A recent study featured in *Ornithological Advances* reveals that climate change-induced warmer winters have led to a 25% decrease in the number of young produced each year by the federally endangered Florida scrub-jay since 1981.
Due to warmer winters, Florida scrub-jays are now starting their nesting season a week earlier compared to 1981. However, these early nests might not be as successful.
This new analysis, based on long-term research, indicated that the increase in winter temperatures is having a negative impact on the reproductive success of the Florida scrub-jay. The study found that, from 1981 to 2018, the average winter temperature at Archbold Biological Station rose by 2.5 degrees Fahrenheit, making jay nests more vulnerable to snake predation during the longer Florida spring.
According to Sahas Barve, the lead author and director of avian ecology at Archbold, “The warmer weather leads to increased snake activity, which is a major threat to the nests.”
Compounding the problem, Florida scrub-jays continue to build nests and lay eggs, even after experiencing losses from predators, until they eventually give up, as noted by John Fitzpatrick, director emeritus of the Cornell Lab of Ornithology.
Fitzpatrick, a co-author of the study, pointed out, “Despite a rise in the number of nests and eggs during the extended breeding season, Florida scrub-jays are not producing more offspring. In the avian world, there exists a known trade-off between the quantity of breeding attempts and the longevity of the species. The more energy spent on breeding each year, the less likely they are to survive for five or ten additional years.”
“The prospect that jays are experiencing an ongoing decline in reproductive success, along with decreased lifespan, is concerning,” Fitzpatrick remarked.
The results indicate that climate change may hinder conservation efforts for this species at risk. Barve stated, “Even in permanently protected regions like Archbold, the chances for jay populations continue to worsen. For decades we’ve worked on managing habitats for the Florida scrub-jay, but climate is an uncontrollable factor. A population that seems healthy now may not remain so in the next 10 to 20 years, even if nothing changes on the ground.”
This research was supported by Archbold Biological Station, the Cornell Lab of Ornithology, and the National Science Foundation.
