{"id":11271,"date":"2024-12-13T08:18:56","date_gmt":"2024-12-13T06:18:56","guid":{"rendered":"https:\/\/ditsong.org.za\/en\/?p=11271"},"modified":"2024-12-13T08:20:08","modified_gmt":"2024-12-13T06:20:08","slug":"ageing-egyptian-rousette-fruit-bats","status":"publish","type":"post","link":"https:\/\/ditsong.org.za\/en\/ageing-egyptian-rousette-fruit-bats\/","title":{"rendered":"AGEING EGYPTIAN ROUSETTE FRUIT BATS"},"content":{"rendered":"\n

By: Teresa Kearney – Curator: Vertebrate Department, Small Mammals, DITSONG: National Museum of Natural History (DNMNH)<\/strong><\/em><\/p>\n\n\n\n

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Rousettus aegyptiacus<\/em> observed in Uganda by Yizhar Amir (licensed under http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/)<\/p>\n\n\n\n

Volume 25, issue 1 of the Journal Acta Chiropterologica, a scientific journal dedicated to bat research, has a paper by Dr Tedson Nkoana (University of Pretoria, https:\/\/www.up.ac.za\/centre-for-viral-zoonoses\/view\/staffprofile\/38814)) and his supervisors, Prof Wanda Markotter (Director, Centre for Viral Zoonoses, Pretoria University, https:\/\/www.up.ac.za\/research-matters\/news\/researchers\/view-2989059-professor-wanda-markotter) and myself. This paper, entitled \u201cAssessing age related cranial characteristics and morphometrics of Egyptian rousette (Rousettus aegyptiacus<\/em>) from Central Africa\u201d, is a chapter from the thesis Tedson prepared for his PhD thesis, which was submitted late last year. The Egyptian rousette bat Tedson studied is a fruit eating species that lives in caves and is found across Africa where there are suitable cave roosts. Along with other bat species the Egyptian rousette bat has been extensively studied by Prof Markotter, her collaborators, and students to understand their potential disease risk (https:\/\/www.up.ac.za\/centre-for-viral-zoonoses\/article\/3060677\/southern-africa-bat-research-network).<\/p>\n\n\n\n

An understanding of what times of the year diseases are more prevalent and identifying which individuals in a population \u2013 such as males or females, the young or the old – are more susceptible or play a larger role in disease transmission, can aid in developing plans to restrict and reduce disease risks to both people and livestock. A global approach called \u201cOne health\u201d (https:\/\/www.who.int\/health-topics\/one-health#tab=tab_1<\/a>) provides holistic guidelines for disease control that considers people, animals and ecosystems. A challenge with bats is identifying how old adult individuals are. Adults can be distinguished from subadults by the fusion at the ends of the finger bones in the wings, which happens when the bones stop growing in length. However, once the bones are fused there are few other known, reliable indicators of age. Given that bats have a longer lifespan compared to similarly sized non-flying \/ non-volant small mammals, it would be useful to know if the disease profile of bats that are younger, such as those around two years, differ from those of older bats, perhaps five or ten years old. Understanding the age profile of a population is also essential for conservation assessments and management planning. Hence the interest for Tedson\u2019s PhD research investigating age related morphological changes in the Egyptian rousette bat.<\/p>\n\n\n\n

In this paper (https:\/\/bioone.org\/journals\/acta-chiropterologica\/volume-25\/issue-1\/15081109ACC2023.25.1.010\/Assessing-Age-Related-Cranial-Characteristics-and-Morphometrics-of-the-Egyptian\/10.3161\/15081109ACC2023.25.1.010.full) Tedson used a large collection of Egyptian rousette bat skulls in the DITSONG: National Museum of Natural History (DNMNH) small mammal collection originating from Durba in the Democratic Republic of Congo (DRC). These were collected and later donated by Prof Swanepoel as part of investigations into an outbreak of Marburg in a mine where the bats were roosting in, in the DRC (https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC2876776\/).<\/p>\n\n\n\n

For obvious conservation reasons very rarely are large numbers of bats collected at the same place and time. However, a collection like this provides value baseline information for the growth of a species without having to consider possible influences of different geographic places and time. The skulls in this collection were categorised in relation to degree of eruption of the teeth and fusion of different bones on the skull. These are features that change as an individual ages. To see how size changed in relation to these features, this information was then related to linear measurements taken from the same individuals.<\/p>\n\n\n\n

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Figure from https:\/\/bioone.org\/journals\/acta-chiropterologica\/volume-25\/issue-1\/15081109ACC2023.25.1.010\/Assessing-Age-Related-Cranial-Characteristics-and-Morphometrics-of-the-Egyptian\/10.3161\/15081109ACC2023.25.1.010.full<\/p>\n\n\n\n

Among the seven measurements investigated, two from the skull – greatest skull length and mastoid width \u2013 along with forearm length (that had been measured when the bats were originally collected), were identified to be more important in separating the measured individuals. Forearm length is a common measurement made on a live bat, and the skull measurements can be related to measurements that can be made on a live bat. Being able to relate the measurements between the Museum specimens and live bats was important if the results were useful and could be applied in fieldwork to age live bats that were captured, measured, and subsequently released. Relating different degrees of tooth eruption and bone fusion to these measurements showed a linear growth pattern, with larger sizes being related to older individuals with erupted teeth and fused skulls. While this might seem an obvious result it was an essential step in confirming this pattern, to build on in the next phase of Tedson\u2019s research. This involved linking these characters and measurements to actual age in years, by counting cementum layers in a sectioned tooth. However, that was covered in another chapter of Tedson\u2019s thesis, which I will report on once it is published.<\/p>\n","protected":false},"excerpt":{"rendered":"

By: Teresa Kearney – Curator: Vertebrate Department, Small Mammals, DITSONG: National Museum of Natural History (DNMNH) Rousettus aegyptiacus observed in Uganda by Yizhar Amir (licensed under http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/) Volume 25, issue 1 of the Journal Acta Chiropterologica, a scientific journal dedicated […]<\/p>\n","protected":false},"author":28,"featured_media":11274,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","ngg_post_thumbnail":0,"footnotes":""},"categories":[106],"tags":[],"table_tags":[],"class_list":["post-11271","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"publishpress_future_action":{"enabled":false,"date":"2026-08-27 19:18:24","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category"},"_links":{"self":[{"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/posts\/11271","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/comments?post=11271"}],"version-history":[{"count":1,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/posts\/11271\/revisions"}],"predecessor-version":[{"id":11276,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/posts\/11271\/revisions\/11276"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/media\/11274"}],"wp:attachment":[{"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/media?parent=11271"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/categories?post=11271"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/tags?post=11271"},{"taxonomy":"table_tags","embeddable":true,"href":"https:\/\/ditsong.org.za\/en\/wp-json\/wp\/v2\/table_tags?post=11271"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}