Crocodiles and turtles with the most unusual features are most at risk of extinction. Oxford University reports.
Turtles and crocodiles are the two most endangered animal groups in the world, and about half of the species in these groups are threatened. Rob Salguero-Gomez and colleagues decided to find out which species of these animals are most at risk.
Turned out to be the greatest risk of extinction threatening species that have developed unique survival strategies. These animals often play very specific roles in their ecosystems that are unlikely to be taken over by other species when they become extinct. “The important implication is that threats do not affect all species equally; they tend to be associated with certain life strategies. For example, human extinction of turtles and crocodiles mainly affects the longest-lived species with the largest clutch size, such as sea turtles,” the scientists say.
In total, if all turtle and crocodile species considered “endangered” die, 13% of their unique survival strategies will be lost. The authors mention that species with a “slow” life cycle (characterized by late maturity and low offspring) are particularly vulnerable to threats from invasive species and diseases. A serious threat to the gharial crocodile in Sumatra (Tomistoma schlegelii) is to eat its eggs by an introduced wild boar. The long-lived Asian giant tortoise (Manuria emerys) is typically killed and butchered by the local population for their meat, and this happens every time hunter-gatherers encounter it. For comparison, humanity has almost no opportunity to exterminate rats or rabbits, because they are evolutionarily adapted not for longevity, but for accelerated reproduction.
ancient biologists perceivedthat cockroaches have found new ways of courtship because of sugar traps.