No evidence for parent–offspring competition in the burying beetle Nicrophorus vespilloides

• Published in: Behavioral ecology 2018-09, Vol.29 (5), p.1142-1149
• Main Authors: Gray, Francesca E, Richardson, Jon, Ratz, Tom, Smiseth, Per T
• Format: Article
• Language: English
• ISSN: 1045-2249; 1465-7279
• DOI: 10.1093/beheco/ary091

When parents and offspring share food, there should be less left for offspring when parents eat more. We found no evidence that this was the case in burying beetles. Although hungry mothers ate more food, their offspring were just as large and survived just as well when food was limited. However, offspring of hungry mothers fared less well when food was plentiful, presumably reflecting that hungry mothers are poorer parents. Abstract In species where family members share a limited pool of resources, there may be competition between parents and their dependent offspring for access to these resources. Parent–offspring competition may impose a cost to family living that would constrain the evolution of parental care and family living. Yet, few studies have tested for evidence of parent–offspring competition. Here we test for parent–offspring competition in the burying beetle Nicrophorus vespilloides. This species breeds on carcasses of small vertebrates that serve as food for both parents and offspring. We used a two-by-two factorial design, where we manipulated female nutritional state (food deprivation vs. control treatments) and the amount of resources (small vs. large mouse carcasses). We find that food-deprived females lost more mass than controls over the 9-day long food deprivation treatment, confirming that food deprivation caused a substantial decline in female nutritional state at the start of breeding. However, we find no evidence that increased food consumption by food-deprived females had a greater impact on offspring growth or survival when breeding on small carcasses. Instead, poor female nutritional state had a negative impact on offspring survival when females bred on large carcasses. There was more mould on the carcass when food-deprived females bred on a large carcass, suggesting that such females provided less indirect care serving to suppress microbial growth. We conclude that parent–offspring competition is associated with relatively minor costs to family members in this species, suggesting that it may not necessarily constrain the evolution of parental care and family living.