Calling rhythm as a predictor of the outcome of vocal interactions: flight departure in pale-winged starling pairs
- Hausberger, Martine, Giacalone, Aline, Harmand, Mariane, Craig, Adrian J F K, Henry, Laurence
- Authors: Hausberger, Martine , Giacalone, Aline , Harmand, Mariane , Craig, Adrian J F K , Henry, Laurence
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449283 , vital:74808 , https://doi.org/10.1007/s00114-019-1658-1
- Description: Vocal communication plays an important role in the regulation of social interactions and the coordination of activities in many animal species. Synchrony is an essential part of the establishment and maintenance of pair bonds, but few reports have investigated decision-making at the pair level. We investigated temporal characteristics of call exchanges in pale-winged starlings (Onychognathus nabouroup) that could predict whether one, two, or neither members of a pair would take off. Our analysis of these interactions revealed that the overall rhythm of a call exchange, as well as the acceleration towards the end of an interaction, were significantly associated with the type of behavioural outcome. Faster rhythms were associated with higher probabilities that both birds would fly away. Our results confirm the findings of previous studies showing that higher rates of alarm calls indicate imminent departure and highlight the relationship between temporal features of vocal interactions and their outcome.
- Full Text:
- Date Issued: 2020
- Authors: Hausberger, Martine , Giacalone, Aline , Harmand, Mariane , Craig, Adrian J F K , Henry, Laurence
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449283 , vital:74808 , https://doi.org/10.1007/s00114-019-1658-1
- Description: Vocal communication plays an important role in the regulation of social interactions and the coordination of activities in many animal species. Synchrony is an essential part of the establishment and maintenance of pair bonds, but few reports have investigated decision-making at the pair level. We investigated temporal characteristics of call exchanges in pale-winged starlings (Onychognathus nabouroup) that could predict whether one, two, or neither members of a pair would take off. Our analysis of these interactions revealed that the overall rhythm of a call exchange, as well as the acceleration towards the end of an interaction, were significantly associated with the type of behavioural outcome. Faster rhythms were associated with higher probabilities that both birds would fly away. Our results confirm the findings of previous studies showing that higher rates of alarm calls indicate imminent departure and highlight the relationship between temporal features of vocal interactions and their outcome.
- Full Text:
- Date Issued: 2020
Conservation and human livelihoods at the crossroads: Local needs and knowledge in the management of Arabuko Sokoke Forest
- Chiawo, David O, Kombe, Wellington N, Craig, Adrian J F K
- Authors: Chiawo, David O , Kombe, Wellington N , Craig, Adrian J F K
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448843 , vital:74765 , https://doi.org/10.1111/aje.12462
- Description: Arabuko Sokoke Forest is the largest remaining single block of indigenous dry coastal tropical forest in Eastern Africa. Households within a 5 km buffer zone depend heavily on the forest for their livelihood needs, and the pressure on forest resources is on the increase. In May 2015, 109 households were interviewed on resources they obtain from the forest, in terms of the self‐reported level of monthly income. We found household income and farm size significantly positively correlated with benefits from the forest, highlighting the possible influence of household wealth in exploiting forest resources. A large proportion of households (32%) had limited knowledge of local birds, while human–bird conflict was reported by 44% of the households. While many households were keen to participate in conservation projects that maintain the forest, 44% had no knowledge of the forest management plan, and 60% of those interviewed had no idea of how forest zones were designated for particular activities. Drivers for local community participation in conservation projects appear to be sustainable income and fulfilment of basic household needs.
- Full Text:
- Date Issued: 2018
- Authors: Chiawo, David O , Kombe, Wellington N , Craig, Adrian J F K
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448843 , vital:74765 , https://doi.org/10.1111/aje.12462
- Description: Arabuko Sokoke Forest is the largest remaining single block of indigenous dry coastal tropical forest in Eastern Africa. Households within a 5 km buffer zone depend heavily on the forest for their livelihood needs, and the pressure on forest resources is on the increase. In May 2015, 109 households were interviewed on resources they obtain from the forest, in terms of the self‐reported level of monthly income. We found household income and farm size significantly positively correlated with benefits from the forest, highlighting the possible influence of household wealth in exploiting forest resources. A large proportion of households (32%) had limited knowledge of local birds, while human–bird conflict was reported by 44% of the households. While many households were keen to participate in conservation projects that maintain the forest, 44% had no knowledge of the forest management plan, and 60% of those interviewed had no idea of how forest zones were designated for particular activities. Drivers for local community participation in conservation projects appear to be sustainable income and fulfilment of basic household needs.
- Full Text:
- Date Issued: 2018
The status of the southern ground-hornbill in the Grahamstown region, Eastern Cape, South Africa
- Hulley, Patrick E, Craig, Adrian J F K
- Authors: Hulley, Patrick E , Craig, Adrian J F K
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447909 , vital:74683 , https://www.tandfonline.com/doi/pdf/10.2989/OSTRICH.2007.78.1.13.57
- Description: The Eastern Cape has been the southernmost limit of distribution for the Southern Ground-Hornbill Bucorvus leadbeateri throughout the period for which there are written records (Vernon 1986, Vernon and Herremans 1997). No records are known west of Port Elizabeth and the only ones from this 1 map square (33 S 27 E) date from the nineteenth century. Vernon (1986) noted that nest and roost sites for groundhornbills were in large trees or on cliffs, from which the birds commuted to forage in open country. The forest/thicket and grassland mosaic in the Eastern Cape is apparently ancient (Skead 1987), but the grassland sector has been greatly modified by agriculture and human settlement. Since the assessment of the Southern Ground-Hornbill’s status as ‘vulnerable’in the latest Red Data Book (Barnes 2000), it has been suggested that populations in South Africa have declined to a point where its true status is ‘endangered’but this revision was not accepted by IUCN (AC Kemp, pers. comm.). The recent initiative by the Mabula-based NGO, the Ground-hornbill Research and Conservation Project, to reintroduce birds to the Eastern Cape, prompted us to examine records of sightings in this region. The main focus is the Grahamstown map square 33 S 26 E, in which the release site of the first birds—Shamwari Private Game Reserve—is situated. Our source is the published records in Diaz Diary, the newsletter of the Diaz Cross Bird Club, which has branches in Grahamstown and Kenton-on-Sea, covering the period 1978–2004 inclusive.
- Full Text:
- Date Issued: 2007
- Authors: Hulley, Patrick E , Craig, Adrian J F K
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447909 , vital:74683 , https://www.tandfonline.com/doi/pdf/10.2989/OSTRICH.2007.78.1.13.57
- Description: The Eastern Cape has been the southernmost limit of distribution for the Southern Ground-Hornbill Bucorvus leadbeateri throughout the period for which there are written records (Vernon 1986, Vernon and Herremans 1997). No records are known west of Port Elizabeth and the only ones from this 1 map square (33 S 27 E) date from the nineteenth century. Vernon (1986) noted that nest and roost sites for groundhornbills were in large trees or on cliffs, from which the birds commuted to forage in open country. The forest/thicket and grassland mosaic in the Eastern Cape is apparently ancient (Skead 1987), but the grassland sector has been greatly modified by agriculture and human settlement. Since the assessment of the Southern Ground-Hornbill’s status as ‘vulnerable’in the latest Red Data Book (Barnes 2000), it has been suggested that populations in South Africa have declined to a point where its true status is ‘endangered’but this revision was not accepted by IUCN (AC Kemp, pers. comm.). The recent initiative by the Mabula-based NGO, the Ground-hornbill Research and Conservation Project, to reintroduce birds to the Eastern Cape, prompted us to examine records of sightings in this region. The main focus is the Grahamstown map square 33 S 26 E, in which the release site of the first birds—Shamwari Private Game Reserve—is situated. Our source is the published records in Diaz Diary, the newsletter of the Diaz Cross Bird Club, which has branches in Grahamstown and Kenton-on-Sea, covering the period 1978–2004 inclusive.
- Full Text:
- Date Issued: 2007
Sexual dimorphism and tail-length in widowbirds and bishopbirds (Ploeeidae: Euplectes spp.): a reassessment
- Craig, Adrian J F K, Villet, Martin H
- Authors: Craig, Adrian J F K , Villet, Martin H
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442306 , vital:73974 , https://doi.org/10.1111/j.1474-919X.1998.tb04551.x
- Description: No evidence for sexual selection in the evolution of tail‐length or wing‐length in widow birds and bishopbirds (genus Euplectes) was found when the methods used by previous authors were applied to a larger set of data. Nuptial tail‐length dimorphism scaled with body size dimorphism except in Euplectes progne, and interpopulation variation in taillength could be explained by genetic drift alone. Wing‐length appears to be under stabilizing selection and scales allometrically with body size, with no relation to tail‐length unless E. progne is included in the analysis.
- Full Text:
- Date Issued: 1998
- Authors: Craig, Adrian J F K , Villet, Martin H
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442306 , vital:73974 , https://doi.org/10.1111/j.1474-919X.1998.tb04551.x
- Description: No evidence for sexual selection in the evolution of tail‐length or wing‐length in widow birds and bishopbirds (genus Euplectes) was found when the methods used by previous authors were applied to a larger set of data. Nuptial tail‐length dimorphism scaled with body size dimorphism except in Euplectes progne, and interpopulation variation in taillength could be explained by genetic drift alone. Wing‐length appears to be under stabilizing selection and scales allometrically with body size, with no relation to tail‐length unless E. progne is included in the analysis.
- Full Text:
- Date Issued: 1998
Ecology and genetics of hybrid zones in the southern African Pycnonotus bulbul species complex
- Lloyd, Penn, Craig, Adrian J F K, Hulley, Patrick E, Essop, M Faadiel, Bloomer, Paulette, Crowe, Timothy M
- Authors: Lloyd, Penn , Craig, Adrian J F K , Hulley, Patrick E , Essop, M Faadiel , Bloomer, Paulette , Crowe, Timothy M
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447801 , vital:74675 , https://doi.org/10.1080/00306525.1997.9639720
- Description: The closely related Blackeyed Bulbul Pycnonotus barbatus, Cape Bulbul P. capensis and Redeyed Bulbul P. nigricans have parapatric to locally sympatric distributions within southern Africa. Extensive hybridization along narrow transition zones between each of the three species pairs is described in a region of the Eastern Cape province, South Africa. The transition zones coincide with ecotones between different vegetation types, which in turn follow escarpments or mountain ranges. The lack of population density depressions within the hybrid zones, together with the variability of the hybrids, suggests the hybrids are viable. Sharp step clines in various phenotypic characters are described across the P. barbatus/P. nigricans hybrid zone. A mtDNA analysis found evidence of possible introgression between P. barbatus and P. capensis. All eight P. barbatus x P. nigricans hybrids analysed possessed P. barbatus mtDNA, suggesting the existence of either positive assortative mating or strong directional selection, but our data are unable to distinguish which.
- Full Text:
- Date Issued: 1997
- Authors: Lloyd, Penn , Craig, Adrian J F K , Hulley, Patrick E , Essop, M Faadiel , Bloomer, Paulette , Crowe, Timothy M
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447801 , vital:74675 , https://doi.org/10.1080/00306525.1997.9639720
- Description: The closely related Blackeyed Bulbul Pycnonotus barbatus, Cape Bulbul P. capensis and Redeyed Bulbul P. nigricans have parapatric to locally sympatric distributions within southern Africa. Extensive hybridization along narrow transition zones between each of the three species pairs is described in a region of the Eastern Cape province, South Africa. The transition zones coincide with ecotones between different vegetation types, which in turn follow escarpments or mountain ranges. The lack of population density depressions within the hybrid zones, together with the variability of the hybrids, suggests the hybrids are viable. Sharp step clines in various phenotypic characters are described across the P. barbatus/P. nigricans hybrid zone. A mtDNA analysis found evidence of possible introgression between P. barbatus and P. capensis. All eight P. barbatus x P. nigricans hybrids analysed possessed P. barbatus mtDNA, suggesting the existence of either positive assortative mating or strong directional selection, but our data are unable to distinguish which.
- Full Text:
- Date Issued: 1997
Comparisons of the vocalizations and social behaviour of southern African Pycnonotus bulbuls
- Lloyd, Penn, Hulley, Patrick E, Craig, Adrian J F K
- Authors: Lloyd, Penn , Hulley, Patrick E , Craig, Adrian J F K
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447774 , vital:74673 , https://doi.org/10.1080/00306525.1996.9639696
- Description: Vocalizations and associated behaviour of three Pycnonotus species are described, based on field observations and tape recordings from which sonagrams were produced. These species, which are locally sym-patric and hybridize, have similar vocalizations and displays; differences are most apparent in their contact calls and songs. Quantitative analysis of the songs showed that P. barbatus and P. capensis are easily distinguished, whereas the song characteristics of P. nigricans overlap those of both the other species. Playback experiments with territorial male P. barbatus in an area of allopatry showed similar responses to songs of conspecifics and of P. nigricans, but almost no response to the song of P. capensis.
- Full Text:
- Date Issued: 1996
- Authors: Lloyd, Penn , Hulley, Patrick E , Craig, Adrian J F K
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447774 , vital:74673 , https://doi.org/10.1080/00306525.1996.9639696
- Description: Vocalizations and associated behaviour of three Pycnonotus species are described, based on field observations and tape recordings from which sonagrams were produced. These species, which are locally sym-patric and hybridize, have similar vocalizations and displays; differences are most apparent in their contact calls and songs. Quantitative analysis of the songs showed that P. barbatus and P. capensis are easily distinguished, whereas the song characteristics of P. nigricans overlap those of both the other species. Playback experiments with territorial male P. barbatus in an area of allopatry showed similar responses to songs of conspecifics and of P. nigricans, but almost no response to the song of P. capensis.
- Full Text:
- Date Issued: 1996
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