Sex differences in social odor discrimination by southern giant pouched rats (Cricetomys ansorgei)

Abstract

of conspecifics. The recognition of these signals can then mediate behavioral responses regarding territoriality, aggression, mating, and parental care (Curtis et al., 2007). It has been suggested that individual recognition, or the ability to discriminate between the idiosyncratic features of two individuals of similar sex, age, and reproductive status, can evolve when there is a possibility for "costly confusion" (Tibbetts & Dale, 2007). For example, animals can avoid aggressive conspecifics, selectively invest in specific offspring, and identify mates using individual recognition (Tibbetts & Dale, 2007).These behaviors can impact fitness through increased reproductive success, and through improved survival for individuals and their kin (Brennan & Kendrick, 2006). An animal's expression of behavioral responses toward conspecifics can reveal that individual's assessment of conspecific attractiveness (or aversiveness). For example, paired prairie vole (Microtus ochrogaster) males do not show a preference between odors from their mate and a virgin female, suggesting that both females have equivalent attractiveness to the male (Newman & Halpin, 1988).

Characterization of oxytocin and vasopressin receptors in the Southern giant pouched rat and comparison to other rodents

“…Whether tuco-tucos rely on AVP signaling in olfactory circuitry instead of OT signaling for social recognition is an open question. Pouched rats are exceptional at olfactory discrimination ( 32 , 35 , 37 , 38 ), which also raises questions about what OT-OTR in the olfactory sensory system does and whether (or how) low levels of OTR in the OB and parts of the PFC impact sensory processing. Potentially, AVP-V1aR signaling in the olfactory regions of the forebrain might impact social recognition in the pouched rat ( 59 ).…”

“…This species is known for its peculiar reproductive physiology, in which females show profound delays in the development of external genitalia well past ‘adulthood’, and they demonstrate incredible plasticity, such that reproductively active females can revert to a vaginally non-patent (or closed to the outside world) state ( 31 ). Furthermore, pouched rats are recognized for their astounding olfactory system and odor discrimination ( 32 – 36 ) and this species has been used as biodetectors for diseases and unexploded ordinances, although it is occasionally mischaracterized as C. gambianus ( 37 – 39 ). The pouched rat’s common name is partially based on its convergent rat-like appearance, but they are only distantly related to traditional lab rat species ( 39 , 40 ).…”

“…There are very few studies describing the behavior of pouched rats, and fewer describing C. ansorgei specifically. However, the aggressive behavior between unfamiliar animals and territorial scent marking behavior ( 32 , 34 , 41 ) suggests that these animals might prefer to live in small family groups. The closely related congener, C. gambianus , evidently demonstrates uniparental maternal care, and only one male and female successfully pair and mate when housed in groups of up to six animals ( 42 ).…”

Isolation ofActinomyces cricetomyissp. nov from orocervicofacial abscesses of African giant pouched rats (Cricetomys ansorgei)

“…are large terrestrial rodents from the family Nesomyidae, native to savannahs and evergreen forests of sub-Saharan Africa. These rodents stand out among other rodents for their relatively large olfactory cortex, bulbs, and ample olfactory receptor repertoire, which provide them with strong olfactory capabilities [1][2][3][4]. Due to their acute sense of smell, they have been successfully trained to diagnose tuberculosis cases in humans [5,6], localize people trapped in collapsed structures [7], and employed in life-saving operations to detect anti-personnel landmines [8].…”

Evidence for individual vocal recognition in a pair bonding poison frog? Insights from no-choice and two-choice paradigms

“…Yet the importance of individual vocal recognition depends on a species’ social system, and the ability to produce and recognize distinct vocalizations should only evolve when more general recognition systems will not suffice (Carlson et al ., 2020). Even within populations, individual vocal recognition has been shown to vary according to sex (Insley et al ., 2003; Freeman & Ophir, 2021), age (Sieber, 1986; Balcombe, 1990; Leonard et al ., 1997), and reproductive status (Pultorak et al ., 2017; Shave & Waterman, 2017), and may be context-dependent. For instance, single male prairie voles are able to discriminate between male conspecifics but not between female conspecifics (Zheng et al ., 2013), yet pair bonded males can discriminate conspecifics independent of their sex (Blocker & Ophir, 2015).…”