How some species are adapting to climate change and what that means for the rest of us.
The overarching term ‘Climate Change’ has been used to identify many causes for environmental and ecological system shifts, impacting vital biodiversity equilibria. When we consider the effects of some of the aspects of a changing climate, such as increasing land and sea temperatures, habitat fragmentation and competition for resources, it is clear why many species are suffering. However, what is relevant for understanding our changing world is knowing which species are actually thriving and why.
Across habitats, there is a huge array of species, all evolutionarily crafted to fill an ecological niche. When considering highly specialised animals, such as tropical forest understory birds, destruction of their habitat and the subsequent depletion of their limited food groups and breeding resources can cause the species population to plummet. In contrast, generalist species, such as crows, can adapt with the resources they have, such as neutral beak shapes and large brains. This allows them to dominate urban landscapes and edge habitats, where natural areas border human settlements. The lack of competition in these new areas allows the species population to increase without a clear imminent threat.
Scaling out, the major worldwide impact of climate change is on weather systems. Increased extreme weather and heating have left huge depletions of biodiversity hotspots; some areas of coral reefs around Florida have recently reported a 37C sea surface temperature.
Despite this alarming increase from the twentieth century mean of 27C in the same area, some organisms are surviving and increasing in population. Jellyfish species serve as a primary example, as they have begun to bloom more frequently in response to warming seas, attributed to the increased availability of phytoplankton, which serves as their primary source of nutrition. A redistribution and increase in jellies have been found to impact many aspects of human life, ranging from suffocating livestock in fish farms to blocking offshore power plants from functioning correctly. We can also expect species shifts from other walks of life to affect human life as well.
An individual that serves as a form of transit for a disease is called a vector. In this context, the female Anopheles mosquitoes are a vector for malaria, and the Aedes mosquito spreads dengue and zika. Looking at their life history strategies and methods distinct to their survival, mosquitoes require warmth, humidity and stagnant waters in which to breed. As the world warms and more frequent storms retain humidity, providing more water in which to breed, the species are thriving. An increase in mosquitoes across the Global North, as they survive more winters and reproduce more, brings the threat of these diseases spreading across the human population.
Pests and pathogens ‘winning’ in such a way benefit in the short term from the changing ecosystem and place additional pressure on suffering species. The contrast between successful species reproducing at a fast rate instantly puts slower-reproducing, typically larger animals, at a disadvantage.
In conjunction, once population headway has been made, successfully adapting species place stronger demands on food and habitat and can even increase predation risks for threatened species. The ultimate example of such a group is rodents. Widespread and smart, species of rats and mice in particular take root in any ecological niche they enter. These pests dominate urban and edge environments, affecting the food web by pushing other species into the centre of habitat patches and increasing competition for resources.
As more animals have lower fitness and weakened immune systems with poorer diets and increased stress, they are left more susceptible to disease and in search of easier food sources. This can then lead to contamination, as the increased movement between rural and urban habitats in tropical areas has increased the contact of humans with diseases such as hantavirus.
It is in everyone’s interest to maintain biodiversity. The value placed on our need for a healthy world is insurmountable, with some ecologists claiming ecosystem goods and services are worth $145 trillion a year.
So, when reflecting on the above, what can we do? With this issue, the answer is much like many of the other environmental crises we face. We must create hotspots and link habitats so that pockets of species can connect with each other. Creating urban habitats for insects and birds is also a must in areas where we have taken over their environment.
Finally, predation control. The short-term beneficiaries, such as rodents and invasive bird species, must continue to be kept under strict control in areas of biological importance.
Indeed, with such high stakes and a shifting ecology, we must focus on what we can do to limit the impacts of a changing environment on biodiversity. While a short-term gain for these species may seem good, it is a long-term net loss for us all.