Our newest paper just became available in one of my favorite journals, The American Naturalist. Using data from over 1,000 oaks across California, we investigated the predictions of the Terminal Investment Hypothesis, which suggests that organisms should invest disproportionally into reproduction preceding their death. Using annual acorn counts and growth rates of trees, we found no changes in the absolute or relative investments in seed production in California oaks over the last 6 years before their natural death. This is the first study to address this important life-history strategy in long-lived plants.
Read it here: http://www.journals.uchicago.edu/doi/abs/10.1086/691161
In this study, Walt Koenig and I show that avian hoarders - birds that store their seeds for the winter - play an important role in mediating competition among oak species. California scrub-jays (Aphelocoma californica), high-quality seed dispersers of acorns, show up in large numbers on valley oaks (Quercus lobata) when no other acorns are available in the landscape. For the oaks, this means that a majority of their acorns is at least given a chance because jays cache their acorns in the ground. Whenever possible, however, the jays avoid valley oaks because acorn woodpeckers (Melanerpes formicivorus) defend them vigorously and thus attack the foraging jays. Therefore, the seed production by oaks that compete with valley oaks, in this case California blue oaks (Q. douglasii) results in increased predation of acorns by acorn woodpeckers - birds that store their acorns in so-called granary trees which provide no chance for germination or seedling establishment. All together, the blue oaks are thus indirectly competing with valley oaks, a phenomenon termed apparent predation, via the jays and the woodpeckers.
Find the early access version of the article here:
The last of my Ph.D. papers has just been published in the journal Current Zoology. We show that island scrub-jays have strong spatial (habitat) preferences when caching acorns. Because they cache a majority of acorns in areas of oak recruitment - identified by seedling counts - we argue that the jays have contributed to the rapid passive restoration of Santa Cruz Island.
Read the paper here [link]
Kathleen Wong, the communication specialist for the University of California's Natural Reserve System interviewed me about the role of jays in reforesting Santa Cruz Island after the removal of sheep and pigs.
I was asked to write a blog post for the BOU Blog. They regularly invite authors to provide lay summaries of their work for a broad audience to read. Here is what I wrote:
The unique science blog, The Last Word on Nothing, featured a wonderful piece penned by the writer Sarah Gilman which summarizes our review paper on the role of corvid seed dispersal in tree population dynamics. Sarah also created two wonderful illustrations that capture aspects of the paper in vivid color.
Check it out here:
The official travel blog of Natural Habitat Adventures/WWF with a nice summary of the utility of corvid seed dispersal to habitat restoration.
Check it out here:
Our new paper in the Journal of Animal Ecology: Context-dependent seed dispersal by a scatter-hoarding corvid.
Here is the third paper from my dissertation work, which is probably my favorite. Using more than 200 hours of observation, and with more than 800 caching observations, we show that seed dispersal rates and distances vary with acorn crop, and dispersal rates with territorial aggression. This has major implications for the role of masting behavior by trees, that affects seed dispersal directly, but also indirectly via social interactions that ultimately depend on population density which is driven by acorn crop.
Check the article out here:
Our new paper in the Journal of Ecology: Individual and population-wide drivers of seed production in valley oaks
Exciting news! Our article that dissects the seed production behavior of valley oaks and describes how individual resource-limitation could interact with population-wide pollen limitation to drive masting has just been published in the well-respected Journal of Ecology.
Find out more here: