Decline of the House Sparrow

[Peter]

I don’t know if folk were aware of one of the more plausible theories for the decline in House Sparrows, but I thought it might be of interest to publish it here.

The House Sparrow's extinction theory was that the unleaded fuel, believed to be eco-friendly, had harmful byproducts. The fuel uses Methyl Tertiary Butyl Ether (MTBE) as an anti-knocking agent. Along with byproducts of combustion, this kills small insects. The insecticidal nature of the byproducts makes the food for those birds feeding on insects scarce. Though adult sparrows can survive without insects in their diet, they need them to feed their young, so with fewer insects; the infant mortality rates of sparrow went up.

Peter

[indalo]

Hello all

I have observed also one detail about sparrows, along the 2 last years, that I have been inventoring birds in winter at Almería province (all the province).

It is about changes in humanlife habits. Rural areas have been abandoned looking for cities. I have detected that in the small villages and cortijos where there is an intense rural human life, there are lots of sparrows, and the populations comes down at the urban areas. Under the rural life they find lot of direct or indirect food, but they haven´t this at the cities, where every rubbish is plastified and quickly driven to the garbage places, where they are not competitive with bigger birds feeding there in great quantities, as gulls, jackdaws or cattle eggrets. I´m not able to stablish a scientific relationship between these factors (village-city) but think seriously that they are also highly linked to the sparrow populations development.

Regards

Jesús

[Peter]

Jesús

Interesting. I think the causes are likely to be more complex, the piece I had posted could be more tangible given little to no decline in more remote areas of Europe.

Peter