Passer domesticus

House sparrow (Passer domesticus) is a native bird from Europe and Asia and  is considered the most widely distributed wild bird in the world. This species was introduced in many regions and today is encountered in basically every continent such as Africa, Americas and Australia.

Figure 1 - Passer domesticus - Photo John White

House sparrow in Australia: P. domesticus was introduced in Australia between 1863 and 1870 from Britain in Victoria, but as a well adapted bird to urban areas this species has spread throughout eastern Australia. The success of this species is because the house sparrow is an opportunistic species which lives around the humans added to variable diet, P. domesticus eats insects, flower, bugs and fruits but the main compound of the diet of this species that characterize their adaptability are seeds and  scavenged food waste.

Distribution of P. domesticus in Australia.

In Brazil there are some beliefs about the introduction of this species. According to Ihering (1924) the major of Distrito Federal (which was Rio de Janeiro) in 1902-1906 ordered a group of house sparrow wishing increase the number of birds in the city. According to Camargo (1976) the idea was introduce the sparrow to combat some caterpillar species which destroyed the local trees. As happened in Australia this species spread fast around the country.

Distribution of P. domesticus in Brasil (The colour are Biomes and states separated by black line) 

In United States was not different in the early 1950's the House Sparrow was introduced in New York City, some European immigrants released this bird in their attempt to establish familiar species from their homeland and also to insect control. As happened in many places, this species has spread rapidly and had become established across the contiguous United States (Johnson & Violett, 2009). To sum up, this species is considered good as a potential pest controller but the effects of this species in native species is not calculable.

Distribution of P. domesticus in US.

References:

CAMARGO, Hélio F. Almeida - 1976 - Informação sobre o pardal. Suplemento Agrícola, O Estado de S. Paulo, 22 (1076):2, edição de 11 de janeiro.

IHERING, Rodolpho von - 1924 - Contos... de um Naturalista. Editora Brazão, S. Paulo, 189 pp., il.

Johnson, S. A., & Violett, H. (2009). Florida’s Introduced Birds: House Sparrow (Passer domesticus). Florida: University of Florida.

Weber, W.J. (1979) Health Hazards from Pigeons, Starlings and English Sparrows. Thomson Publications: Fresno, California.

Websites:

http://www.birdsinbackyards.net/species/Passer-domesticus

http://www.dpi.nsw.gov.au/agriculture/pests-weeds/vertebrate-pests/pest-animals-in-nsw/sparrows

http://www.wikiaves.com.br/pardal

http://www.mbr-pwrc.usgs.gov/bbs/htm96/map617/ra6882.html

Invasive Species?

Since I started to study the biological sciences and someone talks about invasive species I ask to myself some intriguing and philosophical questions "When some species can be consider invasive? When this species become adapted Species instead of invasive? Are humans invasive Species or adapted Species?"

According to Department of environment of Australian Government an invasive species is a species that occurs, resulted by human activities, beyond its distribution threatening valued environmental, agricultural or social. Richardson et. al (2000) defines introduction as meaning that the species has been transported by humans across a major geographical barrier and invasion requires that this species produces reproductive offspring in distant sites from introduction.

Figure 1 - Cane toad, considered one of the biggest threats to native Species in Australia.

Cane toads have becoming completely adapted to rainforest and environments where it was introduced. It is considered an invasive species because of the damage caused in native species and it is subject of hate by native population. Why this species that became totally adapted to a new environment should be destroyed as defended by some people? (Just to be clear: The species control is important and the Australian government do it well, despite being a way to fix a mistake committed by themselves).


Following the idea of invasive species as threatening species to environmental area and the production of reproductive offspring in distant sites. Would be humans an invasive species? or the idea of Invasive Species should always be related to humans dispersion? isn't it an egocentric vision?

Figure 2 - Human migration.

This map uses the terminology migration for human, even humans have had destroyed the environment wherever they went. The concept of invasive species is controversial related always to a vision where humans are on the outside. There is a big distance or a wall between Homo sapiens and the nature that shouldn't exist.

Last but not least, a video about awareness which bring the idea of Humans as invasive that destroy the nature but could do different:

Works used:

Colautti, R., & MacIsaac, H. (2004, March). A neutral terminology to define ‘invasive’ species. Diversity and Distributions, 10, 135-141.

Environment, D. (2014, May 17). Invasive Species. Retrieved from Australian Government: http://www.environment.gov.au/topics/biodiversity/invasive-species/

Richardson, D. M., Pyšek, P., Rejmánek, M., G., B. m., F.D., P., & C.J., W. (2000, March). Naturalization and invasion of alien plants: concepts and definitions. Diversity and Distributions, 6, 93-107.