Subtle Differences In Breeding Performance Between Great Titsparus Majorand Afrocanarian Blue Titscyanistes Teneriffaein The Peripheral Zone Of The Species Geographic Ranges In Ne Algeria

Because of the geological history of North Africa, populations of Great TitsParus majorexisting in this region experienced less geographical isolation from populations of continental Europe than populations of Afrocanarian Blue TitsCyanistes teneriffae. As a result, North African Great Tits are more ephemeral in their distribution and habitat choice as well as less ecologically generalist than their European continental conspecifics. By contrast, the Afrocanarian Blue Tit forms a separate species which is closely related to the Blue TitCyanistes caeruleusof Europe, including Mediterranean islands. Afrocanarian Blue Tits are a versatile generalist species. Here we compare some aspects of the breeding ecology of Great Tits and Afrocanarian Blue Tits in a highland area of the Algerian Aures Mountains facing the Sahara in the south. For both the tit species this area constitutes peripheral part of their distributions. We found that in two breeding seasons Great Tits started laying eggs on similar average dates as Afrocanarian Blue Tits, whereas in one year they preceded the latter species. Great Tits laid larger clutches than Afrocanarian Blue Tits. Fledging success was similar between the two species, with Great Tits prospering slightly better in the year when broods of Great Tits were also less infested by blow flies than broods of Afrocanarian Blue Tits. The subtle differences we found between the breeding ecology of Great Tits and Afrocanarian Blue Tits seem to be consistent with Snow's idea that these species in North Africa differ in a degree of adaptation to local conditions.