Monday, February 20, 2012

Monsters in the Night

For many of us, once the sun goes down it is time to wind down and get ready for some sleep. For much of the natural world, though, it is time to become active. While there are a variety of activity patterns--diurnal, nocturnal, and crepuscular (during dawn and dusk)--we mainly only experience other animals with similar patterns to us.

One way to break from this daytime comfort is to go on a night hike. Not only is it a sensory challenge, but if you brave turning off the flashlight I'm sure you will have to re-confront some fear of the dark. Night hiking let's you experience familiar places through a whole new perspective of shadows, sounds, and imagination.

Or, if you get the chance like I did, you can explore unfamiliar places in an unforgettable manner. When I went to Costa Rica, I befriended a tropical zoologist named Andres who worked at the place I was staying. This friendship led to forays into the dark, damp rain forests of the Osa Peninsula.

Andres scoping out a potential critter. 

Using headlamps we would try and find any animal we could. By using headlamps, it is easier to see eyeshine, a reflection of light off of eyes that makes them appear to glow. The tissue in the eye that is responsible is the tapetum lucidum, and if you have taken a picture with flash of your dog, it is what can give them the glowing eyes. 

Imagine walking along trails in the blackness of night in an exotic rain forest. Beams of light from the headlamp would reflect back little tiny specks of light. Was it a water droplet tricking us? Was it a frog? It moved! Chase it down! Scrambling through brush and leaves, we could only hope to snag the critter before it escaped. Other times, we would catch snoozing lizards who may not have chosen very sneaky hiding places.

 Costa Rica's most common lethal snake, the Fer-de-Lance, using its heat sensing pits
and specially adapted eyes to ambush prey in the dark. (Bothrops asper)

 The Masked treefrog hanging out. (Smilisca phaeota)

The shocked look of a snoozing basilisk. If we made too much noise walking around,
these lizards would jump from their perch in the trees into streams. (Basiliscus basiliscus) 

This anole wins the award for most inconspicuous sleeping spot.  
The highly sophisticated lay-under-a-leaf strategy is being employed here. (Norops polylepis)

While the thrill of the search and the play of lights helped us find many of the critters, there was more to experience than the learning of species new to me. When we were tired, we took a rest near a small waterfall and turned off the headlamps. Resting on a log, conversation dwindled and the darkness continued to settle in. Even with my eyes adjusting, I could barely make out any shapes.


The glass frogs were calling, rain was dripping from leaves, the stream was murmuring, and the immensity of the rain forest became apparent. On this tropical adventure, it was hard to know what creatures were moving unnoticed under the cover of sound and darkness. Perhaps monkeys were creeping through the treetops, or perhaps the ocelot whose claw markings we had seen on a tree was stalking its prey. Whatever was there, my imagination enjoyed them as the monsters in the night. 


If any of the herps pictured interest you, check out Jay M. Savage's The Amphibians and Reptiles of Costa Rica: A Herpetofauna between Two Continents, between Two Seas.

Wednesday, February 8, 2012

The Tale of Two Lovers

Mythology has multiple benefits. For those who believe, it can provide meaning and purpose. For those who study, it can shed light on the way humans perceive their experience and develop values. For those who enjoy, it can share its wisdom but also add another layer of intrigue and beauty to something we may already know about.


Hawaiian mythology is no different, and the tale of two lovers, 'Ohi'a and Lehua, adds a fine component of storytelling to an already fascinating plant: the 'Ohi'a Lehua tree (Metrosideros polymorpha). As the story was shared with me while I was in Hawaii, 'Ohi'a was a demigod who lived in the forest. Being a demigod, 'Ohi'a was highly attractive, and this made him catch the eye of Pele, the goddess of volcanoes and fire. Pele was so smitten by 'Ohi'a , that she approached him and asked for his love and adoration. What she didn't know was that 'Ohi'a already had a lover, Lehua, and so he refused the goddess's advance. Enraged by his disregard for her longing and love, Pele turned 'Ohi'a into a tree.


The goddess Pele and her ever-changing forms. 
Courtesy of marinebio.net and the Jagger Museum at Volcanoes National Park


Lehua, once she discovered the spell that had been cast on her companion, went to Pele and begged for her forgiveness. In her lament, Lehua asked for 'Ohi'a to be turned back to his human form. Pele, despite her power, could not undue the spell, and took pity on Lehua. Thus, she turned Lehua into the red flower that blooms on the 'Ohi'a tree, keeping the two lovers with each other forever. And, as people say, it is looked down upon to pick the flowers from the 'Ohi'a Lehua tree, for you are separating the two lovers from each other once again.


Lehua in her captured form, the red blossom of the ʻOhiʻa Lehua tree.




Ecologically, M. polymorpha is a unique species that is significant in both the final stage of succession, and the pioneering stage of succession. After fresh lava flows or cinder deposits, it is one of the first plants to recolonize a totally decimated area. It's seeds travel particularly well on the wind; therefore, it is able to disperse to remotes parts of the volcanic landscape. On the contrary however, the  'Ohi'a   Lehua plant is also one of the dominant trees in cloud forests and both wet/dry forests. It is unusual for a species to take a lead role both the beginning and the end of succession. Typically, as habitats mature into forests from shrub-lands, the types of plants found in the habitat will shift and change. Indicated in its species epithet, polymorphos, it is not too surprising the plant is so tolerant of varying conditions.Considering poly means "many" and morphos means "forms", the 'Ohi'a Lehua can appear as a tree growing to the height of 100 feet or as a shrub.




The plant also has other useful attributes. For instance, in order to
absorb more water from the moisture in the air, the tree will
grow aerial roots that will hang from the branches.


While the tree had many historic uses--construction, tools, weapons, boats--currently it is most renowned for its honey. So, if in need of some grand romance this Valentine's day, feel free to tell your sweet honey bee how your love is legendary like that of the 'Ohi'a Lehua tree. (Disclaimer: results may vary)


A handy resource about this species can be found at Pacific Island Agroforestry.

Wednesday, February 1, 2012

Normal Mountain Activities

Well, this is the first post of what hopefully will become a good record of the adventures I've gotten to do as a budding ecologist (and the lessons I've learned from them). I'm not sure how frequent these posts will be, but nonetheless, stay tuned.


This past summer, I did what the average person does in the mountains of North Carolina--I looked for giant salamanders. Along with folks from the NC Wildlife Commission and the NC Zoo, surveys were conducted to find the giant salamanders. The elusive critter the surveys were aimed at was the Hellbender (Cryptobranchus alliganiensis). Don't worry, this isn't a monster that can manipulate the fires of the inferno (perhaps I've watched too many episodes of Avatar the Last Airbender). Their genus name is derived from kryptos "hidden" and branchos "gills". This accurately describes the folds of skin that cover the areas of oxygen exchange. Perhaps what common name you might enjoy even more is the "Snot Otter." These creatures win no conventional beauty contests.

Hellbenders occupy swift moving streams in the Appalachian and Ozark mountains
as well as eastern parts of the Mississippi drainage.

These large, ancient salamanders can get up to 74 cm (29 in) when adults. In the clean waters they inhabit, Hellbenders stay hidden under rocks on the bottom, and they feed on anything from insects to crayfish. When competition is stiff or territory is trespassed, they will also eat each other. 


Awaiting size measurements

Hellbenders are important because of their role in the stream ecosystem, but they are also significant because they are "indicator" species. When water quality continues to decline, these dwellers of the creek begin to disappear. As you can imagine with the ever-expanding reach of human development, the streams Hellbenders inhabit are becoming dirty and chemically unfit for them to survive. This has led to drastic declines in Hellbender populations across their geographic distribution. They are the canary in the coal mine as far as these bodies of water are concerned.

The surveys I participated in recorded a  variety of information to determine the age, gender, and health of individuals that made up a population. Along with Passive Integrated Transponders (PIT) tags, this information helps monitor and assess the status of the population. PIT tags are tiny devices (essentially RFID chips) that are carefully inserted into the Hellbenders, and, with a tag reader, researchers merely have to walk along the stream bank to survey for past individuals. Data like this can give a sense of how long individuals survive as well as how the demographics of the population are changing.

So, my experience with these fascinating salamanders involved the fun task of snorkeling in mountain streams. As it was only the second time I've been snorkeling, the plain act of snorkeling was exciting in and of itself. Now, on top of that, I was searching for rare, giant salamanders. Never have rocks and boulders looked so much like presents to be unwrapped, for it was definitely a surprise to lift a rock and see these creatures looking back up at you! Catching a Hellbender is a tricky ordeal too. It's like trying to grab a wet bar of soap, except Hellbenders are even slimier and more slippery than soap--not too mention they tried their best wriggle out of your hands.

Never will mountain streams be perceived the same way again

Hopefully as more attention gets drawn to Hellbenders, more people will be concerned about the conservation of their habitat--a habitat that is home to numerous other salamander species, unique fish, and other wildlife.





For more information look at hellbenders.org or see Salamanders of the United States and Canada by James Petranka.