Agelena Consociata is a unique species. Native to the rainforests of equatorial Africa, this funnel web spider is one of few communal spider species. Social in nature, A. Consociata communities consist of one or more nests. Their nests alone range from one female and her offspring to as many as 1500 females and their offspring.
In their article “The Importance of Being Larger: Intraspecific Competition for Prime Web Sites in Orb Spiders (Aranea, Araneidae)” A.M. Heiling and M.F. Herberstein assert that larger orb web spiders occupy better habitats. Using Larinioides Sclopetarius as study objects, these ecologists found that large female spiders almost exclusively occupied the “prime habitat,” an area with the highest prey abundance. However, does Heiling and Herberstein’s research also apply to the communal species A. Consociata? Though communal, A. Consociata acts and breeds independently and only cooperates in catching large prey. Although males and females are of similar size, only females can separate from the original colony and create their own colony. Thus, I hypothesize that like L. Sclopetarius, the largest females will almost exclusively occupy the “prime habitat.”
This hypothesis will be tested through two complimentary research plans. The first experiment will survey the A. Consociata that occupy the “prime habitats” of a natural A. Consociata nest. This research plan borrows heavily from the experiment presented by Susan E. Riecherst in her article “Why Do Some Spiders Cooperate?”. It will be conducted near Makoku, Gabon at the Institute for Tropical Ecology between January and June. The survey will include five, 1000 m² plots on the M’passe Reseve. These plots will be sites of A. Consociata communities. From these communities experimenters will discover the areas of highest prey abundance. Furthermore, researchers will observe these communities over a 7 day period each month. These researchers will observe the occupants of the “prime habitats” taking note of their sex, mass, and volume.
The second experiment will test this hypothesis by showing which spiders will occupy the area of highest prey abundance. Inspired by Anja Kleintech and Jutta M Schneider’s research surrounding spider plasticity, the research plan will be conducted over a six month time span. This experiment will take place in a constructed and controlled habitat. The habitat will be a 1000 m² tank partitioned equally into three levels of prey abundance (1) high prey abundance and thus the “prime habitat” (2) low prey abundance (3) lowest prey abundance. There will be five of these habitats created in order to ascertain that the data collected is not an isolated incident, but rather a behavioral trend. Additionally, there will be two habitats constructed that have a consistent level of prey abundance that will acts as controls to the experiment. It should be noted that there will be no physical barrier between the partitions.
There will be approximately 100 spiderlings released into each habitat. These spiderlings will be 50% male and 50% female and of comparable sizes. This number will allow for spider death without greatly affecting the research. A. Consociata will be fed crushed dog food (Purina). The first feeding will take place the first day the spiderlings are released into the habitat. Approximately 500 g of crushed dog food will be placed in the highest level of prey abundance; approximately 300g will be placed in the low prey abundance partition and approximately 100g will be placed in the lowest prey abundance habitat. About 300g of crushed dog food will be placed in the control habitats. Food will be distributed on a daily basis and placed at the farthest end of each partition.
Specimen will be observed for 5-10 days every month. Observations will include general notes, such as the sizes of each habitats respective nest and an approximation of total inhabitants. More specifically researchers will remove the five largest spiders from each habitat and each partition as well as the controls and record their respective sex, mass, and volume.
I believe that both research plans will support my hypothesis and that both experiments will show that large female spiders almost exclusively occupy the area of highest prey abundance, the prime habitat. Providing information both within a controlled experimental context as well as data of a nature based context, the combination of these tests will provide a more complete look at the behavior of A. Consociata.
Kleinteich, A., & Schneider, J.M. (2011). Developmental Strategies in an Invasive Spider: Constraints and Plasticity. Ecological Entomology. 36. 82-93, Web.
Heiling, A.M. & Herberstein, M.E. (1999) The Importance of Being Larger: Intraspecific Competition for Prime Web Sites in Orb Spiders (Aranea, Araneidae). Behaviour Vol. 136. 5. 669-677, Web.
Riechert, Susan E. (1985) Why Do Some Spiders Cooperate? The Florida Entomologist, Vol. 68. 1. 105-116, Web.