Nejnovější poznatky o rodu Rhynchocyon

Kristýna Jiráčková

Bachelor's thesis

Recent knowledge about the genus Rhynchocyon

Abstract:

Tato práce se zaměřila na souhrn nejnovějších poznatků o rodu Rhynchocyon, a to zejména z hlediska taxonomického zařazení rodu a jeho vývoje v některých obdobích. Jsou zde také uvedeny příklady dřívějšího mylného řazení tohoto rodu do určitých taxonomických skupin, jako je například řád hmyzožravci Eulipotyphla. Další částí práce je anatomie a morfologie tohoto rodu a jednotlivých druhů, které jej zastupují. Charakteristickými znaky, které se u nich shodně vyskytují, jsou prodloužené zadní končetiny a nos výrazně protažený do jakéhosi „chobůtku“, který jim pomáhá při hledání potravy. Rod čítá celkem čtyři druhy, které lze od sebe rozpoznat podle velikosti a zbarvení srsti. V rámci ekologie bylo v závěrečné práci popsáno, kde se jednotlivé druhy nachází a jak vypadají jejich teritoria. V rámci etologie je důležité se pozastavit u sociálních struktur. Zástupci řádu Rhynchocyon žijí v párech po celý život. Většinu času svého života žijí samotářsky a komunikují mezi sebou pomocí pachových značek. Samec se samicí přijde do kontaktu v období říje. Po úspěšném páření nastává 42denní březost. Samice rodí jedno až dvě mláďata, výjimečně i větší počet. Jediná mateřská péče, které se potomkům dostane, je mléčná výživa. Jinak jsou mláďata po celý den schována v hnízdě. Dospělci se živí převážně živočišnou potravou. Jedná se o hmyz, žížaly či jiné bezobratlé. Ve výjimečných případech přijmou i složku rostlinnou. U téměř všech druhů je zřetelný trend poklesu populace; z tohoto hlediska by se v budoucnosti nemělo zapomínat na ochranářské projekty. Všechny druhy jsou na Červeném seznamu ohrožených druhů IUCN. Bércoun udzungwaský (Rhynchocyon udzungwensis) je zranitelný, bércoun Petersův (Rhynchocyon petersi) a bércoun skvrnitý (Rhynchocyon cirnei) je málo dotčený a bércoun zlatořitný (Rhynchocyon chrysopygus) je na seznamu uveden jako ohrožený druh. Příčinou těchto stavů je kácení deštných pralesů za účelem těžby, stavebních prací a tvorby zemědělských plantáží. To způsobuje ztrátu přirozených stanovišť bércounů. Dalším faktorem je místní lov těchto malých savců tamějšími obyvateli. Pro ochranu afrických druhů je nejdříve nezbytné zmapovat zdejší terén a také zapojit do ochrany africké obyvatelstvo, ochranáře a patřičné instituce. Zájem o ochranu bércounů stoupá. V lidské péči je nejvíce chován bércoun Petersův (Rhynchocyon petersi), se kterým se můžeme setkat i v České republice, konkrétně v Zoo Praha. V práci jsou uvedeny informace ohledně chovu v zoologické zahradě. Zajímavá je ubikace v expozičním celku, kde si mohou jedinci přirozeně hledat potravu, což jim slouží i jako nanejvýš vhodný enrichment.

Abstract:

This work is focused on a summary of the latest knowledge about the genus Rhynchocyon, especially regarding the taxonomic classification of the genus and its development in some periods. There are also examples of previous misclassifications of this genus into certain taxonomic groups, such as the order Eulipotyphla. Another part of the work is the anatomy and morphology of this genus and the individual species that represent it. Common characteristic features are elongated hind limbs and a nose significantly stretched into a kind of trunk, which helps them in their search for food. The genus includes a total of four species, which can be distinguished from each other by size and coat color. Within the ecology, the final work described where the individual species are located and what their territory looks like. In terms of ethology, it is important to note their social structures. Rhynchocyon representatives live in pairs for all of their life. For most of their lives, they are solitary and communicate with each other using scent marks. The male comes into contact with the female during the breeding season. Successful mating is concluded by a 42 day pregnancy. Females rarely give birth to more than one or two offspring. The only maternal care provided their young is milk nutrition. Otherwise, the chicks are hidden in the nest throughout the day. The diet of adult Rhynchocyon mainly consists of meat (insects, earthworms or other invertebrates). Less commonly, they supplement their diet with plants. There is a notable decrease in the population of most species, therefore, conservation projects should not be forgotten in the future. All This work is focused on a summary of the latest knowledge about the genus Rhynchocyon, especially regarding the taxonomic classification of the genus and its development in some periods. There are also examples of previous misclassifications of this genus into certain taxonomic groups, such as the order Eulipotyphla. Another part of the work is the anatomy and morphology of this genus and the individual species that represent it. Common characteristic features are elongated hind limbs and a nose significantly stretched into a kind of trunk, which helps them in their search for food. The genus includes a total of four species, which can be distinguished from each other by size and coat color. Within the ecology, the final work described where the individual species are located and what their territory looks like. In terms of ethology, it is important to note their social structures. Rhynchocyon representatives live in pairs for all of their life. For most of their lives, they are solitary and communicate with each other using scent marks. The male comes into contact with the female during the breeding season. Successful mating is concluded by a 42 day pregnancy. Females rarely give birth to more than one or two offspring. The only maternal care provided their young is milk nutrition. Otherwise, the chicks are hidden in the nest throughout the day. The diet of adult Rhynchocyon mainly consists of meat (insects, earthworms or other invertebrates). Less commonly, they supplement their diet with plants. There is a notable decrease in the population of most species, therefore, conservation projects should not be forgotten in the future. All Rhynchocyon species have been put on the IUCN Red List of Threatened Species. Rhynchocyon udzungwensis is categorized as „vulnerable“, Rhynchocyon petersi and Rhynchocyon cirnei as of “least coconcern” and Rhynchocyon chrysopygus as „endangered“. The cause of these conditions is the destruction of rainforests for mining, construction and agricultural plantations, which leads to the loss of natural environment. A contributing factor is the hunting of these small mammals by the locals. To protect the African species of Rhynchocyon, it is first essential to map the local terrain and to involve the African population, conservationists and relevant inst

Abstract:

itutions. Interest in sengi (Rhynchocyon) protection is growing. The species most commonlyi kept in captivity is black and rufous sengi (Rhynchocyon petersi), which we can also see in the Czech Republic, specifically in the Prague Zoo. This theses contains information about the Rhynchocyon petersi breeding progams in place at the Prague Zoo. Also notable are the enrichment programs employed by the Zoo that allow the individual Rhynchocyon petersi to obtain food themselves in their natural environment. Rhynchocyon species have been put on the IUCN Red List of Threatened Species. Rhynchocyon udzungwensis is categorized as „vulnerable“, Rhynchocyon petersi and Rhynchocyon cirnei as of “least coconcern” and Rhynchocyon chrysopygus as „endangered“. The cause of these conditions is the destruction of rainforests for mining, construction and agricultural plantations, which leads to the loss of natural environment. A contributing factor is the hunting of these small mammals by the locals. To protect the African species of Rhynchocyon, it is first essential to map the local terrain and to involve the African population, conservationists and relevant institutions. Interest in sengi (Rhynchocyon) protection is growing. The species most commonlyi kept in captivity is black and rufous sengi (Rhynchocyon petersi), which we can also see in the Czech Republic, specifically in the Prague Zoo. This theses contains information about the Rhynchocyon petersi breeding progams in place at the Prague Zoo. Also notable are the enrichment programs employed by the Zoo that allow the individual Rhynchocyon petersi to obtain food themselves in their natural environment.

Keywords

fylogeneze, ochrana, chov, bércoun, Rhynchocyon, taxonomie, ekologie, chování, stupeň ohrožení

Keywords

giant sengi, Rhynchocyon, taxonomy, phylogeny, ekology, behavior, degree of threat, protection, breeding

Language used: Czech

Date on which the thesis was submitted / produced: 22. 4. 2022

Thesis defence

• Supervisor: Ing. Olga Kracíková, Ph.D.
• Reader: Renata Masopustová, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Bachelor programme / field:
Animal Science / Companion Animals