Birds are truly beautiful creatures. They are fascinating and all around us, roosting and nesting on our buildings and feeding in our gardens. We can travel to see them in exotic places, or just look out our window ... they are easy to find and fun to observe. Birds are probably the most beloved group of wild animals on the planet. Their ubiquitous presence, colorful form, intelligent actions and cheeky mannerisms endear them to us all. They are easy to love.

There are roughly 300 billion birds of nearly 10,000 species that now inhabit the earth. This only a small fraction of the number of birds that have existed since the Age of Dinosaurs. While new species are occasionally discovered in remote areas, 150,000 species have been identified from fossil remains proving that most bird species are now extinct. Birds can be found on all major land masses from the poles to the tropics, as well as in or over all our seas, oceans and islands.

The most common or populous wild bird in the world is the Red-billed Quelea (Quelea quelea) in Africa. The most common bird in the world is the domestic chicken which breeders have developed from the Red Jungle Fowl (Gallus gallus). Fear has been expressed that pure Red Jungle Fowl may now be extinct in the wild. The most widespread commonly seen wild bird is probably the European House Sparrow (Passer domesticus) which has been transported all over the world by European settlers. It can now be found on two-thirds of the land masses of the world including Europe, North America, Australia, New Zealand and India.

There are three ways of measuring size in birds ... heaviest, tallest and wingspan length. To date the records are held, as follows:

* Heaviest - The extinct Dromornis stirtoni from Australia, also known as the Thunder Bird. This flightless giant lived between 8-6 million years ago and stood nearly 3m/10ft tall, weighing in at a massive 500kg/1100lb. Around same height as the Giant Moa of New Zealand (below), this huge bird weighed about twice as much.

* Tallest - Dinornis, the extinct Moas from the North and South Island of New Zealand were the tallest of the flightless birds in this Genera. Dinornis giganteus lived on the North Island of New Zealand and D. robustis on the South Island. They ranged in height to over 3m/10ft (with some statistics indicating up to 4m/13ft) and weighed about 250kg/550 lbs. By studying the cross-sections of fossils, scientists found that Moas took more than 10 years to reach adult size, in contrast to our modern birds, including ostriches, that tend to reach full size within a year.

* Longest Wingspan - Another extinct bird, this time from South America, has the record for largest flying bird and longest wingspan. The Giant Teratorn (Argentavis magnificens) had a wingspan of at least 6m/19.5ft and could possibly have been as large as 7.5m/25ft.

* Smallest - It is generally agreed that this record is held by the Bee Hummingbird (Mellisuga helanae) from Cuba. This tiny bird is 5.7cm/2.25in and weighs less than 1/10 of an ounce. Shortest wings and body length are not really appropriate measurements because they are disproportionately affected by whether or not the bird is flightless and/or it's beak length. Another major contender for smallest bird is the Little Woodstar from South America. Both these tiny miracles of life fly very competently. The smallest flightless bird is the Inaccessible Island Rail (Atlantisia rogersi). Reaching a mere 12.5cm/5in in length and weighing 35g/1.45oz. This little beauty can only be found in the southern Atlantic Tristan da Cunha Islands.

* Bird Feathers - It must be a tedious job, but there are people who've taken the time to count the feathers on different species of birds. Who has the fewest feathers? That distinction goes to the Ruby-throated Hummingbird (Archilochus colubris) with 940. And the bird with the most ... the Swan with about 20,000.

* How Long Do Birds Live? - Survival is tough business if you are a bird. Life brings many challenges from natural and man-made dangers. Unfortunately, banding studies show that most birds die in their first year of life. But here are some record lifespans: Great Blue Heron (Ardea herodias) 23.25 years, Canada Goose (Branta canadensis) 23.5 years, Blue Jay (Cyanocitta cristata) 18.33 years, Red-winged Blackbird (Agelaius phoeniceus) 15.75 years and Northern Cardinal (Cardinalis cardinalis) 15.75 years.