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n Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie - Dieetsamestelling van vee-reiers () in die sentrale Vrystaat : research and review article

Volume 23, Issue 4
  • ISSN : 0254-3486
  • E-ISSN: 2222-4173

Abstract

<b>Dietary composition of cattle egrets (<i>Bubulcus ibis</i>) in the central Free State</b> <br>Analysis of 152 stomach samples of adult cattle egrets (<i>Bubulcus ibis</i>) collected over a period of five years in the central Free State showed this species to be mainly insectivorous. The Insecta, occuring in almost all stomach samples, are represented by prey items from 13 orders of which the Orthoptera, followed by the Coleoptera, Isoptera, Diptera and Lepidoptera, showed the highest frequency of occurrence. Amongst the non-insect invertebrates, the Araneae and Solifugae occured most frequently. Based on dry mass the Orthoptera and Isoptera constitute by far the most important components. Prey items of vertebrates combined represent only ca. 10% of the diet. Overall, the stomach contents of 75 chicks correspond with that of the adults, except that vertebrates make a significant contribution to the diet during the first week of the nesting phase. In general cattle egrets can be considered opportunistic feeders that concentrate on easily obtainable food sources which become sporadically available (partly because of their regular association with mammalian hosts).

Maaginhoud-ontledings van 152 volwasse vee-reiers (<i>Bubulcus ibis</i>) wat oor 'n tydperk van vyf jaar in die sentrale Vrystaat versamel is, dui daarop dat die voëls oorwegend as insekvreters beskou kan word. Die Insecta, wat in feitlik alle maaginhoude voorgekom het, word deur prooisoorte van 13 ordes verteenwoordig waarvan die Orthoptera, gevolg deur die Coleoptera, Isoptera, Diptera en Lepidoptera, die hoogste voorkomsfrekwensie toon. Onder die nie-insek invertebrate het die Araneae en Solifugae die meeste voorgekom. Gebaseer op droë massa maak die Orthoptera en Isoptera verreweg die belangrikste komponente uit. Prooi-items van vertebrate gekombineerd is vir slegs sowat 10% van die dieet verantwoordelik. Die maaginhoude van 75 neskuikens stem grootliks met dié van volwassenes ooreen, behalwe dat vertebrate tydens die eerste week van die nesfase 'n beduidende bydrae tot die dieet lewer. Oor die algemeen kan vee-reiers as opportunistiese voeders beskou word wat op maklik bekombare voedselbronne wat sporadies beskikbaar raak (deels as gevolg van hul gereelde assosiasie met soogdiergashere), konsentreer.

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/content/aknat/23/4/EJC20354
2004-12-01
2019-10-14

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