August 2009, for example, but this is the first documented instance of a toxic poison theft in a placental (eutherian) mammal. The only other mammal known to perform a similar behaviour is the hedgehog, which applies toxins from the poison glands of certain toads to its quills; however, this merely causes pain and irritation for potential predators, a long way short of the heart-stopping death which can ensue from messing with the African crested rat!

Hercules Beetle

Originally published in The Manitoban, November 10, 2010.

Love 'em or hate 'em, insects are arguably the most important animals on earth. They are often viewed as the most successful animals on the planet. Many insects are essential for the continuation of life on earth as we know it due to their roles as plant pollinators and degraders of waste products left by other organisms, which prevents massive build-up of organic wastes that would otherwise bury the planet in filth. In fact, about two-thirds of all flowering plants are pollinated by insects. 

Insects are also among the most important carriers of and vectors for diseases that kill millions of humans and other economically important mammals annually. Insects are frequently used as models in scientific research—due to their (often) small size and rapid generation times, many can be bred quickly and in large numbers in laboratories for experimentation in various areas, including genetics and medicine. 

Insects have been around for a long time, too—at least 400 million years. For comparison, the first mammals appeared roughly 225 million years ago. Man are there lots of insects! Estimates vary, but it is thought that there are anywhere from six to ten million living species of insects alive today, and these species are grouped into 29 different orders.

Beetles make up the order Coleoptera which, I don't mind telling you, with over 360, 000 described species, is the largest order of insects in the world. In fact, at least 25% of all species rambling about the planet today are beetles. How will you know if you are looking at one of these wonderful, wildly abundant beetles or just some other type of insect, you might want to know? 

Beetles are perhaps most easily recognized by their two sets of wings. One set is the kind of wing you think of when you imagine insects flying (I'm sure you imagine insects flying quite often), while the other set of wings, called elytra, are hardened into a protective, leathery sort of cover that protects the more delicate wings underneath, and may also act as aerofoils. 

The order Coleoptera is amazingly diverse and contains both the largest and some of the smallest insects on the planet today. It is about one of the largest living insects that you, the enthralled reader, are going to learn—the Hercules beetle.

The Hercules beetle, Dynastes hercules, is a type of rhinoceros beetle (subfamily Dynastinae) and is a member of the family Scarabaeidae, the scarab beetles. These Hercs, as I'll call them, are native to South and Central American rainforests and the Lesser Antilles. They range from 50 to 170mm (over 6 inches) in body length—making them one of the world's largest beetles1 and the largest of the six beetles in the genus Dynastes. As if their size weren't impressive enough, male Hercs have two big horns that can be even longer than their body; one that comes from the lower (ventral) portion of the head, curving upward, and another that comes from the thorax at the base of the upper (dorsal) region of the head curving downward, like a pair of pincers or pliers. When males fight, they try to pick one another up with their horns and slam them headfirst to the ground. Females lack horns.

Hercules beetles are not poisonous and they do not attack humans. They mostly just hang out in leaf litter trying to survive the decimation of the rainforest while still managing to look really cool and menacing. They are herbivorous, the larvae eat rotting wood and dung while adults feed on decaying fruit and vegetable matter. Again, just cleaning up the garbage. Really, they are humble civil servants of the rainforest, never complaining about their smelly job or asking for recognition, even though they deserve it.

Hercs can live for about 1.5 years, only 3 to 4 months of which are spent as adults. They are primarily nocturnal and are strongly attracted to light.

My favourite thing about Hercs is that if you correct for size, Hercules beetles are, proportionally, the strongest animals on the planet. They are able to lift up to 850 times their own body weight!

1. The record for world's largest beetle is held by the aptly named Titan beetle, Titanus giganteus, which is a member of the family cerambycidae or longhorn beetles, and reaches 170-175mm in length.

please ignore the pin

 

Water Boatman

Originally published in The Manitoban summer ?? 2011.

Ah – summer in Winnipeg; muggy heat we can't stand after 8 months of zero humidity and freakishly cold winter, freak storms, flooding, mosquitoess, canker worms, E. coli-infested eutrophic lakes – we love it all and by George we'll take it! This sweltering mid-summer issue I would like to tell you about a really cool bug. A bug you can respect: the Water Boatman.

The Water boatman belongs to the insect order Hemiptera, the true bugs (a cold virus is not a bug, a bacterial infection is not a bug, a fly is not a bug). Whether an insect is truly a bug depends on specific details of the wings and mouth parts, which are modified for piercing and sucking, oh my.

Water Boatmen are aquatic and have oar-shaped hind legs used for paddling. They typically inhabit lakes and ponds. These insects do not have gills and must breathe air from the water's surface; however, they frequently carry an air bubble with them during their lengthy underwater adventures and breathe oxygen from within the air bubble!

Over 500 species of water boatman have been identified, more than 100 of which are found in North America. Amazingly, one species in particular, Micronecta scholtzi, has just been credited as the loudest animal on earth! Water boatmen are only about 2.5 millimeters long and yet they create sound at volumes similar to that of a passing freight train or what you would hear sitting front row during a loud orchestra performance. This brain-boggling volume is produced during stridulation, sound produced by rubbing the differently sized ridges of two body parts together. In the case of the water boatman, stridulation is performed by rubbing the penis against the abdomen, which in a sense means the water boatman has the loudest penis in the world (hard to believe, I know).

A recent study by Sueur et al. (2011) reports a peak value of M. scholtzi calls at 100dB SPL (a log ratio between measured sound pressure level and a reference point defined by the threshold of audible hearing for humans). M. scholtzi thus has the highest ratio of dB (decibel) to body size ever recorded, making this water boatman the loudest animal on the planet!

Why do water boatmen need to be so loud? The song produced by stridulation is used to attract females. The males produce a three part song and it is the third part which is the loudest, meant to drown out the songs of competing males. Sueur et al. (2011) propose that the extreme volume achieved by M. scholtzi during stridulation may be the result of runaway sexual selection via intra-male competition.

The idea is this: females localize the acoustic signals produced by loud males more easily than those of quieter males whose songs are masked by the loudest males. Typically, there is a balance between signal volume (high volume = more females) and predation (higher volume = more predators) but in this case, it is possible that the water boatmen either have no predators that use acoustics to find prey or the boatmen are so effectively able to evade these predators that the volume of their signal is not regulated by the negative selection pressure normally imposed by predation (Sueur et al. 2011). In short, the male with the loudest penis gets the most females. 'Nuff said.

Ogopogo

Originally published in The Manitoban, March 30, 2011 (April Fool's special edition)

In British Columbia they have a lot of lakes. The one you should be most concerned with is Lake Okanagan, the home of Ogopogo. Formally recognized by a prominent B.C. scientist in 1872, Ogopogo is a charming aquatic serpent some 20 to 50 feet long and 1 to 3 feet wide with a gruesome horse-shaped head. This serpent-like animal has a long, undulating body with many large spinous processes. These might have evolved to serve as extra sites of muscle attachment for flexion of the long trunk, which would require significant strength to turn quickly in such a viscous medium as water. Ogopogo has dark brown, black, or blue skin and uses counter-shading similar to many fish and other aquatic species. Counter shading is characterized by a lighter epidermal (skin) colouration on the underside of the body and a darker pigmentation on the dorsal surface. This functions to camouflage the animal because, when viewed from above, the dark skin blends in with the dark, deeper waters and when viewed from below, the light skin blends in with the lighter colour of the shallower waters that can be penetrated by the sun’s rays.

Ogopogo is respectfully known to the Aboriginal peoples of the Okanagan area as “N’ha-a-tik”, which roughly translates to “water god” or “water demon”. Those who have encountered this fearsome and secretive animal report escaping near death by boat tippings and general goring by the sacrifice of any other animal they might have with them at the time. 

So let it be known that Ogopogo takes bribes, folks and that is definitely good news for humanity, but bad news for designer dogs going on vacation to “Beautiful British Columbia” this summer.

Ogopogo is still seen today, but less frequently than in the past. This may be due to the animal’s reported penchant for eating horses, which are no longer a popular mode of transportation and hence are less common in the Okanagan region in these technologically advanced times. Of course, environmental factors other than food availability may be playing a role in Ogopogo’s apparent decline. The ever-bearing crush of human development may be partly responsible, as well as nutrient loading and water pollution. 

While the exact reasons for Ogopogo’s decline are not yet known, this beautiful monster’s conservation status is, at least for the time being, quite certain. Ogopogo is protected under provincial legislation and has been so since 1989, “It is illegal to harm, kill, capture or disturb” Ogopogo in British Columbia.

Copyright Edward Fletcher

http://www.bcscc.ca/ogopogo.htm

(this website rules! So does the site “fuck you, penguin” check it out)