Neonicotinoid detection in wild turkeys (Meleagris gallopavo silvestris) in Ontario, Canada
Neonicotinoid detection in wild turkeys (Meleagris gallopavo silvestris) in Ontario, Canada
Amanda M. MacDonald 0 1 2 3
Claire M. Jardine 0 1 2 3
Philippe J. Thomas 0 1 2 3
Nicole M. Nemeth 0 1 2 3
0 Environment and Climate Change Canada, Science and Technology Branch, National Wildlife Research Center , Ottawa, ON K1A 0H3 , Canada
1 Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph , Guelph, ON NIG 2W1 , Canada
2 Department of Pathobiology, Ontario Veterinary College, University of Guelph , Guelph, ON NIG 2W1 , Canada
3 Present address: Southeastern Cooperative Wildlife Disease Study, University of Georgia , Athens, GA 30602 , USA
The use of neonicotinoid insecticides in agriculture is now recognized for the health risks it poses to non-target wildlife, with associated honey bee mortality especially concerning. Research directed toward the presence and effects of these pesticides on terrestrial vertebrates that consume neonicotinoid-coated seeds, such as wild turkeys (Meleagris gallopavo silvestris), is lacking. This study used liquid chromatography attached to a tandem mass spectrometer to assess the liver from 40 wild turkeys for neonicotinoid and other pesticide residues and compared detected levels of these contaminants across the southern Ontario, Canada. Nine (22.5%) wild turkeys had detectible levels of neonicotinoid residues-clothianidin in eight, and thiamethoxam in three. Two (5.0%) of these turkeys had detectable levels of both clothianidin and thiamethoxam. Fuberidazole was detected in two (5.0%) wild turkeys. The highest level of thiamethoxam detected was 0.16 ppm, while clothianidin was detected at 0.12 ppm, and fuberidazole at 0.0094 ppm. Knowledge of exposure in free-ranging wildlife is critical for better understanding the effects of neonicotinoids on wildlife health; thus, these data help establish baseline data for southern Ontario wild turkeys and provide context for reference values in future analyses.
Bioaccumulation; Birds; Insecticides; Neonicotinoids; Non-target species; Pesticides; Treated seeds; Wild Turkey
Introduction
Neonicotinoid insecticides (NNIs) have become the most
widely used insecticides in the world
(Schaafsma et al.
2015)
. Commonly used in agriculture, they are applied as
various formulations including as foliage sprays, seed coating,
and soil treatments. Of NNIs used globally, including those
Responsible editor: Philippe Garrigues
*
used on many large-acreage crops in southern Ontario (e.g.,
corn, soy, grains, dry beans, and canola), 60% are utilized as
seed coatings
(Jeschke et al. 2011; OMNRF 2017)
. NNIs are
systemic insecticides, taken up by the plant following
application and distributed systemically through plant tissues as it
grows. They act by affecting the central nervous system of
insects, causing over-excitation of nerve synapses, followed
by paralysis and eventually death (Fishel 2013). Recently,
these insecticides have been recognized for the risks they pose
to non-target wildlife, including as a potential factor driving
colony collapse disorder in honey bees
(Farooqui 2013)
.
However, little attention has been paid to higher trophic biota,
including terrestrial vertebrates.
Wild turkeys (Meleagris gallopavo), and other avian
species such as gray partridges (Perdix perdix) and pigeons
(Columba palumbus, C. livia, and C. oenas), readily ingest
treated corn or soya seeds
(Mineau and Palmer 2013; Millot
et al. 2017)
; in fact, depending on food availability, these
resources comprise a significant portion of the wild turkey’s
diet (OMNRF 2007). These seeds can contain some of the
highest concentrations of NNIs
(Gibbons et al. 2015)
, making
them of particular concern because of their availability to birds
and the potential for repeat or ongoing exposure. A single corn
Fig. 1 Map depicting the locations and pesticide compounds detected
among 40 hunter-harvested wild turkeys collected during the 2015 spring
hunt (April–May) in Ontario, Canada
kernel is typically treated with approximately 1 mg of active
ingredient
(Rexrode et al. 2003)
and consumption of just one
imidacloprid-treated corn seed, or a few clothianidin- or
thiamethoxam-treated seeds, could be lethally toxic to a bird
the size of a blue jay
(Mineau and Palmer 2013)
. The
persistence of NNIs in the environment as well as their potential
illeffects on non-target species remains unclear. Recently, there
has been a great deal of public and political controversy and
media coverage regarding the use and associated risks of NNIs
to honey bee health and mortality. There has also been
growing concern among natural resource managers,
conservationists, and hunters about whether NNI use may be linked to poor
reproductive output of wild turkeys and potential
bioaccumulation of NNIs in wild turkey meat intended for human
consumption.
The present study was conducted to address knowledge
gaps and the concerns described above. Samples originated
from hea (...truncated)