Uspallata Ecology

As biology continued into its second of three weeks, we got down to the nitty-gritty and had an introduction to biology and statistical analysis so we could infer patterns and relationships in the data we collected on our horseback trip.



Todd Wellnitz leading the TIES crew in a Biology discussion at the hostel

            The next day was an introduction to what the next study would involve with two native Argentine researchers, Erica Scheibler and Paulo Lambias.  They gave us the information we needed for data collection and explained what we would be looking for in Uspallata.  Erica’s research in the Andes is heavily dependent on streams and, for our research purposes, diversity.  Paulo is currently working on his Ph.D. with his research on monogamy in the South American sedge wren.

In Ithaca, New York, and Buenos Aires, Argentina, Paolo is doing a lot of research with these birds to understand different lifestyles and processes of these birds based on their environments.   The sedge wren has an interesting way of building their nests, as the female, aided by the male, often builds more than one nest in the tall Pampas grass.  There are many possible reasons for this, including avoiding predation, creating distractions, or allowing the males of the species to practice polygamy. 

When we arrived at the Uspallata region, we were divided into four groups.  Two groups went with Paolo to a field full of Pampas grass (often taller than us!), even though this is not the mating season for the wrens.  The groups in the fields were to measure the Pampas grass sections by using cups to represent wrens’ nests.  We measured the height of the grass, density of the plant, and the concealment it provided the nest.


Brandon and Alicia measuring the height of the Pampas grass



 The other two groups stayed with Erica and Dr. Wellnitz to collect samples from the stream nearby and then record diversity data of the aquatic organisms they collected. 

  


Alex and Erica gathering samples from RIo Uspallata near our campground



Frank collecting stream ecology samples



 

The night ended for everyone with a campfire and dinner at our campground.  Around the campfire Dr. Wellnitz, with the help of Paolo and Erica, taught us about the evolution of species.

The second day, the stream groups went into the field and the field groups went to the stream.  The new stream team sampled different streams than the group.  One group went about 30 kilometers north of Uspallata to collect data from a stream near Tambillos. 

Kelsey and Kris collecting stream data near Tambillos

  

These transects provided three different locales to evaluate the diversity of streams.  We measured this the same way as the first group at the other stream did.  This was done by holding a net in slow, medium, and fast stream water, and disturbing the ground - catching everything that got picked up by the current.  We did this for five minutes, measuring velocity by timing how long an object took to float five meters. 

When the groups met at the end of the field studies, we headed back to Mendoza to put everything together.  The sedge wren groups looked for patterns in their data, while the stream stream collected all of their critters from their samples. 



Dan and DJ collecting stream ecology data



The next morning, Paulo gave a lecture to answer questions about the information we gathered from the wren’s nests.  This was followed by a short lecture from Dr. Wellnitz and time to work on our group projects.