Climate change is one of the greatest threats to biodiversity and ecosystems on Earth.
It affects animals in various ways, from altering their habitats and food sources, to disrupting their behaviors and physiology, to increasing their exposure to diseases and parasites.
A recent study, published in the journal Trends in Ecology and Evolution, has reviewed the current knowledge and future research directions on the impacts of climate change on animals.
The study reveals that these impacts will be multi-faceted, complex, and often unpredictable.
How does climate change affect animal habitats and distributions?
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Climate change can alter the availability and quality of habitats for animals, by changing the temperature, precipitation, sea level, fire regime, and vegetation patterns of different regions, as per Phys.org.
These changes can force animals to shift their ranges to track suitable conditions, or to adapt to new environments.
However, not all animals can move or adapt fast enough to keep up with the pace of climate change, and some may face barriers or competition along the way.
This can result in habitat loss, fragmentation, degradation, or invasion, which can reduce the population size and genetic diversity of animals.
For example, polar bears depend on sea ice for hunting seals, their main prey.
As the Arctic sea ice melts due to global warming, polar bears have to travel longer distances and expend more energy to find food.
This can affect their body condition, reproduction, and survival.
Some polar bears may also move inland and encounter other bears or humans, which can lead to conflicts or hybridization.
How does climate change affect animal behaviors and physiology?
Climate change can also affect the timing and intensity of animal behaviors and physiological processes, such as migration, hibernation, reproduction, growth, and metabolism, as per the WWF.
These processes are often synchronized with seasonal cues, such as day length, temperature, and food availability.
However, climate change can disrupt these cues and cause mismatches between animals and their environment. This can affect the fitness and survival of animals.
For example, many birds migrate to warmer regions during winter and return to their breeding grounds in spring.
However, climate change can alter the timing of spring arrival and departure of birds, as well as the availability of food and nesting sites.
This can affect their reproductive success and population dynamics. Some birds may also change their migration routes or destinations in response to climate change, which can expose them to new predators or competitors.
How does climate change affect animal diseases and parasites?
Climate change can also affect the occurrence and transmission of diseases and parasites that affect animals, by altering the distribution and abundance of hosts, vectors, pathogens, and environmental factors that influence infection.
Climate change can increase the risk of disease outbreaks by expanding the range or activity of vectors (such as mosquitoes or ticks) or pathogens (such as viruses or bacteria), by reducing the immunity or resistance of animals to infection, or by creating favorable conditions for disease transmission (such as high temperature or humidity).
For example, amphibians are highly vulnerable to a fungal disease called chytridiomycosis, which has caused massive declines and extinctions of many amphibian species worldwide.
Climate change can exacerbate this threat by increasing the temperature or rainfall variability of amphibian habitats, which can favor the growth or dispersal of the fungus or stress or weaken the amphibians.
The study concludes that climate change will have diverse and often synergistic impacts on animals, which will vary depending on the species, the region, and the scenario.
The study calls for more interdisciplinary and integrative research to better understand and predict these impacts, and to develop effective strategies to conserve and manage animal populations in a changing world.
