Parasites of African penguins: diversity, ecology and effect on hosts
| dc.contributor.advisor | Matthee, Sonja | en_ZA |
| dc.contributor.advisor | Hui, Cang | en_ZA |
| dc.contributor.advisor | Waller, Lauren | en_ZA |
| dc.contributor.author | Espinaze Pardo, Marcela Paz Alejandra | en_ZA |
| dc.contributor.other | tellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. | en_ZA |
| dc.date.accessioned | 2019-02-05T09:53:20Z | |
| dc.date.accessioned | 2019-04-17T08:03:19Z | |
| dc.date.available | 2019-02-05T09:53:20Z | |
| dc.date.available | 2019-04-17T08:03:19Z | |
| dc.date.issued | 2019-04 | |
| dc.description | Thesis (PhDConsEcol)--Stellenbosch University, 2019. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: The African penguin (Spheniscus demersus) is a critically endangered seabird species endemic to southern Africa. Recent reports of soft ticks on penguins raised concerns that parasites may pose a risk to the species’ conservation. To date, it is uncertain if parasite populations are similar across colonies and what factors drive parasite infestations. It is further uncertain if current parasite burdens affect penguin health. The aims of the study were to: (1) record the parasite diversity associated with African penguins and their nests across penguin colonies, and determine the factors that shape parasite infestations; (2) document clinical parameters for wild African penguins and establish the relationship between parasite infestations and penguin health across colonies; (3) at a local scale, record the relationship between nest characteristics and nest ectoparasites and determine the potential impact on the health of African penguins at the Stony Point colony; and (4) ascertain the efficiency of a modified Berlese funnel system, with naphthalene as repellent, as a quantitative method for the extraction of nest ectoparasites. Adult penguins (210), chicks (583) and nests (628) were sampled across five colonies along the south-western coast of South Africa in the autumn/winter season in 2016 and 2017, and also in spring 2016 at the Stony Point colony. Ectoparasites were recorded on all penguins and in nests. Helminths were recorded from chick faecal material. Blood samples were screened for haemoparasites and health parameters recorded. Penguin age and morphometric measurements (chicks) were recorded. Across colony data included nest density and weather conditions, while nest characteristic and microclimatic conditions in nests were recorded at Stony point. Ectoparasites (Parapsyllus humboldti, Echidnophaga gallinacea and Ornithodoros capensis s. s.), haemoparasites (Piroplasmorida/Haemospororida and Spirochaetales) and helminth parasites (Cardiocephaloides spp., Renicola spp., Contracaecum spp. and Cyathostoma spp.) were recorded from penguins, while ticks and fleas were recorded from their nests. At a regional scale, parasite infestations were higher in chicks than adult penguins; mainland colonies recorded more on-host and in-nest ectoparasites, Piroplasmorida/Haemospororida and Cardiocephaloides spp. than islands. Nest ticks, Piroplasmorida/Haemospororida and Cardiocephaloides spp. infecting penguins were positively associated with total nest density, while total nest ectoparasites increased with active nest density. Clinical health parameters of wild African penguins varied among colonies and several parameters were adversely affected by ecto- and haemoparasite species richness, but positively related to helminth species richness. At Stony Point, tick abundance in addition to ecto- and haemoparasite richness adversely affected haematocrit values. Chick body condition was significantly lower in spring compared to autumn/winter. At a local scale, tick and flea infestations were higher in artificial nests, nests close to the coastline, warmer and drier nests. Flea burdens were higher in nests occupied by a penguin. Conditions associated with artificial nests were not significantly related to penguin health parameters. Climatic conditions associated with spring were negatively related to on-host and in-nest parasite infections and clinical health parameters. The modified Berlese funnel consistently underestimated the abundance and prevalence of all ectoparasites in nest samples and particularly more so for the abundance of flea larvae. To conclude, although parasites are widely associated with African penguins it seems that at present penguins are able to withstand current infestation levels at most colonies. Regional differences in parasite infestation patterns may be driven by the eastward migration of prey fish, which in the case of Stony Point is intensified by the ability of ticks and fleas to take advantage of conditions associated with artificial nests. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: Die Afrika-pikkewyn (Spheniscus demersus) is 'n krities bedreigde seevoëlspesie wat endemies is in Suider-Afrika. Onlangse verslae van sagte-bosluise op pikkewyne wek kommer oor die risiko wat parasiete vir die spesie se bewaring inhou. Tot op datum is dit onseker of parasietbevolkings in alle kolonies soortgelyk is en watter faktore parasietbesmettings bevorder. Dit is verder onseker of huidige parasietladings die gesondheid van pikkewyn beïnvloed. Die doelstellings van die studie was: (1) om die parasietdiversiteit wat met Afrika-pikkewyne en hul neste in verskeie kolonies geassosieer word aan te teken, en die faktore wat parasietbesmetting veroorsaak te bepaal; (2) die dokumentasie van kliniese waardes vir wilde Afrika-pikkewyne en om die verband tussen parasietbesmettings en pikkewyngesondheid oor kolonies te bepaal; (3) om op 'n plaaslike skaal die verband tussen nes-kenmerke en nes-ektoparasiete waar te neem en die potensiële impak op die gesondheid van Afrika-pikkewyne by die Stony Point-kolonie te bepaal; en (4) om die doeltreffendheid van 'n aangepaste Berlese tregterstelsel, met naftaleen as afweermiddel, as 'n kwantitatiewe metode vir die onttrekking van nes-ektoparasiete vas te stel. Volwasse pikkewyne (210), kuikens (583) en neste (628) is in die herfs / winterseisoen in 2016 en 2017 oor vyf kolonies langs die suidwestelike kus van Suid-Afrika bestudeer en ook in die lente van 2016 by die Stony Point-kolonie. Ektoparasiete is op alle pikkewyne en in hul neste aangeteken, bloedmonsters was bestudeer vir hemoparasiete en klinies-gesondheidswaardes is aangeteken. Die ouderdomsgroep van elke pikkewyn was ook bepaal. Verder, monsters wat by kuikens geneem is sluit in mismonsters om die teenwoordigheid van helminth-parasiete te noteer en morfometriese metings om die kondisie van die diere te bepaal. Oor kolonie-data het nes-digtheid en weerstoestande ingesluit, terwyl nes-kenmerke en mikroklimaat toestande in neste op Stony Point aangeteken is. Ectoparasiete (Parapsyllus humboldti, Echidnophaga gallinacea en Ornithodoros capensis s. s.), haemoparasiete (Piroplasmorida/Haemospororida en Spirochaetales) en helminth parasiete (Cardiocephaloides spp., Renicola spp., Contracaecum spp. en Cyathostoma spp.) was op die pikkewyne aangeteken, terwyl bosluise en vlooie in hul neste aangeteken is. Op 'n streekskaal was parasietbesmettings hoër op kuikens as volwasse pikkewyne; vasteland kolonies het meer ektoparasiete op pikkewyne en in hul nests gehad as ook meer Piroplasmorida/Haemospororida en Cardiocephaloides spp. in vergelyking met eilande. Bosluise in neste en Piroplasmorida/Haemospororida en Cardiocephaloides spp. besmette pikkewyne was positief geassosieer met totale nes-digtheid, terwyl die totale ektoparasietlading in neste met die digtheid van aktiewe-neste toegeneem het. Kliniese-gesondheidswaardes van wilde Afrika-pikkewyne het tussen kolonies verskil en verskeie van die waardes is nadelig beïnvloed deur ekto- en hemoparasiet-spesiesrykheid, maar was positief verwant aan helminth-spesiesrykheid. By Stony Point, het bosluisladings in kombinasie met ekto- en hemoparasiet-spesiesrykheid die hematokrit-waardes nadelig beïnvloed. Die liggaamskondisie van kuikens was aansienlik laer in die lente in vergelyking met herfs / winter. Op 'n plaaslike skaal was bosluis- en vlooibesmettings hoër in kunsmatige neste, neste naby die kuslyn, warmer en droër neste. Vlooibesmettings was hoër in neste waar pikkewyne teenwoordig was. Toestande wat geassosieer was met kunsmatige-neste het nie ʼn beduidend invloed op die gesondheidwaardes van pikkewyn gehad nie. Klimaatstoestande wat geassosieer was met lente was negatief verwant aan parasietinfeksies op pikkewyne en in hulle neste en kliniese-gesondheidwaardes. Die gemodifiseerde Berlese tregterstelsel het die lading en voorkoms van alle ektoparasiete en veral die lading van vlooi larwes in nes-monsters onderskat. Ter afsluiting, alhoewel parasiete wyd verspreid op Afrika-pikkewyne voorkom, blyk dit dat huidige infestasievlakke nie die pikkewyne negatief beïnvloed nie. Streeksverskille in parasietbesmettingspatrone word moontlik aangedryf deur die oostelike migrasie van prooivis, wat in die geval van Stony Point vererger word deur die vermoë van bosluise en vlooie om voordeel te trek uit toestande wat met kunsmatige-neste verband hou. | af_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.embargo.terms | 2020-11-02 | |
| dc.format.extent | xvi, 211 pages : illustrations (some color), map | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/105577 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | African penguin -- Conservation -- South Africa | en_ZA |
| dc.subject | Penguins -- Parasites -- Southern Africa | en_ZA |
| dc.subject | Host-parasite relationships | en_ZA |
| dc.subject | Parasites -- Effect of temperature on | en_ZA |
| dc.subject | African penguin -- Health -- South Africa | en_ZA |
| dc.subject | Sea birds -- Conservation -- South Africa | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.title | Parasites of African penguins: diversity, ecology and effect on hosts | en_ZA |
| dc.type | Thesis | en_ZA |