UD doctoral candidate conducts wood thrush studies around Newark

May 8, 2013 under CANR News

The University of Delaware’s Zach Ladin has been studying the wood thrush for the past three years — continuing research started by Roland Roth 37 years ago and continued by Greg Shriver, associate professor in the Department of Entomology and Wildlife Ecology, in his Forest Fragments in Managed Ecosystems (FRAME) program – and is looking at how breeding birds can provide clues to the relative health of the environment.

“We use birds as environmental indicators,” said Ladin, a doctoral candidate in the College of Agriculture and Natural Resources. “When you go to the doctor, they take different measurements, like blood pressure. By itself, your blood pressure may not mean anything but it gives the doctor insight into whether you’re going to have a heart attack soon or whether you’re suffering from some sort of heart disease, or any number of diseases that might be associated with that. So we’re using birds as a window into the health of the forest.”

To do that, Ladin has expanded the territory of the study originated by Roth.

While Roth’s initial study focused solely on the ecology woods located east of Delaware Stadium, Ladin’s study has spread out all over the city of Newark. Using 21 sites around Newark, Ladin looks at how the birds respond to human impacts in an urban landscape, using areas like Iron Hill, the Newark reservoir and White Clay Creek, among others.

Ladin said that Newark is the “ideal place to study urbanization since we’re right in this Mid-Atlantic region. We’re interested in how these birds are responding to an urban landscape.”

Zach Ladin studies wood thrush in UD's ecology woodsSome sites, like Iron Hill, are doing very well when it comes to having large populations of wood thrush, while other sites, such as the small patch of woods across from the hotel at the intersection of Routes 4 and 896, are completely devoid of wood thrush.

Just because a site has a large number of the birds does not necessarily mean that it is a healthy habitat, however. It could simply mean that the wood thrush are “getting pushed out of all the very high quality spots,” said Ladin. “Maybe they were pushed out of White Clay Creek or Iron Hill and this is a last resort for them, so you end up seeing the refugees getting shoved into a very small and isolated spot. It could be a bad sign.”

Ladin explained he trains crews of students that try to locate wood thrush nests, doing so by listening for audible cues, such as when the birds make an alarm call when the researchers get too close to their nests. Once they find the nests, they input the GPS coordinates and monitor the nest every three or four days.

“We keep close track of the eggs,” said Ladin, explaining that sometimes crew members will find eggs from a different species in the wood thrush’s nest. “There’s actually another type of bird called the brown-headed cowbird that will lay its eggs in other species’ nests. It’s called brood parasitism where they’ve evolved a really clever technique. They don’t raise their own chicks, they just go around and lay eggs in other birds’ nests and let those birds raise their chicks.”

Ladin said that while some species can recognize cowbird eggs and remove them from their nests, the wood thrush do not. “There’s an evolutionary arms race going on and the wood thrush have not figured that out quite yet.”

As far as the number of wood thrush breeding in UD’s ecology woods, Ladin said that there are currently around 20 birds per year, which is down considerably from the peak numbers of 70-80 during the 1990s.

Ladin’s research is trying to determine why the numbers are decreasing not just in the sites around Newark but across the eastern United States.

“One of the things we’re looking at is if the soil calcium is a limiting factor for birds, since they need it for their eggshells and the nestlings need it to grow their bones, and this is one of the highest concentrated areas of acid rain in the country,” said Ladin.

Ladin also wants his research to highlight the fact that on the East Coast, especially around the I-95 corridor, there may not be big patches of forests but there are lots of little patches that play an integral role in improving the environment.

“If you add up all these tiny patches of forests that have been subdivided, it’s actually over 1.2 million acres of forest,” said Ladin. “My motivation is to show people that this is highly critical habitat and that you can’t just discount a small patch of forest because its only three or four acres. Those patches provide really important services for us — like helping clean the water, and helping sequester carbon, reducing CO2 from the atmosphere — so we have to make sure we’re out to conserve their proper functioning. Studying the bird response in those patches is one of the best and most cost-effective ways to do that.”

Article by Adam Thomas

Photos by Danielle Quigley

This article can also be viewed on UDaily.

Share

Professors, students travel to UFLA; interns selected for collaborative work

April 24, 2012 under CANR News

Three professors and two graduate students from the University of Delaware spent spring break in Brazil, visiting the University Federal de Lavras (UFLA) campus, strengthening the academic and cultural bonds between the two universities and taking in the sites and sounds of the South American nation.

In addition, four UD College of Agriculture and Natural Resources (CANR) undergraduate students have been selected for an opportunity to develop international teaching modules in conjunction with professors and students at UFLA and UD, and to visit this University in 2013.

About the UFLA trip

During the spring break trip, the UD delegation spent its time meeting with faculty from UFLA, touring the facilities, teaching classes and taking trips to remote locations ranging from waterfalls to biodiesel factories. They were escorted by Eduardo Alves and Antonia dos Reis Figueira, both professors of plant pathology at UFLA.

Greg Shriver, assistant professor in CANR’s Department of Entomology and Wildlife Ecology, said he found it to be a very informative trip and found that much of the research being conducted by entomologists at UFLA is similar to research under way at UD.

Talking with Jùlio Louzada, the head of UFLA’s applied ecology department, Shriver said, “They actually have a forest fragmentation study going on in and around Lavras, which is a lot like the study we have going on in and around Newark.”

Shriver and Zach Ladin, a CANR doctoral student, were able to visit part of the Cerrado, a vast tropical savannah ecoregion near the UFLA campus where the study is taking place, and said that the two universities hope to collaborate on their studies regarding dung beetles.

Nicole Donofrio, assistant professor in the Department of Plant and Soil Sciences, said she was impressed by the campus, noting that “the academic buildings are gorgeous and equipped with an impressive array of new research equipment,” and added that the trip was crucial in providing strong connections between the two universities for the coming years.

“One of the goals was to make more connections and try to find additional links for people to have ‘sandwich students’ here in the next two years,” Donofrio said. Sandwich students refers to a program established between the universities in which UFLA doctoral students spend one year studying at UD that is “sandwiched” between their studies at UFLA.

Donofrio and Emily Alff, a CANR master’s student, taught a class on fungal transformation for the UFLA students. Alff said that being on the UFLA campus was a tremendous experience. “All the research they do is so applied,” she said. “It really makes you think about the bigger picture of research as a whole.” She added that the food and climate were perfect, saying, “Brazil is just a gorgeous country.”

Tom Powers, assistant professor of philosophy in the College of Arts and Sciences (CAS) and director of UD’s Center for Science, Ethics and Public Policy, said he was impressed by a UFLA practice in which they try to “leave nothing behind.”

Powers joined Donofrio and Alff on a visit to UFLA’s model biodiesel and bioethanol plant, located on the campus. “They use the water from the roof and the parking lot to run a lot of the processes,” he said, adding, “They use everything from, or have the potential to use everything from, fish guts to waste from sugar cane and castor beans. So, in terms of using all of these materials for the production of biofuels, it’s really astounding. And then what they don’t make into biodiesel they make into soap and everything else. They’re really trying to find some use for every byproduct in the production process.”

About the Brazil internships

Four CANR student interns have been chosen for an opportunity to conduct research and teach courses at UFLA.

The four interns who have been chosen for the project are:

  • Sarah Thorne, a junior;
  • Sara Laskowski, a junior;
  • Jacqueline Hoban, a freshman; and
  • Melanie Allen, a junior.

The internship will run from April 2012 through June 2013, with the interns supervised by UD faculty teams.

Hoban said she is looking forward to getting to travel to Brazil, and “excited about getting to work with a lot of interesting people and learning about a wide variety of research topics.” Hoban said that the internship “appealed to me not only because of the exciting travel opportunity, but also because it seemed like a really interesting way to apply the material that I have been studying in class.  The project gives me a different perspective on the subjects that I am interested in learning about. It also opens my mind to the educational aspect of my fields of study.”

Hoban added, “Everyone on the team seems like they have a lot of passion for their research and I cannot wait to work with them.”

The project is led by a faculty team from CANR and CAS and is intended to help build longstanding academic programs and research partnerships with UFLA that will enhance the international nature of curricula in areas of common interest, such as food security, bioenergy animal agriculture and biodiversity.

The project will also aim to stimulate creative thinking in the students who participate about how to develop innovative solutions to complex global agricultural and environmental problems.

There will be a curriculum enhancement portion of the internship, where students will assist faculty on both a part time and eventually a full time basis, and an experiential learning aspect, where the students will travel to Brazil for up to four weeks with UD faculty.

The interns will be responsible for developing a minimum of two teaching modules per course, and the modules will consist of PowerPoint presentations or other innovative learning methods that provide detailed information on the course topics developed by the interns and their faculty advisers.

This new research and teaching project is supported by the U.S. Department of Agriculture’s International Science and Education Program.

Article by Adam Thomas

This article can also be viewed on UDaily

Share