Animals able to adapt to the environment
The effects of global warming on our planet are there for all to see – and it’s hotting up! Since 2016, we have been beating monthly temperature records one after another, on the surfaces of land and ocean, increases taking their toll on a multitude of planet ecosystems.
Rising sea levels, alarming temperature swings, melting poles, changes in rainfall patterns… all adding up to devastating habitat destruction. And this is one of the most serious problems the animal kingdom faces. Many species may be added to the list of endangered animals or, worse still, could become extinct, due to climate change.
Nevertheless, some animals have been able to adapt to their new surroundings. How so? With a little bit of imagination, and developing all kinds of physiological, behavioral and morphological cunning, they are surviving. Read on to find out more…
Lungfish: the art of inventing a lung
When the heat is on, drought is not far behind, so many animals have had to adapt their organisms to cope with alarming water shortages.
The lungfish has done so to the extreme. Now, when it needs to, it ceases to become what it is: a fish. This species of eel lives in marshes and reservoirs. If these habitats dry up, the lungfish is able to make its bladder function as a lung, with which it breathes air to survive during dry season, while wallowing in the mud, out of its natural habitat. Thanks to their ability to secrete mucus, the lungfish can also insulate, waiting it out, up to five years if necessary, until the water returns.
Storks prefer to stay home
Every time we program a journey, we have to get used to looking up what the weather will be at our destination, a factor that sometimes can determine whether we even go or not. Something similar happens with several bird species and climate change.
Many migratory birds are modifying their migration calendars, or even ruling migration out completely, to adapt to the climate conditions of their habitats. Storks are one example. When winters are mild, they are more sedentary and even bring forward their breeding, adjusting it to the earlier springs.
One of the curious things about this adaptation is that the descendants of these storks retain the migratory gene, flying to Africa when they are old enough, but three or four years later they return to settle where they were born.
The water flea that goes it alone, rather than in a couple
Some species keep a reproductive ace up their sleeves that they use when alerted by environmental change. This is known as parthenogenesis, or asexual reproduction, which does not need a male and female to procreate but depends on female sex cells progressing without being fertilized.
In the case of the water flea, hot weather gives it the signal, since this little crustacean depends directly on temperature. Its mechanism for adapting to its surroundings allows it to reproduce more in warm weather, producing more females, while in winter it considerably reduces reproductive activity, a reaction that researchers regard as an indicator of climatic variation.
Polar and grizzly bears, a successful hybridization
Arctic melting is bringing different species into contact with one another in the same region for the first time. This is what is happening with polar bears, who are spending increasing time on land due to the lack of icy areas in summer, and brown bears, which are moving northward due to, for them, the improving climate at altitude. This has given rise to what scientists call hybridization, the genetic crossing of both species to give birth to a new one.
In 2006, a hunter killed a white bear with brown patches. Its genes showed that it came from a polar bear mating with a grizzly. Four years later, another hunter came across another crossbreed, but this time a second generation, a cross from a hybrid with a polar bear, which demonstrates the existence of more than one encounter between the species. The crossing between them is thus an evolutionary success yielding healthy and fertile descendants.
Toads changing their reproductive clock
Crossbreeding between animals is nothing new. Modern humans are also the product of genetic interchange. But the speed at which species are crossing is accelerating due to climate change effects, researchers say.
Another example of hybridization can be found between the Bufo bufo and Bufotes balearicus toads. Global warming has caused one of these species to delay its reproductive cycle to coincide with that of the other, who, for its part, has begun to settle in areas it has never inhabited before. Two varieties trying to survive through genes passed on by their relatives.
Genetics always rule, though, and in this case a wall has risen between them impeding the new species from emerging from the hybridization successfully, and the generation resulting from the crossbreeding seems unable to survive