Global warming... human-induced global warming to be precise, is undoubtedly the biggest threat that the planet is facing today. The fact that its effects on the planet are becoming more and more obvious is a sign of an approaching disaster. We often associate global warming with loss of habitat for species like the polar bear or the Arctic fox. It may come as a surprise for many, but the effects of global warming on wildlife go well beyond this. Going by the rate at which the planet is becoming warm, it will result in irreversible damage to various ecosystems within the next few years, and that will sound the death knell for numerous species thriving in these ecosystems.
Global Warming Effects on the Wildlife
The climatic system of our planet is vulnerable to changes in global temperature, as a result of which a rise in temperature by a few degrees can have severe repercussions on the overall climate pattern. While these changes were unheard of until a few years back, a look around and you will get to see some obvious modifications in your surroundings.
While retreating glaciers and melting polar ice happen to be signs of climate change at high altitudes and in polar areas respectively, extremely hot summers, freezing of lakes well in advance, spring ice breaking way before schedule, untimely precipitation, are signs of the same in your own surroundings. The change in climatic pattern is also fueling natural disasters, and the rise in frequency of hurricanes, wildfires, etc., hint at this very fact. All these changes together are not just coming heavy on humans, but are also taking a toll on plants and animals on the planet.
Loss of Habitat for Species
The impact of global warming on wildlife is best depicted by habitat loss for numerous species of plants as well as animals. The polar region is home to a number of species which have adapted themselves to the cold conditions that exist there. If average global temperature continues to soar, the polar climate will also change, and that in turn, will trigger a series of changes in the polar ecosystem.
It will become difficult for animals like the Arctic fox, polar bear, caribou, snow owl, etc., to adapt to these quick changes, and they will start moving further north in search of ideal abiotic conditions. Similar situation will arise in high altitude regions, wherein the species will be forced to move higher in search of ideal abiotic conditions. More importantly, it's not just the animals which are moving north, but even plants - like the sugar maple trees, are doing the same thing. This will eventually trigger habitat loss for several species - as a result of which the competition within species will intensify, and eventually result in their extinction.
One of the best examples of animals threatened by global warming is the polar bear. In fact, it deserves to be the mascot of global warming affected wild kingdom. Even though this species of bear is enlisted as vulnerable in the IUCN Red List as of today, experts are of the opinion that we will have to shift them to the list of endangered species sometime soon. In fact, trends suggest that the polar bear population will decline to one-third of what it is today by the year 2050.
- These bears tend to rely on the massive chunks of floating ice when it comes to hunting, and melting of these ice chunks makes it difficult for them to hunt - thus leaving them without food.
- Even though polar bears can swim, they require to take rest after short span of time and with no ice chunks to take rest on, things are becoming increasingly difficult for them.
- All this is taking a toll on their biology, and reproduction trends in this species hints at this very fact, with female polar bears having a tough time rearing their young ones.
Habitat loss triggered as a result of global warming has even more disastrous effects on species with a limited range, and the golden toad - native to Monteverde cloud forest of Costa Rica, is one of the best examples of the same. This species became extinct when a fungal epidemic swept through this region, thus bringing about a severe decline in golden toad population.
This epidemic was attributed to warm temperature which resulted in conditions ideal for fungal growth. The few tadpoles which managed to survive this epidemic, eventually succumbed to drying of water sources as a result of increasing temperature. The golden toad is a representative of several amphibian species which succumbed to this condition somewhere between 1980s and 1990s.
Change in Migration Pattern
The effects of global warming on animals which resort to migration have also become quite obvious over the last few years, as their migration timing and pattern are put out of sync by the changes in climatic conditions. Animals rely on temperature changes to begin their migratory journey. For instance, animals which migrate from cold regions of the higher latitudes to the warm regions of the tropics - and back, begin their migration when the temperature reaches certain degrees.
The alteration in climate pattern of late is prompting these animals to begin their journey before schedule, as a result of which they reach their destination way before time, only to be welcomed by shortage of food. This is evident in various parts of the world wherein migratory species returning from breeding grounds to feeding grounds with their young ones before schedule are facing a severe shortage of food.
Severe Shortage of Food
Shortage of food is also resulting in quite a few complications among species. Krill population in the Antarctic Ocean has come down by 80-85 percent, and this has left the penguins, with krill as a major constituent of their diet, with no food to eat. This has brought down the population of species like the Emperor penguin by 50 percent.
The penguins are not the only ones who are affected by the decline in krill population in Antarctica, even animals like whales and seals are facing food problems because of this. It isn't much surprising that this dearth of food has prompted several species to resort to cannibalism as the last measure of survival.
Change in Reproductive Behavior
All these changes induced by global warming have brought about several changes in the behavior of animals as well. Several species are giving birth to their young ones before or after schedule to make sure that the birth of these young ones coincides with availability of food. One of the apt examples of the same is the blue tit species (Parus caeruleus) which is known to feed on leaf-eating grubs.
Unfurling of leaves before time is attracting leaf-eating grubs in large numbers. Blue tits have started laying their eggs two weeks earlier than the schedule so as to make sure that food is available in plenty for their young ones when these eggs hatch. Even hibernating animals - like marmots, have pre-poned their hibernation by approximately 3 weeks.
Rising Instances of Pest Outbreaks
Warm temperatures have created conditions ideal for the growth of insects, and this in turn has increased the instances of pest outbreaks in various forests of the world. Insects that were restricted to the tropical regions of the world at one point of time, are now found in abundance in higher latitudes. Rise in the instances of spruce budworm outbreak is turning out to be lethal for the spruce trees, as they don't just lay eggs on these trees but also feed on their leaves.
If the coyotes, native to North American prairie grasslands, and tigers, native to the sundarbans of southeast Asia, are encroaching on human settlements today, it is only because of loss of habitat and severe shortage of food that they are facing as a result of change in global temperature. This is just one example on how global warming can affect us indirectly, and it wouldn't be surprising to see more of such instances in future, as more than a million plants and animals are expected to be put on an irreversible path of extinction by global warming by the year 2050.