Insekter

80 % of European insects have disappeared in thirty years https://up-magazine.info/en/planete/biodiversite/8414-80-des-insectes-europeens-ont-disparu-en-trente-ans/ 

This is the most massive episode of species extinction since the disappearance of the dinosaurs. More than half of all insects are disappearing worldwide at an accelerated rate; the hecatomb is reaching the staggering figure of 80 % for Europe. When insects disappear, the entire living chain is affected. More food for birds dying en masse, fewer pollinators for key food crops. A frightening assessment in a synthesis of 73 studies pointing to the responsibility of intensive agriculture in this collapse of life.

'Decimated': Germany's birds disappear as insect abundance plummets 76% https://news.mongabay.com/2017/10/decimated-germanys-birds-disappear-as-insect-abundance-plummets-76/

While declines in bees and butterflies have been fairly well documented in many regions around the world, this is one of the few studies that have examined biomass trends in flying insects generally. The researchers say their results indicate a more extensive problem than previously thought. 

Scientists think bird populations may already be declining in response to reductions in insects. A recent study of government data by German environmental organization Nature And Biodiversity Conservation Union (NABU) estimates that more than 25 million birds disappeared from Germany over the past 12 years. That's about 15 percent of the country's total bird population. 

An avian apocalypse has arrived in North America. Birdsong could become a rare sound. https://www.businessinsider.com/birds-disappearing-in-north-america-2020-1?r=US&IR=T

Nearly 3 billion birds have disappeared across North America since 1970 - a 29% decline.

These findings are further evidence that the Earth may be in the middle of a sixth mass extinction.

18 signs we're in the middle of a 6th mass extinction https://www.businessinsider.com/signs-of-6th-mass-extinction-2019-3?r=US&IR=T