Adélie Penguin Bird Count

Transcription

1 Adélie Penguin Bird Count Knowing how many of any animal is one of the first questions researchers seek to answer when they study a population. Getting to that answer is not always easy. If you wanted to know how many robins were in your county how would you do that? If you wanted to know how many deer were in the forest, what would be your procedure? How about whales in the ocean? Unlike plants that don t move, each specie of animal provides its own challenges when it comes to population counts. Our research team monitors four breeding colonies of Adélie Penguins in the Ross Sea area, three of them are on Ross Island. Here are some of the questions we are asking: How many penguins are there? Are their number increasing or decreasing? What would cause one colony to increase in numbers, while another one declines? Do penguins always return to the colony of their birth to create their own nests? If they don t where do they go and why? If you would like to read about our research and meet the team go to: There are so many factors to consider both biotic and abiotic when coming up with answers. It takes creativity, long term commitment to the project and many long hours working with the penguins. Many people would think penguins are easy to count. There are no trees for them to hide in, they are not afraid of us so won t run away, and if they are on a nest, they stay on the nest. However it is not that easy. Penguins are always walking around and there are many of them in a small area. Counting individuals is difficult and it s hard to know if we double count or missed one. To solve this problem we use a special camera and a helicopter to take aerial photos of the three colonies on Ross Island. We then use the computer to count them. But even that is not always easy. The photo is from a long way up, many penguins look like rocks from 3000 ft. So we add a process called ground-truthing, which means we also do a ground count and compare it with what the aerial photo says. We do it on the same day which doubles the count and helps us with the confidence level of the real number. The sample photo below shows a small breeding group which is easy to count and here are the various categories of census. To make a complete survey we need all these categories counted. 1. Number of adults in the breeding area. 2. Number of pairs 3. Number of occupied nest areas 4. Number of non-active nests

2 A. This bird is laying on a pile of rocks which indicates a nest. We assume there are eggs so consider this an active nest. Counted as a) 1 adult, b) 1 occupied nest B. Notice the bird on the nest. The bird standing close to it must be the mate or the nested bird would never allow it to be that close. Counted as a) 2 adults, b) 1 occupied nest c) 1 pair. C. This bird is a long way from the group which usually means they are just resting. Note he is outside of the brown area which means he is not part of the breeding group. Do not count this bird. D. This is a South Polar Skua. Do not count. E. This bird is alone and near the group but not on a nest. Notice there are no rocks under him. Counted as a) 1 adult. F. This is another nesting pair. You can see the pile of rocks under the one adult and since the second adult is so close, it must be the mate. Counted as a) 2 adults, b) 1 occupied nest c) 1 pair. Try the next two photos on your own. In your group, decide how to count the selected birds. Key to Practice Test #1 1. Counted as a) 1 adult, b) 1 occupied nest area c) 1 non active nest ( notice no rocks, so probably no eggs. 2. Counted as a) 2 adults, b) 1 occupied nest area, c) 1 pair 3. Counted as a) 1 adult, b) 1 occupied nest area 4. Counted as a) 1 adult, b) 1 occupied nest area c) 1 non active nest

3 Now try these. Key to Practice Test #2. 1. Counted as a) 1 adult, b) 1 occupied nest area, 2. Counted as a) 2 adults, b) 1 occupied nest area, c) 1 pair 3. Counted as a) 1 adult, b) 1 occupied nest area, c) 1 non active nest (no eggs) 4. Counted as a) 2 adults, b) 1 occupied nest area, c) 1 pair ( the one in front of it) Now count these two groups and see how your numbers compare to the researcher.

4 If your counts are within 1-2 of the researchers, call it good and go on to the real photos. Use whatever method you prefer to count the penguins in the following pictures. Send us the data in table form based on the categories described above and the picture number. The area to be counted in each picture is outlined in red. 6_112811, 9S_112811, 10S_112811, 9N_112811, 1A_112811, 11_12a_112811, 11_12b112811, 11_12c_112811, 11_12d_112811, 11_12e_

5 Keys to Practice Tests Here are the counts the researcher came up with and the marked photo. Category Color Group #1 Group #2 Adult red Occupied nest area Lt blue Pair yellow 3 3 Non active nest pink 5 6