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.
Selection for sexual dichromatism is thought to arise mainly from intersexual niche divergence or sexual selection, including mate‐choice and intrasexual competition. However, overt sexual dichromatism is rare in snakes, limiting inference regarding its origin and maintenance in these animals. We thus aimed to assess whether boomslang (Dispholidus typus) – a species of overtly sexually dichromatic African snake – exhibits evidence for intersexual niche divergence based on three ecologically relevant morphological variables (snout‐vent length, tail length and head length) and one ecological variable (diet). We measured morphological variables on 203 museum specimens, and characterized diets for male and female snakes on the basis of dissected specimen gut contents, supplemented with literature reports of feeding, as well as online photographs. Male and female boomslang show broadly similar gross morphology and do not differ in mean snout‐vent, relative tail length or head length. Moreover, male and female snakes do not differ in the frequency with which they consume different prey classes. Similarly, diets of adult and juvenile snakes did not differ significantly. The abundance of chameleons and bird chicks (36% and 54% of prey items respectively) in the diet of boomslang suggests dietary restriction due to arboreality rather than dietary specialization per se. Despite examining a range of morphological and ecological variables, we fail to detect evidence for intersexual niche differentiation. Rather, our results suggest that juvenile coloration is likely a result of selection for camouflage from visually oriented predators, and that the overt sexual dichromatism of adults following maturation represents a shift toward either intersexual mate‐choice or intrasexual competition. We therefore recommend that boomslang visual acuity and colour differentiation be directly examined in the future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.