Biodiversity Crisis: Dramatic Decline of Birds and Insects Threatens Global Ecosystems
Biodiversity Crisis: Dramatic Decline of Birds and Insects Threatens Global Ecosystems
Global bird populations have seen a significant decline since 1980. According to various scientific studies and reports, overall wild bird populations are estimated to have declined by around 25-30% globally.
– Some key data:
Europe: A 2021 report found that Europe has seen a loss of around 600 million birds since 1980, with common species (such as larks, sparrows and swallows) most severely affected.
North America: Between 1970 and 2019, an estimated 3 billion birds (almost 30% of the total population) disappeared. Grasslands and wetlands are among the most affected habitats.
Global: An analysis published in Science in 2022 suggests that around half of global bird species are showing population declines, while only 6% have seen increases.
– Main causes:
Habitat loss due to intensive agriculture, urbanization and deforestation.
Climate changes that alter migration patterns and food availability.
Pesticides and pollution that reduce insect populations, the main food source for many birds.
Invasive species and predators (for example, domestic cats).
Direct exploitation (hunting and illegal trade).
These data underline the urgency of adopting measures for the conservation of birds and their natural habitats.
But the decline of birds is not the only thing that worries the scientific community, a large part of living organisms are suffering the same fate, including insects.
From 1980 to today, the global insect population has decreased dramatically, with some estimates speaking of a decline of between 40% and 75%, depending on the areas and species studied. Studies and meta-analyses conducted in recent years have revealed a phenomenon known as the “Insect Apocalypse”, highlighting particularly significant reductions in agricultural areas and temperate zones.
– Here are some key figures from different research studies:
Flying insect biomass: A 2017 study in Germany documented a 76% decline in flying insect biomass in nature reserves between 1989 and 2016.
Global research: A 2019 meta-analysis published in Biological Conservation estimated a decline of about 40% in insect species globally in recent decades, with an annual decline rate close to 2.5%.
Butterflies and bees: Species such as butterflies and pollinators (wild and domesticated bees) have suffered even more marked declines, often exceeding 50%, with devastating impacts on ecosystems and agricultural production.
– Main causes
Habitat loss: Due to urbanization, deforestation and intensive agriculture.
Use of chemical pesticides and fertilizers: In particular neonicotinoids.
Climate change: Which alters life cycles and interactions between species.
Light and air pollution: Interfering with the life of insects.
Invasive species: Competing with or preying on native insects.
– Implications
This decline has serious consequences for biodiversity and essential ecosystem services, such as pollination, nutrient recycling and pest control.
Therefore, there is a close relationship between the decline of insects and that of birds. Insects are a major food source for many bird species, especially during the breeding season, when chicks require a protein-rich diet. The decline in insect populations can therefore have a direct impact on bird populations. Here are some key points about this relationship:
1. Insecticides and habitat destruction
Use of pesticides and insecticides: Increasing agricultural intensification and widespread use of pesticides (such as neonicotinoids) drastically reduce the number of insects. These products not only affect insects considered “pests” for crops, but also a wide range of beneficial insects that are an essential component of the diet of birds.
Loss of natural habitats: The conversion of meadows, forests and wetlands to agricultural or urban areas reduces habitats for both insects and birds, making the situation even worse.
2. Impact on bird reproduction
Many bird species, such as swallows, house martins and redstarts, depend on insects to feed their young. The decline in insects leads to a reduction in available food resources, with negative effects on reproductive success and population growth.
Furthermore, in some cases, birds are forced to search for food elsewhere or compete for limited resources, wasting energy and putting their survival at risk.
3. Cascading effects on ecosystems
Birds are not just consumers of insects: they play a fundamental role in ecosystems, as predators of parasites, pollinators and seed dispersers. Their decline can therefore have a knock-on effect on the entire environmental balance, further exacerbating the ecosystem crisis.
4. Recent data
Studies conducted in Europe and North America have highlighted a significant decline in both insect and bird populations in recent decades:
According to a 2019 study, bird populations in North America have declined by around 29% since 1970, with a loss of 3 billion individuals. Many of these were insectivorous birds.
In Europe, the decline in insects, especially in agricultural areas, has been estimated at between 30% and 75% in recent decades.
5. Possible solutions
Reduce the use of pesticides and promote sustainable farming methods.
Restore natural habitats such as flower meadows, hedgerows and wetlands.
Promote awareness of the importance of insects and birds to ecosystems.
The decline of insects and birds is an interconnected problem, requiring coordinated interventions to preserve biodiversity and ecosystem health.
Guido Bissanti