Blog Post 3: Ongoing Field Observations

The organism that I plan to study is the bullfrog (Lithobates catesbeianus) present at the Champlain Lake south wetland/swamp site chosen for observation. I had taken note that the stationary presence of a Lithobates catesbeianus in stagnant water appeared to be dependent on its location featuring sub-merged aquatic vegetation. None of the seven total observed Lithobates catesbeianus were present in an area of water that had no aquatic vegetation beneath the organism.

The three locations I have chosen to observe the organism of interest is the interior small channel flowing south, the main open body, and the lake mouth channel running into the wetland body (see photo for location references).

1. Location 1: Interior small channel (south flowing)
   The water in the wetland had dropped approximately 1 foot, leaving the channel to be very shallow and featured minimal room for aquatic vegetation. The channel was very stagnant and I did not observe any bullfrogs (Lithobates catebeianus) present in this area. I assume their absence in this channel was due to low water levels causing restriction for travel along the channel.
2. Location 2: Main Open Body
   The main open body of the wetland also had signs of lower water levels along the shoreline, exposing previously submerged rocks and some dried up aquatic vegetation. This location had the majority of Lithobates catebeianus present and featured ample aquatic vegetation beneath each organism. I noted in my field journal the surrounding areas lacking visible aquatic vegetation, also lacked the presence of a Lithobates catebeianus. The water was very stagnant in this location as well.
3. Location 3: Lake Mouth Channel (running southbound into wetland body)
   The lake mouth channel had a few sections of submerged aquatic vegetation and featured one smaller Lithobates catebeianus on the interior side of the channel. This channel had slight/low flow entering southbound into the wetland body and I predict the lack of Lithobates catebeianus presence throughout the lake mouth channel location is due to minimal aquatic vegetation coverage and difference in water velocity.

I postulate that the presence of a stationary Lithobates catebeianus is dependent on ample (>50%) coverage of submerged aquatic vegetation beneath the organism. Based on the postulate hypothesis, one potential response variable could be the Lithobates catesbeianus and one potential explanatory variable being the percentage of submerged aquatic vegetation coverage. The response variable would be categorical in this case, being the presence/absence of the Lithobates catesbeianus, and the predictor variable would be continuous, being the percentage of aquatic vegetation coverage. I expect the Lithobates catebeianus is stationary in water with ample aquatic vegetation beneath the organism to evade other predators present in the wetland.

I had a few images to accompany this post, however, are too large to include.