An inconsistent relationship between mouse traits and acorn dispersal

Paulina Celebias, Aleksandra Wróbel, Milena Zduniak, Michael Steele, Michał Bogdziewicz, Rafał Zwolak

This is a plain language summary of Functional Ecology research article which can be found here.

Plants often depend on animals to spread their seeds, and the unique traits of each animal can greatly affect how well plants reproduce. We studied how certain traits (like being male or female, body mass, and the tendency to explore surroundings during behavioral tests) of yellow-necked mice affected how acorns from oak trees were dispersed. We collected data for three years on which mice were moving acorns, and what happened to these seeds. We found that the connection between each mouse’s traits and how they disperse the seeds was not constant, but changed from year to year. For example, larger mice tended to carry seeds farther away, but this was not found every year. Also, how much they explored during tests did not consistently affect how many seeds they ate or how far they carried them; these relationships changed from year to year. However, exploration did help them spread the seeds farther from the nearest tree.

A yellow-necked mouse during an open-field test (Credit: Paulina Celebias)

Our findings show that each mouse’s role in seed dispersal can vary significantly over time. This means that there is not just one type of mouse that is always best in seed dispersal. Instead, what makes a mouse effective at seed dispersal can change over time, depending on the environment.