Long-term, climate-driven phenological shift in a tropical large carnivore.

Area of Science:

• Ecology
• Climate Change Biology
• Conservation Science

Background:

• Phenological shifts are crucial for predicting ecological responses to climate change.
• Top predators' phenological responses are understudied, limiting understanding of climate impacts on ecosystems.
• Theoretical expectations suggest weaker phenological shifts in species at high trophic levels, but empirical evidence is scarce.

Purpose of the Study:

• To investigate changes in African wild dog (Lycaon pictus) reproductive phenology over 30 years in response to climate warming.
• To assess the relationship between phenological shifts, temperature changes during birthing and denning, and reproductive success.
• To determine if phenological shifts in this top predator are adaptive or becoming maladaptive.

Main Methods:

• Analysis of a 30-year dataset encompassing 60 African wild dog packs and 141 pack-years.
• Examination of trends in parturition timing and associated temperatures during birthing and denning periods.
• Correlation of reproductive success with observed changes in phenology and denning temperatures.

Main Results:

• African wild dogs have delayed parturition by an average of 7 days per decade, tracking stable birthing temperatures.
• Denning temperatures have increased over time, despite the phenological shift.
• Increased denning temperatures were significantly associated with reduced reproductive success.

Conclusions:

• Climate-driven phenological shifts in top predators may be more common than previously thought.
• The observed phenological shift in African wild dogs may become maladaptive due to increasing denning temperatures.
• This study extends theoretical understanding of species traits and environmental factors influencing phenological shifts under climate change.