A comprehensive study by the University of Birmingham reveals the catastrophic impact human activities have had on bird species and their ecological roles. The research found that human-driven extinctions over the past 130,000 years have resulted in a loss of 3 billion years of evolutionary history and significant declines in functional diversity.
A study published in Science underscores the vast extent of bird species extinctions due to human activity over the last 130,000 years, revealing a notably greater impact than previously understood. This monumental loss spans approximately 3 billion years of unique evolutionary history and 7% of global avian functional diversity.
While the diminishing of species richness owing to human actions has been recognized for centuries, the broader ramifications for other biodiversity dimensions have been less examined. Researchers led by the University of Birmingham delve deeper into how the past extinctions resonate through ecological functions and phylogenetic diversity.
“The sheer number of bird species that have become extinct is of course a big part of the extinction crisis,” lead author Tom Matthews, a senior research fellow at the University of Birmingham, said in a news release. “But what we also need to focus on is that every species has a job or function within the environment and therefore plays a really important role in its ecosystem.”
Notable bird extinctions driven by humans range from the well-known Dodo to the recently declared extinct Kauaʻi ʻōʻō songbird. Evidence points to at least 600 bird species having vanished since the Late Pleistocene, corresponding to the period when modern humans began expanding globally.
The study utilizes the most comprehensive dataset of known avian extinctions from the Late Pleistocene and Holocene. It assesses the broader implications beyond mere extinction numbers on planetary health.
“In addition to functional diversity, each species also carries a certain amount of evolutionary history,” Matthews added. “Therefore, when that species becomes extinct, it’s basically like chopping off a branch of the tree of life and all of that associated phylogenetic diversity is also lost.”
The research highlights the severe repercussions of these losses.
Birds undertake various crucial ecological roles, such as controlling pest populations, recycling dead organic matter, pollinating flowers and dispersing plant seeds.
The loss of these roles results in cascading ecological issues, such as reduced flower pollination, decreased seed dispersal and disrupted control of insect populations, including pests and disease vectors.
Furthermore, a reduction in carrion consumption may lead to increased outbreaks of diseases.
“This information is vital for setting effective targets for global conservation strategies, as well as ecosystem restoration and rewilding efforts,” Matthews concluded. “Our findings highlight the urgent need to understand and predict the impacts of past anthropogenic extinctions on ecosystem function to prepare for the magnitude of expected future loss from the projected 1,000 bird species that are expected to die out completely over the next two centuries.”
The research serves as a critical reminder of the profound and interconnected impacts of human-driven extinctions and underscores the urgency for comprehensive conservation and restoration initiatives.