What the pluck? The theft of mammal hair by birds is an overlooked but common behavior with fitness implications

Cleaning Interactions Between Crows and Sika Deer: Implications for Tick-Borne Disease Management

Cleaning interactions between mammals and birds have been widely observed worldwide. Here, we report cleaning interactions between sika deer and crows in Japan, based on a field observations using camera traps and online research. Online research was performed on social media platforms such as X (formerly Twitter), YouTube, and personal blogs. We finally collected 27 cases of cleaning associations between sika deer and crows. Crows associated with male more than female deer and mainly pecked their heads or necks, suggesting that crows remove Ixodid ticks from the deer's surface. Given that ticks on sika deer are vectors of several zoonotic pathogens such as Rickettsia and Borrelia spp., further studies should be conducted to examine the roles of crows as biocontrol agents of ticks and tick-borne diseases.

Tits (Paridae sp.) use social information when locating and choosing nest lining material

Abstract 

As an important determinant of reproductive success, avian nest building is under strong selection and requires behavioral plasticity to optimize conditions in which offspring develop. Learning is a one form of plasticity that allows adaptation to the local environment. Birds may refine nest-building behavior with personal experience or use social information to guide their choices. While there is mounting evidence for an effect of experience-based learning on nest building and social information use when selecting nesting material in the laboratory, experimental evidence for social information use in wild birds is lacking. Here, we provided sources of two differently colored wool as nest lining material in a wild mixed-species community of tits (Paridae sp.) to investigate experimentally (i) whether females use social information to locate lining materials and (ii) whether preferences for specific materials (here color) are socially influenced. We investigated pathways of social transmission through a foraging association and a spatial breeding network using the time of arrival at the wool in a network-based diffusion analysis. Our results gave evidence that birds learned about the location of lining resources from foraging associates. Furthermore, we found significant non-random clustering of wool colors in nest boxes across the study area, suggestive of a social influence on selecting lining materials. Taken together, we provide quantitative evidence for a role of social information use in both finding and selecting lining material in wild tits and demonstrate that social information use constitutes an important factor towards behavioral plasticity in nest building in wild birds.

Significance statement

As vessels of reproduction, avian nests are under strong selection to provide optimized conditions for developing offspring. Learning is one mechanism that allows individuals to adapt to local environmental conditions. Previous work has shown that nest-building birds use both social information and personal experience to refine their nests. Yet, evidence for social information use for nest construction in the wild has been purely anecdotal and experimental evidence lacking. Here, we demonstrate for the first time experimentally that in wild tits (Paridae sp.), females rely on social information from their foraging associates to locate and choose material to line their nests. This research highlights the importance of social information use as a potential mechanism of behavioral plasticity in wild nest-building birds.

The psychology of natural history

Natural history observations are an integral part of ecology and evolution. However, they can be underappreciated because they operate independent of the scientific method. Here, we illustrate that the science of natural history has its own methodology based on a well-known psychological paradigm that describes how the human mind learns.