Natural selection is expected to favor males that invest more in offspring they sire. We investigated the relationship between paternity and male behavior in the acorn woodpecker (Melanerpes formicivorus), cooperative breeders that live in family groups including offspring that remain on their natal territory, sometimes for years, and cobreeders of both sexes. Regardless of group composition, only one communal nest is attended at a time. Whereas cobreeding females share maternity equally, one male often sires the majority of young in the group’s communal nest. Copulations are rarely observed, and thus it has not been possible to link paternity to sexual behavior. There were no differences among cobreeder males that did or did not sire young in their propensity to roost in the nest cavity at night. However, cobreeder males that attended females continuously prior to egg-laying were more likely to successfully sire young than males that did not, and the relative share of feeding visits and time spent at the subsequent nest were positively related to a male’s realized paternity. These differences in male behavior were partly due to differences among males and partly to plasticity in male behavior covarying with paternity share. Feedings by males successfully siring young also involved a larger proportion of nutritionally valuable insect prey. Males are aware of their paternity success, apparently because of their relative access to females prior to egg-laying, and provide more paternal behavior at nests in which they are more likely to have sired young.

Datasets are mostly from field observations combined with parentage analysis

Most of the fields are labeled so as to be self-explanatory in conjunction with the published paper. NA = missing values. LED = Last Egg Date. 

There are 3 datasets: (1) Mate_guard.xls has the data for individual mate-guarding watches. It was used for the analyses in Table 2.

(2) Nocturnal_roosting.xls has the data for cobreeder male nocturnal roosting in the nest cavity. It was used for part of Table 3.

(3) Provisioning_behavior.xls has the data for provisioning and feeding at the nest by cobreeder males. It was the main datafile used for Table 3 (except for the nocturnal roosting models), Table 4, and Table 5.