Journal
OECOLOGIA
Volume 196, Issue 1, Pages 89-100Publisher
SPRINGER
DOI: 10.1007/s00442-021-04918-7
Keywords
Aquatic insects; Diet; Ponds; Tree swallow; Temperature
Categories
Funding
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Mathematics of Information Technology and Complex Systems (MITACS) Accelerate fellowship
- Environment and Climate Change Canada
Ask authors/readers for more resources
The study revealed that the pre-fledging quality and annual recruitment of nestling tree swallows are influenced by dynamic interannual changes in climate, pond availability, and aerial insect food supply. The abundance of ponds is found to have a strong impact on nestling mass and inter-annual apparent recruitment, suggesting higher quality aquatic prey for aerial insectivores like tree swallows.
Wetland systems, including shallow palustrine ponds, are hotspots for emergent aquatic insects but are globally threatened by land-use practices and climate change. Loss of insects is hypothesized as a key driver of population declines in aerial insectivores, but studies of climate-driven fluctuations in pond abundance during wet-dry periods and aerial insects on nestling quality and apparent recruitment are lacking. Using tree swallow (Tachycineta bicolor) data spanning 14-28 years we evaluated: (1) whether nestling quality based on pre-fledging (similar to 12 days old) body mass changed over the time series; (2) how annual estimates of aerial insect biomass and variability, temperature, and pond abundance influenced nestling mass; and (3) whether the annual number of recruits produced was related to the annual mean mass of nestlings, aerial insects, and pond abundance in their year of hatching. Average nestling body mass varied annually but no long-term temporal trends were detected. Nestlings were heavier when raised during periods of stable insect biomass, warmer temperatures, and higher pond abundance. Pond abundance consistently had strong effects on nestling mass and inter-annual apparent recruitment, suggesting that this metric provides a complementary index of either higher prey abundance or higher-quality aquatic prey. Overall, pre-fledging quality and annual recruitment of nestling tree swallows reflects dynamic interannual changes in climate, pond availability, and aerial insect food supply. Our findings further suggest the abundance of ponds in this semi-arid prairie landscape is likely a strong predictor of regional population stability in tree swallows and possibly other ecologically similar species.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available