Tarantulas

1. Tarantulas

2. Purpose • The purpose of this lab is to study the behavior of two species of tarantulas in varied climates. We studied their eating habits, weight, span, and activity level over an extended period of time.

3. Background • To prepare for our a experiment we did some research and we found some interesting information. • Because tarantulas have no external skeleton to fossilize, historical evidence is limited (source: tarantulas online). • Tarantulas are different from spiders because: • They have two claws and two adhesive pads on each foot • The fangs of tarantulas move up and down (source: Janssen)

4. Background • Tarantulas can be found worldwide. Thirty species alone inhabit North America (source: Bear) • Most tarantulas will not harm humans unless provoked (source: desertusa). • Tarantulas harbor formidable fangs that contain poison, and when threatened, the tarantula will assume an attack position by throwing itself back on it haunches and lifting up its front legs (source: Strener).

5. Background • Tarantulas are exceptional predators because of their extreme hunting skills. Due to their poor eye sight, they must rely on smell to pursue and capture their prey (source: Douglass). • Brazilian Tarantulas have been known to eat small birds, snakes, lizards, and rodents, but most North American tarantulas only feed on insects (source: Douglass). • Tarantulas are very important to the environment because they keep insect populations at bay while posing very little threat to humans (source: Vener).

6. Lab Design • We began the experiment with twelve baby tarantulas. Six California Ebonys and six Brazilian Salmon Pink Birdeaters. Two of each species were raised in three different climate zones; room temperature, below room temperature, and above room temperature. The tarantulas were fed crickets and data was collected twice a week for the extent of the experiment.

7. Our Hypothesis • Ultimately, we felt that the different temperatures would have an effect on the daily lives of the tarantulas. • It was our belief that the Tarantulas would be most active at the room temperature climate. • We also thought that they would be less active in the below room temperature setting, and therefore consume less food.

8. Materials • Six California Ebony Tarantulas • Six Pink Salmon Brazilian Birdeaters • Twelve Tupperware containers • Weighing vials • Heat lamp • Electric Scale • Measuring tape • Baby crickets • Cricket food • Nature for the tarantulas’ living habitat • Paper towels • Water

9. Timeline • Tarantulas were checked and fed twice a week throughout the experiment • When fed the tarantulas and their food were weighed • Also, the span was taken and general observations were made • The towels in the cages were kept moist all the time

10. Lab Results

11. Species Weight Vs. Time • This graph provides information concerning the weight of each tarantula species and how it was affected by the passage of time. It is clear that the Birdeaters gained more weight over an extended period of time than the California Ebony species. However, an interesting observation can be made concerning the weights of the two species and how they mirror one another, even between the three separate environments.

12. Location & Species Vs. Weight • This graph portrays the affect location according to species had on the respective weight of each tarantula species. It is evident that the Birdeaters in the below room temperature environment thrived over the same species in the control or above room temperature groups. Similarly, the California Ebony tarantulas also thrived in the below room temperature group, but continued to thrive in the control group as well. The Birdeaters did not do well in the control group at all.

13. Species & Location Vs. Weight & Time • This graph, similar to the last, provides a clear view of the relationship between the two species of spider and their weight according to their respective locations. However, this graph also adds the variable of time, so one is able to see the progression of weight gain/lose over a period of time. As one can see, the Birdeaters tend to gain more weight, yet the California Ebony are consistent with the weight gain, only on a smaller scale.

14. Conclusion • The Brazillian Birdeater tarantulas proved to grow larger and faster than the California Ebony tarantulas. • The California Ebony tarantulas did the best in the control (room temperature) environment; they did the worst in the above temperature environment. • The Brazillian Birdeaters did the best in the below temperature environment; they did the worst in the control environment. • Overall, the cooler environment proved to be the most conducive to both tarantula species… all four tested survived!!! • The above room temperature environment was the least conducive to all species… Two California Ebony tarantulas were lost, while the Birdeaters were the smallest out of all tested.