Showing papers in "Ostrich in 1995"
TL;DR: Meyburg et al. as mentioned in this paper tracked an adult female Wahlberg's eagle from northern Namibia over a total distance of 8816 km and located 104 times between 11 February and 4 November 1994.
Abstract: Summary Meyburg, B.-U., Mendelsohn, J. M., Ellis, D. H., Smith, D.G., Meyburg, C. & Kemp, A.C. 1995. Year-round movements of a Wahlberg's Eagle Aquila wahlbergi tracked by satellite. Ostrich 66: 135–140. An adult female Wahlberg's Eagle from northern Namibia was tracked by satellite over a total distance of 8816 km and located 104 times between 11 February and 4 November 1994. It migrated on an almost due north heading to northern Cameroon, north-eastern Nigeria and western Chad through the rain forest belt of the Congo and Zaire after the breeding season. The total trans-equatorial distance between the breeding and non-breeding ranges was 3520 km. During the non-breeding season the bird ranged over a large area (ca. 60 000 km') for about six weeks (29 April – 14 June) in these three countries in a rather nomadic pattern covering a minimum distance of 1256 km. During two further months (14 June – 14 August) it restricted its movements to an area of about 5000 km2 near Maiduguri in the Sudan savannah of no...
30 citations
TL;DR: The effect of rainfall from 1964 to 1994 on the annual reproductive rate and number of resident pairs of Black Eagles Aquila verreauxii in the Matobo Hills, Zimbabwe, and on the abundance of their staple prey, hyrax, Procavia capensis and Heterohyrax brucei is reviewed.
Abstract: Summary Gargett, V., Gargett, E. & Damania, D. 1995. The influence of rainfall on Black Eagle breeding over 31 years in the Matobo Hills, Zimbabwe. Ostrich 66: 114–121. The effect of rainfall from 1964 to 1994 on the annual reproductive rate and number of resident pairs of Black Eagles Aquila verreauxii in the Matobo Hills, Zimbabwe, and on the abundance of their staple prey, hyrax, Procavia capensis and Heterohyrax brucei is reviewed. The number of resident pairs of Black Eagles increased with increased rainfall, when hyrax numbers were estimated to be at a very high level. Subsequent poor rainfall years coincided with a decrease in the number of resident pairs, a smaller proportion of pairs breeding, a lower reproductive rate and a dramatic decline in prey numbers.
18 citations
Journal Article•
17 citations
TL;DR: Polyandry in the African Jacana: the roles of male dominance hierarchies and rate of clutch loss and the breeding success and mating relationships between indi...
Abstract: Tarboton, W. R. 1995. Polyandry in the African Jacana: the roles of male dominance hierarchies and rate of clutch loss. Ostrich 66: 49–60. The breeding success and mating relationships between indi...
14 citations
TL;DR: Summary Hartley, R.R., Newton, I., & Robertson, M. 1995.
Abstract: Summary Hartley, R.R., Newton, I., & Robertson, M. 1995. Organochlorine residues and eggshell thinning in the Peregrine Falcon Falco peregrinus minor in Zimbabwe. Ostrich 66: 69–73. Several types of organochlorine residues were found in eggs of Peregrine Falcons Falco peregrinus minor taken in Zimbabwe in 1990. DDE (range = 0.2–22 ppm wet weight; geometric mean 1.8 ppm) was found in all eggs (n = 15) from 13 sites, including two pars in captivity. Eggs from two sites in the mid-Zambezi Valley, the most recently and heavily sprayed areas (5–8 times for tsetse fly Glossina sp. control), had the highest levels, one beyond that regarded as critical for successful reproduction. Mean shell thickness (Ratcliffe index) of the 1990 eggs was 10% (range = 2–29%) lower than the presumed pre-DDT mean. HEOD was detected in two eggs, HCB in one egg, and PCBs in all eggs, but at levels too low to affect breeding performance. Young were fledged from each of 12 sampled sites, yielding 1.86 young per site.
14 citations
TL;DR: Watson et al. as discussed by the authors survey populations of dune-breeding birds along 237 km of sand and dune coastline between Huisklip and The Great Fish River, Eastern Cape, South Africa.
Abstract: Summary Watson, J.J. & Kerley, G.I.H. 1995. A survey of the dune-breeding birds in the Eastern Cape, South Africa. Ostrich 66:15-20. Increasing human activity in sensitive dune areas may negatively impact dune-breeding birds. The aim of this study was to survey populations of dune-breeding birds along 237 km of sand and dune coastline between Huisklip and The Great Fish River, Eastern Cape. The numbers of Whitefronted Plovers Charadrius marginatus, African Black Oystercatchers Haematopus moquini and Damara Terns Sterna balaenarum were recorded in 33 sections along the coast. A total of 589 African Black Oystercatchers (2.49 birds/km), 537 Whitefronted Plovers (2.27 birds/km) and 28 Damara Terns (0.12 birds/km), were observed. Only one Damara Tern was seen outside the Alexandria Dunefield, which provides 74% of the total potential Damara Tern nesting sites in the Eastern Cape. The area between the Kabeljous and Maitland Rivers and between the Sundays River and Woody Cape (Alexandria Dunefield) are importan...
13 citations
TL;DR: Blue-naped Mousebirds are altricial birds that are naked and blind at hatching and within 12 days individual birds are essentially endothermic at Ta + 20°C and at this age the birds leave the nest.
Abstract: Summary Finke C., Misovic, A. & Prinzinger, R. 1995. Growth, the development of endothermy, and torpidity in Blue-naped Mousebirds Urocolius macrourus. Ostrich 66:1-9. Blue-naped Mousebirds are altricial birds that are naked and blind at hatching. The nestling period is extremely short (12.5 ± 0.8 d). During the first 7 days the nestlings are unable to thermoregulate actively but from 3 day old the nestlings already show approximately the same body temperature (Tb) as adults under “natural conditions” in the nest with siblings. At an ambient temperature (Ta) of + 35°C the nestlings are nearly endothermic by the age of 9 days (Tb 39.1 ± 0.8°C) and within 12 days individual birds are essentially endothermic at Ta + 20°C (Tb 39.4 ± 0.4°C = 97% of adult-Tb). At this age the birds leave the nest. They are sufficiently feathered but still unable to fly and have only reached 55% of adult mass. Coordinated shivering thermogenesis was observed for the first time on day 6 (Ta ± 20°C), and panting and gular flutteri...
11 citations
TL;DR: It remained high for both sexes when feeding nestlings and both made more strikes from hovers when breeding, especially females that also increased the number of bouts of hovering preceding a strike...
Abstract: Summary Kemp, A. C. 1995. A comparison of hunting behaviour by each sex of adult Greater Kestrels Falco rupicoloides resident near Pretoria, South Africa. Ostrich 66:21-33. During 1975–79,I observed the hunting behaviour of territorial, colour-marked, adult Falco rupicoloides that were resident on grass and croplands near Pretoria, South Africa. I recorded 686 strikes by males and 796 by females. Both sexes mainly hunted from perches or hovers and captured invertebrates 10 g. In monthly comparisons, both sexes made more and shorter strikes from perches when moulting and not breeding (December-May). They made more and longer strikes at vertebrate prey during courtship (June-August). When breeding (September-November), hunting success of males was highest when feeding the incubating female. It remained high for both sexes when feeding nestlings and both made more strikes from hovers when breeding, especially females that also increased the number of bouts of hovering preceding a strike...
10 citations
10 citations
TL;DR: It is concluded that Whitechinned Petrels at Marion Island are similarly sized and breed in a similar manner to other studied populations of the nominate race, which should now lead to a slow population recovery.
Abstract: Summary Berruti, A., Cooper, J. & Newton, I.P. 1995. Morphometrics and breeding biology of the Whitechinned Petrel Procellaria aequinoctialis at sub-Antarctic Marion Island. Ostrich 66: 74–80. Aspects of adult morphometrics and the breeding biology of the summer-breeding Whitechinned Petrel at sub-Antarctic Marion Island, southern Indian Ocean, are given, based on a study conducted in 1980/91, along with additional observations on breeding success made in 1990191. It is concluded that Whitechinned Petrels at Marion Island are similarly sized and breed in a similar manner to other studied populations of the nominate race. The eradication of cats at Marion Island in 1991 should now lead to a slow population recovery.
10 citations
TL;DR: There was no correlation between pairs in occupancy of territory, productivity or development periods of young: this confirms the flexible breeding abilities of the Secretarybird Sagittarius serpentarius which are unusual for such a large bird.
Abstract: Summary Kemp, A. C. 1995. Aspects of the breeding biology and behaviour of the Secretarybird Sagittarius serpentarius near Pretoria, South Africa. Ostrich 66: 61–68. Secretarybirds in three adjacent territories were monitored from 1977 to 1988 on grass- and croplands near Pretoria, South Africa. Most observations of breeding biology and behaviour confirmed or extended previous studies. There was no correlation between pairs in occupancy of territory, productivity or development periods of young: this confirms the flexible breeding abilities which are unusual for such a large bird. Some aspects of breeding biology (egg shape and texture, watering of chicks) and behaviour (Wings open and Up-down greeting displays) may be homologous with storks and important in understanding the phylogeny and evolution of the Sagitariidae and other diurnal raptors.
TL;DR: The generalized linear model with a binomial distribution and logistic link function is shown to be the appropriate statistical tool for analysing blood parasite data and supported the prediction that bright males tend to be parasitized more frequently.
Abstract: Summary Underhill, L.G. & Kalejta-Summers, B. 1995. Blood parasites in bright birds: testing the Hamilton-Zuk hypothesis in sub-Saharan Africa with an improved statistical method. Ostrich 66:10-14. The data contained in a catalogue of avian haematozoa for sub-Saharan Africa were examined in the light of the Hamilton-Zuk hypothesis. The males of 464 passerine species were assigned six brightness scores. The generalized linear model with a binomial distribution and logistic link function is shown to be the appropriate statistical tool for analysing blood parasite data. With caveats, results from the model supported the prediction that bright males tend to be parasitized more frequently. However, the group of species with the highest brightness score, had infection rates similar to the dullest group. When phylogenetic associations were taken into account, support for the Hamilton-Zuk hypothesis was equivocal. Further research on the ecology and natural history of the interactions between blood parasites, the...
TL;DR: A previously unreported tail-uphill-wiping display is described and male tarsus length was weakly, but positively, related to the size of feeding area (a possible indicator of territory quality), but there were no other significant correlates with territory size, or frequency of frequency.
Abstract: Summary Savalli, U. M. 1995. Morphology, territoriality and mating system of the Pintailed Whydah Vidua macroura. Ostrich 66: 129–134. The biology of the Pintailed Whydah Vidua macroura was studied at the Kakamega Forest, western Kenya. This species is sexually dimorphic in plumage and size (males are brighter, long tailed and larger). Males defended large (1.4 ha) territories which contained areas of bare ground (9% of total area) suitable for feeding on grass seeds such as Paspalum scrobiculatum. There were two breeding peaks: during the long rains (April-August) and the short rains (November-December). Territorial interactions were frequent; a previously unreported tail-uphill-wiping display is described. Females frequently visited male territories and were pursued and courted by the males. Male tarsus length was weakly, but positively, related to the size of feeding area (a possible indicator of territory quality), but there were no other significant correlates with territory size, or frequency of int...
TL;DR: The hunger status of the birds at the time of the experiment and the way in which the experiments were designed and carried out probably influenced the size of fish chosen by the birds.
Abstract: Summary Hustler, 1995. Cormorant and Darter prey size selection under experimental conditions. Ostrich 66:109-113. The most profitable sized cichlid fish for Reed Phalacrocorax africanus and Whitebreasted Cormorants P. carbo lucidus and Darter Anhinga melanogaster were determined experimentally. A range of sizes was fed to all three species in captivity to determine whether, given a choice, they would choose the most profitable fish. All species chose certain sizes of fish preferentially, but not in accordance with their profitability. The hunger status of the birds at the time of the experiment and the way in which the experiments were designed and carried out probably influenced the size of fish chosen by the birds.
TL;DR: During July-December 1992, the diet, home range, hunting and reproductive behaviour of a pair of Dickinson's Kestrel Falco dickinsoni was recorded in the Kruger National Park, South Africa.
Abstract: Summary BENN, G.A. & KEMP, A.C. 1995. Diet, home range, hunting and reproductive behaviour of a pair of Dickinson's Kestrel Falco dickinsoni in the Kruger National Park, South Africa. Ostrich 66: 81–91. During July-December 1992, the diet, home range, hunting and reproductive behaviour of a pair of Dickinson's Kestrel Falco dickinsoni was recorded in the Kruger National Park, South Africa. Numerically, for both sexes combined, invertebrates formed the majority (56%) of the diet, while separately the female caught 75% and the male 49% invertebrate prey. During courtship and incubation the male supplied the female with primarily vertebrate prey and both provisioned mainly vertebrates to the nestlings (male = 80%; female = 57%). The non-breeding home range of the female was 27.8 km2, and the breeding home range of the male was 26.3 km2. Both utilised their home ranges differentially, the area within a 2 km radius of the nest (12.6 km2) being used proportionally more than the remaining area. The home range of...
TL;DR: New light is shed on the nest building techniques and nest building behaviour of the Masked Weaver species and it is demonstrated that nest building can be flexible in the same individual.
Abstract: Summary Howman, H.R.G., & Begg, G.W. 1995 Intra-seasonal and inter-seasonal nest renovation in the Masked Weaver, Ploceus velatus. Ostrich 66:122-128. This paper describes a series of observations relating to the intra-seasonal and inter-seasonal renovation of nests by a single male Masked Weaver Ploceus velatus, over a period of three breeding seasons (1991 to 1993). These data shed new light on the nest building techniques and nest building behaviour of the species and demonstrate that nest building can be flexible in the same individual. It is suggested that the partial demolition of nests and the renovation of nests would be advantageous because of the energetic savings.