Posted by: Mark Andrew Conboy and Frank Phelan
Wild turkey (Meleagris gallopavo) is one of the largest and most spectacular birds at QUBS. It is also a relative newcomer to the region. Numerous releases by the Ministry of Natural Resources (since the 1960’s but mainly since the mid 1980’s) of wild turkeys throughout Eastern Ontario have resulted in the establishment of a substantial breeding population (Weir 2008). Turkeys are now a common sight at QUBS throughout the year. We report on the diet of three wild turkeys (2 adult males and 1 juvenile) collected at QUBS in October 2010 (Table 1).
The two adults were harvested by hunters near the Dowsley Ponds and the juvenile was hit by a car on the QUBS driveway. Although the sample size is too small to draw broad conclusions about wild turkey diets, analysis of crops shows that in at least this case there is a marked difference in diet between age classes.
We decided to measure the different food stuffs by dry weight. All crop contents were dried for 5 days at room temperature then weighed using a Mettler AE100 electronic balance.
For all three turkeys the main food source by dry mass was vegetable materials, particularly forest mast. The adults ate oak (Quercus sp.) acorns. All four of our oak species germinate in the autumn and most of the acorns contained in the turkey crops had already sprouted. It is unclear whether turkeys actively select sprouted acorns over those that have not sprouted. Presumably sprouted acorns are more nutrient-rich than acorns that have not sprouted. The juvenile crop contained hickory (Carya sp.) nuts but no acorns. It is unclear why the adults should choose acorns and juveniles choose hickory nuts with no overlap. Perhaps there are nutritional differences, digestion requirements or other age-related factors that influence nut selection. This is especially interesting because Northern Red (Q. rubra) and Common White (Q. alba) Oaks produced vast amounts of acorns this autumn, making them an easily obtainable food source, especially for juveniles which presumably have less success in foraging than experienced adults.
In adults Lepidoptera pupae also feature prominently in the diet. We were unable to positively identify the pupae to species but they closely resemble the all black and smooth case of Hickory Tussock Moth (Lophocampa caryae), which was very common in the summer of 2010. Acorns and pupae together comprise 99.38% and 98.32% percent of crop contents for the two adults respectively. There were no pupae in the crops of the juvenile; again another presumably easily obtained food source not taken advantage of by the juvenile.
There were many other differences in the juvenile’s crop contents compared to that of the adults. After hickory nuts, the next most important item in the juvenile’s diet was sedge (Carex sp.) seeds followed by Orthoptera. There was a wide diversity of orthopteran species in the juvenile’s crop including 11 Northern Green-striped Grasshoppers (Chortophaga viridifasciata), 7 ground crickets (Allonemobius sp.), 4 Grizzly Grasshoppers (Melanoplus punctulatus), 3 Northern Mottled Grasshoppers (Spharagemon marmorata), and 1 Fall Field Cricket (Gryllus pennsylvanicus). Nuts, insects and probably to some extent sedge seeds provide protein to growing juvenile turkeys. But insects and other invertebrates probably contribute amino acids or other important nutritional components to the diet that are unavailable in mast and seeds alone. It’s known that snail shells are an important source of calcium for egg laying hen turkeys (Eaton 1992).
Unlike many of our smaller birds, wild turkeys afford us the opportunity to examine their crop contents because they are collected by hunters and as road kill every year. As we collect more crops we’ll compile a larger database of wild turkey foods that may someday be useful for tracking seasonal and long term changes in diet. The dried crop contents described here are housed in the QUBS natural history collection.
Posted by Mark Andrew Conboy and Frank Phelan
- Eaton, S.W. 1992. Wild Turkey (Meleagris gallopavo), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.
- Weir, R.D. 2008. Birds of the Kingston Region 2nd edition, Quarry Press, Kingston.