The numbers
Warming temperatures from climate change have led tree swallows to nest up to two weeks earlier than they did in the 1970s. This shift in nesting behavior has significant implications for their survival, particularly during unexpected cold snaps that can occur during the breeding season.
Tree swallows, which belong to a guild of birds that exclusively consume flying insects, have shown a marked decline in some regions, such as southeastern Canada. A recent study highlighted that even a few days of cold temperatures during the breeding season can adversely affect the weight of adult swallows, as well as the growth and survival of their nestlings. Conor Taff, a researcher involved in the study, noted, “For parents that are more robust to cold temperature changes, their nestlings are more likely to grow larger and survive under those challenging conditions.”
As climate change progresses, the variability in spring temperatures may paradoxically increase the likelihood of cold snaps. Taff further explained, “Climate change, somewhat paradoxically, might increase exposure to cold snaps, because the birds breed earlier in warmer springs when the temperature is more variable.” This phenomenon underscores the complexity of climate impacts on wildlife.
In addition to the challenges faced by tree swallows, Southern Illinois University Carbondale (SIU) has been proactive in addressing environmental concerns through its tree planting initiatives. Since the initiative began over 20 years ago, SIU has planted more than 100 trees and boasts over 5,200 living trees on its main campus. The university has been recognized as a Tree Campus Higher Education institution by the Arbor Day Foundation each year since 2015.
Opie Piper, a representative from SIU, stated, “SIU is proud to have one of the nation’s most beautiful campuses, and the diversity and number of trees found here is one of the reasons.” The campus has also been designated as a level 2 accredited arboretum since 2019, showcasing its commitment to maintaining a rich and diverse tree population.
Participants in SIU’s tree planting events are encouraged to meet at parking lot 44, located at the corner of Lincoln Drive and Chautauqua Street. Proper care for newly planted trees is essential; it is recommended to apply about five gallons of water to each tree after planting to ensure their healthy establishment.
As the effects of climate change continue to unfold, the relationship between tree swallows and their environment will likely remain a focal point for researchers and conservationists alike. Observers are keen to see how these birds adapt to the changing conditions and what measures can be taken to support their populations in the face of these challenges. Details remain unconfirmed regarding the long-term impacts of these changes on tree swallow populations.
