TY - JOUR
T1 - Effects of an introduced, novel prey on diet and reproduction in the diet-specialist european starling (Sturnus vulgaris)
AU - Williams, T. D.
AU - Cornell, A.
AU - Gillespie, C.
AU - Hura, A.
AU - Serota, M.
N1 - Funding Information:
We thank D. Davis and the whole Davis Family for their continued support for our European Starling work on the Davistead Farm in Langley, British Columbia, Canada. This work was funded by Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery (155395-2012) and Accelerator (429387-2012) grants to T.D.W. and an NSERC Undergraduate Research Award to C.G.
PY - 2019
Y1 - 2019
N2 - Diet specialization has important consequences for how individuals or species deal with environmental change that causes changes in availability of prey species. We took advantage of a “natural experiment” — establishment of a commercial insect farm — that introduced a novel prey item, black soldier flies (Hermetia illucens (Linnaeus, 1758)), to the diet-specialist European Starling (Sturnus vulgaris Linnaeus, 1758). We investigated evidence for individual diet specialization (IDS) and the consequences of diet specialization and exploitation of novel prey on breeding productivity. In all 4 years of our study, tipulid larvae were the most common prey item. Soldier flies were not recorded in diets in 2013–2014; however, coincident with the establishment of the commercial insect farming operation, they comprised 22% and 30% of all prey items in the diets of European Starling females and males, respectively, in 2015. There was marked individual variation in use of soldier flies (4%–48% and 2%–70% in females and males, respectively), but we found little evidence of dichotomous IDS, i.e., where only some individuals have a specialized diet. We found no evidence for negative effects of use of soldier flies on breeding productivity: brood size at fledging and chick quality (mass, tarsus length) were independent of the number and proportion (%) of soldier flies returned to the nest.
AB - Diet specialization has important consequences for how individuals or species deal with environmental change that causes changes in availability of prey species. We took advantage of a “natural experiment” — establishment of a commercial insect farm — that introduced a novel prey item, black soldier flies (Hermetia illucens (Linnaeus, 1758)), to the diet-specialist European Starling (Sturnus vulgaris Linnaeus, 1758). We investigated evidence for individual diet specialization (IDS) and the consequences of diet specialization and exploitation of novel prey on breeding productivity. In all 4 years of our study, tipulid larvae were the most common prey item. Soldier flies were not recorded in diets in 2013–2014; however, coincident with the establishment of the commercial insect farming operation, they comprised 22% and 30% of all prey items in the diets of European Starling females and males, respectively, in 2015. There was marked individual variation in use of soldier flies (4%–48% and 2%–70% in females and males, respectively), but we found little evidence of dichotomous IDS, i.e., where only some individuals have a specialized diet. We found no evidence for negative effects of use of soldier flies on breeding productivity: brood size at fledging and chick quality (mass, tarsus length) were independent of the number and proportion (%) of soldier flies returned to the nest.
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U2 - 10.1139/cjz-2018-0168
DO - 10.1139/cjz-2018-0168
M3 - Article
AN - SCOPUS:85062978398
VL - 97
SP - 225
EP - 231
JO - Canadian Journal of Zoology
JF - Canadian Journal of Zoology
SN - 0008-4301
IS - 3
ER -