The Sandgrouse are a unique set of birds found only in Africa and Eurasia.
The relationship of these birds to other groups has been one of the most
hotly debated issues over a period of centuries. They are primarily ground-feeding
birds of deserts, scrub, and grasslands, recalling small long-winged grouse
-- indeed, Linnaeus originally assigned them to the same genus as European
grouse. All of them do have feathered tarsi as can be seen in this photo
of Lichtenstein's Sandgrouse (left) of North Africa and the Middle
East, one of the most desert-loving of all species. Its beautifully patterned
upperparts provide fine camouflage amongst its pink & white rocky habitat. |
 But
sandgrouse share several attributes of pigeons, including their long wings
and the practice of making long flights daily between breeding or feeding
grounds, and pools of water at which they drink. This pair of Madagascar
Sandgrouse (right) are engaged in such a long-distance flight, well
above the ground and set off against a glooming sky. Some of their plumage
and musculature is pigeon-like, but in 1867 Thomas Huxley reviewed their
skeletons and came to the conclusion they were "perfectly balanced" between
grouse and pigeons, and assigned them to their own distinctive order, the
"Pteroclomorphae." Over time, however, the idea they were related to grouse
at all was slowly dropped and by the mid-20th century many placed them
as a suborder among the pigeons.
This all changed in 1967 when G. L. Maclean proposed a relationship between sandgrouse and shorebirds, based primarily on field observations. The fact they do not drink like pigeons, they don't give cooing sounds, they don't build stick nests, that their eggs were pigmented (not white) and that the young can immediately fend for themselves are all reasons they aren't that close to pigeons. More recently, DNA and other biochemical evidence confirms a closer relationship to waders in the Charadriformes. But the birds are still quite unusual, and de Juana (1997) in the Handbook of the Birds of the World series places them in their own order -- the Pterocliformes -- between the waders and the pigeons. |
  Whatever their relationships, all are closely related to each other and all but two are considered to be within a single genus Pterocles. Two African examples are the Double-banded Sandgrouse of south Africa (above left) and the Black-faced Sandgrouse of east Africa (above right; a fine shot by Dale & Marian Zimmerman as my own photos of this bird don't come close to matching theirs). |
 One
special feature of sandgrouse is their long flights to water holes in desert
and semi-desert country where not only do they drink, but during breeding
they wet their belly feathers to carry water to the chicks. The male's
belly feathers are specially adapted to hold up to 15-20 ml of water. The
nests may be over 25 miles distant, and it may take several trips, but
adults carry enough water back to their chicks so that they survive (more
details in de Juana 1997). By far the best way to see sandgrouse is to
await their arrival at waterholes. Here Chestnut-bellied Sandgrouse
are flying in (left) and then landing in flocks beside East African pools
(below). The flocking behavior helps them avoid predation because not only
are individuals in a flock more difficult for a predator to catch, but
because some members can always be on the lookout for danger while others
drink. The Burchell's Sandgrouse P. burchelli in the Kalahari desert
has been known to fly over 100 miles each day to water. |
It is a coincidence that I've photographed all six sandgrouse that I've seen so far, but all are members of the genus Pterocles. There are two species in the genus Syrrhaptes that live from the Tibetan plateau to Mongolia. One of them, the Pallas's Sandgrouse S. paradoxus, stages irregular irruptions that spin off vagrants far from these remote steppes. Irruptions in 1863, 1888, and 1908 sent some birds all the way to western Europe! |