Saturday, November 21, 2009

Class Post - Owl Pellets

Over the course of the past week we have learned all about owls. We got into groups and dissected owl pellets. Owl pellets are basically the owls waste in the form of a pellet. The contents of the pellet are bones and fur along with some stomach acids. The process of excretion for an owl is known as regurgitation. Owls aren't able to digest very big animals so they either eat small animals or eat only part of an animal. The owl cannot digest the bones or fur of an animal, so they take the nourishment from the meat of the animal and leaves the rest to be excreted. This process takes about 24 hours to complete. The owl has two stomachs: the proventriculus and the ventriculus, or gizzard. In the proventriculus is where the digestion starts to happen. In the ventriculus the owl pellet is formed. The pellet is then stored in the gizzard for several hours. Then it is brought back up to the proventriculus and then it is regurgitated.

Our teacher got us owl pellets to dissect. This was part of a lab. We got into groups of two and three. But before we could dissect we needed to learn more about owls, so we got some worksheets about owls and how the owl pellet is formed. After looking over the worksheets and answering a few questions, we started the "lab". The first thing we did was measure our pellet. Our pellet was fairly small. Next we started to dissect the owl pellet with our tools. Our teacher told us to separate the fur from the bones. We picked through the pellet for two days until we didn't find any more bones. Then our teacher told us to use the bones we found and try to create a complete skeleton of an animal. Our group only found a couple of bones so it was kind of tough to put together a skeleton. Also most of our bones were crushed. We used a sheet to help us arrange the bones. Once we put the bones in order, we glued it down on to piece of paper in the shape of a skeleton. To me that was the most fun part about this whole lab. We learned about all the ones about what the owl ate and how it looked too. The final part of out lab was to answer the analysis questions which in my opinion was very easy to finish. After doing all of those steps we finally finished the Owl Pellet Lab.

After finishing the lab I wanted to learn something new I didn't already no from learning from the lab. I went to various sites and learned two things. Before I thought that the owls only regurgitate to get rid of the fur and bones. But now I learned that regurgitation is helpful. Actually the pellet helps clean the esophagus. It is proven that raptors that eat just the meat of animal are not as healthy as raptors that eat their food whole. I also learned about a useful safety procedure while researching the owl pellets. It is said that the rodents inside the pellet may carry disease. One should always sterilize the pellet in the microwave before studying.

http://www.kidwings.com/owlpellets/flash/v4/index.htm

http://en.wikipedia.org/wiki/Pellet_%28ornithology%29



My favorite part about this lab was building the skeleton of the rodent that we found. It was my favorite part of the lab because I learned all about the different bones of the rodent. Also I learned exactly how a rodent looks. This part was also the hardest part of the lab because our group didn't have too many bones, so it was hard to put it all together in the end. Most of our bones were crushed too which made it hard to identify them. This lab was very amusing because I learned so many things about owls and how they form their pellets. With all this information I could become an owl expert! There was one drawback in this lab for me only. This lab was repetitious for me. this was my third time doing this lab. Once in third grade, once in sixth grade, and now. In third grade we didn't do this lab so thoroughly. In sixth grade we did exactly what we did this past week. I forgot most of what I did learn, but this lab was a great refresher course!

animefreak44