Experimenting with Geckos

By Geoffrey Nathan

2 weeks into our stay at Las Cruces Biological Station, the OTS group was given our 2^nd faculty led project of the trip. My group of six was assigned to work with invited researcher Chelsea Ward on parasites and their relationship with gecko performance. I had never worked with geckos before and had very little experience with identifying parasites. However given that a majority of the trip up to that point had dealt with plant investigations, I was keen to do something different by experimenting with animal interactions.

            The first part (and arguably the most fun) of the experiment was capturing these geckos. We set out to the Las Cruces dining area at night, looking high and low on walls for these nocturnal climbers. Knowing we had to capture 10, I originally believed it would take all night. However, to the group’s and my pleasant surprise, these geckos were all over the walls. When one person spotted a gecko, someone would attempt to gently pluck the gecko off from the wall with a long net while another person stood underneath to catch the gecko with another net. If the gecko hit the floor our reflexes were tested. We were dealt with the tough task of not only scooping up the scampering gecko, but also ensuring not to grab it by the tail. If the tail was grabbed, as I learned from personal experience, the gecko would wiggle it off and we could not use it for the experiment.

            The following morning was time to put the geckos to the test. We used swim stamina in order to test for the geckos’ performance. One-by-one, we released geckos into a bucket of water and recorded the time until they attempted to float out of exhaustion rather than swim. We then quickly removed the geckos from the bucket. Interestingly enough, the geckos showed a wide range in stamina, some swimming for over a minute and others giving up within 10 seconds. Some of the large geckos proved too strong for the containment of bucket and even managed to crawl up the walls and escape!

            In order to determine parasite load in these geckos, Chelsea then brought us to the Biological Station Lab to perform gecko dissections. Gecko anatomy quickly became clear to me, as after peeling back the skin, most of the organs were easily visible. We examined most of the body looking for lungworm, intestinal worms, and mites on the fingertips and toes of the gecko. Astonishingly, one student found five 2-4 mm worms in the lungs of a gecko, prompting Chelsea to place these parasitic specimens in vile for further research.

            Our findings did not show any relationship between parasite load and gecko performance. However the entire process of capturing, testing, and analyzing our data was rewarding. It provided me with a better sense of how to properly conduct a scientific experiment out in the field in an efficient, meticulous, and fun manner.