Breeding biology of lanner falcons near pretoria, south africa
TL;DR: Aspects of the breeding biology of the Lanner Falcon Falco biarmicus were recorded from seven territories near Pretoria, South Africa during 1970 to 1988, but after 1982 few young were fledged and by 1987 there were no longer any falcons breeding in the area.
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.
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Book•
01 Jan 1997
TL;DR: In this paper, a major work covering the breeding and non-breeding birds of the Southern African sub-region is presented, which sets new standards in its scope and in its methods, for setting a measured baseline against which to judge environmental trends across the great range of southern Africa.
Abstract: This is a major work covering the breeding and non-breeding birds of the Southern African sub-region. Published in two volumes, Volume One includes introductory chapters describing methodology and the 'avi'-geography of the region, with habitat photos, and coverage of the non-passerines, whilst Volume Two covers the passerines. Some 900 species are covered in total, including 200 vagrants, with detailed species accounts, maps and statistics for at least 500 species. Conservation issues are discussed for most species. '...sets new standards in its scope and in its methods...it will come to be valued ever more as years go by, for setting a measured baseline against which to judge environmental trends across the great range of southern Africa.' - Colin Bibby, "BirdLife International".
347 citations
TL;DR: This review focuses on research examining the effects of EMFs on birds; most studies indicate that EMF exposure of birds generally changes, but not always consistently in effect or in direction, their behavior, reproductive success, growth and development, physiology and endocrinology, and oxidative stress under EMF conditions.
Abstract: Electrical power lines are ubiquitous in the developed world and in urban areas of the developing world. All electrical currents, including those running through power lines, generate electric and magnetic fields (EMFs). Electrical power lines, towers,and distribution poles are used by birds for perching, hunting, and nesting. Therefore, many bird species, like humans, are exposed to EMFs throughout their lives. EMFs have been implicated in adversely affecting multiple facets of human health,including increasing the risks of life-threatening illnesses such as leukemia, brain cancer, amyotrophic lateral sclerosis, clinical depression, suicide, and Alzheimer's disease. A great deal of research and controversy exists as to whether or not exposure to EMFs affects the cellular, endocrine, immune, and reproductive systems of vertebrates. Laboratory work has used mice, rats, and chickens as models for this EMF research in an effort to understand better the possible implications of EMF exposure for humans. However, EMF exposure of wild birds may also provide insight into the impacts of EMFs on human health. This review focuses on research examining the effects of EMFs on birds; most studies indicate that EMF exposure of birds generally changes, but not always consistently in effect or in direction, their behavior, reproductive success, growth and development, physiology and endocrinology, and oxidative stress under EMF conditions. Some of this work has involved birds under aviary conditions, while other research has focused on free-ranging birds exposed to EMFs. Finally, a number of future research directions are discussed that may help to provide a better understanding of EMF effects on vertebrate health and conservation.
89 citations
Journal Article•
TL;DR: P Peregrine Falcons on the Orange River had the broadest feeding niche and preyed mainly on 'commuter' species rather than sedentary residents, and Lanner Falcons in the Soutpansberg took mainly terrestrial or cursorial species, but columbids were also important.
Abstract: -•The diets of breeding Peregrine (Falco peregrinus) and Lanner (F. biarmicus) Falcons in South Africa were determined from the analysis of prey remains collected at nest sites and through direct observations to determine the regional variation in Peregrine Falcon prey and to measure diet overlap, and the potential for competition between Peregrine Falcons and sympatric congeners. Direct observations suggested that remains under-sampled small prey by about 10% and over-sampled large prey by about 8%. Peregrine and Lanner Falcons preyed mostly on birds. Pigeons and Streptopelia doves comprised the bulk (38-66% by frequency; 68-85% by mass) of the Peregrine Falcon prey in each of three study areas. Columbids were supplemented by starlings (mostly European Starling [Sturnus vulgaris]) on the Cape Peninsula, sandgrouse (Pterocles spp.) and swifts (Apus spp.) on the Orange River, and mousebirds (Colius spp.) in the Soutpansberg. Cape Peninsula Peregrine Falcons had the least diverse diet, the narrowest feeding niche and they took the largest proportion of juvenile birds. Peregrine Falcons on the Orange River had the broadest feeding niche and preyed mainly on 'commuter' species rather than sedentary residents. Lanner Falcons in the Soutpansberg took mainly terrestrial or cursorial species, particularly young chickens (Gallus gallus, 40%; 37%) and charadriids, but columbids were also important. The diets of sympatric Peregrine and Lanner Falcons overlapped by about 35%. Peregrines Falcons concentrated their foraging on woodland and cliff-dwelling prey, while Lanner Falcons took mainly open-country species. Close-neighboring pairs of congeners did not obviously affect the foodniche parameters of either species suggesting that they were not actively competing for food.
22 citations
TL;DR: Jenkins et al. as mentioned in this paper measured geographic and interspecific variation in reproductive performance of Peregrine and Lonner Falcons in South Africa and determined environmental correlates of productivity, including territory occupancy, frequency of breeding per occupied territory and clutch size.
Abstract: Jenkins, A.R. 2000. Factors affecting breeding success of Peregrine and Lonner Falcons in South Africa. Ostrich 71 (384): 385-392. Breeding success was recorded for three Peregrine Falcon, Falco peregrinus, populations in South Africa over nine years, and for Peregrine and Lanner Falcon, Ebiarmicus, populations in an area of sympatry over three years. The objectives of the study were to measure geographic and interspecific variation in reproductive performance, and determine environmental correlates of productivity. Territory occupancy, the frequency of breeding per occupied territory and clutch size did not vary significantly between the three Peregrine populations. However, Peregrine breeding success was generally lower on the Cape Peninsula (1. 11 young fledged per territorial poir), higher in the Soutpansberg (1.36) and highest on the Orange River (1.70). Overall, fledging rates of Soutpansberg Peregrines and Lanners were not significantly different, although annual productivity of the Lonner populati...
19 citations
18 Aug 2015
TL;DR: In this article, carrion is dened as any dead animal or parts of dead animals, and consumers are divided into scavengers and decomposers, where scavengers feed on the carcass by ingesting it and often physically removing pieces of it.
Abstract: Many areas of Africa are inhabited by a rich abundance of organisms that produce or consume carrion.
In this chapter, carrion is dened as any dead animal or parts of dead animals, and carrion consumers are
divided into scavengers and decomposers. Scavengers feed on carrion by ingesting it and often physically
removing pieces of it, whereas decomposers, such as microbes, are largely saprophytic or saprozoic and
utilize carrion as a food source exclusively in situ (Putnam 1983). The focus of this chapter will largely
be on scavengers, as they profoundly inuence carrion degradation in most African ecosystems.
17 citations
References
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Book•
[...]
01 Jan 1982
TL;DR: This is the eighth and final volume in the authoritative Birds of Africa series as discussed by the authors, which covers the Malagasy region which comprises Madagascar and the various islands and archipelagos of the Indian Ocean including the Seychelles, the Comoros, Mauritius and Reunion.
Abstract: This is the eighth and final volume in the authoritative Birds of Africa series. It covers the Malagasy region which comprises Madagascar and the various islands and archipelagos of the Indian Ocean including the Seychelles, the Comoros, Mauritius and Reunion. Every resident and migrant species is covered in full detail, comparable to other volumes in the series, and with a colour map for each species. Vagrants are treated in less detail. All species are illustrated on a beautiful series of 64 colour plates, with original artwork from John Gale and Brian Small.This is a major work of reference on the birds of the region and will remain the standard text for many years to come."
1,035 citations
Book•
01 Jan 1982
TL;DR: The Description for this book, An Atlas of the Birds of the Western Palaearctic, will be forthcoming.
Abstract: The Description for this book, An Atlas of the Birds of the Western Palaearctic, will be forthcoming.
385 citations
TL;DR: Pairs of Aplomado falcons consistently showed signs of cooperative behavior such as use of a simple coordinative signal, and some division of labor between participating individuals, but there was no evidence that cooperative hunting increased the range of feasible prey sizes.
Abstract: Aplomado falcons (Falco femoralis) often hunt in pairs when chasing birds; 29% of 349 hunts observed in eastern Mexico involved mated pairs of falcons simultaneously chasing the same prey animal; and 66% of 100 hunts of birds were tandem pursuits. Although true cooperative hunting is uncommon in birds of prey, hunts by pairs of Aplomado falcons consistently showed signs of cooperative behavior such as use of a simple coordinative signal, and some division of labor between participating individuals. Pairs were more than twice as successful as solo falcons hunting birds (44% vs. 19%), however, there was no evidence that cooperative hunting increased the range of feasible prey sizes. The frequent use of cooperative foraging in this and similar species may relate to necessities of efficient nest defense, and food and nest procurement in savannas inhabited by a diversity of nest-site predators.
83 citations