Paternal Care

Commentary by Susan Sam

In the Nautilus article, The Groundhog Watchers by Brandon Keim, https://nautil.us/the-groundhog-watchers-514825/, C Maher expressed doubt about our interpretation of the behavior of our male groundhogs as fatherly attention. Are our males biological fathers of the offspring or some other unknown male? We can’t answer that because we don’t have DNA evidence. In the case of Ash’s offspring (2021), we believe that Stubby was Ash’s mate and the biological father of the offspring based on observations of his behavior with Ash. (In her study, Maher uses behavioral observations of juveniles associating with females to determine maternity). After Stubby’s presumed death, Milo came in and acted as a companion and helper to Ash. We are skeptical that Milo was a biological father to Ash’s young though he displayed behavior we interpreted as paternal towards them. Please check out our paper. “Backyard observations of the behavior and role of the male woodchuck (Marmota monax)” – https://www.woodchuckwonderland.com/woodchuck-male/

Only a small percentage of mammals provide paternal care to the young. Included among species that do are rodents. (Wikipedia) Studies of paternal care are often evaluating male behavior towards unrelated young. A majority of studies on paternal care have been done under artificial, not natural, conditions. Researchers may refer to males’ behavior towards young as either paternal (biological father) or allopaternal. (non-descendant young). (N. D. Horrell, P.W. Hickmott, and W. Saltzman 2019 ) In her paper, Charlotta Kvarnemo states her preference for the term male care instead of paternal care because care is not always directed to the males’ biological offspring. (Behavioral Ecology 2006)

What factors promote paternal behavior? Little research has been done. Some factors that may promote paternal care include hormonal factors, being raised in a biparental environment, copulation, and a continued mated relationship or cohabitation. (M. Numan 2010 Encyclopedia of Behavioral Neuroscience.) We have documented the continued relationships of our mated groundhogs, which may be a factor in the paternal behavior of our males. Maher’s groundhogs do not develop long-term pair-bonds, and she has not observed paternal behavior in her population. (Maher 2010)

As stated in our paper, we urge long-term studies of the Woodchuck mating systems and family relationships throughout the season in varying environments.

Reference:
Neural Regulation of Paternal Behavior in Mammals: Sensory, Neuroendocrine, and Experiential Influences on the Paternal Brain, N. D. Horrell, P.W. Hickmott, and W. Saltzman 2019
Paternal Care, Wikipedia