Department of Statistical Sciences
University of Cape Town
| Avian Demography Unit
Department of Statistical Sciences University of Cape Town |
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Projects of the Avian Demography UnitCWAC - Coordinated Waterbirds CountsReport on Summer 2004 CWAC at BlesbokspruitStan MaddenThe following is a report on the CWAC summer count for the Blesbokspruit sites which includes Marievale Bird Sanctuary. This count took place on 25 January 2004. The count commenced at 6.30 and finished at approximately 10.30. The following is areport on the count and some of the highlights of the morning. The were six major areas counted along the Blesbokspruit starting with Cowles Dam up in the north, Grootvaly Wetland Reserve, a private site registered as Grootvaly on Blesbok, Anglo's Reserve, Marievale Bird Sanctuary and at the southern end the Stan Madden Bird Sanctuary. Generally lower populations were counted this summer when compared with last year's count, 4568 birds compares with 6401 last summer, the only exception to this was at Marievale Bird Sanctuary where the total counted was 2912 birds (56 species) compared with 2192 (60 species) last summer. Climatic conditions have also effected the count. There has been well below average summer rainfall in the catchment area and it is my opinion that this usually means that higher population densities of most of the species are confined to the more permanent water of the Blebokspruit Ramsar site during these dry periods. Warwick Tarboton does regular quarterly counts along the Blebokspruit and his last count on 22 December 2003 showed it was the highest count and the driest for the past 8 years which confirms my opinion. These higher than normal numbers remained fairly constant until the first good rains fell in the catchment area during the period 19th to 22nd January - 3 days before the CWAC count. The water levels at all the count sites rose aproximately 200mm.The sudden rise in water levels reduced the bird numbers present, wader numbers were significantly lower, Avocets which had numbered -+ 150 before the rain totaled 44 on the 25th. Most of the duck species showed the same reduction in their populations. A few highlights were: One Slaty Egret, one immature Fish Eagle, 3 Yellowbilled Stork, 4 South African Shelduck, 2 Marsh Owl, 17 Black Egret, 2 Little Bittern and 9 Goliath Herons.45 persons participated in the count with a good turnout of members from the Cuckoo Bird Club, the President Ridge Bird Club and a few stalwarts from the Wits Bird Club. I would like to use this report to place on record my thank to these keen birders for making this CWAC count a great success and to again stress the need for bird club members to be involved in worthwhile projects of this nature. Stan Madden 18 Rudd Road , Dunnottar, 1496 Tel/fax 011 734 3661 |
