Spatiotemporal variation of a Pinus seed rain available for an endemic finch in an insular environment

Abstract

A major goal of avian ecological research is to determine how distribution and abundance of preferred resources available influence population dynamics and contribute to understand life-history characteristics. Food is widely considered the ultimate factor influencing these traits. We studied, with seed traps, the spatiotemporal variability of Pinus canariensis seed rain during 2007-2008, as a means to explain why a post-dispersal seed predator of conservation concern, the endemic blue chaffinch Fringilla teydea, can adjust its annual life cycle with this variation in an insular environment. Generalized linear mixed models and geostatistical tools were used. Results highlight that temperature and relative humidity are important predictors of seed release rates. Additionally, a high temporal variation was detected in seed abundance (i.e., peaks of massive seed release during the summer months, intermediate values in the autumn, and minimum release rates in winter and spring). Finally, withinstand spatial variation in seed flux was surprisingly large with the most productive microsites receiving three to four times more seeds than the least productive ones. Pine seeds showed a high protein value and a low germination rate.Based on these findings, we suggest that the fortunes of the blue chaffinch should be intimately related to spatiotemporal annual P. canariensis seed crops, temperature acting as a proximate cue, and food availability as the ultimate factor. For the endangered blue chaffinch population on Gran Canaria, we recommend, until more data are available, improving the seed supply during the winter season, either artificially (feeders) or naturally (planting Myrica faya shrubs).

Reproductive modification in forest plantations: impacts on biodiversity and society

“…Vander Wall, ). This includes several species of conservation concern including the Tenerife Blue Chaffinch ( Fringilla teydea ), a species endemic to Spain that primarily eats Pinus sylvestris seeds (Garcia‐del‐Rey et al ., ). Similarly, the Maroon‐fronted Parrot ( Rhynchopsitta terrisi ) and Thick‐billed Parrot ( Rhynchopsitta pachyrhyncha ) are spermivores native to the southwest USA and Mexico that feed primarily on seeds from pines such as Pinus ponderosa , P. menziesii , Pinus engelmanii and Pinus arizonica (Snyder et al ., ).…”

High seed dispersal ability of Pinus canariensis in stands of contrasting density inferred from genotypic data

“…A previous study conducted in site 1, evaluating the seed rain along one year (García-del-Rey et al, 2011) showed a remarkable variation in seed deposition between the upper and the lower parts of the plot. However, all seed-traps received more than 25 seeds m -2…”

Optimal Selection of Seed-Trees Using the Multi-Objective NSGA-II Algorithm and a Seed Dispersal Model

“…We utilized an existing dataset obtained from a mature, even-aged stand of Canary Islands pine located on the island of Tenerife (refer to [38,39] for details). The climate in this region is Mediterranean, characterized by an average annual temperature of 12.6 • C and annual precipitation levels ranging from 460 to 930 mm [40].…”