Diet and feeding in the Cape Cobra, Naja nivea

Abstract

It is widely reported that African cobras (genus Naja) are generalist predators, but examination of formal literature yields relatively little evidence of this for most species. Here, we review the diet of cape cobras (Naja nivea) based on examination of museum specimens, an extensive literature review, and social media reported natural history observations. We quantify dietary niche breadth and test the hypothesis that cape cobras are generalist predators. Additionally, we test the hypotheses that diet varies significantly (1) across biomes, and (2) across winter, summer and year-round rainfall regions. We gathered 101 feeding records for cape cobras and based on family-level prey frequencies calculated Levins’ measure of niche breadth as B = 6.57, which we standardised to B_A = 0.29. We found no association between prey classes and biomes or rainfall region. Our data indicate that cape cobras consume a wide range of vertebrate prey from all four tetrapod classes, including a large number and diversity of snakes. Our findings suggest that cape cobras may be involved in several important ecological processes. Moreover, our study demonstrates the utility and value of collating natural history observations reported on social media platforms.

Key words:

• Cannibalism
• dietary specialisation
• foraging ecology
• intraguild predation
• ophiophagy

Acknowledgments

We thank the University of the Western Cape and the National Research Foundation (unique grant number 99186). D. Hamerton, J. Opperman, L. Mahlangu, L. Mashinini, W. Conradie and B. Wilson provided access to specimens in their care. T. Kearney, A. Engelbrecht, W. Conradie, and B. Wilson assisted with identification of specimens. R. Maritz, B. Wilson and H. Fölscher assisted in the examination of museum material. Special thanks to R. Shine for kindly providing the raw data of his study. We thank the numerous citizen scientists for their photographic records on social media.

Supplemental Material

Supplemental data for this article can be accessed at https://doi.org10.1080/21564574.2017.1388297.