Questions:
A. What is the shape of a barn owl pellet?
The shape of a barn owl pellet is an oval.
B. Do the pellets differ much from each other in weight or length? What does this mean?
Yes, the barn owl pellets may differ from each other in weight and length. This shows us how much the owl ate in that feeding.
C. All the pellets came from the same roost. How many kinds of skulls did you find in them? To what kinds of animals did the skulls belong?
We found four different kinds of skulls from the pellets used in our lab. They belonged to mice, voles, shrews, and rats.
D. If these pellets had come from several roosts, would you expect to find the same kinds of skulls? Why or why not? What 3 factors would determine the types and numbers of skulls
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Based on the class data, what is the average number of skulls found in one pellet.
Based on our class data the average number of skulls found in one pellet are around 8 skulls.
F. Look up the answer to this question: on the average, how many pellets are produced daily by one owl (of any species)? What 2 factors might determine the number of pellets produced?
Owls will produce one to two pellets per day depending on how much they have eaten that day.
“Evans and Emlen (1947) estimated that a Barn Owl in California ate 150 g per day. This may be too high as it was based on two pellets per day and available evidence indicates that American Barn Owls average less than that per day (Wallace, 1948 and this paper).”
G. Why don’t most birds produce pellets? Of what value, then, is pellet production? Thousands of years from now, do you expect more birds will be pellet producers? Why or why not?
Most birds do not produce pellets because they have a crop- an organ used to store food so it can be digested later. In owls, the food passes from the moth to the gizzard. The gizzard does not let harmful things such as teeth, skulls, and claws pass through it. Instead, it compacts the material into a pellet. More birds in the future might become pellet producers. This is because their bodies will evolve and adapt to them eating things such as bones. Therefore, their bodies will be able to identify these things as
The 11th generation of forkbeaks would probably average out to two beaks, as they have plenty of time to hunt for enough wildloops.
The Pacific Northwest is perhaps most commonly known for its awe-inspiring old growth forests that have been gracing the land for hundreds and hundreds of years. The land in British Colombia, Canada, Washington state, Oregon, and parts of Northern California are the only areas in the world where these forests exist. One of the most unique and amazing inhabitants of this age-old forest is the Northern Spotted Owl. The Northern Spotted Owl has been on the endangered species list for over ten years now. The Northern Spotted Owl can only be found in these old growth forests. The northern spotted owl requires many acres old forests to survive, due to its scarce food supply. They are very sensitive to their habitat, and simply cannot survive in any other environment. These owls, as well as the forests have been disappearing at an alarming rate due to the immense logging industry in its area.
Roise, J., Chung, J., Lancia, R., and Lennartz, M. 1990. Red-cockaded Woodpecker habitat and timber management: production possibilities. Southern Journal of Applied Forestry. 14(1):6-12.
Four hypotheses of how the bodies got there occupation, water transport, predation, and death trap were ruled out. A new hypothesis was formulated what if Homo naledi intentionally buried their dead? Although there is not enough evidence yet to confirm this, such behavior would be significant in that it would precede previous cases of the behavior in Neanderthals and humans. This would add to the argument that Homo naledi are of the genus Homo. After the examination of these fossils and extensive research, it was concluded that Homo naledi were a new species of the Homo genus.
Most of the bones are pneumatic, meaning they are hollow and filled with air spaces connected to the respiratory system. Thus the hollow bones reduces the weight of birds which makes the lighter to fly freely.
The spotted owl is an eighteen-inch tall bird-of-prey that roams the thick forests of the Pacific Norwest. The adult spotted owl enjoys a life at the top of the food chain for the region. This bird has only one enemy, the logging companies that inadvertently threaten its natural habitat. Clear-cutting operations of old growth forests destroy breeding and hunting areas. Clear-cut logging is the timber industry's version of strip mining. Almost nothing remains that resembles the forest that once stood there except for thousands of tree stumps the size of Volkswagens.
The Northern Spotted Owl can only live in old growth environment, it is considered an “indicator species”: The health of the Northern Spotted Owl population indicates the health of the old-growth forest ecosystem. An individual Northern Spotted Owl needs more than 3,000 acres of old growth to survive, because of its scarce food supply. The Northern Spotted Owl is found in the cool, moist woodlands on the Pacific Northwest. The habitat of the Northern Spotted Owl can be described as trees relatively large in diameter in the stand, multi-layered canopy, large tall live trees with cavities, broken tops, mistletoe, or platforms of branches capable of holding accumulated organic matter suitable for use as a nest, dead standing trees and fallen decayed trees to support abundant populations of prey species, especially northern flying squirrels and woodrats.
5) What are Dryomomys and why are their important from a biological anthropology perspective? What do these fossils tell scientists about early primate evolution?
In conclusion, owls have shown they are excellent at adapting to any environment by the ability to fly silently to stalk prey. They use camouflaged and insulated feathers to hide and keep warm while hunting. Owl’s excellent binocular vision, and hearing helps to track prey from long distances. The only real risk of extinction of the burrowing owl is if people continue to kill off animals that dig holes for them. They have shown the ability to survive for a long time with the help of other animals digging holes for them. Owl’s will continue to evolve long after humans have
direction, the major problem for their decline would have to be remedied – loss. of the habitat of the sailor. This fact combined with the owls' short life expectancy and late age. breeding only exacerbates the problem. When loggers remove old growth owl loses habitat for its food, housing, as well as protection from predators.
8. Taylor, Dan. 1998. Audubon Society Inspired to Action by Bird Die -offs . 17 Jan. 1998 . E-mail . Available bkus@sunstroke.sdsu.edu
Chapter 6: Mary Roach explains the use of cadavers for weapon experiments. Although it was sometimes ineffective for evidence evaluation scientist replaced them with animals such as pigs to receive better data. Changes like these were made to have more efficient experiments and have easier removal.
American Crows can reach a length between 17 to 21 inches, with a wingspan of 39 inches, while the Common Raven is a larger bird that has an average length of 24 inches (Burton et al. 2010; Marzluff et al, 2013). Both the American Crow and the Common Raven have black coloration, but their feathers and beaks differ. Common Ravens have a larger, stronger beak, a wedge-shaped tail, and spikey feathers on their throat. American Crows, on the other hand, have a smaller and less bulky bill, smooth throat feathers, and they have tail feathers that fan out instead of forming a wedge (Marzluff et al, 2013). The two birds have different styles of flying.
The variation in finches is one in three and the variation in sparrows is four in ten thousand.