{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/35903"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/35903","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Coevolutionary causes and consequences of high-fidelity mimicry by a specialist brood parasite","abstract":"Mimicry is often invoked as a classic demonstration of the power of natural selection. However, mimicry systems are diverse and the accuracy of mimicry, or mimetic fidelity, varies from crude to near-perfect. There is growing evidence that low-fidelity mimicry is the norm, with cases of high-fidelity mimicry being rarer. This is particularly evident in avian interspecific brood parasites, which are birds that lay their eggs in the nests of other species, or ‘hosts'. A possible rare example of a “perfect mimic” is the African cuckoo Cuculus gularis (a specialist parasite of fork-tailed drongos Dicrurus adsimilis) which, to the human eye, exhibits some of the most sophisticated mimicry seen in a brood parasite-host system. In this work, I quantify the degree of mimetic fidelity in this system and investigate its consequences on the two antagonists, using experimental, observational and genetic data I collected in the field in Zambia. In Chapter 1 I first define perfect mimicry, and explore how mimetic fidelity can be quantified. I then review the factors responsible for the variability in mimetic fidelity among different mimicry systems. In Chapter 2 I use quantitative measures of egg colour and pattern, from models that approximate avian vision, to show that mimicry of drongo eggs by African cuckoos is near-perfect. I subsequently use field experiments and simulations to show that a high degree of interclutch variation (egg ‘signatures') means that drongos still have the upper hand in the arms race against this near-perfect mimic. In Chapter 3 I investigate the genetic architecture of perfect mimicry by comparing cuckoo egg phenotypes to their mitochondrial DNA haplotypes, providing evidence that the African cuckoo likely shows bi-parental inheritance of egg phenotype. Together these results highlight the effectiveness of egg signatures as a defence against brood parasites, even when mimicry shows high accuracy and precision, and underline the role of mechanistic factors in enabling high-fidelity mimicry to evolve.","abstract_html":"Mimicry is often invoked as a classic demonstration of the power of natural selection. However, mimicry systems are diverse and the accuracy of mimicry, or mimetic fidelity, varies from crude to near-perfect. There is growing evidence that low-fidelity mimicry is the norm, with cases of high-fidelity mimicry being rarer. This is particularly evident in avian interspecific brood parasites, which are birds that lay their eggs in the nests of other species, or ‘hosts'. A possible rare example of a “perfect mimic” is the African cuckoo Cuculus gularis (a specialist parasite of fork-tailed drongos Dicrurus adsimilis) which, to the human eye, exhibits some of the most sophisticated mimicry seen in a brood parasite-host system. In this work, I quantify the degree of mimetic fidelity in this system and investigate its consequences on the two antagonists, using experimental, observational and genetic data I collected in the field in Zambia. In Chapter 1 I first define perfect mimicry, and explore how mimetic fidelity can be quantified. I then review the factors responsible for the variability in mimetic fidelity among different mimicry systems. In Chapter 2 I use quantitative measures of egg colour and pattern, from models that approximate avian vision, to show that mimicry of drongo eggs by African cuckoos is near-perfect. I subsequently use field experiments and simulations to show that a high degree of interclutch variation (egg ‘signatures') means that drongos still have the upper hand in the arms race against this near-perfect mimic. In Chapter 3 I investigate the genetic architecture of perfect mimicry by comparing cuckoo egg phenotypes to their mitochondrial DNA haplotypes, providing evidence that the African cuckoo likely shows bi-parental inheritance of egg phenotype. Together these results highlight the effectiveness of egg signatures as a defence against brood parasites, even when mimicry shows high accuracy and precision, and underline the role of mechanistic factors in enabling high-fidelity mimicry to evolve.","abstract_has_math":false,"creators":["Lund, Jess"],"institution":"Department of Biological Sciences","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Spottiswoode, Claire N","Jamie, Gabriel A"],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021","date_published":"2021","updated_at":"2026-07-22T22:23:16Z","subjects":["Biological Sciences"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/35903","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Spottiswoode, Claire N","Jamie, Gabriel A"]},{"key":"dc:creator","label":"Author","values":["Lund, Jess"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-03-04T08:05:17Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-03-04T08:05:17Z"]},{"key":"dc:date.issued","label":"Date","values":["2021"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Biological Sciences"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters","MSc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biological Sciences"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/35903"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Mimicry is often invoked as a classic demonstration of the power of natural selection. However, mimicry systems are diverse and the accuracy of mimicry, or mimetic fidelity, varies from crude to near-perfect. There is growing evidence that low-fidelity mimicry is the norm, with cases of high-fidelity mimicry being rarer. This is particularly evident in avian interspecific brood parasites, which are birds that lay their eggs in the nests of other species, or ‘hosts'. A possible rare example of a “perfect mimic” is the African cuckoo Cuculus gularis (a specialist parasite of fork-tailed drongos Dicrurus adsimilis) which, to the human eye, exhibits some of the most sophisticated mimicry seen in a brood parasite-host system. In this work, I quantify the degree of mimetic fidelity in this system and investigate its consequences on the two antagonists, using experimental, observational and genetic data I collected in the field in Zambia. In Chapter 1 I first define perfect mimicry, and explore how mimetic fidelity can be quantified. I then review the factors responsible for the variability in mimetic fidelity among different mimicry systems. In Chapter 2 I use quantitative measures of egg colour and pattern, from models that approximate avian vision, to show that mimicry of drongo eggs by African cuckoos is near-perfect. I subsequently use field experiments and simulations to show that a high degree of interclutch variation (egg ‘signatures') means that drongos still have the upper hand in the arms race against this near-perfect mimic. In Chapter 3 I investigate the genetic architecture of perfect mimicry by comparing cuckoo egg phenotypes to their mitochondrial DNA haplotypes, providing evidence that the African cuckoo likely shows bi-parental inheritance of egg phenotype. Together these results highlight the effectiveness of egg signatures as a defence against brood parasites, even when mimicry shows high accuracy and precision, and underline the role of mechanistic factors in enabling high-fidelity mimicry to evolve."]},{"key":"dc:title","label":"Title","values":["Coevolutionary causes and consequences of high-fidelity mimicry by a specialist brood parasite"]}]}],"canonical_facts":{"dc:contributor.advisor":["Spottiswoode, Claire N","Jamie, Gabriel A"],"dc:creator":["Lund, Jess"],"dc:date.accessioned":["2022-03-04T08:05:17Z"],"dc:date.available":["2022-03-04T08:05:17Z"],"dc:date.issued":["2021"],"dc:description.abstract":["Mimicry is often invoked as a classic demonstration of the power of natural selection. However, mimicry systems are diverse and the accuracy of mimicry, or mimetic fidelity, varies from crude to near-perfect. There is growing evidence that low-fidelity mimicry is the norm, with cases of high-fidelity mimicry being rarer. This is particularly evident in avian interspecific brood parasites, which are birds that lay their eggs in the nests of other species, or ‘hosts'. A possible rare example of a “perfect mimic” is the African cuckoo Cuculus gularis (a specialist parasite of fork-tailed drongos Dicrurus adsimilis) which, to the human eye, exhibits some of the most sophisticated mimicry seen in a brood parasite-host system. In this work, I quantify the degree of mimetic fidelity in this system and investigate its consequences on the two antagonists, using experimental, observational and genetic data I collected in the field in Zambia. In Chapter 1 I first define perfect mimicry, and explore how mimetic fidelity can be quantified. I then review the factors responsible for the variability in mimetic fidelity among different mimicry systems. In Chapter 2 I use quantitative measures of egg colour and pattern, from models that approximate avian vision, to show that mimicry of drongo eggs by African cuckoos is near-perfect. I subsequently use field experiments and simulations to show that a high degree of interclutch variation (egg ‘signatures') means that drongos still have the upper hand in the arms race against this near-perfect mimic. In Chapter 3 I investigate the genetic architecture of perfect mimicry by comparing cuckoo egg phenotypes to their mitochondrial DNA haplotypes, providing evidence that the African cuckoo likely shows bi-parental inheritance of egg phenotype. Together these results highlight the effectiveness of egg signatures as a defence against brood parasites, even when mimicry shows high accuracy and precision, and underline the role of mechanistic factors in enabling high-fidelity mimicry to evolve."],"dc:identifier.uri":["http://hdl.handle.net/11427/35903"],"dc:publisher.department":["Department of Biological Sciences"],"dc:subject":["Biological Sciences"],"dc:title":["Coevolutionary causes and consequences of high-fidelity mimicry by a specialist brood parasite"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters","MSc"]},"updated_at":"2026-07-22T22:23:16Z"}