Italian House Sparrows

["Philip Veerman" <>]

Thanks John & Barbara, I had forgotten about that one. It reinforces what I wrote on this line yesterday. If this variant is controlled by genes at just one or two loci and the allele(s) for the variant is (are) a recessive gene(s), present at low population levels, then it is entirely reasonable that, especially with a bit of inbreeding, the character will show up every now and then in smallish populations like we have here. The bird reported by Nicola Clark at Uni of Canberra could easily be ancestral to or related to the ones reported by Terry some years later. The only change I would offer to what I wrote on this line yesterday is that there is not even the need for a recent Canberra based mutation. If the gene is already in the population as a recessive gene present at low population level, it will inevitably show up (provided it isn't harmful). Where that phenotype is the standard form (presumably in Italy), it would probably be so because the other allele does not occur there. The article by Nicola Clark was well put together and pointed out some of the other obvious differences between House Sparrows and Tree Sparrows.

 

Philip