Defensive Behavior and Integumentary Morphology of the Hairy Dwarf Porcupine Coendou spinosus (Rodentia: Erethizontidae)

ABSTRACT New World porcupines (Erethizontidae) exhibit behaviors and possess integumentary structures, including the quills, that are used for self‐defense. The North American porcupine (Erethizon dorsatum) has been well studied regarding these features; however, information is lacking for the South American Coendou species. We describe the defensive behavior and integumentary morphology of Coendou spinosus to understand the defensive strategies of this species and to compare with those reported for other species. We assessed the behaviors related to warning, defense, and escape of eight porcupines, as well as the characteristics of their pelage and quills. Furthermore, we microscopically analyzed skin samples of a roadkill adult male specimen. Similar to E. dorsatum, C. spinosus exhibited omnidirectional quill erection, revealing an aposematic color and, with their backs toward the perceived human threat, they performed quick tail and body movements to strike the hands of the human trying to capture them by the tail. Furthermore, C. spinosus presented an integumentary structure similar to that of E. dorsatum, and mechanisms to facilitate quill release when touched, penetration, and fixation in the opponent. The most distinct warning behavior noted was the vibration of the quills, which has not been reported for Erethizon. Our study confirms that, like other erethizontids, C. spinosus does not attack but exhibits warning, defense, and escape mechanisms and behaviors when threatened or touched. The dissemination of such information helps to counter the negative stigma associated with porcupines, as they can be the victims of attacks by dogs and humans, and to promote their conservation. Our study describes, compare, and discuss the morphological characteristics and probable defensive functions of the integumentary components of the Coendou spinosus. We described details of the defensive mechanisms and behavioral repertoire. Our study confirms that this species does not attack and only exhibits warning, defensive, and escape behaviors in the presence of a perceived threat. Our findings suggest that the mechanisms responsible for the defensive efficiency of quills are similar between species of the genera Coendou and Erethizon.