Many of the blogs that I have posted before discussed the human influence on the decline of the African penguin population. So, imagine my surprise when I came across a study that examines the influence of natural predators on mainland African penguin colonies. For once, humans aren’t the villain in this study.
Instead, the bad guys are land-based predators of African penguins – namely leopards, caracals, domestic dogs, and mongooses. While they are natural predators of the African penguin, they can sometimes go on killing sprees [1] in which they kill many penguins in a short period of time, eating almost nothing.
While many predators exhibit this “surplus killing” behavior, it’s particularly problematic when their prey is an endangered species. As a result, it’s important to successfully and quickly identify the culprit of killing sprees on African penguins.
In this study, researchers obtained 52 penguin carcasses killed by caracals, 27 by leopards, 10 by domestic dogs, and four by mongooses [1]. Experienced veterinarians performed autopsies on the penguins, examining and comparing lesions and bite marks to differentiate between predators [1].
In the African penguin carcass, both leopards and caracals bite the neck, although leopards aim for the lower neck and exert a greater force through their larger bite [1]. However, domestic dogs use blunt-force trauma to kill penguins rather than biting, causing lung and kidney damage by crushing the chest, thereby resulting in a “messy” kill [1]. Finally, mongooses ate the neck muscles of the penguins, resulting in decapitation or near-decapitation, and opened the skulls of chicks [1].
I think the value of this study lies in its report on attacks specific to the African penguin. Because the researchers documented attacks by each predator on penguins exclusively, veterinarians can better identify the type of animal that killed the penguins. As a result, authorities will hopefully be able to manage predator species and react more quickly when killing sprees occur to reduce the number of African penguins involved.
References:
- Ralph ET Vanstreels, Nola J Parsons, Cuan McGeorge, Renata Hurtado, Katrin Ludynia, Lauren Waller, Monique Ruthenberg, Arne Purves, Lorien Pichegru, Pierre A Pistorius (2019). Identification of land predators of African Penguins Spheniscus demersus through post-mortem examination, Ostrich, 90:4, 359-372.
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The Penguin Researcher 