Studies were conducted to document that European starlings consume Russian olive fruits and determine subsequent effects on seed germination. In the first study, avian feeding patterns at Russian olive trees were monitored over a 1-yr period using motion activated digital photography. Starlings fed on Russian olive fruits with highest activity occurring in November and December. In a second study, 20 captive European starlings were fed Russian olive fruits and seed germination rates were determined for three categories: consumed by starlings, hulled fruits (pericarp removed), and whole fruits. Starlings readily consumed Russian olive fruits and most seeds were regurgitated 30 min after consumption. Germination rates of ingested/regurgitated seeds (57%) and pericarp-removed seeds (40%) were greater than whole fruits (0%). Viability tests confirmed that 85% of starling ingested seeds remained viable after consumption. Our data suggest that Russian olive dispersal may be dependent upon animals for effective spread.
