There is an Isabelline Shrike in Spain at the Guadalhorce river mouth, Málaga.
First found on 1st February it was still present on 5th. The photographs clearly illustrate that it is of the form isabellinus, with a strong (burnt-) orange wash to the cheeks, chest and flanks - the photo of the bird in flight also shows this wash extending to the undertail coverts (though mostly on the feather bases). The supercilium is also washed orange. I would age this bird as an adult and the strength of the colour makes me believe it to be a male.
An interesting element of the images is how much they can differ from each other through photographic/light effect. The image at Rare Birds in Spain is very much more washed out and greyer, with the underpart colour more subdued, than the others – but I suspect the three taken on 5th Feb are more correct.
A very nice bird to have overwintering.