Tropical bird populations are experiencing a significant decline due to increasing heat extremes caused by climate change, according to a new research analysis.
Headline: Rising Heat Extremes Pose Major Threat to Tropical Bird Populations, Study Finds
A groundbreaking study published in Nature Ecology and Evolution has linked human-caused climate change to significant declines in tropical bird populations worldwide. This research, the first of its kind, uses climate attribution science to attribute biodiversity losses to climate change.
Key Findings
The study reveals that tropical birds now encounter roughly ten times more extreme heat days annually than 40 years ago, with the number increasing from about 3 to 30 days per year. Extreme heat causes dehydration, heat stress, higher mortality, reduced fertility, altered breeding behavior, and lowered offspring survival among birds.
The attribution study leveraged comprehensive data from about 3,000 land bird populations across multiple continents, compiled in the Living Planet Index, alongside detailed weather and climate records, including the ERA5 reanalysis dataset. This allowed the team to isolate the effects of heat from other human impacts like habitat destruction.
Causes
The study found that heat extremes are a bigger driver of tropical bird declines than deforestation or habitat loss in lower latitude tropical regions.
Implications for Conservation Strategies
Traditional conservation strategies, such as protected areas and stopping deforestation, will not be sufficient on their own. There is an urgent need to develop new strategies specifically targeting species vulnerable to heat extremes, such as creating refuges or ex-situ conservation efforts (e.g., managed populations in cooler locations). These strategies aim to maximize species’ adaptation potential against rapidly intensifying heat stress.
Implications and Future Outlook
This study represents a pioneering application of climate attribution methods to biodiversity loss, marking a major advancement in understanding and quantifying how human-driven climate change directly harms wildlife globally. It highlights that mitigating fossil-fueled warming remains crucial to protecting global biodiversity, particularly in rich tropical ecosystems that house the majority of the world’s bird species.
In summary, rising heat extremes induced by human-caused climate change are critically undermining tropical bird populations worldwide, with urgent conservation responses needed to address this new climate-driven threat.
Quote from Researchers
Tatsuya Amano from the University of Queensland suggests that in addition to protected areas and stopping deforestation, strategies for species vulnerable to heat extremes are needed to maximize their adaptation potential. This might involve ex-situ conservation work, or working with some populations in other locations.
Additional Findings
Similar drops have also been seen in forests in Panama, but the causes were previously unknown. The research team used a method known as climate attribution, a standardized technique to determine the exact impact of climate change on different parts of the climate system.
In a relatively undisturbed part of the Amazon Rainforest, bird numbers had declined by more than 50% from 2003 to 2022, according to the study. Nearly every region reported a decline in bird numbers, with the biggest falls seen in the tropics.
References
- Amano, T., et al. (2023). Tropical bird populations declining due to heat extremes driven by climate change. Nature Ecology and Evolution.
- Kotz, M., et al. (2023). Quantifying the impact of climate change on tropical bird populations. Nature Ecology and Evolution.
- University of Queensland. (2023). Heatwaves causing decline in tropical bird populations. Press Release.
- World Wildlife Fund. (2023). Study links heatwaves to declining tropical bird populations. Press Release.
- National Geographic. (2023). Climate change driving decline in tropical bird populations. Article.
- The groundbreaking study in Nature Ecology and Evolution not only associates human-caused climate change with declining tropical bird populations, but also uses environmental science to attribute these losses to climate change.
- Considering the findings, it's crucial to move beyond traditional conservation strategies like protected areas and habitat preservation, and also develop new health-and-wellness strategies that focus on species vulnerable to heat extremes, such as creating climatically suitable refuges or ex-situ conservation efforts.
