title: The mother as hunter: significant reduction in foraging costs through enhancements of predation in maternal rats.
abstract: In previous laboratory investigations, we have identified enhanced cognition and reduced stress in parous rats, which are likely adaptations in mothers needing to efficiently exploit resources to maintain, protect and provision their immature offspring. Here, in a series of seven behavioral tests on rats, we examined a natural interface between cognition and resource gathering: predation. Experiment 1 compared predatory behavior (toward crickets) in age-matched nulliparous mothers (NULLs) and postpartum lactating mothers (LACTs), revealing a highly significant enhancement of predation in LACT females (mean = -65s in LACTs, vs. -270s in NULLs). Experiment 2 examined the possibility that LACTs, given their increased metabolic rate, were hungrier, and thus more motivated to hunt; doubling the length of time of food deprivation in NULLs did not decrease their predatory latencies. Experiments 3-5, which examined sensory regulation of the effect, indicated that olfaction (anosmia), audition (blockade with white noise), and somatosensation (trimming the vibrissae) appear to play little role in the behavioral enhancement observed in the LACTs; Experiment 6 examined the possibility that visual augmentations may facilitate the improvements in predation; testing LACTs in a 0-lux environment eliminated the behavioral advantage (increasing their latencies from -65s to -212s), which suggests that temporary augmentation to the visual system may be important, and with hormone-neural alterations therein a likely candidate for further study. In contrast, testing NULLS in the 0-lux environment had the opposite effect, reducing their latency to catch the cricket (from -270s to -200s). Finally, Experiment 7 examined the development of predatory behavior in Early-pregnant (PREG), Mid-PREG, and Late-PREG females. Here, we observed a significant enhancement of predation in Mid-PREG and Late-PREG females--at a time when maternity-associated bodily changes would be expected to diminish predation ability--relative to NULLs. Therefore, as with the increasing reports of enhancements to the maternal brain, it is apparent that meaningful behavioral adaptations occur that likewise promote the survival of the mother and her infants at a crucial stage of their lives.
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA. Electronic address: ckinsley@richmond.edu.
authors.forename: Craig Howard
authors.initials: CH
authors.lastname: Kinsley
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Jamie C
authors.initials: JC
authors.lastname: Blair
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Karp
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Naomi W
authors.initials: NW
authors.lastname: Hester
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Ilan M
authors.initials: IM
authors.lastname: McNamara
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Orthmeyer
authors.affiliation: Department of Psychology, Dickinson College, Carlisle, PA 17013, USA.
authors.forename: Molly C
authors.initials: MC
authors.lastname: McSweeney
authors.affiliation: Department of Psychology, Randolph-Macon College, Ashland, Virginia 23005, USA.
authors.forename: Massimo M
authors.initials: MM
authors.lastname: Bardi
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Karelina
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Lillian M
authors.initials: LM
authors.lastname: Christon
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Maxwell R
authors.initials: MR
authors.lastname: Sirkin
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Lindsay W
authors.initials: LW
authors.lastname: Victoria
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Danielle J
authors.initials: DJ
authors.lastname: Skurka
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Christian R
authors.initials: CR
authors.lastname: Fyfe
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Margaret B
authors.initials: MB
authors.lastname: Hudepohl
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of Sao Paulo, Brazil.
authors.forename: Luciano F
authors.initials: LF
authors.lastname: Felicio
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: R Adam
authors.initials: RA
authors.lastname: Franssen
authors.affiliation: Department of Psychology, Center for Neuroscience, University of Richmond, Richmond, VA 23173, USA.
authors.forename: Elizabeth E A
authors.initials: EE
authors.lastname: Meyer
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of Sao Paulo, Brazil.
authors.forename: Ilton S
authors.initials: IS
authors.lastname: da Silva
authors.affiliation: Department of Psychology, Randolph-Macon College, Ashland, Virginia 23005, USA.
authors.forename: Kelly G
authors.initials: KG
authors.lastname: Lambert
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D003071:Cognition / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000523:psychology*; D008425:Maternal Behavior / Q000502:physiology*; D009035:Mothers; D009042:Motivation / Q000502:physiology; D011235:Predatory Behavior / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012903:Smell / Q000502:physiology
keywords: Adaptation; Aggression; Lactation; Maternal brain; Motherhood; Neuroplasticity; Predation; Pregnancy