Nest prospecting brown-headed cowbirds ‘parasitize’ social information when the value of personal information is lacking

Abstract

Brood parasites face considerable cognitive challenges in locating and selecting host nests for their young. Here, we test whether female brown-headed cowbirds, , could use information acquired from observing the nest prospecting patterns of conspecifics to influence their own patterns of nest selection. In laboratory-based experiments, we created a disparity in the amount of personal information females had about the quality of nests. Females with less personal information about the quality of two nests spent more time investigating the nest that more knowledgeable females investigated. Furthermore, there was a strong negative relationship between individual's ability to track nest quality using personal information and their tendency to copy others. These two contrasting strategies for selecting nests are equally effective, but lead to different patterns of parasitism.

Male black widows parasitize mate-searching effort of rivals to find females faster

“…Our results indicate that social information (chemical and/or structural cues) on the silk of earlier searchers can allow a male to find a female efficiently even when access to personal information (volatile sex pheromone) is minimized. This is consistent with the prediction that animals should use social information when personal information is out of date, unreliable or expensive to obtain [22][23][24]27]. Male black widows apparently move upwind to seek personal information (figure 3c), but when weak or absent wind makes detection of a pheromone source difficult or impossible, they can nonetheless find females by following the silk trails of rivals ( figures 2b,d and 3d).…”

“…How and when animals use personal and social information to make mating-related decisions will depend on conditions including temperature/weather, physical structure of the habitat, and ecological variables such as predation risk and the spatio-temporal distribution of conspecifics. These factors will affect the fitness benefit and feasibility of acquiring and using social compared to personal information, so information use is expected to be contextdependent [22,27].…”

Cognition and the brain of brood parasitic cowbirds

“…Further tests of the idea that superior female spatial ability is associated with search for host nests could be performed in large enclosures (e.g. White et al 2017) that more closely resemble the spatial scale at which females search for host nests. Superior performance by male brown-headed cowbirds in breeding condition on the touchscreen spatial task is puzzling but the domain of this sex difference could be further examined by varying the kind of spatial task presented on the touchscreen, in more naturalistic foraging tasks or in tests of memory for the spatial location of females.…”

Cognition and reproductive success in cowbirds

“…Successful reproduction is a product of a lifetime of interactions with the world, and thus documenting the effect of any one aspect of cognition on reproductive success can be less than straightforward. For example, the efficacy of cognitive abilities may vary by context, being useful in some environments but not others (Cole et al, 2012), cognitive skills may interact positively or negatively with each other (Kawecki, 2003), and alternative cognitive strategies for dealing with specific challenges may exist (White et al, 2017). Cole et al (2012) provide an illuminating example of a complex interaction between cognition and reproductive success.…”

“…White and colleagues have studied the cognitive processes that female cowbirds use when prospecting for nests in aviaries (Davies & White, 2018;White, 2019;White et al, 2007aWhite et al, , b, 2009White et al, 2017). This work has revealed that females are extremely adept at finding nests, and once found, select among nests based on size, pattern, and the number of eggs present.…”