Differences in Pre-Laying Behavior between Floor-Laying and Nest-Laying Pekin Ducks

SIMPLE SUMMARY: Floor-laying is a behavior seen in farmed ducks, where eggs are laid onto the shed floor rather than in the nest boxes provided. This behavior costs producers, due to damaged eggs, and may be a negative experience for those birds performing it. However, factors contributing to floor laying in Pekin ducks are not well understood. We aimed to identify whether behavioral differences exist between floor and nest-laying ducks. We found that some floor-laying ducks never interacted with nest boxes, while other floor-layers used nests in a similar way to nest-laying ducks. Floor-layers that did not interact with nests experienced less aggression than the other two groups. We concluded that competition is a contributing factor to floor-laying in ducks, and it is possible that those ducks not using nests avoid doing so to reduce agonistic encounters. Developing strategies to reduce competition for nest boxes may help improve production efficiency and minimize negative welfare outcomes that might exist for floor-laying ducks. ABSTRACT: Floor-laying in commercially farmed Pekin ducks is not well understood. This exploratory study aimed to determine if behavioral differences exist between floor-laying and nest-laying ducks. Retrospective analysis of video footage from a small commercial breeding flock (n = 60 birds) was used to quantify the behavior of floor-laying and nest-laying birds (n = 24 events per group) in the hour prior to oviposition site selection. The frequency, percentage of time spent, and duration of bouts were compared for nest box interactions, behaviors inside and outside of boxes and aggressive interactions. Some floor-laying birds did not enter or investigate nest boxes (FL-Out), whilst some floor-layers (FL-In) used nest boxes similarly to nest-laying birds (NL). Nest-building behavior differed only in location, with FL-Out performing the behavior on the shed floor and the other groups performing it primarily in boxes. FL-Out sat more, walked less, and engaged in less aggression (p < 0.05) than FL-In and NL. The occurrence of multiple birds in a nest box was strongly correlated with the number of aggressive interactions that occurred in the box (R = 0.81). Competition appears to contribute to floor-laying in Pekin ducks; FL-Out birds may not engage with nest boxes as a coping strategy to avoid agonistic behavior. These findings indicate that developing practical strategies to reduce nest box competition could help mitigate floor-laying. However, other factors such as nest design may also contribute to FL-Out birds’ reluctance to use nest boxes and require further investigation.