Country Matters: High-rise birds and beaks that grow
In New York City, to where (in the long ago) I used to regularly travel, spray-painters are splashing giant pictures of endangered birds on the sides of buildings.
John James Audubon, celebrated 19th century US painter of bird life, once lived in Manhattan in a house by the Hudson. Near his final resting place at West 155th Street and Broadway, a local art gallery owner and a painting crew have been decorating the sides of apartment buildings with multi-storey murals of birds in vivid colours. There are even scattered nocturnal flocks that burst into view when shop owners pull down the shutters where they are painted.
This is a new sort of birdwatching, according to reports in The New York Times - and it takes time to track a Williamson's Sapsucker down the West Side Highway!
The artists are not graffiti vandals but spray-painting professionals. It is a brilliant idea. That's New York for you!
In dead bird archives in natural history museums across America's Midwest, there are filing cabinets full of thousands of bird carcasses carrying dirty secrets from the polluted past - because the soot preserved on their feathers has data on urban air quality over a 130-year period.
These feathers of filth reveal social changes across America from 1880. The dirtiest birds in the sky were just before 1910 at the height of industrialisation.
Scientists at the University of Chicago say they can estimate how much smoke was in the atmosphere during those significant coal-burning years.
Some common songbirds which visit suburban gardens for their daily seed and nut quotas are developing longer beaks to more readily scoff their treats. That's the amazing news from US journal Science, which reports on a scientific study that reveals that over the past 40 years bigger beaks have evolved on great tits (Parus major), the suggested cause being garden seed feeders!
The study compared beak lengths of tits in the UK and in Holland where there are much fewer seed feeders.
Beak length has increased on UK birds between the 1970s and now, says study co-author Prof John Slate, of the University of Sheffield. He adds: "We now know the increase in beak length between UK and continental birds is down to genes that have evolved through natural selection."
Researchers screened genes from 3,000 tits in order to uncover genetic differences between the UK and the Dutch. They found that birds with genetic variants for longer beaks were more frequent visitors to garden feeders. "It seems remarkable that longer beaks have evolved as a response to supplementary feeding," says report co-author Dr Lewis Spurgin, of the University of East Anglia.