In this lab we worked with owl pellets and dissected them to discover the animals the owl had eaten. The purpose of the lab was to identify what type of animal our owl had eaten, weather it be a rodent or bird. To unearth the bones we had to use tweezers and a prod and slowly chip away at the vomit… gross. Once we classify as a rodent or bird, we were told to use our bone identity sheet in which we would identify key features of the bones. After identifying the key bones, we then put together as much of a skeleton as possible. For us we did not have a skull to confirm our speculations, so we had to base them off of the pelvis we found.
Claim: The animal that the owl had eaten was a shrew.
Evidence:
^ Femur joins to the target bone and the target bones parallelism of structures and the way they seem to fit together
^ bones laying flat depicts similarities. Joint location on bone above loops.
Reasoning:
We can conclude that the animal consumed by the owl was a shrew as the pelvis bones resemble that of the classification table. The bones are long and skinny, similar to that of a shrew. Another defining characteristic of the bone is the location of the loops. In the shrew the loops are very large and are composed of very little bone in comparison to the other rodents pelvis. Another defining characteristic is the # of loops found in the pelvis. The shrew only has 2 loops whereas the mole has 4. This evidence immediately eliminates a mole as the possible animal. Another defining characteristic is the smoothness of the bones. Where vole has a rigid pelvis, the shrew has a smooth one. This means that the animal that was likely consumed was a shrew.
Compare and contrast to humans:
Similarities of structures:
- Both bones serve the same function which is allowing the animal to move
- Both skeletons contain lumbar vertebrae
- Both skeletons contain ribs that protect vital organs
Differences in structures:
- elongated pelvic bone as the shrew uses all 4 limbs to move whereas humans only use our legs
- the pubis is proportionally longer
- The pelvis of humans is anatomically different as it allows the vertebrate to connect, leaving a ‘hole’ in the middle of the pelvis
