MISSOULA — A University of Montana scientist was recently awarded a National Science Foundation grant and believes his research into the effects of elevation and climate change on tropical birds will inform science’s understanding of how those species survive in a warming world.
Tom Martin leads the study, which is called “Dimensions: Collaborative Research — Historical and Contemporary Influences on Elevational Distributions and Biodiversity Tested in Tropic Asia.” It was recently backed by a $2 million National Science Foundation grant, and has partners from the Smithsonian Institution, the University of Kansas and Louisiana State University.
A large sum of the grant, $1.3 million, will come to UM for the study, and Martin will lead a group of student researchers to the tropical island Borneo to study birds in two superfamilies — the Sylvoidea and Muscicapidae families. The team of researchers will depart in early February and return in June.
The study examines the effects of elevation and temperature change on tropical birds, which Martin describes as ideal test subjects due to their narrow tolerance for environmental shifts. In the wild, species in the same genus are stacked on top of one another, separated both by elevation and latitude. As you move higher up a mountain or to higher latitudes, you will see species change with little to no bleed-over, he said.
Martin and the team of researchers hypothesize that these species’ ranges aren’t based solely on competition or physiology, but rather as a result of those traits interacting with fecundity and survival strategies.
“One of the things that’s becoming increasingly recognized, especially in the tropics, is that as things warm up, some species don’t have the physiological tolerance to deal with global warming,” Martin said. “So they’re being pushed up the mountain, and the species that are at the top of the mountain are then being pushed off. There’s no habitat that’s suitable for them.”
Martin will use a team of three doctoral students and about 10 postgraduate students for the study. They will locate nests, measure eggs, take temperature probes, record video of the parental behavior, and more. The group also will measure the metabolism of eggs, nestlings and adults in the lab before returning them safely to the wild. The data will help them understand how changes in temperature affect the most basic bodily functions of the birds.
Martin said the two bird superfamilies have broad variation within their species, which allows for detailed study of the impact of small changes on related subjects. Even the wild behavior of the birds is a good indicator of the importance of temperature on their development.
“If you look at the Sylvoidea, you have a species there where parents will spend 90 percent of the time on the nest and the embryos will develop in 13 days,” Martin said. “And then you have another species there that takes eight-hour off-bouts every day in the middle of the day, and so they’re only on the nest 40 percent of the time and their embryos — same size — take 24 days.
“So the exact same size eggs grow in 13 days versus 24 days because of the differences in the way parents take care of them.”
Researchers at the Smithsonian, and at universities in Kansas and Louisiana, will study separate data gathered from the birds, such as genetics of the populations and the potential parasites identified in blood smears. The team will take a cross-disciplinary look at the biology, behavior and impact of external factors on the birds to develop a better understanding of what causes species to separate. The predominant theory of competition doesn’t explain current developments, according to Martin.
“The fact that we see species moving elevationally as temperature rises suggests that there is an influence of physiological tolerance and not competition,” he said. “If it were competition, they shouldn’t move.”