Weeks 6 and 7: Boat Rides with Bushmasters
This afternoon I managed to wash my clothes in gasoline. For context, I usually mix a little bit of bleach into my underwear and socks. The hand-washing process is subpar at best and it gives me a little extra comfort knowing that I am killing anything that soap may have missed. But today the bleach bottle was not full of bleach. Rather, it contained some kind of gasoline-like mixture. You would think that the pungent smell of the liquid would have prevented me from pouring it on my clothes, but by the time I realized, it was too late. During my desperate scramble to deep rinse my clothes, I was stung by a large wasp. It was a chaotic afternoon to say the least. I am a bit worried I am going to smell like car exhaust for the next week. Hopefully I don't spontaneously burst into flames in this crazy heat.
On to less combustible things- herpetology! The umbrella term of herpetology (herps for short) includes snakes, frogs, turtles, lizards, and any other reptiles and amphibians. We have had quite a snake-heavy past couple of weeks and I am excited to talk about some of our captures!
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| Basin tree frog: Hyla lanciformis |
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| Measurements being taken of an Osteocephalus taurinus |
I'll briefly describe the methodology of herp data collection and then detail some of the species we've seen. The herp research we do only occurs at night as the majority of species are nocturnal. We leave for transects around 7 pm and finish anytime between 10 and 11 pm. These nights involve walking slowly along designated transects and plots whilst capturing/recording everything that is seen during this time. We move at a pace of about a kilometer every two hours. This crawl of a walk gives us plenty of time to scan the forest floor, canopy, and intermediate zones. Once a species is spotted, it is identified before grabbing. This is to avoid any potentially dangerous encounters. It is important that we are aware of the venomous species and their look-alikes. The determination of a species can be difficult in some cases and can only be defined by using subtle field marks and scale counts, so it is important to not be too hasty with ids. Once the species has been identified as non-threatening, it is grabbed with a specific hold that is safe for the species. Measurements are taken on each individual and recorded in a data app. These measurements include the height and distance they were spotted from, weight of the individual, body length, age and sex.
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| Jaguar Leaf Frog: Pithecopus palliatus |
I am dedicating an entire section to venomous snakes- we have been lucky enough to find 4 different species in the past couple of weeks! The capture of these snakes is, as you can imagine, handled a bit differently. These snakes are never picked up directly. Rather, they are captured through the use of snake hooks and grabbers and placed in a large bag attached to a pole. The bag is securely tied and the snake is brought back to our station. It is then fed (very gently) through a tube so that the head is held securely in place and out of bite range. Measurements are recorded and it is taken back to the location in which it was originally found for release.
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| These are pictures of our team taking measurements on a Bushmaster (venomous snake species). The first picture is of the tubing process. In the second picture, length measurements are being taken. |
Here are a few of the venomous snakes we have encountered this past month:
South American Bushmaster (Lachesis muta)- This snake is quite infamous in South America for its ambush behavior and venomous bite. A bushmaster bite, if left untreated, can lead to circulatory system failure and death. They are not very common captures- we have only caught one specimen during my stay. The snake that we processed was not actually found on a transect. It was found at a nearby property during a construction operation. There can be a lot of fear surrounding this species due to its dangerous reputation. We were lucky that the Peruvian rangers (guardaboschis) who found it knew not to kill it. After processing this snake, it was boated across the river to an undisturbed area of forest where it could live out its best danger noodle life. I got to be part of the release process. It felt pretty surreal to be on a boat with a bushmaster in the middle of the Amazon rainforest.
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| Bushmaster: Lachesis muta |
Ribbon Coral Snake (Micrurus helleri)- This beautiful snake was spotted on a transect in terrafirma habitat. Its venom is a neurotoxin and can cause an irreversible neuromuscular block in vertebrates. Due to its potentially fatal effect, several other species, often referred to as “false” corals, mimic its coloration to ward off potential predators. We have also caught several of these mimic species during our transects.
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| Ribbon Coral Snake: Micrurus helleri *Photo taken by _al_naturale_ |
Two-striped Forest Pit Viper (Bothrops bilineatus)- this viper species was found about 20 feet up a tree. One of the interns, a Dutch climber, monkeyed his way up the small tree until it bent at an angle in which the snake was reachable. This species is a beautiful, pale green. Its coloration allows it to camouflage in trees and prepare for ambush. Eating frogs, lizards, other snakes, and mammals, these snakes will wiggle their tails to create a lure for their prey before injecting them with venom.
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| Two-striped Forest Pit Viper: Bothrops bilineatus |
Our main other herp captures are frogs. The diversity of webbed little guys here is quite incredible. There are over 70 species in the Tambopata region of Peru. Here are a few of the highlights species I have seen so far:
Pacman frog (Ceratophrys cornuta): I love pacman frogs! I have one at home and it's so fun to see them out in their natural habitat. There are a variety of morphs in this region so individuals can vary a lot in coloration. Pacmans are ambush hunters, burrowing themselves under leaf litter and attacking any small animals passing by. They eat basically anything that can fit in their disproportionately large mouths. Their mouth to body ratio has got to be 50% mouth, maybe even more. It is certainly no mystery why they were named after the ghost-eating arcade character.
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| Pacman hiding under leaf litter in ambush position |
The family Hylidae encompasses a number of different species we have encountered at Secret Forest. This group of frogs tends to be very waxy. This is because these frogs hang out very high up in the trees and therefore, need to be more water conservative. They hold less water and a coating of wax prevents excessive evaporation. Because they retain so much water, their pee tends to be quite acidic. These frogs also commonly lay their eggs on vegetation above water or in vernal pools.
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| Dendropsophus triangulum (giraffe morph) |
A common capture in Hylidae that utilizes these pools is Boana boans. The males of this species make shallow, basin-like depressions on river banks in the dry season. Females will then deposit their eggs in these depressions. As we are in the middle of the dry season, it is fairly easy to see these vernal pools when walking along the river bank.
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| Giant Gladiator Treefrog: Boana boans *Picture taken by _al_naturale_ |
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| Vernal pool belonging to Boana boans with tadpoles |
Another frog species with a unique breeding strategy is Osteocephalus castaneicola. These frogs fill a very specific niche within the forest. They use water-filled Brazil nut trees for reproduction and egg deposition. These Brazil nuts have hard, thick shells that can only be broken into by agouti. Belonging to the same family as capybara, agouti look a bit like large guinea pigs. Agouti carve circular holes into Brazil nuts to access the fruit inside. This allows for the frogs to utilize these broken-into shells as nurseries. I have come across several Brazil nuts that have been opened by agouti and it is really cool to know that these double as little frog homes.
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| Osteocephalus castaneicola *Picture taken by _al_naturale_ |
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| Agouti with Brazil nut *Photo taken from the internet, www.ardeaprints.com |
Another interesting frog species is the Pipa pipa. These guys don't have to find nut shells to store their eggs- they keep them on their backs! Eggs are fertilized, then attached by males onto the female's back. Her skin absorbs them and a cyst-like structure forms over the eggs to fully enclose them until they are ready to hatch. The young then emerge when the mother molts and sheds her skin. It is quite a weird and freaky process. Certainly the worst nightmare for someone with trypophobia but quite an impressive reproductive strategy. Pipa pipa tend to mate during the rainy season so I have not had the privilege of experiencing their baby-filled backs but they have been a cool capture nonetheless.
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| Suriname toad: Pipa pipa |
Hopping back over to our reptilian friends: Caiman!
There are 3 species in this area, all of which I've been lucky enough to get to see. We can often
see their glowing red eyeshine on our night-time boat rides to the other side of the river. We will
occasionally go out for caiman-specific boat rides at night in which the lead coordinator, Chris Ketola,will expertly catch them for study. This process is quite impressive and tricky. The caiman are fairly sensitive to disturbed water, so it is important that Ketola moves quietly and swiftly. Nocturnal river dwellers, caiman ambush their prey by submerging themselves in water and waiting for unsuspecting prey to pass by. They are generalist carnivores, eating birds, small mammals, fish, crustaceans, and basically anything they can get a hold of.
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| Spectacled Caiman: Caiman crocodilus |
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| Smooth-fronted Caiman: Paleosuchus trigonatus |
We also get to see a lot of really beautiful lizards around camp and have seen a couple of unique turtle species but I am giving them an honorable mention for today to avoid making this post too long.
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