Caring for the Birds in Our Backyard

[dcwsb inline="true"]

Zoo InternQuest is a seven-week career exploration program for San Diego County high school juniors and seniors. Students have the unique opportunity to meet professionals working for the San Diego Zoo, Safari Park, and Institute for Conservation Research, learn about their jobs and then blog about their experience online. Follow their adventures here on the Zoo’s Website!

IMG_0048In the field of wildlife conservation, it can often be difficult to get concrete results fast. When big changes are made to restore a damaged environment, it can take years or even decades before see any major improvements can be seen. That’s why it’s up to field researchers to monitor the progress of animals and plants in a given region, and to ensure that the population remains stable. Field researchers also categorize the problems seen in the wild to find out what can be done to help them in the future. For ecologists like Colleen Wisinski, a research coordinator at the Applied Animal Ecology Division at the Zoo’s Institute for Conservation Research, this means surveying large swaths of land, and describing in detail the status of the ecosystem. Without her research coming directly from the field, it would be nearly impossible to know how well these animals are doing in their natural habitat.

Ms. Wisinski’s field research focuses around monitoring threatened bird habitats. In our time with her, Ms. Wisinski took us to Biodiversity Reserve, 900 acres of undeveloped land that sits behind the San Diego Zoo Safari Park, to take a look at the site of an older project involving the endangered San Diego cactus wren. Cactus wrens are small birds, which build elaborate nests inside large prickly pear cactus plants. The birds use the cactus as protection from potential predators, as well as a strong foundation for their big nests. Cactus wrens require coastal sage scrub habitat, which means lots of drought-resistant foliage, a lack of human presence, and most importantly, the prickly pear cactus. In order to boost the wrens’ numbers in the region, the Institute for Conservation Research received a grant to repopulate several key habitats throughout San Diego with prickly pear cactus. These cacti won’t just benefit the wrens, but all the native San Diego wildlife, which depend on these plants for food and shelter. However, those cacti were planted years ago, and now that time has passed we can look back to see just how the cactus wrens have adjusted to the new homes.

In order to measure the success or failure of a wild population, such as the cactus wren, scientists need unique methods to accurately determine the estimates of changes in population numbers. For us humans, we measure changes in population with the census. Somebody comes to our home every 10 years to measure how many people live there. It’s a bit trickier with animals, because there’s really no way to know the exact population. As a result of this, scientists have had to find new ways to survey an ecosystem and determine how many animals live there. With small vocal birds, like the cactus wren, one approach is known as point counting. Point counting is a system, in which a field researcher simply watches and listens from a certain point and counts how many birds she can hear or see from a certain distance. The region is first divided up into a grid, and the corners of each grid square are used as a point from which the scientist will perform the point count. These studies require a lot of patience and have to be performed several times in order to get the most accurate data. Sometimes repeated point counts are done at different times of day to help make the survey as random as possible. By keeping the time of day random, biologists ensure that they aren’t counting the same birds, keeping the population counts as diverse as possible.

Being a field biologist is hard work, requiring hours of observing and cataloging data outside. However, its benefits are very tangible, allowing us to measure with more certainty exactly how effective these conservation programs have been. Field biology is looking at conservation from the big picture, and asking the simple question “Is this working?” In the case of the wrens and burrowing owls, the answer seems to be yes, though it is still too early to say for sure. All of the hugely important discoveries made in the lab mean nothing if we can’t see how they affect what happens out in the wild. That is why working in the field is so crucial to our understanding of conservation.

Mark, Conservation Team
Fall Session 2014