Research Project from my Internship in the Amazon - Tarantulas!

A. avicularia Abundance and Behavior on Attalea phalerata Palms in Relation to Artificial Light Proximity at Kawsay Biological Station, Peru

During my internship in the Amazon, I created a research project studying the arboreal Pinktoe tarantulas (Avicularia avicularia). In my project I investigated the abundance and behavior of A. avicularia exposed to artificial light at night versus those in natural darkness. 

My idea for this project sparked when my roommates told me that the palm right in front of our bungalow was called the ‘tarantula tree’ because of the ridiculous number of tarantulas present on it every night. While this may have been a cause for alarm for some people, I was excited to get to see so many wild tarantulas. The first night I went out to look at the tree I found eight tarantulas, far more than anyone had expected. I also found a similarly high number on another palm outside of the common room. Knowing that there simply could not be eight tarantulas on every palm in the area, I began to wonder what made these palms special. This curiosity was driven further when I went out into the jungle at night for the first time on a night walk, I was surprised by the utter lack of tarantulas I found. I would look closely at every palm we passed, peaking around the branches and scanning the tree with my flashlight but found only one the entire night. It was these observations and curiosities that led me to develop my research project. In the end, I was astounded by how much I had learned and uncovered. 

To set up my project I chose a total of six sample sites, all Attalea phalerata palms, three of which were in close proximity to artificial light sources and three of which were in total darkness in the jungle. Each night I collected data I would visit the sample sites to count the tarantulas I could find on them, take information on the individuals I observed, and document their behavior.

My Research Question:

Does the proximity to artificial light sources at the Kawsay research station affect the abundance and behavior of A. avicularia individuals observed on Attalea phalerata palms?

• Do A. avicularia exhibit different levels of exposure and activity on the sample sites exposed to ALAN (artificial light at night)? 

• Are age and sex distributions of A. avicularia individuals different between sample sites exposed to ALAN and those in natural darkness?

• Do the A. avicularia exposed to ALAN (artificial light at night) exhibit altered behavioral responses to stimuli?

  
  

My research aims were to quantify the number of A. avicularia on palm trees near artificial lights versus in darkness, describe and compare movement and exposure levels in both environments, document age and sex of observed tarantulas in both light conditions, and note behavioral responses to stimuli such as light (from flashlights), movement, and sound.I hypothesized, based on my primary observations, that there would be a greater abundance of tarantulas on the sample sites exposed to the artificial light at night from our station and that behavioral responses to stimuli would vary between the subject groups.  

What I found was fascinating. Using analysis done in similar studies performed on orb spiders and my own data I was able to draw conclusions about the possible neurological changes occurring in the tarantulas due to the artificial light and how that is altering their behavior. I had a total of 57 tarantula sightings on the sample sites exposed to artificial light and a total of 15 tarantula sightings on those in natural darkness across 5 nights of data collection. The most interesting differences I found during my observation was in the tarantulas behavior, specifically predator response and light dependent behaviors. In my analysis I found that exposure to artificial light at night suppresses indoleamine melatonin synthesis in the brain. This can impact visual sensory processing and behavioral flexibility. The brains may also devote fewer resources to vision-processing areas when they become less useful in their environment. ALAN can alter predator avoidance behaviors and lead to decreased sensitivity to surroundings and possibly impaired cognition  The tarantulas proximity to ALAN offers ecological tradeoffs, increasing prey abundance but possibly altering their neurology, development, behavior, cognition, and survival strategies.  

For more details into my results, the reference material for my conclusions, my final graphs and statistics, comparative analysis, and in-depth description please look at my attached research presentation slide deck here - https://sienna-homsher.my.canva.site/ Feel free to ask me any questions about my research!

This project was such a joy to work on. Having access to so many other researchers to use as mentors and resources for my project was extremely valuable and I loved the nights going out into the field to collect data. Having a research team with me each night made the experience so much fun and I loved being able to teach people about tarantulas. By the time I left the jungle even my slightly arachnophobic roommate had held a baby tarantula and many people I talked to said they had gained a new appreciation for them. By bringing my passion and knowledge I was able to transform the way many people saw tarantulas and bring new levels of curiosity towards them by bringing them into the field to work with me. I am so grateful to the Kawsay Biological Station for the incredible opportunity to conduct my own research and to everyone who ventured into the jungle with me at night to look for some very large spiders! This experience taught me so much about field research, real-world science, challenging myself, and introduced me to many incredible mentors. Presenting my work to the rest of the station when I was the youngest person there was intimidating but ended up being an incredible experience and gave me further confidence in the work I had done.

With the head researchers Stephanie and Roxanna after my final presentation

A juvenile pinktoe tarantula in its nest

Giving my final presentation