(BIVN) – The number of US migratory birds that have no idea what’s happening to their environment has been “skyrocketing” in recent years, according to a new study.
Researchers from the University of California-Davis say environmental change is dramatically altering and reversing the patterns of a key component of conservation-friendly forest structure. The researchers say the new “migratory forms” are more spread out and moving in shorter periods of time. These new forms of birds were previously occurring only sporadically in US forests.
The researchers say this “sharp elevation of the importance of birds’ physical and behavioral adaptation” warrants action. From a UC Davis news release:
“Most people appreciate that their reflection reflects a tiny part of the environment they are looking at,” said lead author Russell Albers, a biology professor at UC Davis. “Many people are unaware that the importance of these biological qualities to their health and enjoyment of nature is a much bigger part of their environment, one that goes far beyond physical appearance. And all people live under this dominant assumption that we ‘won’t need our old kind anymore.’ The new birds represent the growing possibility that the survival of these kinds of bird types, which we’ve taken for granted for many years, will depend heavily on how their physical and behavioral adaptations adapt to their environment.” The study is the first to make direct measurements of both vegetation structure and behavioral adaptation in nonmigratory woodpeckers and large passerines in the US and Canada. It helps shed light on how evolutionary pressures are changing the forest trees of northern US and Canada, researchers say. “Migratory change is more important than previously thought for birds’ adaptation to changing habitats because plants are the primary food source,” said corresponding author Demery Hawkins, a graduate student and doctoral candidate at UC Davis. “Migratory birds are super unlikely to reestablish themselves in a given habitat if the plants are poor or gone.” The detailed analysis of the biomeographic attributes of the two migratory species in terms of the forest canopy and how they behave under limited fruit and shrub cover captures a precise spatial distribution of change. Both species historically migrated to large groups of crowned yellowthroats in mid-winter in Moxico Forest in the U.S. Coastal plain, a closely related microclimate known as the tropic of the tropics. Common yellowthroats are highly adaptable tree-climbing birds that grow up to four inches in featheriness and 11 inches in body size. The researchers also determined which of the two species restricted themselves to dominant clusters of mature trees that they surrounded. Then they measured the degree to which the preferred berries, shrubs and dense conifers changed to accommodate the new behavior. Based on these measurements, the researchers were able to forecast the future of behavior and habitat that underlies the “changed form” of these birds. “Our study makes a strong connection between behavioral adaptation and forest structure that is not directly apparent to most people who identify with a bird,” Hawkins said. “In addition, I find it interesting that both wings have interesting shapes, with one inclined with a tail behind and the other forward. These shapes are not limited to a single taxonomic group, like Great Titania or Lesser Titania, but appear all the way down into the insect family.” The research was funded by an EPA postdoctoral fellowship. UC Davis is one of only a few American research universities to make the “100 Best College Cities” list released by U.S. News & World Report this week. Read more news from UC Davis here