Author Archives: Forman Rainforest Project

Mammal Population Survey in Lowlands and Highlands of Costa Rica


In the deep jungles of Costa Rica, a highschool called Forman has a program we like to call Rainforest. This program has been active for the past 27 years collecting data on the ecosystem of Costa Rica and sending it to people who are using it to protect the environment. We were split into three teams but this is the Mammals team of 2020. For the past 25 years we have been going to the same location, until this year. We wanted to find the difference in ecosystems in low elevations and high elevations. And the findings were not just breathtaking but fascinating as well. We traveled to Tirimbina in the lowlands and Cuerici in the mountains and the findings were very interesting. We captured footage with our trail cameras of big cats and small mammals. This year was the year with the most findings by trail cameras in all of our 27 years of doing research. We made a plaster footprint from a rare mammal cat we found. We found scat that led to the conclusion that we had found the scat of an Oncilla. How we concluded that it was an Oncilla, you will have to read the article as to how we did it. If you would like to find out more about our research, then take a peek at our research.



We need to gather more data on what is in the Sarapiqui region of the rainforest. In prior years our project has recorded signs of Leopard, Tayassu tajacu, Puma, Ossolats, Margay, Jaguars, and the Tapirus bairdii in the form of trail cameras and plaster prints. Another organization has done some studies that can be found here. Also, track large cats and their movements. We hope to have this data to share with Panthera to prevent poaching of there beautiful cats within the Costa Rican Rainforest. Our data on cats will hopefully give us a better understanding of where large cats move through and how we can prevent poaching. We share our data with Panthera, a nonprofit conservational organization dedicated to protecting larg cats. This is important because majestic hunters like Jaguars are crucial to the ecosystem and to keep the lushes rainforest alive. But it is also crucial that we protect these animals from extinction. Especially when there are so few of them left, and we don’t want yet another animal to go into the extinct section. We have also sighted non-large cat mammals such as Basyprocata punctata, Nasua nasua, Philander opossum, Tapirus bairdii, and Eira barbara. We hope to continue our data on our field study of the area where we use traps to catch small rodents for archiving. Our rodents project could reveal more data on the effect of shrinking natural habitats as logging increases within the area. Rodents account for the majority of secondary consumer’s food supply. There has been other research done by other individuals on bats in Costa Rica that can be found here. These are the hopes and goals of the Mammals Team.




How to decide where

We suggest that you place the camera attached to a tree using the included strap. The camera should be placed near an area of high traffic (river bridge, trales, of water supplies). 

How to set

The camera should not be placed towards objects that may move because this will trigger false pictures (moving water, windy grass, or windy branches). When setting, use a white board to take a picture of the location and time to keep pictures in order. On the white board we would record in order the camera number, date/time (military), altitude, longitude, latitude, scientific name, and direction lens is facing.

How to retrieve/ review

When retrieving the camera make sure to bring an umbrella incase of rain. This umbrella will ad in keeping the camera dry while opening it in the rain. Make sure to use the same white board to take an ending picture. Make sure that camera is off, and that there is no damage to the camera.

What to Record

REC# Date/ Time TRap # TAXA Sex/ Age Mark Mass HB TV EAR HF FA TR Perf Preg Mam NIps Obs Comments



Mist Nets

Mist nets are set for population inventory of bats.

Where/when to set

Set bats nets following the same methods as the birds team but at nite due to bates being nocturnal. On top of birds thought you should make sure to never set nets in the rain due to this leading to hypothermia and drowning.

How to take out

Bats should be carefully taken out one my one wings first then head. After being taken out, it should be stored in a breathable bag. While taking bats out make sure to give them something to bite on.

What to record

REC# Date/ Time TRap # TAXA Sex/ Age Mark Mass HB TV EAR HF FA TR Perf Preg Mam NIps Obs Comments




Live Traps ( Terrestrial mammals)

Live traps for mammals that do not fly we use Havahart traps. 

       *When the animal’s steps on the bait pan, it will trigger doors on both sides to automatically shut without harming the animal in any way shape or form. 

        *Never use Snap traps or Sticky traps because they can cause harm to the animal. If you are trying to catch nocturnal animals then set the traps in the late afternoon then check on them first thing in the morning. 

        * Never leave traps open when the temperature drops below 10c

How to hide traps 

Put some leaves and twigs on the traps to hide them in plain sight that are on the ground. As for flying mammals like bats, the fishing line net traps are designed to go against their echolocation and trick them to be tangled but not harmed.

How to care for traps 

Check on them every few hours or so. Make sure to never set traps if it is above 24oC or below  10oC. Always set in the shade due to a fear of overheating.

How to decide where to set up 

A place where there is high traffic like on a log on a stream. Or in plain sight like on in relatively tall grass. But once placed make sure you take note or pin point where on your map your trap is placed.

What to use to bait the animals

A common bait is rolled oats mixed with peanut butter for the smell, or even fish. 

How to extract land mammals from traps

For a box trap you open one side with gloves on and encourage the animal to go into the bag. Once in the bag tie up the top and treat it with care but hold the bag with one hand on the top and the other right above it with the bag suspended in the air. The animals will most likely be terrified so it will squirm and try to fight its way out. Remember to wear gloves. 

What do you do once you have analyzed the animal?

Go back to the location that you captured the animal, make sure there is no harm to it then release it where it was captured. 

What to record

REC# Date/ Time TRap # TAXA Sex/ Age Mark Mass HB TV EAR HF FA TR Perf Preg Mam NIps Obs Comments



Mist Nets( Bat species caught)

    • Tirimbina


  • Myotis riparius
  • Carollia castanea
  • Artibeus phaeotis
  • Ectophylla alba (3)
  • Lionycteris spurrelli 


    • Curerici


  • Montane oxynotus
  • Sturnira lilium



    • Tirimbina


  • Potos flavus



  • Curerici
    • Believed Puma yagouaroundi (Based off of footprint)
    • Believed Leopardus tigrinus or Leopardus wiedii (The scat we dissected had a  Talamancan Shrew(Cryptotis gracilis)in it.  The IUCN lists this species as vulnerable.  This is listed as a common food for an Oncilla but the Margay also has a similar diet as well.)

Camera Traps

    • Tirimbina


  • Dasyprocta punctata
  • Nasua narica
  • Eira barbara 
  • Leopardus pardalis
  • Puma concolor




Our bat data is going to the reservations we stayed at, Tirimbina & Cuerici, it is also going to iNaturalist. Our Mammals data is going to Wildlife Insights, INaturalist, and our Cats data is going to Panthera. We had astonishing results in Tirimbina and were excited to compare it to the highlands. The lack of camera trap sightings in Cuerici we attribute to needing more time there to find the smaller population of wild cats.

All the terrestrial species caught on camera are all listed Least Concern by the IUCN.  All but the 

Central American Agouti ( Dasyprocta punctata) populations are decreasing. Dasyprocta population remain stable.


Literary Cites

  1. Author Andrew L. Mack, Debra D. Wright, Pages 1/143, Training Manual for Field Biology Papua New Guinea 
  2. Bushnell Camera Trap Guide Book 
  3. Author Fiona Reid, Pages 1/334, A Field Guide To Mammals of Central America and South East Mexico




Appendix I Appendix II Appendix III
Puma Tyra Agouti
Ocelot  Coatimundi 


Red List

Least Concerned Near Threatened
ChestNut Short Tailed Bat Hondorian White Bat
Riparian Mitosis Bat 
Myotis Oxytus 
Pygmy Fruit-Eating Bat
Little Yellow Shouldered Bat
ChestNut Long Tailed Bat



Thank you to Wendy Welshans, Loren Hazard, Sean Graesser, Dr. Alex Shepack, Dr. Twan Leeneers, and Viviana Gutirrez for making this trip possible and giving us this experience that we are going to remember for the rest of our lifetime. Thank you again from the Rainforest team.

Variance in Herpetofauna populations of Costa Rica in regard to altitude: the Highlands vs. the Lowlands


The Forman 2020 reptiles and amphibian team initial questions included what species would be found at 590 feet (180 meters) vs. 9500 feet (2895 meters) in elevation. The second question compared the concentration and deadly effect of chytrid fungus (Batrachochytrium dendrobatidis (Bd) on amphibian species at these elevations. The team initially planned on hiking daily to collect samples and specimens and place them safely in plastic bags.. These samples would be brought back to the research station to be processed and recorded. After being measured and identified of all pertinent data the samples were returned to their habitat. In practice the team followed all of the procedures that were initially planned. Our results suggest a high level of variability in species and populations because of elevation and other environmental variables.



The Reptiles and Amphibians team is part of the 2020 Forman Rainforest Project. The team is: studying populations of reptiles and amphibians, and the effects of chytrid fungus on amphibian populations as well as monitoring reptile populations in the rainforest of Costa Rica. the reptile and amphibian team will be traveling to two new locations. Both are at different elevations and will provide new data that has gone un-recorded in those regions. On March 3rd  2019  the research team will be arriving at the first field station at Tirimbina in the lowlands. The team will be running operations out of this location for four days. Then we will travel to another research station in the Montane rainforest, and stay there for seven days. For the past twenty years our tropical ecology team has been going to a location in the Pre-Montane rainforest.We hope that by going to these two new locations will provide new data to our universities, and uncover new patterns and trends to save the reptiles and amphibians. 



Throughout the entire  two-week period the 2020 Reps and Amps team will go on daily hikes, collecting specimens and filling out data sheets of information on the animal’s catch. We will be filling out the data sheets completely, and adding extra note worthy details and maybe pictures. Some methods of collection include capturing by hand, by using a rubber band, by noose, or by pitfall trap. Methods of observation could be but are not limited to open observation, observation through binoculars, or observation of vocalizations. These approaches are effective in several different ways. The procedures executed during the expedition, however primitive, were very effective. We spent much of the day and night hiking, in search, for herps

Using plastic ziplock bags we stored the specimens with ample air before processing.



Tirimbina ( Elevation 590’-721’)

In Tirimbina we caught a total of:

51 animals

37 different species

17 reptile species to 20 amphibian species

List of species in Tirimbina:

  • Imantodes cenchoa (Common Blunt Headed Vine Snake)
  • Ninia sebae (Red Coffee Snake)
  • Incilius melanochlorus (Wet Forest Toad)
  • Rana warszewitschii (Brilliant Forest Frog)
  • Corytophanes cristatus (Helmeted Iguana)
  • Craugastor mimus (Tilaran Robber Frog)
  • Craugastor megacephalus (Broad Headed Rain Frog)
  • Scinax elaeochrous (Olive Tree Frog)
  • Smilisca puma (Tawny Tree Frog)
  • Diasporus diastema (Common Tink Frog)
  • Craugastor persimilis (Leaf Litter Frog)
  • Anolis limifrons (Slender Anole)
  • Oophaga pumilio (Strawberry Dart Frog)
  • Rhinella horribilis (Cane toad)
  • Anolis humilis (Brown Anole)
  • Holcosus festivus (Central American Whiptail)
  • Iguana iguana (Green Iguana)
  • Basiliscus vittatus (Striped Basilisk)
  • Leptodactylus melanonotus (Black Backed Frog)
  • Lepidodactylus lugubris (Mourning Gecko)
  • Hemidactylus Frenatus (Common House Gecko)
  • Craugastor bransfordii (Bansford Litter Frog)
  • Incilius melanochlorus (Atlantic Forest Toad)
  • Scincella cherrie (Brown Forest Skink)
  • Leptodeira septentrionalis (Northern Cat Eyed Snake)
  • Pristimantis cerasinus (Clay Colored Rain Frog)
  • Anolis Carpenteri (Green Slender Anole)
  • Rhaebo Haematiticus (Smooth Skin Toad)
  • Espadarans prosoblepon (Emerald Glass Frog)
  • Porthidium nasutum (Hognose Viper)
  • Anolis Capito (Pug Nose Anole)
  • Enulius sclateri (Sock Headed Snake)
  • Dendrobates auratus (Green and Black Poison Dart Frog)
  • Anolis oxylophus (Stream Anole)
  • Craugastor fitzingeri (Common Rain Frog)
  • Teratohyla pulverata (Dusty Glass Frog)
  • Pristimantis ridens (Pigmy Rain Frog)


Cuerici (Elevation 8500’)

In Cuerici we caught a total of:

7 animals

3 different species

2 reptile species and 1 amphibian species

List of species from Cuerici:

  • Sceloporus malachiticus (Green Spiny Lizard)
  • Anolis Alocomyos (Talamanca Cloud Forest Anole)
  • Isthmohyla pictipes (Dark Footed Tree Frog)


Study on Sceloporus malachiticus:

We did not record enough data to yield any conclusions (having only three recorded sightings). 

On the map below, our sighting were at:

  • Bottom left of Alberto’s House (in a wall)
  • Between Green House and Classroom (a large decaying stump of a tree)
  • Bottom right of Juvenile Trout Pond (a medium size stump of a tree)


Comments on Isthmohyla pictipes:

Swabs to test for Chytrid Fungus:

Not yet reported


Gender ratio:



Link to Data Sheets

List of Species 



Our decision to do night observation and collection payed off extremely in our first and second location in different ways. Our initial night doing observation and collection was extremely successful, and yielded 18 different herpetofauna alone.  Over the next four days in Tirimbina (at ~180 meters), we caught a total of 34 herpetofauna. In total, we caught 51 herpetofauna or 37 species. 

As opposed to our first location, in Cuertici (~2900 meters), we did not find that many herpetofauna. Instead, we caught and observed a total of 2 reptiles and 1 amphibian species over the course of 6 days (One of which hasn’t been reported in about 40 years!). As you can see from our results, it was very apparent that the elevation, type of rainforest, temperature, and exposure, has a huge effect on the amount and type of species. Although one of our research elements was focused on chytrid fungus (Batrachochytrium dendrobatidis), we did not do any chytrid testing until Cuerici. On our 3rd night, when the Dark-Footed Tree Frog (Isthmohyla pictipes was discovered by Twan Leenders and Alex Shepack, we took swabs of the frogs to be sent back to a lab, in Florida International University, and to be tested for chytrid fungus. Results have not been made publicly available at this time. It’s important to test for chytrid fungus because it could show us possible immunities, lifestyles that prevent it, or possible areas that chytrid fungus have not affected yet.

All in all, we hope that our report, sheds a sliver of light into what is going on in the rainforests in Costa Rica. As we discovered, each location has a possibility of yielding something extraordinary. In our research team, we could have never expected our results to be so successful and exciting. 

Thank you Dr. Twan Leenders and Dr. Alex Shepack for being our group leaders! We have learned so much because of these two, so much so that there are reports on interests into similar future careers. They continuously inspired us through our long hikes, and lended their knowledge and experience, to us a successful team. As a result, we discovered and enjoyed the wonders of being a field researcher. Also thank you to Wendy Welshans for providing us with this amazing class and making this trip possible for us high school students.


Literature Cited

*Training Manual for field Biologists in Papua New Guinea by Andrew L. Mack and Debra D. Wright

*Reptiles and Amphibians of Costa Rica by Twan Leenders

*Amphibians of Costa Rica by Twan Leenders

*Reptiles of Costa Rica by Twan Leenders


Reptiles and Amphibian Team 2019-20

By Celia Stevens, Rex Mack, Jeremiah Cooney

What is the Reptile and Amphibians team?

The Reps and Amps (short for Reptiles and Amphibians) team is one of the longest running studies involving the Forman Rainforest Project, collecting data in the rainforests in Costa Rica. Hopefully, with the data that we collect about reptiles and amphibians, we can contribute to the study (and hopefully the cure) to chytrid fungus. 

What is Chytrid Fungus? 

Chytrid Fungus, more specifically Bd, is a chytrid fungus that appears to be capable of infecting most of the world’s amphibian species. Many of those species that develop the disease are linked to devastating population declines and species extinctions.

Bd is a very important chytrid fungus because it appears to be capable of infecting most of the world’s approximately 6,000 amphibian species and many of those species develop the disease chytridiomycosis which is linked to devastating population declines and species extinctions

In fact, infection with Bd has been called “the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted, and it’s propensity to drive them to extinction (Gascon et al, 2007). Amphibian population declines due to chytridiomycosis can occur very rapidly— sometimes over a just a few weeks (Lips et al., 2006) and disproportionately eliminate species that are rare, specialized and endemic (e.g. those species that are most unique) (Smith et al., 2009).

Infection with Bd occurs inside the cells of the outer skin layers that contain large amounts of a protein called “keratin”. Keratin is the material that makes the outside of the skin tough and resistant to injury and is also what hair, feathers and claws are made of. With chytridiomycosis, the skin becomes very thick due to a microscopic change in the skin that pathologists call “hyperplasia and hyperkeratosis”. These changes in the skin are deadly to amphibians because— unlike most other animals— amphibians “drink” water and absorb important salts (electrolytes) like sodium and potassium through the skin and not through the mouth. Abnormal electrolyte levels as the result of Bd-damaged skin cause the heart to stop beating and the death of the animal (Voyles et al., 2009).


2020 Mammals Team

We are excited to continue the excellent work of the Forman Rainforest Project in the Costa Rican rainforest.

In 2020, we plan to gather more data on what is in the Sarapiqui region of the rainforest. In prior years our project has recorded signs of Leopard, Tayassu tajacu, Puma, Ocelots, Margay, Jaguars, and the Tapirus bairdii in the form of trail cameras and plaster prints. Another organization has done some studies that can be found here.

We will also track large cats and their movements. We hope to have this data to share with Panthera, a nonprofit conservational organization dedicated to protecting large cats, to prevent poaching of the beautiful cats within the Costa Rican Rainforest. Our data on cats will hopefully give us a better understanding of which areas large cats move through and how we can prevent poaching.  This is important because majestic hunters like Jaguars are crucial to the ecosystem and to keep the rainforest alive. But it is also crucial that we protect these animals from extinction as there are so few of them left.   

We have also sighted non-large cat mammals such as Basyprocata punctata, Nasua nasua, Philander opossum, and Eira barbara. We hope to continue collecting data on our field study of the area where we use traps to catch small rodents for archiving. Our rodents project could reveal more data on the effect of shrinking natural habitats as logging increases within the area.

Rodents account for the majority of secondary consumer’s food supply. There has been other research done by other individuals on bats in Costa Rica that can be found here. In our study, our bat findings have largely focused on Melanomys caliginous. We hope to find more data on the Melanomys caliginous bats. Our bat’s data might reveal a population census.

These are the hopes and goals of the 2020 Mammals Team.

Dissertation Day

Listen to the Rainforest Project present their findings on Friday, May 3rd from 8:30am-2:00pm. Watch it LIVE here!

Reps + Amps Methodology

In the rainforest we will be studying Chytrid fungus and we will be using different methods to track reptiles and amphibians that have survived the major wave of the disease that has moved North from South America and is counting through Central America and into North America.

Throughout the two-week period the 2019 Reps and Amps team went on daily hikes, collecting specimens and filling out data sheets of information on the animals that we caught. The data sheets require specific information on the animals and the conditions of their capture. Some conditions that need to be recorded upon capture are country, province, locality, elevation, location description, date, weather, percent cloud cover, time, and air temperature. The information on the actual animal includes species (latin name), common name, sex, age, weight,coloration, snout-vent length, total length, and activity. Other noteworthy details are method of collection/observation, and any photographic images.Some methods of collection include capturing by hand, by using a rubber band, by noose, or by pitfall trap. Methods of observation could be but are not limited to open observation, observation through binoculars, or observation of vocalizations. These approaches are effective in several different ways. The procedures executed during the expedition, however primitive, were very effective. The team would do at least two hikes

Every day… one before noon and one after dark. The difference in temperatures and light

intensity allowed the team to observe a wider variety of species. Most species were collected by hand and put in Ziploc bags to be carried back to camp and catalogued. The more venomous species were collected using a snake hook and were put in a snake bag. Between collection and cataloguing, the specimens were kept in their Ziploc bags and hung on a clothesline (this method does not harm the animals when executed properly).This allowed for organization and easy access to the species needed. They would wait on the line until they were catalogued and photographed, then they would be released in the same spots they were collected at.

For the safety of the animals, the team tried to record and photograph each specimen within twenty-four hours of their capture. The more venomous species would be released by the team leader (Twan Leenders) at an undisclosed location. The sensitive species such as the Crowned Tree Frog would be released close to the location where they were found so that they would not be disturbed. To record the data on the species, the team would first identify it through noting key features and looking in the field guides for a match. When the species was known, the team would take notes on the conditions and characteristics listed above (data sheets). The data compiled from these individual observations is relevant to the observation of trends. This data can then be compared to the observations of past teams in order to detect long-term trends in species population, distribution, and behavior.


The 2019 Bird Team’s Methods

The Bird Team’s Methods

In the Costa Rican rainforest, the Birds Team uses mist nets to catch a variety of birds throughout each day. Our goal is to catch and tag local birds, as well as track migratory bird patterns. In order to set up these mist nets, we use the following: Two Stakes, Two Steel Rebars, A Mist Net, Rope, and Two poles. The nets we use are not tight, which allows the birds to fall into pockets of the net without injuring them, and the threads in the mist net is fine. They’re is a specific way to set up each net to make sure they cannot be blown away. The stakes use be driven deep enough that rain can’t wash it away with the mud, and to ensure a larger bird does not fly through the net and take off with it.

  1. Hammer both steel rebar’s firmly into the ground.
  2. Place the pan also on top of the poles
  3. Put the poles on top of the rebar
  4. Make sure the nets are not drawn taut and are not touching the ground
  5. Hammer two stakes into the ground on opposite sides of the poles
  6. Tie a knot between each stake to a pole to keep it in place to ensure the net does not fall over

2019 Bioacoustics Team

Methods for Bioacoustics

During the research endeavor at Costa Rica, the Bioacoustics Team will be conducting several methods and techniques to gather information of the sound which animals emit. Here are the list of the methods we will use to collect the data in the rainforest:

“Lie and Wait”

For this method, we will find a place with a lot of animal traffic and wait upon until the animals to surface out. It is crucial for the animals to be accustomed to our presence because if we do not, the sound in which the animals emit will be preferably different from what they usually produce. Additionally, most of the “lie and wait”s happen at night, meaning we would be sitting in the dark, bringing some tarps to sit on, and wait until we hear our target animal or animals making noises.

Alarm Call

Several of the sounds are to be recorded through a method called alarm call – a warning cry made by a bird or other animal when startled. For this technique, we will cooperate with the Birds Team; the Birds Team would catch the birds using their net and the Bioacoustics Team would record the birds’ alarm calls congruently.

Voice Announcements

Voice announcements are simply short disclosures at the end of every recording. Within each announcement, the recordist describes themselves and important information about the recording, such as species, current date and time, location, behavioral context of sound, weather or not playback used, number of individuals involved, prominent background species, habitat description, weather, and recording equipment. Voice announcements are crucial because they provide the most relevant information of sound identification on the spot and prevent from losing track of the essential data of the recording.

For instance, a sample voice recording, which will be made this trip, will be similar to the following: “That was a common Pauraque (Nyctidromus albicollis). The date is the 4th of March 2018, and the time is 22:00. The location is El Plastico, Selvatica, Costa Rica. That was a night call. Playback was not used. Two people are involved in the recording, and they are Wendy Welshans and Sam Seo. Background noises are the local birds and insects. The habitat is a tropical rainforest. The recording equipment used is the shotgun mic.”

To cover and remember all of these aspects of voice announcements, we will tape a list of bullet points inside of the microphone case.


Playback is not a method we use to record, but rather, a way to induce potential recordings. For example, playbacks are exercised by playing a recording of an animal in hopes of hearing a response back from the target animal in the vicinity. Though, this is a common way to prompt responses from birds, similar to the previous year, we will not use playback because it often confuses the listeners with the sound of a playback and the sound of a new recording.

Data Entry

At the end of each day, the Bioacoustics Team will enter all of the information, including the voice announcements, into a data sheet on the Bioacoustics Team’s computer. By doing so, we will be able to organize our information in a productive manner and set an agenda, goals for the next day.

Journal entry

Besides the data entry which we organize at the end of each day, the Bioacoustics Team will also write journal entries in our Rainforest notebooks to give a further index, summary of the event, discovery, and day. The format of the journal entry is as the following: date, name, location, collaborators, habitat, weather, description of activities, and important biological observations.

A sample daily journal looks like the following: “15, June 2010, Andi Mack. Gahavasuka Provincial Park, EHP (06 °00’53’’ S, 145° 24’45’’E) 2400 m asl. Mid montane forest as described in detail on 13 April 2010. Overcast all day, temp 15~29 C, light mist in the early morning, heavy rain at 1600h. Conducted mist-netting surveys with Paul Igag and Banak Gamui. Opened 15 12, nets along the main trail at 0600 and tended them for birds until closing at 1530 prior to heavy rain. 28 birds captured and banded, noted on data sheets.”


2019 Mammals Team

The 2019 Mammals Team is excited about tracking mammals this year in Costa Rica.

In 2017, we were asked to conduct studies of Big Cats. We will be doing this by use of trail cameras. Approximately 20 of these cameras will be set up around our reserve to keep track of GPS locations of Ocelots, Pumas, Margays, and Jaguars to name a few. Our data will go into the database at Panthera; the largest Big Cat conservation organization.

Also we will be keeping track of rare, smaller mammals by use of havahart traps and Radio telemetry.

We will also be using plaster of paris to make solid samples of footprints of rare and endangered mammals.

Below are some instructions for our equipment:

Receiver (The unit attached to the antenna that receives signals from the transmitter the instructions)

  1. Put  the cable into the ANT slot
  2. Set the channel to the key number
  3. Set the fine tune to 1
  4. Flip switches on
  5. Adjust the fine tune

Transmitter  (The unit the mammal wears as a collar)

  1. Use the sound of the receiver to guide you to the transmitter

Camera traps

  1. Once the camera is has batters and a SD card in it turn it on
  2. Select weather you want it to take photos( down on the D pad), videos (up on the D pad) while in setup mode
  3. Switch the camera to on
  4. You will have a 10 second grace period to close it, put the camera in place, and leave the area
  5. To set the camera in place use the straps in the back to tie it up in the desired direction
  6. The camera will take photos when the motion sensor is set off
  7. Mark the location of the camera

Plaster of Paris

  1. Slowly mix the powder with water in a separate container
  2. Stir the mixture( make sure there are no air bubbles)
  3. Pour the mixture into the animal print
  4. Let it settle
  5. Slowly dig it up

Effects of Barometric Pressure and Temperature on the Tensile Strength of Nephila Clavipes’ Silk


This paper focuses on the strength of Golden Orb Weaver (Nephila clavipes) silk. Furthermore, this research is dedicated to scientifically finding the root of variation in it’s incredible strength with an ultimate goal of using the silk as a sustainable resource in lue of cattle ranching.  While the research into the strength of this species silk has spanned over a decade for the Forman RainForest Project, the extreme variability lends itself to monitoring atmospheric condition such as barometric pressure and temperature at the time of silking each spider.


The 2018 Spider Silk Team is led by Wendy Welshans, who is assisted by Jason Epstein, a student researcher. The Spider Silk Team has a long history, which started in 1997 as an “accident” when a student silked a Golden Orb Weaver using nothing but his hands and a coke bottle! The program has since evolved to possess two groundbreaking patents to its name as well as becoming the life’s work of Wendy Welshans.

The Nephila Clavipes, common name Golden Orb Weaver, is native to the southern states in the United States of America as well as Latin America.  In fact, it is heavily present in Costa Rica, where the majority of the team’s research is done. Spider silk has many positive qualities: it does not cause immune responses when implanted in the human body– meaning the silk could be used for artificial tendons, tissue scaffolding, or even nerve regrowth; the Nephila’s silk is at least three times stronger than Kevlar, and more elastic– meaning silk could be used as ballistics protection (Cheryl Hayashi, 2010). To further attest to its strength, in 2017, the Spider Team conducted tensile strength testing of spider silk in 250 strand bundles, which are still functionally weightless but have an average of 6.21 Newtons, attesting to its strength.

The overall goal of the Spider Team, besides carefully documenting the amazing properties of one of the strongest natural fibers of the world, is to create a sustainable resource in the tropics of the rainforest that can replace cattle ranching. Harvesting spider silk would utilize land that would otherwise need to be destroyed. The Nephila spider must live in its natural habitat to produce quality silk. The flora in its home, however, is a veritable treasure trove as well. Interestingly, almost 25% of prescription drugs are made using ingredients derived from plants (James A. Duke, 1997), and yet only 1% of plants in the most biodiverse area on earth have been studied.  Preserving the rainforest allows for the study of potential life-saving drugs. Adoption of silking gives access to a valuable animal product as well as flora that can be worth more than gold.

The Forman Rainforest Project had its first official expedition in the spring of 1992. A year later in 1993, the arachnid project was introduced where student researchers studied Argiope spiders as well as the Golden Orb Weaver (Nephila Clavipes). Originally, the arachnid project focused on studying web anatomy and its construction. It was not until Bryan Sullivan (arachnid project 1997) and the “coke bottle incident” did spider silk itself pique interest: Bryan was handling a golden orb weaver when it laid a sticky disc– a sticky glob of silk that a spider drops to anchor its silk line– on Bryan’s hand and continued to let out dragline, the strongest type of silk the spider produces; Bryan started to wrap the silk around a coke bottle and noticed its incredible strength. It would not be until 2002 that the Forman Spider Team was officially founded.


Once the team lands in Costa Rica and everything is settled, a trek to El Plastico commences. The Spider Team collects the Nephila Clavipes in transit; the Nephila clavipes is plentiful in the area. The method employed in capturing the spiders resembles the hand placement one has in order to make a shadow puppet of a crocodile. A team member swiftly closes their hands around the spider. An important note is that the researcher should not be concerned about disturbing the web when apprehending the spider. Another thing to note is when collecting the spiders, the researcher needs only target the females, which are easily identified because they are much bigger than the males, of which there is usually one on the web. After apprehending the spider, the researcher simply traps them in a bag, typically the Spider Team uses an onion bag acquired in town. One should not worry about multiple spiders in the bag cannibalizing each other. It has has occurred that in the bag, one spider has eaten another, but they have been rare occurrences.

Once the team arrives at El Plastico, it is important to immediately set the spiders in their habitat. At the El Plastico basecamp, there is a permanent habitat for the spiders constructed out of wood. It is simply open squares situated vertically. After a team member puts a spider in its own box, its instincts will take over and it should set up a web in that location without any further encouragement. A small note is that the male Nephila clavipes and smaller parasitic spiders will appear in the webs over time; however, this is normal. Mapping all the female spiders in the constructed habitat will be one of the most important tasks to set up the silking operation. Mapping allows to identify all of the spiders and where they are situated. It is important to record which spider was silked and at what time. The time of day and weather conditions at the time can greatly affect the silk quantity and quality. Also, the record is important because oversilking a spider can cause distress or even kill her, not to mention affecting the quality of silk.


This described method of silking should be observed closely, as this procedure has been shaped after almost two decades of the Spider Team’s trial and error.

  1. The first step of silking is removing the female spider from her web. It is important not to disturb the web. The method used is affectionately called the “Welshans’ Cage Method”. The researcher hovers their hand in front of a web, slowly moving it downward towards the spider. The Nephila’s instinct is to travel upwards, which is used to our benefit. The spider should attempt to travel over the researcher’s hand, it is at this point that the hand is gently closed around the spider. The Nephila clavipes is not aggressive, and will only bite if pinched or handled roughly. That being said, if bitten, the only effect will be local redness and swelling.
  2. The Nephila should be supported on the back of the hand, prompting her to lay a sticky disc– a type of silk used to anchor their dragline– in the hand of the handler. It is important to immediately place the sticky disc around the silkinator’s wheel. Using two hands, the handler should move their hands in a waterfalling motion, which tricks the spider in to thinking it is falling, thus stimulating it to continue to let out its silk.
  3. A second researcher should turn the silkinator’s crank. A bike odometer is used to count the number of rotations the wheel has made, which should under no circumstances exceed 350 in order not to overtax the spider. Once 350 rotations has been reached,or the spider stops silking on its own, it is returned to its own web. It is important not to directly handle the silk on the wheel, but to use stainless steel probes so as not to leave oils from the skin on the silk. The current version of the silkinator features collapsible rods, which makes removal much easier. The silk sample should be labeled and tested for strength in current atmospheric conditions.




Note: there are three distinct data tables from the years of 2016, 2017, 2018, this is due to the different organizational tendencies and goals specific to each team, methods and materials were not affected by this, every year tensile strength, barometric pressure, and temperature were recorded.

Date Time Temp. Humidity (%) Rainfall Wind


Spider Name/ # # of rotations Amount Silked Color



Strength (N) B. Press Strand Strength
3-2 11:08 80.7 57.50% NE LGT TEST/Firstie 300 250 Golden Straw 5.37 28.11 0.0179
3-2 12:08 81.5 58.4 NE LGT 1/Phyllis 184 153.33 Summer time 4.407 28.1 0.023951087
3-2 12:11 81.5 57.4 NE LGT 2/ Patrica 280 233.33 Golden Straw 5.221 28.1 0.018646429
3-2 14:04 80.9 59.7 N LGHT 3/ Pricilla 296 246.66 Sunshine 13.05 28.01 0.044087838
3-2 4:18 80.6 60.4 N LGHT 4/Treasre 187 155.56 Tamed Lion 5.25 28.01 0.028074866
3-2 14:38 79.7 62.8 N LGT 5/ Spidey 227 190 Define 2.414 28 0.010634361
3-2 14:52 77.7 69 N LGT 6/Biggie Smallz 240 200 Lion 9.201 27.99 0.0383375
3-2 15:12 77.3 67.8 N LGT 7/ Carmen 70 58.33 Lemon BOT 28
3-2 15:25 77.3 68 LGHT&VAR 8/Betsy 268 223 Neptune 5.407 28 0.020175373
3-2 15:45 76.6 70 NE LGHT &VAR 9/ Urcilla 156 130 Sunlit Mesa BOT 28.01
3-2 16:04 76.6 70.1 N LGHT&VAR 10/Harry 321 267.5 Golden Straw 4.461 28 0.013897196
3-2 16:24 76.4 71.1 N LGT&VAR 11/Budy 162 135 Melted Caramel 6.677 28.01 0.041216049
Date Time Temp. Humidity (%) Rainfall Wind


Spider Name/ # # of rotations Amount Silked Color



Strength (N) B. Press
3-2 16:49 76.4 73 N LGT&VAR 12/trouble 77 64 Starlight 0.388 28.01 0.005038961
3-3 9:55 77.9 70.3 E Agnes 283 235.8333333 School Days 9.572 28.9 0.033823322
3-3 10:00 81.6 61.9 E Dumpling 124 103.3333333 Lemon 0.66 28.1 0.005322581
3-3 10:06 82.7 59.4 None Marge 211 175.8333333 Sunlit Mesa 0.47 28.09 0.002227488
3-3 10:22 86.5 61.8 None Katy 256 213.3333333 Lemon 8.36 28.09 0.03265625
3-3 10:47 83.4 58.4 None Rose 263 219.1666667 Golden Straw 7.81 28.08 0.029695817
3-3 10:56 83.8 58.7 None Madam 225 187.5 Golden Straw 10.21 28.08 0.040039216
3-3 11:20 84.3 58.3 None Biggie Smallz 325 270.8333333 Neptune 9.2 28.07 0.028307692
3-3 11:38 87.6 54.5 E Carmel 310 258.3333333 Golden Straw 6.41 28.06 0.020677419
3-3 11:43 88.8 53.7 E Harry 215 179.1666667 Honeycomb 6.48 28.05 0.030139535
3-3 12:06 84.5 61.1 NE Betsy 191 159.1666667 Lemon 7.93 28.04 0.041518325
3-3 13:47 83.4 61.8 E Phoebe 0 0 n/a 0 27.99
3-3 13:49 83.4 61.8 None Pricilla 219 182.5 Sunny 10.7 27.99 0.048858447
3-3 14:05 85.3 58.1 Patricia 233 194.1666667 Lemonade 7.03 27.99 0.036806283
3-3 14:15 84.7 59.3 Lourde 230 191.6666667 School Days 8.25 27.98 0.035869565
3-3 14:35 84.9 58.1 Valencia 220 183.3333333 Sunny 3.25 27.97 0.014772727
3-3 14:48 84.7 58 Harry 280 233.3333333 Bit of Sunshine 6.48 27.97 0.023142857
3-3 18:04 75.3 75.1 Fiona 100 83.33333333 Sunny 3.15 28.02 0.0315
3-3 18:07 75.3 75.1 Vicki 250 208.3333333 Lemonade 13.72 28.02 0.05488
3-4 9:12 79.5 70 none Donna 180 150 Sunny 8.717 28.09 0.048427778
3-4 9:30 80.9 69.3 Wendy 170 141.6666667 Lemonade 2.986 28.09 0.017564706
3-4 9:43 81.3 65.3 Situation 87 72.5 Sunny 2.068 28.09 0.023770115
3-4 9:51 82.5 68.2 stitch 103 85.83333333 Sunny 4.027 28.09 0.039097087
3-4 10:01 82.7 64.1 Dish Net 40 33.33333333 MoonChina 0.232 28.09 0.0058
3-4 10:09 82 66.4 Sandy 347 289.1666667 Moon China 10.11 28.09 0.029135447
3-4 10:21 81.3 66.5 Black Betty 169 140.8333333 Honeycomb 5.763 28.09 0.034100592
3-4 10:30 80.6 67.5 Steve 274 228.3333333 Honey comb 3.191 28.08 0.011645985
3-4 14:26 80 72.4 Welts 228 190 Honey Comb 4.031 28.01 0.017679825
3-4 14:58 75.6 84.2 Clariz 125 104.1666667 Golden straw 3.667 28.01 0.029336
3-4 15:05 75.6 84.2 Soldier 200 166.6666667 Golden straw 3.959 27.89 0.019795
3-4 15:12 81 77.6 Staniel 260 216.6666667 Lemonade 5.329 27.89 0.020496154
3-4 15:24 85.9 71 Carmel 262 218.3333333 Lemonade 10.03 28.01 0.038282443
3-4 15:57 79.6 76.5 Patricia 250 208.3333333 Lemonade 13.29 27.91 0.05316
3-4 16:07 82.1 77.6 Betsey 250 208.3333333 School Days BOT 27.91
3-4 16:18 82.1 77.6 Biggie Smallz 250 208.33 Golden Straw 27.91
3-5 11:55 84.6 61.3 Buddy 107 89.16666667 Lemonade 5.98 28.09 0.05588785
3-5 12:04 86.9 61.6 Biggie Smallz 245 204.1666667 Golden Straw 2.54 28.09 0.010367347
3-5 12:18 86.4 63.9 Carmel 150 125 School Days 6.17 28.08 0.041133333
3-5 12:26 87.5 61.3 Betsy 250 208.3333333 Golden Straw 9.94 28.07 0.03976
3-5 16:17 78.3 77.3 Fiona 193 160.8333333 Moon China 12.61 28.04 0.065336788
3-5 16:36 77 77.2 Donna 427 355.8333333 Honey comb BOT 27.95
3-5 16:53 77 77.2 Pricilla 225 187.5 Banana Bunch 6.5 27.95 0.028888889
3-5 17:00 76.6 77.6 Clariz 320 266.6666667 Bone China 10.29 27.96 0.03425
3-5 7:15 76.5 77 Chocolate con leche 213 177.5 Bone China 1.439 27.96 0.005347418
987.5 787.5 1775
Date Time Temp. Humidity (%) Rainfall Wind


Spider Name/ # # of rotations Amount Silked Color



Strength (N) B. Press
3-5 17:37 83.2 75.8 CALM 35/staniel 296 246.6666667 Honey comb 27.96
3-5 18:07 83.2 75.8 36/Mikey 130 108.3333333 Honey comb 1.913 27.96 0.014715385
3-6 11:48 85.3 56.2 34/ Soldier 250 208.3333333 Sunny 7.569 27.98 0.030276
3-6 11:57 85.3 56.2 33/Clariz 179 149.1666667 Sunny 5.054 27.98 0.028234637
3-6 12:06 88.8 56.2 35/Staniel 142 118.3333333 Bone China 2.486 27.98 0.017507042
3-6 12:18 88.3 59 28/Sandy 169 140.8333333 Sunny 10.01 27.98 0.059230769
3-6 15:06 82.8 66 31, Steve 118 98.33333333 Bone China 1.89 28.03 0.016016949
3-6 15:35 81.7 67.4 37, Debbie 250 208.3333333 Golden Straw 8.51 28.04 0.03404
3-6 15:37 81.9 67.4 36, Mikey 250 208.3333333 Golden Straw 4.12 28.04 0.01648
3-6 16:00 81.9 67.4 39, Becky 250 208.3333333 Boon China 6.829 28.04 0.027316
3-6 16:25 81.9 67.4 2/Patrcia 250 208.3333333 Golden Straw 6.647 28.04 0.026588
3-6 17:16 80.3 72.6 1/Phyllis 273 227.5 Golden Straw 9.044 28.05 0.033128205
3-6 17:26 81.9 72.6 3/Pricilla 36 30 Golden Straw 1.3 28.05 0.026111111
3-6 17:38 85.8 73 21/Velencia 356 296.6666667 Golden Straw 14.8 28.05 0.041573034
3-6 18:00 85.8 73 10/ Harry 103 85.83333333 Golden Straw 1.807 28.05 0.017543689
3-6 18:08 84 72 24/Wendy 136 113.3333333 Golden Straw 4.8 28.04 0.035294118
3-8 17:30 1/ RA 202 168.3333333 Golden Straw 7.159 27.48 0.035440594
3-8 18:08 73.9 83 1/Sassy Frass 215 179.1666667 Golden Straw 9.15 27.48 0.04255814
3-8 18:15 74.4 81.1 2/Kristy 223 185.8333333 Golden Straw 14.16 27.48 0.063497758
3-9 9:10 75.2 78.5 3/Dureesh 158 131.6666667 Bone China 2.506 27.54 0.015860759
3-9 10:00 77 75.5 4/Tyrome 214 178.3333333 Sunny 1.887 27.54 0.008817757
3-9 10:10 77 75.1 5/Tinky 206 171.6666667 Bone China 0.067 27.54 0.000325243
3-9 10:20 77 75.1 6/Dirty mike 371 309.1666667 Bone China 0.222 27.53 0.000598383
3-9 10:30 77 75.1 7/Adam 114 95 Bone China 0.437 27.53 0.003833333
3-9 10:40 78 74.2 8/Caroline 270 225 Bone China 1.197 27.53 0.004433333
3-9 15:38 76.6 76.3 9/Chris 250 208.3333333 Spotlight 10.5 27.44 0.042
3-9 15:51 76.6 76.3 10/SamuEL 250 208.3333333 Bone China 2.472 27.44 0.009888
3-9 16:00 77.9 77.3 11/TaiChai 250 208.3333333 Spotlight 5.692 27.43 0.022768
3-9 5:20 75.3 76.7 12/Party Pooper 427 355.8333333 Golden Straw 23.92 27.47 0.056018735
3-9 18:00 75.3 76.7 13/ Sean 333 277.5 Spotlight 7.27 27.47 0.021831832
3-9 18:15 75.3 76.7 14/ditsy 397 330.8333333 Golden Straw 10.92 27.47 0.027506297
3-10 9:05 70.3 77.9 15/ Charles (before soak) 100 83.333 Golden Straw 3.848 27.56 STOP
3-10 9:15 70.3 77.9 15/Charles (after soak) 100 83.33333333 Golden Straw 2.848 27.56
3-10 9:20 77.3 71.9 16/lindenberg (wet) 100 83.33333333 bone china 4.245 27.56
3-10 9:25 77.9 71.8 16/lindenberg(dry) 100 83.33333333 bone china 1.615 27.56
3-10 9:30 78 71.6 17/Krinky (soaked) 100 83.33333333 Golden Straw (lemonade before spray) 2.209 27.56
3-10 9:35 78.4 71.6 17/ Kinky (dry) 100 83.33333333 Spotlight 0.827 27.56
3-10 9:41 78.9 71.6 18/George (Soaked) 100 83.33333333 Sunny 3.016 27.56
3-10 9:50 79.7 68.7 18/ George (dry) 100 83.33333333 Sunny 2.48 27.56
3-10 10:00 79.7 68.7 19/Jimmy 250 208.3333333 27.56
3-10 0
3-10 JUAN 4166 feet
3-10 16788.373
3-10 19850.373
3-10 24016.373
session timestamp temp_c dew_point_c spider location Fiber type Strand count session_time rotations k_lux Baro newtons strand_strength_newtons outlier
1 2017-03-02 11:25:00 25.5 N/A 21 N/A 145 6.74 21.02 7 0.04827586207
3 2017-03-02 12:30:00 25.5 N/A 30 N/A 231 1.5 21.02 9.1 0.03939393939
4 2017-03-02 12:45:00 25.6 N/A 20 0:05:26 211 1.5 27.97 17.5 0.08293838863
5 2017-03-02 17:25:00 25.6 17.8 22 0:09:12 229 0.1 27.96 19.8 0.0864628821
6 2017-03-03 9:52:00 25.2 18.8 14 0:03:27 250 7 28.07 2.49 0.0092
7 2017-03-03 11:25:00 23.2 19 8 0:03:35 269 4.8 28.04 13.2 0.04795539033
9 2017-03-03 16:00:00 24.23 18.7 26 N/A 0 N/A 8 o
10 2017-03-03 17:17:00 23.5 18.6 6 0:06:20 350 0 29.97 1.5 0.02285714286
12 2017-03-04 9:16:00 23.9 20.6 10 0:02:22 130 0.1 28.09 2.1 0.01615384615
13 2017-03-04 9:57:00 25.7 20.8 4 0:03:22 258 0.2 28.09 6.9 0.02596899225
14 2017-03-04 10:30:00 25.8 19.2 21 0:03:38 244 3.6 28.09 6.4 0.0262295082
15 2017-03-04 10:50:00 25.2 21.1 17 0:03:12 250 2 28.09 6.8 0.0248
18 2017-03-04 16:56:00 27 19.9 30 0:02:51 162 0.4 27.97 8.7 0.04938271605
20 2017-03-06 11:04:00 22.8 19.5 34 B N/A 50 1.1 27.54 2.9 0.02858
21 2017-03-06 11:39:00 24.3 19.9 44 L N/A 75 8.7 27.51 2.8 0.03733333333
22 2017-03-06 12:10:00 23.4 19.8 38 F N/A 72 0.1 27.51 2.769 0.03101388889
23 2017-03-06 12:22:00 23.4 19.8 38 F N/A 72 0.1 27.51 3.34 0.03101388889
24 2017-03-06 12:31:00 23.4 19.8 38 F N/A 72 0.1 27.51 2.248 0.03101388889
25 3/6/2017 12:50:00 23.3 19.4 39 G N/A 60 0.1 27.51 1.2 0
26 2017-03-06 14:40:00 20.5 18.8 42 J N/A 244 0.6 27.49 4.192 0.01668032787
27 2017-03-06 16:13:00 23.9 19.7 40 H N/A 246 0.1 27.45 9.6 0.03902439024
28 2017-03-06 16:45:00 23.6 19 43 K N/A 52 N/A 27.45 1.186 0.01032692308
29 2017-03-07 9:23 23.5 20.7 33 A N/A 176 N/A 27.57 4.202
30 03-07-2017 9:51 23.5 20.7 35 C N/A 141 N/A 27.56 3.666
31 2017-03-07 10:17 24.5 21.7 37 E N/A 213 N/A 27.55 7.579
32 3/9/2017 15:00:00 ——- ——- ——- ——- nylon 1/6 ——- ——- ——- N/A 9.78
32 3/8/2017 12:58 ——- ——- ——- ——- wool 1/4 ——- ——- ——- N/A 4.57
32 3/8/2017 20:09 ——- ——- ——- ——- hemp 1/4 ——- ——- ——- N/A 7.435
32 3/7/2017 20:20 ——- ——- ——- ——- kevlar 1/6 ——- ——- ——- N/A 5.579
32 2017-03-08 8:34:00 25.7 20.2 45 M 232 0.2 27.55 10.95 0.04719827586
32 3/8/2017 9:30 ——- ——- ——- ——- cotton 1/33 ——- ——- ——- N/A 9.3
32 3/9/17 11:00 ——- ——- ——- ——- Nylon monofilament 1 ——- ——- ——- N/A 16.4
39 3/8/2017 10:07 26.1 20.3 38 F cotton 1/33 N/A 250 0.2 27.56 15.07
40 3/8/2017 11:55 26.2 21.7 33,44 A,L Hemp 1/4 250 2 27.51 24.072 No Graph
41 3/8/2017 12:21 27.4 22.3 42 J Wool 1/4 N/A 250 0.9 27.5 10.5
43 3/8/2017 1744h 26.7 22.1 36,45 D,M Kevlar 1/6 N/A 250 1.4 27.47 23.85
44 3/9/2017 1015 26.4 20.9 33 A nylon 1/16 N/A 250 2.3 27.51 8.234
45 3/9/2017 1226 27.1 21.9 45,38 M,F nylon monofilament 1 N/A 250 0.2 27.46 18.97
46 3/9/2017 1256 27.7 21.8 44,32 L,J cotton 1/33 N/A 250 0.2 27.44 12.5
48 3/9/2017 1721 25.6 21.3 38 F hemp 1/4 N/A 250 0.3 27.41 34.07
49 3/10/2017 0652 N/A N/A 33, 39 A,G hemp 1/4 N/A 250 N/A N/A 35.75
Date Time Baro (inHG) Temp (C) Humidity Wind Precip Cloud Cover Spider Name # of Rotations Length Silked (cm)(Rounded to Whole #) Color Force to Break (N) Comments
1-Mar-18 15:19 27.91 26.5 61.30% 0 0 Cumulo Stratus Jenny 250 9974 B125 4.7 Cut line twice
1-Mar-18 16:12 27.93 25.9 61.40% 0 0 Cumulo Stratus Jackie 250 9974 B114 ———————— Broke while removing from wheel
1-Mar-18 17:05 27.95 24.8 63.50% 0 0 Cumulo Stratus Rachel 93 3704 B115 ———————— Appeared lethargic, stopped sinking at 93 rotations error with the attenuator affected tensile testing
2-Mar-18 9:00 28.07 21.5 87.10% 0 0 Cumulus Rachel 194 7740 B114 ———————— Human error
2-Mar-18 9:18 28.04 24.1 73.40% 0 0 Cumulus Ariana 250 9974 B113 4.4
2-Mar-18 11:40 28 25.7 62.30% 0 0 Cumulus Adriana 250 9974 B115 3.1 Tenso forward motion on accident
2-Mar-18 12:02 ———————— ———————— 59.40% 0 0 Cumulus Bella 125 4987 B117 ———————— Broke while removing from wheel
2-Mar-18 17:26 27.95 24.2 73.90% 0 0 Cumulus Jenny 224 8937 B127 7.3 Beautiful Gold Color
3-Mar-18 9:50 28.02 26.4 65.70% 0 0 Cumulus Sparkles 128 5147 B124 3.2 4:50 seconds 5 cuts
3-Mar-18 10:01 28.02 26.4 70.30% 0 0 Cumulus Angel 181 7221 B123 2.9 2 cuts
3-Mar-18 10:36 28 27 68.10% 0 0 Cumulus Ariana 141 5625 B125 2.2 4:30 seconds
3-Mar-18 16:42 27.93 25.5 71.40% 0 0 Cumulo Stratus Jane 170 6782 B123 ————————Human error no breaks
3-Mar-18 17:11 27.93 25.4 69.50% 0 0 Cumulo Stratus Jackie 8 319 ———————— ———————— could not even remove web Jackie had not been in her web fir two days, she sat above it in the rafters
3-Mar-18 17:21 27.93 25.6 70.90% 0 0 Cumulo Stratus Ariana 100 3989 B125 0.4 3:10 seconds Silked twice in one day, mistaken for Jenny Johan also broke some strands
3-Mar-18 18:00 27.95 24.8 73.60% 0 0 Stratus Jenny 185 7381 B126 3.9 2 cuts, 4:15
3-Mar-18 20:51 28.03 22.5 82.40% 0 0 too dark to see Rachel 148 5904 ———————— ———————— 3 cuts, broke on removal
3-Mar-18 21:13 28.03 22.8 82.50% 0 0 too dark to see Bella 180 7181 B125 3.9 no breaks, 3:25, lethargic afterwards
4-Mar-18 9:05 28.01 24.4 75.30% 0 0 clear sky Adriana 100 3989 B114 1.3 cut at 100 on purpose
4-Mar-18 9:40 27.94 26.7 60.30% 0 0 clear sky Annie 100 3984 B112 1.6 Cut once, capped at 100
4-Mar-18 17:50 27.45 23.9 74.20% 0 0 ———————— Jenny 64 2553 B132 1 Cut once, she had already been silken the fourth for teleflex
4-Mar-18 18:03 27.96 23.9 74% 0 0 Cumulus Bella 74 2952 ———————— ———————— Broke while removing from wheel, tough time sinking
4-Mar-18 18:14 27.96 24 73% 0 0 Cumulus Adriana 35 1396 B114 ———————— Too small to test
5-Mar-18 6:04 28 21.3 81.70% 0 0 Cumulo Stratus Jane 78 3112 B125 2.5 one cut
5-Mar-18 6:20 28 20 80.60% 0 0 Cumulo Stratus Angel 47 1875 ———————— 1.8 possibly put on wrong
5-Mar-18 9:15 27.94 25.6 76.80% 0 Yes,


Cumulus Jenny 75 2992 B124 1 Cut once
7-Mar-18 19:05 27.55 19.2 86.60% 0 Yes. .5 cm Heavy Stratus Jolene 10< ———————— ———————— ———————— Very hard time silking, multiple cuts before even reaching ten rotations (Rara Avis)
7-Mar-18 19:13 27.55 18.2 86.60% 0 Yes. .5 cm Heavy Stratus Charlotte 28 1117 ———————— ———————— Broke while removing from wheel, very difficult to silk, multiple cuts (Rara Avis)


Note: Because this paper looks specifically at tensile strength, barometric pressure, and temperature, a second raw data chart was made isolating spiders, barometric pressure, and average strand strengths of those silk collections. Spiders silked three or more times are highlighted with their own specific color and used in the following data graphs


Strand Strength Temperature (C) Barometric (inHG)
Patrica 0.018646429 27.5 28.1
Patricia 0.036806283 29.6 27.99
Patricia 0.05316 26.44 27.91
Patrcia 0.026588 27.72 28.04
Strand Strength Temperature (C) Barometric (inHG)
Pricilla 0.044087838 27.16 28.01
Pricilla 0.048858447 28.55 27.99
Pricilla 0.028888889 25 27.95
3/Pricilla 0.026111111 27.72 28.05
Strand Strength Temperature (C) Barometric (inHG)
Betsy 0.020175373 25.16 28
Betsy 0.041518325 29.16 28.04
Betsy 0.03976 30.83 28.07
Strand Strength Temperature (C) Barometric (inHG)
Biggie Smallz 0.0383375 25.38 27.99
Biggie Smallz 0.028307692 29.05 28.07
Biggie Smallz 0.010367347 30.5 28.09
Strand Strength Temperature (C) Barometric (inHG)
Carmel 0.020677419 30.88 28.06
Carmel 0.038282443 29.94 28.01
Carmel 0.041133333 30.22 28.08
Strand Strength Temperature (C) Barometric (inHG)
Harry 0.013897196 24.77 28
Harry 0.030139535 31.55 28.05
Harry 0.023142857 29.27 27.97
Strand Strength Temperature (C) Barometric (inHG)
Clariz 0.029336 24.22 28.01
Clariz 0.03425 24.77 27.96
Clariz 0.028234637 29.61 27.98
Strand Strength Temperature (C) Barometric (inHG)
Jenny 0.0188 26.5 27.91
Jenny 0.032589286 24.2 27.95
Jenny 0.021081081 24.8 27.95
Jenny 0.015625 23.9 27.45
Jenny 0.013333333 25.6 27.94





Barometric pressure (inHG) values; 27.91, 27.96, 28.08, 28.04, 27.99, 27.99. 28.05, 27.95.

Barometric Pressure had a difference of .17 from the highest to the lowest value

The Mean value for highest tensile strength in this lab in regards to barometric pressure was 27.99625


The Temperature (celcius) values; 31.55, 26.44, 28.55, 29.16, 25.38, 30.22, 24.77, 24.2

Temperature had a difference of 7.35 degrees from the highest to lowest values

The mean value for highest tensile strength in this lab in regards to temperature was 27.5

For use in abstract??



Though we used the past three years of data, based on our findings, we cannot affirmatively say that barometric pressure or temperature has any obvious effect on the tensile strength of the Nephila clavipes. It is possible that the results were influenced by 2018’s findings, in which prior to this team’s arrival, a cold snap had killed the majority of the resident spiders and presumably induced stress in the surviving ones. Again, while no obvious relationship between barometric pressure, temperature and silk tensile strength was observed, within this study; the average for optimal conditions of silk strength was a barometric pressure of 27.99625, and a temperature of 27.5 degrees Celsius.This paper’s authors used  three years, 2016, 2017 and 2018 for data. Spiders that had been silked three times or more, were graphed twice with temperature (in celsius) over strand strength (in newtons). And barometric pressure (inHG) over strength (Newtons). For each spider, we looked at the highest tensile value, and its coinciding temperature and barometric values.


A Thank you to all the previous teams for their data gathering and construction of materials and methods,


Bryan Sullivan

Jerry Kersten

Danielle Odell

Brady Rose

John Small

Luke Bornheimer

Rachel Clarkin

Addison Keilty

Megan Blair

Winston Macdonald

Nick Manzella

Zachary Bitan

Ryan Lowe

Jacob Sussman

John Goldstein

Ariel Blum

Lawton Jeffords


Special thanks to Linus Trahair, assistance in data analysis



AUTHORSHIP: Wendy L. Welshans, Jason M. Epstein