. Bulletin of the British Ornithologists' Club. 27#'«' fS^Al' /S*4S'. /€*4V /S°4S' Figure 3. Location of Y'alco chicquera ncst-sites in the Kafue River floodplain, in the vicinity and mainly below the junction of the Nampongwe tributary. by Jourdain (in Witherby et al. 1943), are generally darker, smoother and (usually) rounder. In our view the eggs of the Red-necked Falcon more closely resemble those of the hobby group, differing only from the "typical" hobbies' such as cuvieri, subbuteo or the Australian longipennis in their greater variation and normally more chalky appearance. Al
. Bulletin of the British Ornithologists' Club. 27#'«' fS^Al' /S*4S'. /€*4V /S°4S' Figure 3. Location of Y'alco chicquera ncst-sites in the Kafue River floodplain, in the vicinity and mainly below the junction of the Nampongwe tributary. by Jourdain (in Witherby et al. 1943), are generally darker, smoother and (usually) rounder. In our view the eggs of the Red-necked Falcon more closely resemble those of the hobby group, differing only from the "typical" hobbies' such as cuvieri, subbuteo or the Australian longipennis in their greater variation and normally more chalky appearance. All three races of chicquera commonly lay four eggs, whereas hobbies of about the same size usually lay only three. Over 80 years ago Hume, quoting Anderson (see Oates, E. W. ed., 1890), made the same point, comparing the eggs of the Indian race with those of F. subbuteo. Ali & Ripley (loc. cit.) give the average size of 120 eggs of F. c. chiquera as 42-4 X 31*1 mm (from Stuart Baker). McLachlan & Liversidge (1970) give the average of four eggs of F. c. horsbrughi as 43-4 x 33-3 mm. Brown & Amadon (1968) combine both African races and quote the average of 10 eggs as 42-0 x 32-7 mm. Both the two last-mentioned works overlooked a short note by Malherbe (1963), in which four eggs of horsbrughi from the Transvaal are described, measuring 44-4 x 31-3; 43-1 X 31-8; 42-5 x 31-8 and 42-3 x 31-3 mm. Incidentally, these had been laid in July also in an old Pied crow's nest and in a thorn tree. Our average of 45 eggs of ruficollis is 42-0 x 32-0, max. 45-1 x 31*6 and 42*5 x 33*4 and min. 39-4 x 31*2 and 39-5 x 30-9 mm. Like other falcons the red-necked regularly re-lays if the original clutch is lost, but only three eggs at the second attempt. In the one case that was accurately determined the replacement clutch was completed in 19 days and hatched 33 days later. Malherbe gives an estimated incubation period of 32-33 days; maximum 34 days. One of us () accurately recor
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