Human activities are causing plants and animals to disappear at a staggering rate. From habitat loss, overfishing and poaching to global warming and pollution, species are disappearing faster than we can comprehend.
A new study, led by conservation ecologist Haydee Hernandez-Yanez and two colleagues from the Alexander Center for Applied Population Biology at Chicago’s Lincoln Park Zoo, has identified common traits among plants, birds or mammals at risk of disappearance – with unexpected results.
“Certain combinations of life history traits and demographic rates can make a population more prone to extinction than others,” Explain Hernandez-Yanez of the Woodwell Climate Research Center and colleagues in their article.
But, as they point out, until recently few studies have tested predictions of what makes one species more vulnerable to the next in various taxonomic groups using real-world data on a global scale.
The patterns and timing of survival, growth, and reproduction are all factors that determine whether plant and animal populations can withstand or adapt to an onslaught of human-induced environmental change.
In this new study, Hernandez-Yanez and his team compiled data on the growth rates, lifespans and reproduction of 159 species of herbaceous plants, trees, mammals and birds, and cross-referenced the most current endangered status of the species. IUCN Red Listthe world’s largest register of threatened species.
“Despite our relatively small sample of species, we found that species with certain demographic patterns are more at risk of extinction than others, and that important predictors differed between taxonomic groups,” writing the trio of researchers.
For example, mammals that have longer generation times are most at risk of extinction, perhaps because the longer species take to mature and reproduce, the harder it is for them to adapt to changes. fast-paced environments – and especially if the animals breed only once in their lifetime. lifetime.
Meanwhile, birds that breed often and grow rapidly, from chicks to nestlings to mature adults, are more vulnerable to extinction, which was somewhat unexpected – one would think that producing lots of offspring increases the chances of survival of a species.
In contrast, other studies have shown that birds with smaller clutches face greater extinction risks, so the data varies and the differences could reflect the many ways of measuring reproduction, the researchers note. .
As for the species similarities between the plants, soft-stemmed herbaceous perennials – the type that die before winter and flower in spring and summer – are more likely to die if they mature early and have lower rates. survival bred as juvenile seedlings. However, no clear trend was observed for endangered woody trees.
“After all, deforestation for growing crops and urbanization do not discriminate between tree species,” Hernandez-Yanez and colleagues write.
The findings add to those of another recent study predicting extinction risk that found species that sit at the top of the food chainhave sparse populations or small geographic areas are the most vulnerable.
But these types of studies are often limited by the scope of the IUCN Red List, which captures only a fraction of threatened species – mostly in highly threatened biodiversity hotspots – and is heavily biased towards birds. and mammals.
Amphibians, for example, are among the most vulnerablewith a third of all known amphibian species threatened with extinction and thousands of species not yet assessed by IUCN or lacking data to do so.
And that’s before we get to the insects and other invertebrates that pollinate plants, disperse seeds and cycle nutrients through ecosystems – and the countless yet-to-be-discovered species that are on the verge of extinction. faster than we can describe.
“Most of these extinctions go unrecorded, so we don’t even know what species we’re losing,” conservation ecologists Elizabeth Boakes and David Redding wrote in a 2018 paper describing the “untold loss.”
All this to say, despite the best efforts of scientists, we most likely underestimate the true extent of biodiversity loss and risk of extinction. Nearly 350 herbaceous plant species analyzed in this study did not have IUCN status
Conservationists refuse to stick their heads in the sand when the threat is near and the stakes are high. We know what to do halt the loss of biodiversity and protect endangered species; it’s about whether or not we can reverse the trend of extinction before it’s too late.
Recognizing this, Hernandez-Yanez and his colleagues hope that a better understanding of the characteristics that put plants and animals most at risk of extinction helps conservation efforts. The results could be used to assess which species are more or less vulnerable to extinction, especially when abundance data are lacking.
The research has been published in PLOS One.