A Western biology master’s student has made a discovery about American goldfinches, which is garnering attention for being the first of its kind.
Thomas Luloff, who studied 120 goldfinches in captivity, showed mating patterns for the birds are influenced by their surroundings.
“This work is the first to show that birds are capable of integrating multiple sources of environmental information to fine-tune when they choose to breed,” he explained, noting the findings provide insight into how climate change and altered weather variables might affect songbirds in the future.
Splitting the birds into either a summer room with hot temperatures and a long day length, or a spring room with cooler temperatures and a shorter day length, Luloff used thistle plants at various stages of bloom to cue the birds visually.
Considering food availability, Luloff hypothesized the birds in the summer room that were exposed to blooming thistles would develop reproductive organs fastest as a response to the indication of food being on the way, as well as to the warmer temperatures.
Confirming his hypotheses, the findings offered an extra element of interest.
“Birds in the hot room overall had greater and faster reproductive development compared with birds in the cold (spring) room, showing that temperature affects songbird reproduction. But more importantly, we found that there was an enormous response to the visual cues,” he said, explaining the birds who saw the blooming thistles had over twice the amount of testosterone compared to the other birds in the same temperature room.
“This is important because it shows that even just by looking at the plants without being able to eat or touch them was enough to strongly affect their breeding,” he elaborated.
To continue his research, Luloff plans on looking at different plant cues, populations and species.
“By studying how the environment affects reproductive potential, we can begin to understand what factors affect breeding and hopefully try to solve them.”