The Lincolnshire Bird Club

Having glimpsed what looked like a good candidate a couple of times in March visiting the feeders in our Dunston garden, what appears to be the same bird was seen again today (5th Dec). I got a much better look at it and it is certainly an interesting individual and shows pretty obvious characters of both species.

From a very quick bit of research it would appear that hybrids are pretty scarce between the two species but I'm sure further investigation may unearth a few more. Not sure if any have been documented in Lincs before.

Matthew

Some further research into hybridisation between these two common and widespread species seems to reveal that it perhaps not as frequent as one might expect. A couple of useful article studies on the House Sparrow (Brit. Birds 87: 593-602, December 1994) and the Tree Sparrow (Brit. Birds 91: 124-138, April 1998) give some detail on such occurrences. Up to 1997 just 63 occurrences of hybridisation in Europe were uncovered, although this did include single cases involving an 'Italian Sparrow' and Spanish Sparrow.

Reported instances of hybridisation in Europe (including UK records) can be traced back to the 1880s, but remained relatively stable in occurrence (with no more than 5 records per decade) until the 1960s. Since then a dramatic increase occurred (with up to 20 reports in the 1990s) although this is largely attributed to an increase in observer awareness and birdwatching skills. One hypothesis for this increase is mate restriction linked to dramatic changes in the numbers of both species, just the situation to cause increased difficulty in marginal areas for a bird to find a mate of its own species.

A trawl of the internet for recent UK records produced very few, with a bird in Derbyshire in 2011 and two records from Norfolk (in 2013 and 2014) seemingly the most recent. There are also several documented records from Sweden and Finland.

In a Lincolnshire context, reference to Lorand and Atkin 1989 and LBRs since 1979 produced no documented records of House x Tree Sparrow hybrids. Is my garden record really the first? I would be surprised if it is, but unless anyone else can come forward with any other records it may well appear to be the case.

The bird seen on 5th was certainly an interesting individual and hopefully it will hang around so as I can get some slightly better photos to support this record.

Matthew

Interesting, Matthew. I look forward to seeing the photos. Your post has pushed me to look at the literature which suggests that this hybridisation may be a fairly regular event - and that the hybrid young may be fertile.

I've also been looking more carefully at the house sparrow colony in my garden - they are very varied in appearance!

Jonathan