Do Birds Have Knees?: All Your Bird Questions Answered (RSPB)
Format: PDF / Kindle (mobi) / ePub
This RSPB-endorsed book answers all those burning questions about birds that beginners and experts alike may ask themselves:
How do ducks keep their feet from freezing in winter? Why don't swallows stay in Africa? Are birds really dinosaurs, or were dinosaurs really birds? And do birds have knees?
Taking a "questions and answers" approach, each specific question leads to an answer which expands the theme under discussion, so that all aspects of bird life and the hobby of birding are covered. The scientifically rigorous answers together form an impressive and fascinating body of bird-related information. This highly readable book will intrigue anyone with an interest in birds.
number of bird species to have lived since Archaeopteryx (thought by scientists to have been one of the first birds – see Chapter 2) range from roughly 150,000 to more than 1.5 million. This is despite the fact that only about 900 extinct birds have been identified from fossil remains, and is based on palaeontologists’ theories of the rate at which species become extinct over time. However, the latest thinking is that today’s 10,400 or so species represent about six per cent of those that have
the species was extinct in the wild, probably as a result of persecution, hunting and habitat loss. The last captive bird, a female named Martha, died in Cincinnati Zoo on September 1st 1914. She is now on display at the US National Museum in Washington, a testament to the folly of humankind. How do we know when a species has become extinct? We don’t. As a bird gets more and more rare, the number of sightings dwindles to a trickle, until eventually some time has passed since the last verifiable
plumage, as does a juvenile following the shedding of its original downy feathers. What are ‘breeding’ and ‘non-breeding’ plumages? These describe the very different plumages adopted by some species during and outside the breeding season. However, because birds moult at different times of year, a bird may have acquired ‘breeding’ plumage well before courtship actually starts, or may attain its ‘non-breeding’ plumage while still feeding young. To make things even more confusing, many otherwise
year, then lifespan varies between species: most songbirds live for between two and 10 years, waders from about five to 10 years, and raptors from five to 20 or even 30 years. Parrots and seabirds are among the longest lived, with many species regularly topping 20 years and a few individuals breaking the half-century barrier. The longest surviving birds are those in captivity, which have no predators to face and an unending supply of food, and may possibly live for as long as 100 years. But very
directly or indirectly to human agency. Disease, lack of food and predation are the three biggest natural killers, while non-natural deaths arise from factors such as shooting, deliberate or accidental poisoning, and collisions with buildings or motor vehicles. For garden birds, one of the biggest causes of death is predation by domestic cats. It is estimated that each year, cats are responsible for anything from 28 to 75 million bird deaths in the UK and as many as 118 million in the US. Many