Shane McPherson | University of KwaZulu-Natal (original) (raw)
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Papers by Shane McPherson
The paper based on this dataset has been published in Behavioral Ecology with the title "Con... more The paper based on this dataset has been published in Behavioral Ecology with the title "Contrasting parental color-morphs increase regularity of prey deliveries in an African raptor"<br>Abstract: Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of color polymorphism in populations. Selection for such a mating system may occur if there are fitness advantages of mating with a contrasting morph. In the black sparrowhawk (Accipiter melanoleucus), mixed-morph pairs may have a selective advantage, since they produce offspring which have higher survival rates. Two hypotheses, which may explain the mechanism, are the 'avoidance-image' and 'complementarity' hypotheses: The first suggests that within a predator's territory, prey develop a search-image for the more commonly encountered parental morph, for example, the male morph during incubation and brooding. Females of a contrasting morph to their partner woul...
Urban Ecosystems, 2015
The study of diet is pivotal in understanding a species, particularly for quantifying a predatory... more The study of diet is pivotal in understanding a species, particularly for quantifying a predatory raptors’ economic niche and potential for human-wildlife conflict. The crowned eagle (Stephanoaetus coronatus) is one of Africa’s apex predators and a population is present within the urban greenspace mosaic of Durban and Pietermaritzburg, KwaZulu-Natal, South Africa. In close association with urban development, the local population of crowned eagles has the potential to be a concern to the safety of domestic stock and pets. Time-lapse cameras were positioned at urban nest sites (n = 11) to identify the prey composition during breeding, particularly in regards to taxa with human associations. The numerical proportion of avian prey, particularly hadeda ibis (Bostricia hagedash) pulli, was several times greater than any previous diet description. The methodology used and the abundance of hadeda ibis in these urban environments are potential contributing factors. Rock hyrax (Procavia capensis) was the primary prey and where hyrax were unavailable, the diet composition was broader and included more vervet monkeys (Chlorocebus pygerythrus). It was found that domestic stock comprised 6 % of the identifiable prey. Contrary to popular belief, no dogs (Canis familiaris) and few cats (Felis domesticus) were delivered to the nest by breeding eagles in this study. The negative consequences of small proportions of pet losses should be considered against the majority of wildlife prey consumed, which also have various wildlife conflict interactions. Juvenile and sub-adult eagles are most frequently identified at in situ attacks of pets, particularly toy dog breeds. Further research on juvenile dispersal and winter diet will provide insights on the ecological impacts of eagle management strategies in the region.
Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to hum... more Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to humans and domestic animals’ safety, which generate the need for management and removal strategies. These issues become especially challenging when humans and wildlife coexist close to one another, for example, in urban landscapes. African Crowned Eagles (Stephanoaetus coronatus) are powerful forest raptors that breed within the metropolitan green-space system of Durban and Pietermaritzburg, South Africa. Negative human-wildlife interactions can occur because eagles occasionally predate on pets, such as cats (Felis catus) and small dogs (Canis lupus familiaris), and provisioning domestic stock to nest sites has previously been quantified. Here, wildlife management becomes critical, usually aimed at reducing or eliminating causes of economic or social harm, but have to be balanced against conservation goals regarding threatened species. In this study, we (i) identified causes of harm or loss...
Urban areas can be attractive to certain species because of increased food abundance and nesting ... more Urban areas can be attractive to certain species because of increased food abundance and nesting availability, which in turn may increase productivity or breeding rates. However, there are also potential costs associated with urban living such as higher nest failure, poorer body condition, or increased prevalence of disease. These costs may result in species trading off the number of young produced against the condition of their young. African Crowned Eagles (Stephanoaetus coronatus) are a rare example of large, powerful apex predators that breed in some urban areas in Africa. In this study, we explored the breeding performance of these eagles across an urbanization gradient in KwaZulu-Natal Province, South Africa, over 7 breeding seasons. We predicted that living in an urban environment would increase productivity through an increase in breeding rate (shifting from typically biennial breeding to annual breeding). We then explored if there were any hidden costs associated with such ...
Journal of Raptor Research
Abstract. Apex predators are sensitive to human disturbance and persecution, often becoming the f... more Abstract. Apex predators are sensitive to human disturbance and persecution, often becoming the first losses in a declining urban wildlife community. A population of Crowned Eagles (Stephanoaetus coronatus) within eThekwini municipality, KwaZulu-Natal, South Africa, persists in a green space network called the Durban Metropolitan Open Space System (DMOSS). We used GPS–UHF telemetry to investigate the home range and habitat use of five breeding adult Crowned Eagles for 1 yr. We documented a mean annual home range for four birds of 13 km2 (Minimum Convex Polygon [MCP] 100%), or 6.3 km2 (Kernel Density Estimator [KDE], bandwith HLSCV 95%), equating to small home ranges for this large eagle, compared with other large eagles. Habitat use within home ranges and correlation with DMOSS area underscored the importance of retaining forest patches in the urban mosaic landscape to encourage the persistence of this large raptor. Our study highlighted the importance of planning green space in future city expansion and land development. The spatial and habitat associations of Crowned Eagles may be used to inform urban planners who wish to support biodiverse communities that include apex predators in an urban landscape.
African Journal of Ecology
Behavioral Ecology
Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of... more Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of color polymorphism in populations. Selection for such a mating system may occur if there are fitness advantages of mating with a contrasting morph. In the black sparrowhawk (Accipiter melanoleucus), mixed-morph pairs may have a selective advantage because they produce offspring that have higher survival rates. Two hypotheses, which may explain the mechanism, are the “avoidance-image” and “complementarity” hypotheses. The first suggests that, within a predator’s territory, prey develop a search image for the more commonly encountered parental morph, for example, the male morph during incubation and brooding. Females of a contrasting morph to their partner would then have higher capture rates once they commence hunting in the later nestling phase. Thus, the “avoidance-image” hypothesis predicts higher provisioning rates for mixed-morph pairs. Alternatively, the “complementarity” hypothesi...
Landscape and Urban Planning, 2016
• Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances w... more • Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances were less than in natural landscapes within the Region. • Most nests were in green-space zones near an interface with formal residential areas. • An exotic invasive Eucalyptus tree was the most frequently used nest tree species. a b s t r a c t Globally, dramatic land use change typical of urbanisation negatively affects biodiversity, especially for top predators. The Durban Metropolitan Open Space System (D'MOSS), South Africa, faces the challenge of conserving biodiversity in a regional hotspot in the face of rapid urban growth in one of Africa's major commercial hubs. Consequently, we investigated nest site selection of crowned eagles (Stephanoaetus coronatus) on various spatial scales within this urban mosaic. Unexpectedly the inter-nest distances were small in this human-dominated landscape. However, breeding sites were not evenly distributed through the landscape and were closely associated with natural forest, while nest trees were most frequently in patches of exotic large riverine Sydney blue gum (Eucalyptus saligna, Smith 1797) within the D'MOSS planning zones. Crowned eagles showed a strong tendency to avoid informal settlement areas; however they were tolerant of proximity to established formal settlements and occupied dwellings. Consequently, continued protection of the D'MOSS system, and a considered approach to management of E. saligna are necessary for the persistence of the crowned eagle in this landscape. Future research should focus on food requirements, post-fledging survival, and recruitment to determine which nest sites are most productive and whether this population is acting as a source or a sink.
Landscape and Urban Planning, 2016
• Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances w... more • Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances were less than in natural landscapes within the Region. • Most nests were in green-space zones near an interface with formal residential areas. • An exotic invasive Eucalyptus tree was the most frequently used nest tree species. a b s t r a c t Globally, dramatic land use change typical of urbanisation negatively affects biodiversity, especially for top predators. The Durban Metropolitan Open Space System (D'MOSS), South Africa, faces the challenge of conserving biodiversity in a regional hotspot in the face of rapid urban growth in one of Africa's major commercial hubs. Consequently, we investigated nest site selection of crowned eagles (Stephanoaetus coronatus) on various spatial scales within this urban mosaic. Unexpectedly the inter-nest distances were small in this human-dominated landscape. However, breeding sites were not evenly distributed through the landscape and were closely associated with natural forest, while nest trees were most frequently in patches of exotic large riverine Sydney blue gum (Eucalyptus saligna, Smith 1797) within the D'MOSS planning zones. Crowned eagles showed a strong tendency to avoid informal settlement areas; however they were tolerant of proximity to established formal settlements and occupied dwellings. Consequently, continued protection of the D'MOSS system, and a considered approach to management of E. saligna are necessary for the persistence of the crowned eagle in this landscape. Future research should focus on food requirements, post-fledging survival, and recruitment to determine which nest sites are most productive and whether this population is acting as a source or a sink.
The study of diet is pivotal in understanding a species, particularly for quantifying a predator... more The study of diet is pivotal in understanding a species, particularly for quantifying a predatory raptors’ economic niche and potential for human-wildlife conflict. The crowned eagle (Stephanoaetus coronatus) is one of Africa’s apex predators and a population is present within the urban greenspace mosaic of Durban and Pietermaritzburg, KwaZulu-Natal, South Africa. In close association with urban development, the local population of crowned eagles has the potential to be a concern to the safety of domestic stock and pets. Time-lapse cameras were positioned at urban nest sites (n=11) to identify the prey composition during breeding, particularly in regards to taxa with human associations. The numerical proportion of avian prey, particularly hadeda ibis (Bostricia hagedash) pulli, was several times greater than any previous diet description. The methodology used and the abundance of hadeda ibis in these urbanenvironmentsarepotential contributing factors. Rock hyrax (Procavia capensis)was the primary prey and where hyrax were unavailable, the diet composition was broader and included more vervet monkeys (Chlorocebus pygerythrus). It was found that domestic stock comprised 6 % of the identifiable prey. Contrary to popular belief, no dogs (Canis familiaris) andfew cats(Felisdomesticus) weredelivered tothe nest bybreedingeagles in this study. The negative consequences of small proportions of pet losses should be considered against the majority of wildlife prey consumed, which also have various wildlife conflict interactions. Juvenile and sub-adult eagles are most frequently identified at in situ attacks of pets, particularly toy dog breeds. Further research on juvenile dispersal and winter diet will provide insights on the ecological impacts of eagle management strategies in the region.
The paper based on this dataset has been published in Behavioral Ecology with the title "Con... more The paper based on this dataset has been published in Behavioral Ecology with the title "Contrasting parental color-morphs increase regularity of prey deliveries in an African raptor"<br>Abstract: Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of color polymorphism in populations. Selection for such a mating system may occur if there are fitness advantages of mating with a contrasting morph. In the black sparrowhawk (Accipiter melanoleucus), mixed-morph pairs may have a selective advantage, since they produce offspring which have higher survival rates. Two hypotheses, which may explain the mechanism, are the 'avoidance-image' and 'complementarity' hypotheses: The first suggests that within a predator's territory, prey develop a search-image for the more commonly encountered parental morph, for example, the male morph during incubation and brooding. Females of a contrasting morph to their partner woul...
Urban Ecosystems, 2015
The study of diet is pivotal in understanding a species, particularly for quantifying a predatory... more The study of diet is pivotal in understanding a species, particularly for quantifying a predatory raptors’ economic niche and potential for human-wildlife conflict. The crowned eagle (Stephanoaetus coronatus) is one of Africa’s apex predators and a population is present within the urban greenspace mosaic of Durban and Pietermaritzburg, KwaZulu-Natal, South Africa. In close association with urban development, the local population of crowned eagles has the potential to be a concern to the safety of domestic stock and pets. Time-lapse cameras were positioned at urban nest sites (n = 11) to identify the prey composition during breeding, particularly in regards to taxa with human associations. The numerical proportion of avian prey, particularly hadeda ibis (Bostricia hagedash) pulli, was several times greater than any previous diet description. The methodology used and the abundance of hadeda ibis in these urban environments are potential contributing factors. Rock hyrax (Procavia capensis) was the primary prey and where hyrax were unavailable, the diet composition was broader and included more vervet monkeys (Chlorocebus pygerythrus). It was found that domestic stock comprised 6 % of the identifiable prey. Contrary to popular belief, no dogs (Canis familiaris) and few cats (Felis domesticus) were delivered to the nest by breeding eagles in this study. The negative consequences of small proportions of pet losses should be considered against the majority of wildlife prey consumed, which also have various wildlife conflict interactions. Juvenile and sub-adult eagles are most frequently identified at in situ attacks of pets, particularly toy dog breeds. Further research on juvenile dispersal and winter diet will provide insights on the ecological impacts of eagle management strategies in the region.
Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to hum... more Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to humans and domestic animals’ safety, which generate the need for management and removal strategies. These issues become especially challenging when humans and wildlife coexist close to one another, for example, in urban landscapes. African Crowned Eagles (Stephanoaetus coronatus) are powerful forest raptors that breed within the metropolitan green-space system of Durban and Pietermaritzburg, South Africa. Negative human-wildlife interactions can occur because eagles occasionally predate on pets, such as cats (Felis catus) and small dogs (Canis lupus familiaris), and provisioning domestic stock to nest sites has previously been quantified. Here, wildlife management becomes critical, usually aimed at reducing or eliminating causes of economic or social harm, but have to be balanced against conservation goals regarding threatened species. In this study, we (i) identified causes of harm or loss...
Urban areas can be attractive to certain species because of increased food abundance and nesting ... more Urban areas can be attractive to certain species because of increased food abundance and nesting availability, which in turn may increase productivity or breeding rates. However, there are also potential costs associated with urban living such as higher nest failure, poorer body condition, or increased prevalence of disease. These costs may result in species trading off the number of young produced against the condition of their young. African Crowned Eagles (Stephanoaetus coronatus) are a rare example of large, powerful apex predators that breed in some urban areas in Africa. In this study, we explored the breeding performance of these eagles across an urbanization gradient in KwaZulu-Natal Province, South Africa, over 7 breeding seasons. We predicted that living in an urban environment would increase productivity through an increase in breeding rate (shifting from typically biennial breeding to annual breeding). We then explored if there were any hidden costs associated with such ...
Journal of Raptor Research
Abstract. Apex predators are sensitive to human disturbance and persecution, often becoming the f... more Abstract. Apex predators are sensitive to human disturbance and persecution, often becoming the first losses in a declining urban wildlife community. A population of Crowned Eagles (Stephanoaetus coronatus) within eThekwini municipality, KwaZulu-Natal, South Africa, persists in a green space network called the Durban Metropolitan Open Space System (DMOSS). We used GPS–UHF telemetry to investigate the home range and habitat use of five breeding adult Crowned Eagles for 1 yr. We documented a mean annual home range for four birds of 13 km2 (Minimum Convex Polygon [MCP] 100%), or 6.3 km2 (Kernel Density Estimator [KDE], bandwith HLSCV 95%), equating to small home ranges for this large eagle, compared with other large eagles. Habitat use within home ranges and correlation with DMOSS area underscored the importance of retaining forest patches in the urban mosaic landscape to encourage the persistence of this large raptor. Our study highlighted the importance of planning green space in future city expansion and land development. The spatial and habitat associations of Crowned Eagles may be used to inform urban planners who wish to support biodiverse communities that include apex predators in an urban landscape.
African Journal of Ecology
Behavioral Ecology
Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of... more Disassortative mating in color-polymorphic raptors is a proposed mechanism for the maintenance of color polymorphism in populations. Selection for such a mating system may occur if there are fitness advantages of mating with a contrasting morph. In the black sparrowhawk (Accipiter melanoleucus), mixed-morph pairs may have a selective advantage because they produce offspring that have higher survival rates. Two hypotheses, which may explain the mechanism, are the “avoidance-image” and “complementarity” hypotheses. The first suggests that, within a predator’s territory, prey develop a search image for the more commonly encountered parental morph, for example, the male morph during incubation and brooding. Females of a contrasting morph to their partner would then have higher capture rates once they commence hunting in the later nestling phase. Thus, the “avoidance-image” hypothesis predicts higher provisioning rates for mixed-morph pairs. Alternatively, the “complementarity” hypothesi...
Landscape and Urban Planning, 2016
• Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances w... more • Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances were less than in natural landscapes within the Region. • Most nests were in green-space zones near an interface with formal residential areas. • An exotic invasive Eucalyptus tree was the most frequently used nest tree species. a b s t r a c t Globally, dramatic land use change typical of urbanisation negatively affects biodiversity, especially for top predators. The Durban Metropolitan Open Space System (D'MOSS), South Africa, faces the challenge of conserving biodiversity in a regional hotspot in the face of rapid urban growth in one of Africa's major commercial hubs. Consequently, we investigated nest site selection of crowned eagles (Stephanoaetus coronatus) on various spatial scales within this urban mosaic. Unexpectedly the inter-nest distances were small in this human-dominated landscape. However, breeding sites were not evenly distributed through the landscape and were closely associated with natural forest, while nest trees were most frequently in patches of exotic large riverine Sydney blue gum (Eucalyptus saligna, Smith 1797) within the D'MOSS planning zones. Crowned eagles showed a strong tendency to avoid informal settlement areas; however they were tolerant of proximity to established formal settlements and occupied dwellings. Consequently, continued protection of the D'MOSS system, and a considered approach to management of E. saligna are necessary for the persistence of the crowned eagle in this landscape. Future research should focus on food requirements, post-fledging survival, and recruitment to determine which nest sites are most productive and whether this population is acting as a source or a sink.
Landscape and Urban Planning, 2016
• Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances w... more • Eagle nest site preferences were examined on a landscape scale. • Nearest neighbour distances were less than in natural landscapes within the Region. • Most nests were in green-space zones near an interface with formal residential areas. • An exotic invasive Eucalyptus tree was the most frequently used nest tree species. a b s t r a c t Globally, dramatic land use change typical of urbanisation negatively affects biodiversity, especially for top predators. The Durban Metropolitan Open Space System (D'MOSS), South Africa, faces the challenge of conserving biodiversity in a regional hotspot in the face of rapid urban growth in one of Africa's major commercial hubs. Consequently, we investigated nest site selection of crowned eagles (Stephanoaetus coronatus) on various spatial scales within this urban mosaic. Unexpectedly the inter-nest distances were small in this human-dominated landscape. However, breeding sites were not evenly distributed through the landscape and were closely associated with natural forest, while nest trees were most frequently in patches of exotic large riverine Sydney blue gum (Eucalyptus saligna, Smith 1797) within the D'MOSS planning zones. Crowned eagles showed a strong tendency to avoid informal settlement areas; however they were tolerant of proximity to established formal settlements and occupied dwellings. Consequently, continued protection of the D'MOSS system, and a considered approach to management of E. saligna are necessary for the persistence of the crowned eagle in this landscape. Future research should focus on food requirements, post-fledging survival, and recruitment to determine which nest sites are most productive and whether this population is acting as a source or a sink.
The study of diet is pivotal in understanding a species, particularly for quantifying a predator... more The study of diet is pivotal in understanding a species, particularly for quantifying a predatory raptors’ economic niche and potential for human-wildlife conflict. The crowned eagle (Stephanoaetus coronatus) is one of Africa’s apex predators and a population is present within the urban greenspace mosaic of Durban and Pietermaritzburg, KwaZulu-Natal, South Africa. In close association with urban development, the local population of crowned eagles has the potential to be a concern to the safety of domestic stock and pets. Time-lapse cameras were positioned at urban nest sites (n=11) to identify the prey composition during breeding, particularly in regards to taxa with human associations. The numerical proportion of avian prey, particularly hadeda ibis (Bostricia hagedash) pulli, was several times greater than any previous diet description. The methodology used and the abundance of hadeda ibis in these urbanenvironmentsarepotential contributing factors. Rock hyrax (Procavia capensis)was the primary prey and where hyrax were unavailable, the diet composition was broader and included more vervet monkeys (Chlorocebus pygerythrus). It was found that domestic stock comprised 6 % of the identifiable prey. Contrary to popular belief, no dogs (Canis familiaris) andfew cats(Felisdomesticus) weredelivered tothe nest bybreedingeagles in this study. The negative consequences of small proportions of pet losses should be considered against the majority of wildlife prey consumed, which also have various wildlife conflict interactions. Juvenile and sub-adult eagles are most frequently identified at in situ attacks of pets, particularly toy dog breeds. Further research on juvenile dispersal and winter diet will provide insights on the ecological impacts of eagle management strategies in the region.