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Updated: Aug 25, 2026
Using a Comparative Species Approach to Investigate the Neurobiology of Paternal Responses
Published on: September 19, 2011
Prolactin levels in paternal striped mouse (Rhabdomys pumilio) fathers
Carsten Schradin1, Neville Pillay
1Ecophysiological Studies Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa. schradin@mweb.co.za
Abstract:
Paternal behavior is associated with an increase in prolactin levels in fish, birds and mammals, including rodents. The striped mouse (Rhabdomys pumilio) from southern Africa shows highly developed paternal care. We investigated whether striped mouse fathers have higher prolactin levels than nonfathers, and whether there is a relationship between tactile stimulation with pups and prolactin secretion in fathers. We measured serum prolactin in 42 male striped mice assigned to one of four different experimental groups (single males, paired males, fathers housed with mother and pups, and fathers separated from their family by a wire-mesh partition). Our results revealed no increases in prolactin levels in fathers, and fathers with tactile contact with pups did not have higher prolactin levels than the fathers that were prevented from making tactile contact with pups. In contrast, experienced males had higher prolactin levels than inexperienced males. Male striped mice are polygynous in nature, living in groups, with three breeding females, and are permanently associated with pups during the breeding season. In a field study, males had higher prolactin levels during the breeding season than during the nonbreeding season. Thus, prolactin secretion in the polygynous striped mouse might be regulated by environmental stimuli, whereas social stimuli might be important for monogamous species. This is the first study to demonstrate seasonal changes in prolactin levels in a free-living male mammal.
Insights
Paternal care in striped mice doesn't increase prolactin. Instead, experienced males and seasonal changes, not pup contact, influence prolactin levels in this polygynous species.
Area of Science:
- Reproductive Biology
- Behavioral Ecology
- Endocrinology
Background:
- Paternal behavior in many species, including mammals, is linked to elevated prolactin levels.
- The striped mouse (Rhabdomys pumilio), a southern African rodent, exhibits pronounced paternal care.
- Previous research suggests a correlation between prolactin and paternal duties.
Purpose of the Study:
- To investigate if male striped mice exhibit increased prolactin levels associated with fatherhood.
- To determine the role of tactile stimulation with pups in prolactin secretion in fathers.
- To explore seasonal and experience-related variations in prolactin levels in male striped mice.
Main Methods:
- Serum prolactin levels were measured in 42 male striped mice across four groups: single, paired, fathers with pups, and fathers separated from pups.
- A field study assessed prolactin levels during breeding and non-breeding seasons.
- Experience levels of males were also considered in the analysis.
Main Results:
- No significant increase in prolactin was observed in fathers compared to nonfathers.
- Tactile contact with pups did not correlate with higher prolactin levels in fathers.
- Experienced males showed higher prolactin levels than inexperienced males.
- Male striped mice exhibited higher prolactin levels during the breeding season than the non-breeding season.
Conclusions:
- Prolactin secretion in polygynous striped mice appears to be influenced by environmental and seasonal factors rather than direct interaction with pups.
- Social stimuli may play a more significant role in prolactin regulation in monogamous species.
- This study provides the first evidence of seasonal prolactin level changes in a free-living male mammal.
