Ranging behaviour of Long-crested Eagles Lophaetus occipitalis in human-modified landscapes of KwaZulu-Natal, South Africa
06 Aug 2020-Ostrich (Taylor & Francis)-Vol. 91, Iss: 3, pp 221-227
TL;DR: The ranging behaviour of raptors in human-altered environments, such as agricultural and suburban landscapes, is becoming increasingly important for conservationists in the context of unprecedented changes.
Abstract: The ranging behaviour of raptors in human-altered environments, such as agricultural and suburban landscapes, is becoming increasingly important for conservationists in the context of unprecedented...
TL;DR: This paper reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa, to determine trends and presented a novel modification to the final of three phases of the framework described by Evans et al. (2010).
Abstract: Urbanisation is rapidly transforming natural landscapes with consequences for biodiversity. Little is documented on the response of African wildlife to urbanisation. We reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa to determine trends. Connected habitat mosaics of natural and anthropogenic green spaces are critical for urban wildlife persistence. We present a novel modification to the final of three phases of the framework described by Evans et al. (2010), which documents this sequence for vertebrate species persistence, based on the perspective of our research. Species in suburbia exhibit an initial phase where behavioural and ecological flexibility, life-history traits and phenotypic plasticity either contribute to their success, or they stay at low numbers. Where successful, the next phase is a rapid increase in populations and distribution; anthropogenic food resources and alternate breeding sites are effectively exploited. The modified third phase either continues to spread, plateau or decline.
TL;DR: In this article , the variability in spatial estimates for the seasonal habitat use of the ocellated lizard was compared within the two sites using the Autocorrelated Kernel Density Estimation (AKDE).
Abstract: The knowledge of a species’ spatial ecology is essential for its conservation as it helps to implement targeted protection measures to suitable habitats. In 2011 and 2013, two French populations of ocellated lizards Timon lepidus were monitored through very high frequency (VHF) radio telemetry in two distinct Mediterranean habitats: a 77 ha scrubland (n = 8) and a 1590 ha semi-arid steppe (n = 11) corresponding to a heterogeneous and homogeneous habitat respectively. The variability in spatial estimates for the seasonal habitat use of the ocellated lizard was compared within the two sites using the Autocorrelated Kernel Density Estimation (AKDE). Recursive movement patterns and spatial repartition of shelters were further assessed to study the habitat influence on the species’ space use. No significant differences between sexes or sites were identified in the computed AKDE ranges. This inter-site approach demonstrated higher shelter revisits in core-areas than in the rest of estimated home ranges for both sites. A higher shelter density was observed in the core areas of the lizards than in the rest of their home-ranges for the Mediterranean scrubland but not for the semi-arid steppe. Such findings might attest to the species’ adaptive capabilities within two distinct Mediterranean ecosystems.
TL;DR: In this article , the authors investigated the occupancy and detection probabilities of the Near-Threatened African crowned eagle (Stephanoaetus coronatus) in Durban, EThekwini Municipality, South Africa.
Abstract: Diminishing forests as a result of anthropogenic activities continues to impact the persistence of terrestrial species negatively. Raptors are particularly susceptible to human activities because of their low population densities and large home range sizes. In this study, we investigated the occupancy and detection probabilities of the Near-Threatened African crowned eagle (Stephanoaetus coronatus) in Durban, EThekwini Municipality, South Africa. Using point count surveys, we documented the presence/absence of African crowned eagles in 42 sampling sites in the urban mosaic landscape of Durban. We used the presence/absence data to model their occupancy and detection probability in our surveyed sites. The naïve occupancy of African crowned eagles was 0.6, and the estimated occupancy and detection probability were 0.78 + 0.061 and 0.40 + 0.085, respectively. Based on the best models, the occupancy of African crowned eagles was positively influenced by forests (β = 1.24 + 0.69) and negatively influenced by disturbance (β = −1.69 + 0.78) and roads. The detection probability of these eagles was positively influenced by disturbance (β = 0.34 + 0.29) and the presence of exotic tree plantations (β = 0.33 + 0.47) and negatively influenced by the type of surrounding settlements (i.e., urban or rural) (β = −0.59 + 0.43). Based on the averaged models, occupancy is positively influenced by forests (β = 0.15 + 1.48) and negatively influenced by roads (β = −0.05 + 0.34), building density (β = −0.07 + 0.79) and disturbance (β = −0.24 + 3.36). Detection probability is negatively influenced by surrounding settlement (β = −0.12 + 0.41) and positively influenced by disturbance (β = 0.04 + 3.21) and plantations (β = 0.01 + 0.12). Overall, our results showed the persistence of African crowned eagles in the urban mosaic landscape as a consequence of natural and managed green spaces, especially forests. This highlighted the importance of natural forests and exotic tree plantations in ensuring the survival and thriving of African crowned eagles and the key role these green spaces play in species conservation in this urban mosaic landscape.
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