When it comes to vulnerability to anthropogenic extinction, the largest and the smallest vertebrates face the greatest risk
When it comes to extinction, there exists a Goldilocks zone—an animal that is not large or too small is more likely to escape extinction than species at either ends of the size spectrum. Scientists at the Oregon State University in the US say anthropogenic factors and climate change pose a greater threat to smaller vertebrates—habitat loss, climate change, logging, etc. Larger animals, whether mammals, birds, fish or reptiles, teeter at the verge of extinction primarily because they are being hunted either for their meat or other products like fur, fat and hide or because shrinking habitats are increasingly bringing them into clashes with humans.
Many scientists believe—thanks to the dying out of individual animals and plants at such a massive scale—that the planet is already in the middle of its sixth major extinction phase. The Oregon researchers, as per a BBC report, studied extinction data across species and found that the impact was disproportionate at the large and small ends of body size spectrum. Larger animals such as elephants, big cats, rhinos are being hunted for various reasons, from licensed trophy-hunting to illegally feeding traditional-medicine markets (body parts of poached tigers and rhinos still make their way into China). Conservation efforts have been mounted for these large, charismatic animals. However, fish like the whale-shark, birds (Somali ostrich), reptiles and giant amphibians (giant salamander) have received much lesser attention while the smaller species—frogs, shrews, etc,—have been near completely overlooked. With nearly 4,000 of the 25,000 vertebrate species studied currently threatened with extinction, efforts need to be recalibrated to ensure that all energy is not directed towards just saving the majestic. The smaller animals, like the Canarian shrew and the Bavarian pine vole need to be protected too. Given how, in the wild, they are key links in the food-chain, it is likely that their extinction will hasten the wipe-out of the larger vertebrates as well.