Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models

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dc.contributor.advisorAltwegg, Res
dc.contributor.advisorMaphisa, David
dc.contributor.authorKani, Luvuyo
dc.date.accessioned2025-11-25T09:08:22Z
dc.date.available2025-11-25T09:08:22Z
dc.date.issued2025
dc.date.updated2025-11-25T09:05:51Z
dc.description.abstractBirds can respond to seasonal environmental fluctuations through migration. Among different migratory species and populations, there is varying sensitivity to different seasonal environmental cues, thus leading to different seasonal range dynamics and migration strategies. In this study, I used dynamic occupancy models on the South African Bird Atlas Project 2 (SABAP 2) data to investigate the seasonal range dynamics of a selection of five migratory and six nomadic bird species in western South Africa. In the context of this study, seasonal range dynamics are defined as when a species arrives and departs a given area. I used dynamic occupancy models to estimate monthly changes in occupancy between 2014 and 2018. I modelled local extinction (departure) and colonisation (arrival) as a function of changes and anomalies in average monthly rainfall, temperature and vegetation. Among the obligate migrants, the best performing models indicated that colonization and extinction parameters were mostly driven by seasonal changes in average rainfall, temperature and vegetation. In nomadic species, colonization was driven by seasonal changes in average rainfall, temperature and vegetation, while extinction was driven by anomalies in rainfall, temperature and vegetation. The models successfully captured the generally known seasonal pattern in occupancy (arrival and departure) of all five obligate migrants, while no regular seasonal fluctuation in occupancy was evident among the nomadic species. Over the four-year period, no species showed a strong shift in seasonal range dynamics in both groups. However, I do suspect that the same methodology done at a finer spatial and temporal scale may reveal changes in seasonal range dynamics of some species. This study demonstrates that dynamic occupancy modelling using citizen science data is a viable methodology for investigating seasonal range dynamics.
dc.identifier.apacitationKani, L. (2025). <i>Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models</i>. (). University of Cape Town ,Faculty of Science ,Department of Statistical Sciences. Retrieved from http://hdl.handle.net/11427/42330en_ZA
dc.identifier.chicagocitationKani, Luvuyo. <i>"Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models."</i> ., University of Cape Town ,Faculty of Science ,Department of Statistical Sciences, 2025. http://hdl.handle.net/11427/42330en_ZA
dc.identifier.citationKani, L. 2025. Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models. . University of Cape Town ,Faculty of Science ,Department of Statistical Sciences. http://hdl.handle.net/11427/42330en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Kani, Luvuyo AB - Birds can respond to seasonal environmental fluctuations through migration. Among different migratory species and populations, there is varying sensitivity to different seasonal environmental cues, thus leading to different seasonal range dynamics and migration strategies. In this study, I used dynamic occupancy models on the South African Bird Atlas Project 2 (SABAP 2) data to investigate the seasonal range dynamics of a selection of five migratory and six nomadic bird species in western South Africa. In the context of this study, seasonal range dynamics are defined as when a species arrives and departs a given area. I used dynamic occupancy models to estimate monthly changes in occupancy between 2014 and 2018. I modelled local extinction (departure) and colonisation (arrival) as a function of changes and anomalies in average monthly rainfall, temperature and vegetation. Among the obligate migrants, the best performing models indicated that colonization and extinction parameters were mostly driven by seasonal changes in average rainfall, temperature and vegetation. In nomadic species, colonization was driven by seasonal changes in average rainfall, temperature and vegetation, while extinction was driven by anomalies in rainfall, temperature and vegetation. The models successfully captured the generally known seasonal pattern in occupancy (arrival and departure) of all five obligate migrants, while no regular seasonal fluctuation in occupancy was evident among the nomadic species. Over the four-year period, no species showed a strong shift in seasonal range dynamics in both groups. However, I do suspect that the same methodology done at a finer spatial and temporal scale may reveal changes in seasonal range dynamics of some species. This study demonstrates that dynamic occupancy modelling using citizen science data is a viable methodology for investigating seasonal range dynamics. DA - 2025 DB - OpenUCT DP - University of Cape Town KW - Birds KW - South Africa LK - https://open.uct.ac.za PB - University of Cape Town PY - 2025 T1 - Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models TI - Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models UR - http://hdl.handle.net/11427/42330 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/42330
dc.identifier.vancouvercitationKani L. Bird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models. []. University of Cape Town ,Faculty of Science ,Department of Statistical Sciences, 2025 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/42330en_ZA
dc.language.isoen
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Statistical Sciences
dc.publisher.facultyFaculty of Science
dc.publisher.institutionUniversity of Cape Town
dc.subjectBirds
dc.subjectSouth Africa
dc.titleBird's response to seasonality: investigating the range dynamics of birds through dynamic occupancy models
dc.typeThesis / Dissertation
dc.type.qualificationlevelMasters
dc.type.qualificationlevelMSc
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