The town of Abha sits on the Asir mountains at over 2,000m where the air is cool all year round and so in summer the population triples as Saudis escape the desert heat. In February it is quiet like any out of season resort; from here we travel north along the mountain ridge where at 3,000m the remnant juniper forests jostle with terraced farms and many new holiday homes.

There is an escarpment facing west with narrow wadis below and which are only accessed by precipitous roads and tracks. The farms are freshly ploughed and the climate is dry but cool; the land appears quite parched. The spring rains will soon come bringing with them a greening of the land and a host of summer migrant birds. The landscape is spectacular and very different from the rest of the country.

We take a long and winding road from Raidah Sanctuary to Wadi Marabah at the base of the escarpment. Here there are frequent pairs of hornbills in the fig trees, also Rueppell’s weavers, sunbirds and rock thrushes. Porcupines leave distinctive tracks through the dense shrubs and there are occasional discarded quills.

The butterflies are diverse with many species common both in the Asir Mountains and across the Red Sea in mainland Africa. Some birds have a similar range too, such as dusky turtle dove; others like Yemen linnet are endemic although they don’t look very different from their more widespread northern neighbour, the common linnet. The attractive desert rose Adenium obtusum is common in the scrub woodlands and it too also occurs across sub-Saharan Africa. South west arabia was separated from mainland Africa some 25 million years ago but the strong biogeographical connections remain clear.