Showing papers in "Ostrich in 1993"

Abstract: Summary Goodman, S. M., Langrand, O. & Raxworthy, C. J. 1993. The food habits of the Barn Owl Tyro alba at three sites on Madagascar. Ostrich 64:160-171. Regurgitated food remains of the Barn Owl Tyro alba were collected within the rain forest of the Eastern Region of Madagascar (Andasibe and Manombo) and in the sub-arid thorn scrub of the Western Region (Beza Mahafaly). The material from Andasibe and Manombo represent sine point samples, while 24 samples were collected from Beza Mahafaly between November 1990 and November 1991. A minimum or 176 individual vertebrates, representing 18 taxa, was identified from the Andasibe sample, and a minimum of 90 individual vertebrates of 5 taxa from the Manombo sample. The Beza Mahafaly samples included a minimum of 1013 individual vertebrates of 22 taxa. At all three sites introduced rodents made up the bulk of the prey by number and by biomass, but at Beza Mahafaly lemurs and amphibia were also significant prey items. Insects constituted a small proportion of the p...

Abstract: Summary Goodman, S M, Langrand, O & Raxworthy, C J 1993 Food habits of the Madagascar Long-eared Owl Asio madagascariensis in two habitats in southern Madagascar Ostrich 64:79-85 Food remains recovered from regurgitated pellets of the Madagascar Long-eared Owl Asio madagascariensis were collected at two sites on Madagascar with different habitats and weather regimes The localities are Beza Mahafaly, a sub-arid thorn scrub area in the southwest, and Bezavona Forest, a lower montane rain forest in southeastern Madagascar At Beza Mahafaly prey composition varied according to season Vertebrate prey included: frogs, lizards, birds, terrestrial insectivores, bats, lemurs and rodents The total biomass of lemurs (Microcebus) represented varies from approximately 8 to 40% Two samples from the Bezavona Forest included: frogs, geckos, birds, bats, lemurs and rodents Lemurs (Microcebus and either Hapalemur or Avahi) made up a total biomass of 24 % at this locality At both sites a significant proportion

Abstract: Summary Kalejta, B. 1993. Diets of shorebirds at the Berg River estuary, South Africa: spatial and temporal variation. Ostrich 64: 123–133. The diets of three common migrant waders; Curlew Sandpiper Calidris ferruginea. Grey Plover Pluvialis-squatarola and Greenshank Tringa nebularia and three resident species, Blacksmith Vanellus armatus, Kittlitz's Charadrius pecuarius and Whitefronted Plovers C. marginatus, were studied at the Berg River estuary, South Africa from December 1987 to April 1989. Direct observations of feeding were combined with analyses of stomach contents, pellets and droppings. Nereid worms, Ceratonereis erythraeensis and C. keiskama, were the principal food of all species studied except Greenshanks, which fed mostly on crabs, Hymenosoma orbiculare. Despite considerable overlap in the diets of all bird species, there were differences in the size classes of nereids taken by different bird species. Visually-foraging plovers (Charadriidae) were highly selective, feeding on the largest nere...

Abstract: Simmons, R.E. & Mendelsohn, J.M. 1993. A critical review of cartwheeling flights of raptors. Ostrich 64: 13–24. Aerial cartwheelin flights of raptors, particularly eagles, are spectacular interactions in which birds lock feet and fall earthward while cartwheeling about a common axis. This is traditionally seen as courtship behaviour, despite the fact that injuries and some fatalities have been reported. We solicited unpublished accounts from 20 raptor biologists world-wide and reviewed published evidence for the courtship interpretation among 39 species of large and small falconiforms. In 82% of 107 cases in which detailed observations were available whirling flights were aggressive interactions between territorial birds and intruders. Cartwheeling also occurs as play behaviour and as aggression during parent-offspring conflicts. Cartwheeling in Fish Eagles Haliaeetus vocifer was confirmed as mainly intra-sexual aggression by T. Liversedge (pers.comm), who induced over 200 cartwheeling events in 5 years b...

Abstract: Summary De Swardt, D.H. 1993. Factors affecting the densities of nectarivores in Protea roupelliae woodland. Ostrich 64:172-177. Between December 1986 and December 1992, 812 birds were captured at eleven selected Protea roupelliae sites at Lydenburg in the eastern Transvaal, South Africa. In this sample were 638 nectarivores, of which high densities of Gurney's Sugarbird Promerops gurneyi (41,3%) and Malachite Sunbird Nectarinia famosa (27,7%) were captured. Mean densities of 4,6 Gurney's Sugarbirds ha−1 and 3,5 Malachite Sunbirds ha−1,746) were recorded. No significant correlation was found between the clump-sizes and the number of birds although higher densities were recorded at some of the smaller sites. Protea flowering period, dump-size and the effect of fire are factors influencing bird densities. Male sugarbirds show site tenacity while localized movements have been observed in individual sugarbirds.

Abstract: Summary Seddon, P. J. & Y. van Heezik. 1993. Behaviour of the Jackass Penguin Chick. Ostrich 64:8-12. The ontogeny of Jackass Penguin Spheniscus demersus chick behaviour follows the order of development determined for Adelie Pygoscelis adeliae and Yelloweyed Megadyptes antipodes Penguins. Feeding and comfort behaviours occur from day one, followed by locomotion and aggressive behaviours. Jackass Penguin chicks are largely inactive during both the day and at night; chicks less than 20 days old are usually prone beneath the attending adult. Begging, feeding and preening are the major chick activities. Begging and feeding become restricted to late afternoon and evening following the commencement of the post-guard phase when chicks are between 26–45 days old. Feeding episodes last on average less than 30 minutes. The frequency of preening increases as chicks moult from about 40 days.

Abstract: Summary Little, R.M., Gous, R.M. & Crowe, T.M. 1993. The distribution and abundance of Greywing Francolin Francolinus africonus on the Stormberg Plateau, eastern Cape Province, South Africa, in relation to diet and substrata. Ostrich 64:105-114. Previous research indicates that Greywing Francolin Francolinus africanus in conserved grasslands are isolated on areas over igneous substrata and are highly qualitatively selective in their diet, but are more widespread in grazed grasslands. This study examines whether this variation in dispersion and ecology is a result of quantity and/or quality of diet, or because of veld management policies. We studied quantitative and qualitative aspects of the diet of Greywing Francolin populations, and the distribution and abundance of these populations over various land-form types and substrata on the Stormberg Plateau, eastern Cape Province, south Africa. Within the montane grassland areas of the range of the Greywing Francolin, veld management and the resultant structur...

Abstract: Bruderer B. & Bruderer H. 1993. Distribution and habitat preference of Redbacked Shrikes Lanius collurio in southern Africa. Ostrich 64: 141–147. Reporting rates of Redbacked Shrikes provided by th...

Abstract: Summary Komen, J. & Brown, C.J. 1993. Food requirements and the timing of breeding of a Cape Vulture colony. Ostrich 64:86-92. Annual food requirements of a Cape Vulture Gyps coprotheres family, comprising one nestling and two adult birds, and a breeding colony were estimated. A family required 226,1 kg meat during a nestling period of 136 days, and 524,4 kg annually. The greatest family food requirements (average 1,98 kg/day) occurred between 60 and 100 days after hatching. The period between 60 and 100 days after hatching was the most critical period of food demands, because (a) this was the period of greatest nestling food requirements, (b) only one parent could be away from the nest at a time, and (c) daily family food intake was effectively constant due to temporal constraints on foraging. The estimated food requirements of a breeding colony comprising 152 breeding pairs and 98 nonbreeding birds was 89 388 kg meat annually, and 36 892 kg during the nestling period, with the highest food requirements ...

Abstract: Summary Kemp, A. C. 1993. Breeding biology of Lanner Falcons near Pretoria, South Africa. Ostrich 64:26-31. Aspects of the breeding biology of the Lanner Falcon Falco biarmicus were recorded from seven territories near Pretoria, South Africa during 1970 to 1988. Nest were on average 6,9 km apart (n = 9, range 0,2-10,0 km) and in most territories were in old crow nests on electricity pylons. Birds formed 79% of the diet (n = 58) but hunting success at birds was low (15%, n = 34) except when pairs hunted in combination (50%, n = 8). Pairs that fledged young raised on average 2,4 per season m = 16), but after 1982 few young were fledged and by 1987 there were no longer any falcons breeding in the area.

Abstract: Summary Bennett, G. F., Earle, R. A. & Peirce, M. A. 1993. The Leucocytozoidae of South African birds: The Falconiformes and Strigiformes. Ostrich 64: 67–72. The leucocytozoids of the raptors are reviewed and Leucocytozoon toddi of the Falconiformes and Leucocytozoon ziemanni of the Strigiformes are re-described; Leucocytozoon beaurepairei of the Sagittaridae is resurrected from synonymy.

Abstract: Summary Savalli, U.M. 1993. The timing of breeding and moult of the Yellowmantled Widowbird Euplectes mac-rourus in western Kenya. Ostrich 64:49-56. This paper describes the breeding and moulting seasons of Yellowmantled Widowbirds Euplectes mac-rourus at the Kakamega National Reserve in western Kenya. Egg laying began in May, peaked in June, and continued into September. The presence of brood patches on females followed a similar pattern. Most moulting occurred prior to breeding, in March and April. Rainfall was greatest in April and May, with a second peak in August to September. The pattern of grass seed abundance closely matched rainfall, and breeding appears to start about one month after the start of the rains. An exceptionally dry spell in May and June 1990 may have resulted in few breeding attempts that year.

Abstract: Summary Bennett, G. F., Earle, R. A. & Peirce, M. A. 1993. The Leucocytozoidae of South African birds: Musophagiformes, Cuculiformes and Piciformes. Ostrich 64:73-78. The leucocytozoids of the avian orders Musophagiformes, Cuculiformes and Piciformes are reviewed. Leucocytozoon dinizi Tendeiro, 1947 of the Musophagidae is re-described and a neohapantotype designated. Leucocytozoon centropi Fantham, 1921 is re-described and L. coccyzus Coatney & West, 1938 is synonymized with it and a neohapantotype designated. Leucocytozoon squamatus Nandi, 1986 of the Pi-cidae is re-described and compared with Leucocytozoon capitonis n. sp. of the piciform family Capitonidae.

Abstract: Summary Savalli, U. M. 1993. The behaviour of male Yellowmantled Widowbirds Euplectes macrourus in western Kenya. Ostrich 64: 57–62. Male Yellowmantled (Yellowbacked) Widowbirds Euplectes macrourus use two displays in territorial defense. The territory boundary display involves a specific, upright posture along with the hiss-trill vocalization, but the song does not have a visual component. Courtship displays involve flicking up the wings and tail, sometimes leaning toward the female with the tail elevated, and a slow, bouncing flight display. The swivelling display described by Emlen (1957) was not observed, and seems to be replaced by the flicking displays. During the breeding season, male Yellowmantled Widowbirds defend territories from conspecifics but do not exclude Marsh Widowbirds E. hartlaubi. At night they form communal roosts off their territories. During the non-breeding season they form mixed species flocks with other finches. Male widowbirds are most active in display before 10h00, and often ...

Abstract: Summary Nuttall, R.J. 1993. Vocal behaviour of the Quail Finch Ortygospiza atricollis. Ostrich 64:97-104. Vocalizations (contact, take-off, flight, alarm, beckon, nestling begging and nestling threat calls, contact phrases and song of the Quail Finch Ortygospiza atricollis are described from observations and recordings of wild-caught aviary birds, and from individuals in the field. The predominantly terrestrial habits and grassland habitat of this species ma have been important in the evolution of a specialized vocal repertoire, particularly of sex-specific vocalizations necessary for sexual and individual recognition, and the maintenance of contact between individuals.

Abstract: Summary Little, R.M., Verster, A. & Crowe, T.M. 1993. Seasonal and demographical variation in intestinal helminth infection of Greywing Francolin. Ostrich 64:178-181. The proportion of the population carrying intestinal parasites (prevalence of infection) and the mean number of parasites per host within the host population (worm burden) for 312 Greywing Francolin Fran-colinus africanus were recorded on the Stormberg Plateau, eastern Cape Province, during April 1989-De-cember 1990. Most Greywing (86%) had helminths in their small intestine or caeca. Variation in levels of helminth infection (i.e. both prevalence and burdens) was independent of host sex. Nematodes were confined to the caeca where they were present in high numbers throughout the year with two peaks during June-August and November-January. The prevalence and worm burdens of nematodes were independent of host age Nematodes were more prevalent than cestodes. The prevalence and number of cestodes in the small intestine were highest during Septem...

Abstract: Summary Wintle, C. C. & Taylor, P. B. 1993. Sequential polyandry, behaviour and moult in captive Striped Crakes Aenigmatolimnas marginalis. Ostrich 64:115-122. Captive Striped Crakes showed sequential polyandry, the female laying for a second male when the clutch of her first mate was about to hatch. Where aviary space permitted each male set up a breeding territory and each female defended a larger area encompassing the territories of one or two males. Non-territorial subordinate males and females did not breed. The female initiated breeding by attracting the male and soliciting copulation, and the male incubated the eggs and cared for the young. Incubation took 17–18 days, the chicks left the nest at 4–5 days of age and were fully grown and capable of flight at 46–53 days. Breeding occurred from September to March and males normally reared two broods per season. Territoriality was evident only during the breeding season. Juvenile plumage was a duller version of the sexually dimorphic adult plumage; post...

Abstract: Summary Nuttall, R.J. 1993. Seasonal changes in the birdlife of a pen-urban grassland community. Ostrich 64: 1–7. Visits to a grassland habitat near Pietermaritzburg, Natal, South Africa were undertaken over a period of ten months (March-December) to document changes in avifauna, and to investigate possible reasons for any changes. A total of 72 bird species was recorded. Monthly species totals showed considerable fluctuation, with species diversity highest in spring-early summer (n=53) and lowest in winter (n=14). Terrestrial insectivores were the best represented fin terms of number of species) during the course of the study. The influence of rainfall on food availability and on vegetation is considered important in determining the structure of this avian community. Observations of the assumption (and loss) of nuptial plumage in euplectines showed that Longtailed Widows Euplectes progne developed breeding plumage earliest, and retained it for the longest period of time. Both Whitewinged E. albonotatus a...

Abstract: Summary Thompson, J.J. 1993. Opportunistic breeding by the Redbilled Quelea in eastern Kenya. Ostrich 64: 32–37. The demography and breeding patterns of the Redbilled Quelea in eastern Kenya are described with respect to abnormally high rainfall in Tsavo-East National Park during late 1984 and early 1985. The prolonged breeding that occurred, together with the early sexual maturation of young queleas and their entry into the breeding population, underlined the opportunistic nature of quelea migration and breeding strategies. Opportunism may be considered to be the most adaptive breeding strategy for queleas generally, but may be more conspicuous in East Africa than in some other parts of Africa because of more complex rainfall patterns.

Abstract: Summary Kok, O.B. 1993. Diet of the Spotted Dikkop Burhinus capensis. Ostrich 64:182-184. Analysis of 81 stomach samples of Spotted Dikkops Burhinus capensis collected in the central arts of South Africa over a period of eight years showed this species to be predominantly insectivorous. Coleoptera, followed by Isoptera (exclusively represented by the harvester termite Hodotermes mossambicus) made up the bull of the insect material. Coleoptera were the only prey items taken throughout the year, while Isoptera were mainly consumed during the winter months and early summer. The remainder of the animal matter in the diet was dominated by Diplopoda.

Abstract: Summary Slotow, R., Goodfriend, W. & Maclean, G. 1993. The social structure of captive Cape Sparrow flocks. Ostrich 64:63-66. We documented the social structure of two mixed-sex flocks of Cape Sparrows in aviaries. Unlike previous studies on north-temperate passerines, we found that males were not necessarily dominant to females. Some males paired with females, and assisted these females in interactions. By such associations, these females may attain higher status than their individual ability would permit. We removed the dominant male in each group, and noted that the pair bond of the beta pair remained stable, and that a new male paired with the formerly dominant alpha female. The removal of the dominant alpha male may have decreased the alpha female's social status. We found no correlation between any morphometric variable and social status.