Lecture 20 – Fallow Fields (Meadow Voles + Predators) & Alvars
Snow Geese & Rosses Goose & Canada Geese: use flooded fields (like Tundra for them) for
feeding (stop overs while migrating).
Fallow Fields: fields let go wild become fallow fields. Meadow Voles really benefit from this
habitat. They have short tails (good habitat for when in the Tundra zone). They can breed at
the age of 23days (large population expansion at a fast rate). Red Foxes and Coyotes hunt in
these fallow fields (eating Meadow Voles) – thus benefiting from them. Northern Shrike also
eats Meadow Voles (raptorial bill and songbird feet). They are only present in late fall and
winter in our area. Long tailed and short tailed weasels also eat them.
--Coyotes only appeared in Ontario around 1900 (came in through Lake of the Woods &
Southern Ontario) - spreading. They were once called brush wolves, and were heavily
persecuted. When they came in Ontario they hybridized with wolves (they were separated
by a habitat barrier). It’s hard to tell Eastern Wolves from Coyotes as they hybridized in the
past (slight difference in snout broadness and ear length – Coyotes have thinner snouts and
taller ears). Coyotes are not mammals of big forests (would not be found in Algonquin Park)
– they thrive in broken habitat.
Other Predators of Meadow Voles:
In these older fields with seeds available for food for meadow voles, the meadow voles
attract and provide a food source for a large array of predators. Meadow voles are arguably
the most important small mammal in Ontario in terms of being a prey species.
Red-tailed Hawk: strong feet – talons, they will hunt in filed for Meadow Voles.
American Kestrel: often seen on telephone wires over fields will eat meadow voles
and frogs. They are a falcon; falcons are more closely related to parrots then to
Northern Harrier: have facial disks on the face for gathering sound like in owls. They
fly low over the fields.
Short-eared Owls: a ground nesting owl and they feed and nest in fallow fields. In
years with many meadow voles populations of these owls increase (more nests and
offspring per year).
Snowy Owls: also benefit from meadow voles as a food source. They nest in Tundra
zone. In migration (forced south due to lack of food) they will exploit meadow voles
in these fallow fields. The habitat change (clearing of forests) benefits owls and
other predators as this food source is only available due to logging and agriculture.
Younger birds and females have a darker coloration. Even the smallest owls
(Northern Saw Whet Owls) benefit from meadow voles too.
Great Gray Owl: they nest in the Boreal forest, Great Grey Owls usually only occur
here only during irruptions (large numbers of owls coming in due to large food
supply). They did nest in the Ottawa area six years ago (due to the irruption of
Milk Snakes: they are nocturnal and eat meadow voles.
Fallow Field Plants
Most Fallow Field plants share certain characteristics such as;
(a) Shade intolerant -- due to continuously being exposed t