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Lecture: Animals in a particular region: Narrator: Listen to part of a lecture in an ecology class. Professor: So from wildlife management discussion yesterday, we see the biologists and land managers need to know what kind of animals and how many are moving through a particular area. It helps them to better manage natural resources and to make policies for government programs and such. Now when researchers want to identify mammals living in a certain area, they might study tracks, footprints that animals leave there – that's the traditional method – or they might collect animal hair – fur. Hair is a good source of genetic information about an animal. To collect hair, researchers often use devices called hairsnare. To use a hairsnare, you set up some bait like food. And when an animal comes to eat it, it brushes against the hairsnare, which might be something like a piece of wood with special glue or tape on it. A little bit of hair stick to the snare, and then the researchers study it, do DNA test to determine what species of mammal it is. Hairsnares work, but they can be a bit annoying or invasive to the animal whose fur being collected. Recently, a study conducted in Hungary avoided this problem by taking advantage of the nest building behavior of birds. Most nest building birds make new nests almost every year, and they incorporate a lot of organic materials, such as twigs, branches, leaves, and animal hair. You know, animal shed retired hair behind where they sleep, where they have dens, where they rub and scratch against street. You can picture a bear, a bear with an itchy back scratching it against the tree. Well, some pieces of fur get stuck in the tree or fall to the ground and get collected by birds as they pick up leaves or mud for their nest. So anyway, the researchers went through chosen forest areas in the mountains and plains in central Hungary, and collected all the nests they could find. They collected over 3,600 nests. Some nests were in areas relatively isolated from humans, and some were closer to villages and farms. And the best time to collect nests is after the nesting season. For the end of the fall, when the birds have migrated, and nests are uninhabited, which is what the researchers did. In this way, they avoid being invasive and interfering with egg laying and the raising of young. The nests were tested for location and then taken into a lab where they were dried and put into a deep freeze. This helps preserve the nests and also sanitize them because, well, who knows what they could be contaminated with. Then, the researchers carefully disassembled the nests and when the hair was separated, they were able to inspect them under a microscope and do a molecular and DNA analysis. Finally, the hair was categorized according to species and frequency of occurrence. How many nests contained hair from a certain species? So what did they find using the nests collection method? Lots that was expected and some that was not. As you might expect, the most common animal hair came from wild animals that are common in Hungary, such as dear and wild sheep. Surprisingly, in one area with human development, like pastors and thoughts of such, the nests collected their contained only a few hair from domestic animals like dog and some nests have hair from animals where we found in the region like the golden jago. Now, the study also revealed some shortcomings of the nests collection method for wildlife management. While we can let us know what kinds of mammals are in an area, they cannot tell us how many individuals of a particular species are present. While you can find hair of a particular animal, you can't tell how many of these animals are around, either living in or just passing through a certain area. And that's an important aspect of wildlife management. So you still have to use a different technique to determine the number of certain animals in an area.