Tuesday 20th of August 2019

a sparrow fart in the hand is worth two in the bush...

sparrows

The dwindling number of sparrows seen in Australian backyards — and around the world — is considered by some to be one of the great natural mysteries of recent times.

Passer domesticus, known to many as the house sparrow, was introduced to Australia from Britain between 1863 and 1870.

The species usually remain in the same region year-round, but in recent times they have been few and far between.

House sparrow facts
  • Average size is 16 centimetres
  • Average weight is 27 grams
  • Introduced from Britain in 19th century
  • Breeding season is year-round but more concentrated in spring and summer
  • Clutch size is three to six eggs, with an incubation time of 14 days
Source: Birdlife Australia

 

Brisbane resident Catherine Leutenegger said she noticed their numbers had dropped compared to the large populations that were about when she was a child.

"My partner and I were kids in Brisbane in the 1950s, and my partner remembered the threepence bounty from the council for sparrows," she said.

"Kids would shoot them with air rifles, as the sparrows would get under the corrugations in the roofs and into the ceilings — they also brought lice."

 

 

Read more:

https://www.abc.net.au/news/2019-07-17/where-have-all-the-sparrows-gone/...

 

Picture at top: old tramp feeding sparrows in Paris c. 1960s. Picture by Gus Leonisky.

declining for decades...

Once a common sight around London, house sparrow (Passer domesticus) populations have been declining for decades; they’re down 71% since 1995. Now, researchers believe they know why: a mosquito-borne disease called avian malaria.

Scientists collected 3 years of data from 11 sparrow colonies around London where the birds breed. They counted raw numbers of birds each year, and collected blood and excrement from a number of individuals.

Seven out of the 11 colonies were losing birds, and roughly 74% of the sparrows carried avian malaria (Plasmodium relictum). That’s the highest rate of infection with this parasite seen in any wild bird population in Northern Europe, the researchers report today in Royal Society Open Science. Avian malaria may be causing declines in Western Europe, North America, and India as well, the team says.

 

Read more:

https://www.sciencemag.org/news/2019/07/researchers-think-they-know-what...

 

See also:

http://www.yourdemocracy.net.au/drupal/node/30267