Seed-caching responses to substrate and rock cover by two Peromyscus species: implications for pinyon pine establishment

Abstract

We examined whether pinyon mice ( Peromyscus truei) and brush mice ( P. boylii) could act as directed dispersal agents of pinyon pine ( Pinus edulis) through differential responses to soil particle size and rock cover. In field experiments, we allowed mice to either cache pinyon seeds or recover artificially cached seeds (pilfer) from quadrats containing large- or small-particle soils. Both species placed most (70%) seed caches in small-particle soil. Pilfering was the same from both particle sizes in the first year, while more seeds were pilfered from large-particle soils in the second year. In separate experiments, rock cover interacted with soil particle size, with both species placing over 50% of their caches in small-particle soil with rock cover. Overall, we found greater seed-caching in small-particle soils near rocks, with equal or lower pilfering from small-particle soils, suggesting more seeds would survive in small-particle soils near rock cover. Three lines of evidence supported the hypothesis that mice could act as directed dispersers by moving pinyon seeds to beneficial microsites for germination and establishment. First, in greenhouse experiments, pinyon seed germination was 4 times greater in small-particle soil cores than in large-particle soil cores. Second, soils near rocks had significantly higher water content than areas of open soil at the driest time of the year, a critical factor for seedling survival in the arid southwestern USA. Third, 75% of juvenile pinyon trees were growing in small-particle soils, and 45% were growing near rock nurses.

Seed predation by rodents results in directed dispersal of viable seed fragments of an endangered desert shrub

“…Partial consumption of seeds may have important consequences on plant community structure and population dynamics in several systems (e.g., Pearson and Theimer 2004, Perea et al 2010, Shiels and Drake 2011. Our results show that rodents play a dual role in the recruitment dynamics of M. coquimbensis, acting simultaneously as seed predators and effective dispersers of predated seeds.…”

Noise pollution alters ecological services: enhanced pollination and disrupted seed dispersal

“…Peromyscus mice consume a large proportion (approx. 40%) of encountered seeds and typically cache many encountered seeds that are not immediately consumed [44]. Yet, cached seeds are often recovered and eaten (greater than 80%) along with seeds cached by other individuals or species [29].…”

Dispersal patterns of Quercus serrata acorns by wood mice in and around canopy gaps in a temperate forest

“…Directed dispersal has been ascribed to seed dispersal by animals (Howe and Smallwood, 1982), particularly ants (Hanzawa et al, 1988) and birds (Johnson and Webb, 1989;Wenny and Levy, 1998). Several studies suggest the possibility of directed dispersal by mammals (Kiltie, 1981;Stapanian and Smith, 1986;Tutin et al, 1991;Vander Wall, 1993), however, information about the directed dispersal by wood mice is still limited (Hoshizaki et al, 1999;Pearson and Theimer, 2004).…”