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A giant river otter eating his dinner.
Giant Otters

For the past three days I have been working with Helen and Manuel on otter research. On the first day we drove around in a motorboat with Helen, checking for otter signs at all the sites she had marked on the Rio Negro. Helen has a map of all of the sites in her GPS unit, and we scanned the banks for almost five hours that first morning. We did collect a few spraint samples, noting scratchings and old tracks at another. In the afternoon we did the same thing on the other side of the river and were rewarded with three new sites. Helen is very committed to her work, and ignores millions of mosquitoes to get accurate readings and data that she had me carefully record. Most of the sites Helen had previously identified were flooded and did not contain fresh signs, but Helen says this too tells her important information about the otters' movement in the wet season. Helen thinks that perhaps they move to the baias in the wet season where the fishing is easier and they can establish new resting sites, latrines, and dens.

On the next day we went to the Baia da Ariranha, which is a native name meaning Giant Otter Baia. It was an amazing day because we were lucky enough to actually see and hear the giant otter. We carried our canoes across land from the river to the baia. Helen had us canoe in silence, listening and looking for signs and sounds of the giant otter. I heard something behind me, turned quickly and saw a giant otter periscoping (that's when they stretch their necks and look out of the water right at you), and vocalizing an alarm sound that was mostly loud snorting. Helen was able to identify the otter as Island, an adult female, from the markings visible on her neck as she periscoped. Helen knew her to be in a family group of five otters. After vocalizing Island hid from us, so we explored the rest of the baia for signs of otter habitation. Helen marked a new campsite, resting site, and latrine. Afterwards we went back to hide in the bushes across the water from where we first saw the otter to await her reappearance. About an hour later we heard some very interesting sounds form the bushes, Helen said they were sounds of play. Our patience paid off and we were rewarded this time with a view of Island and three other otters. Everything happened so fast that my pictures of otters are just ripples on the water! Though they did not snort at us, they quickly moved away, and Helen said we should leave so they don't get too stressed.

In the afternoon we stayed in the lab to wash spraint samples that Helen had collected and frozen during her last team. Wanda and I took turns using a strainer to rinse each carefully marked sample. Once all of the sand, roots, and debris were removed, we wrapped the contents up to be analyzed later. Most of the samples contained bones and/or scales from fish. Helen says it's important to find out what they are eating during different times of year. The fish that Andrew and Phil helped clean earlier in the week will be taken apart and their bones and scales will be used for reference. Once the spraint was clean, I used the computer to enter all the data I had recorded earlier.

Today, Nick and I left the farm at 4:30 p.m. to go back to the Baia de Ariranha to observe and film Island and her family. We set up our canoes, well hidden across form the campsite. We had to record whatever we saw every ten minutes. Around 8:00 p.m. the otters finally emerged from the den and began vocalizing a sound very similar to a shrieking baby. The sound is used to gather all the animals in the family so they can go do something together, such as fish. We were able to see and film three heads, and two of the otters ran across the beach of the campsite and we were able to see their full bodies. The batteries in my digital camera were dead, so this time I didn't even get water ripples. Since two of us will go back every day with Manuel to document the otterss behavior, hopefully with a fully charged battery we will get some great pictures. As Nick always says, "you win some, you lose some." When I came back I asked Mr. Vacchina (Peter) to play the voice recording he made of the otters' vocalizations. Everyone was amazed — including Helen!

For more information, click on the Hudson School site.

Photo courtesy of Harvey Lowe