Plants and animals are dying at a faster rate due to human activities that negatively impact them. Habitat loss due to illegal fishing or hunting, global heating, and pollution are some of the factors that affect them.
Now, a team of researchers from the Alexander Center for Applied Population Biology led by conservation ecologist Haydee Hernandez-Yanez identified the common traits among plants, birds, and mammals that are at the brink of extinction. Hernandez-Yanez explained that certain combinations of life-history and demographic rates could make some species more prone to extinction than others.
Common Traits of Endangered Species
Only a few studies have tried to identify which traits are common among endangered species. In the study, titled "Demographic and Life History Traits Explain Patterns in Species Vulnerability to Extinction," published in PLOS One, researchers studied the patterns and timing of survival, as well as growth and reproduction factors that determine populations of species that can withstand or adapt to the changes in the environment caused by humans.
Science Alert reported that the study consists of compiled data about the growth, reproduction, and lifespans of 159 species of plants, trees, mammals, and birds and cross-checked them to the species listed in IUCN Red List that records the threatened species.
Researchers wrote that despite a relatively small sample, they were able to obtain certain demographic patterns of species at higher risk of extinction. Here are the following traits for each group of species they identified:
- Mammals - Researchers said that mammals with longer generation times are at most risk of extinction. The longer they mature and reproduce, the harder it is for these species to adapt to a fast-changing environment brought by human activities.
Birds - Although birds often reproduce and grow faster than mammals, they are more vulnerable to extinction, especially those with smaller clutch. The team noted that this finding is somewhat unexpected that made them reflect on different ways that reproduction can be measured.
Plants - Soft-stemmed herbaceous perennials are plants that die back before winter and bloom during springtime and summer. But they are also known to be more likely to perish if they mature earlier than expected. On the other hand, the team did not find any patterns for endangered woody trees since deforestation and urbanization do not discriminate among tree species.
Aside from these general traits, the team also found that those atop the food chain have sparse populations or small geographic ranges and are the most vulnerable species. However, the data on endangered species is limited to the scope of the IUCN Red List, as only a fraction of them are recorded. They noted that habitat loss and extinction risk of many plants and animals are mostly underestimated.
The Difference Between Endangered, Threatened, Imperiled, and At-Risk Species
According to the International Union for Conservation of Nature (IUCN), more than 40,000 species are threatened with extinction. These species include 41% of amphibians, 26% of mammals, 34% of confers, 13% of birds, 37% of rays and sharks, 33% of coral reefs, 28% of selected crustaceans, 21% of reptiles, and 63% of cycads.
But not all of them are considered endangered species since classifications of threatened species are divided into endangered, threatened, imperiled, and at-risk species.
Under the Endangered Species Act (ESA), endangered species are in danger of extinction throughout all or a significant portion of their range. Meanwhile, threatened species are likely to become endangered in the near future. In the US, different states have their own type of ESA, so there are federal and state levels that USGS typically refer to.
Although imperiled and at-risk descriptions are not legally under ESA, these terms are used more on biological instances. Generally, they are animals and plants with declining populations and may be in danger of extinction.
Check out more news and information on Endangered Species in Science Times.
