Home / Environment / Swallows Shrink as Climate Disrupts Food Chain
Swallows Shrink as Climate Disrupts Food Chain
2 Jul
Summary
- Tree swallows are laying fewer eggs and shrinking in size.
- Insect populations have declined by over 60 percent since 1977.
- Warmer springs cause insects to emerge earlier than swallows arrive.
Research at Long Point Bird Observatory, a UNESCO Biosphere Reserve near Lake Erie, reveals climate change is affecting local wildlife. Studies published in the Proceedings of the National Academy of Sciences indicate tree swallows have been producing fewer eggs and shrinking in body size since 1969.
Concurrently, aerial insectivore populations, like tree swallows, have fallen by 43 percent. Insect numbers have also dropped by more than 60 percent since 1977. Researchers attribute this to warmer spring temperatures causing insects to emerge earlier, creating a timing mismatch with swallow migration and breeding.
This phenological mismatch has increased by over three days per decade since 1977. When insect abundance is low, tree swallows, both adults and nestlings, are smaller and lay fewer eggs. This ecological imbalance is exacerbated by a broader decline in insect biomass, affecting both terrestrial and aquatic species due to landscape changes and climate shifts.
Scientists recommend local actions such as planting native wildflowers, reducing pesticide use, and retaining natural habitats like wood and leaves to support insect populations. These measures can help mitigate the impact on the food chain, underscoring the interconnectedness of ecosystems.
