Some arctic terrestrial arthropods such
as insects and spiders have been identified as irreplaceable
plant pollinators, important soil fertilizers and significant
elements of the Arctic food web. However, in the Canadian
Arctic tundra, very little is known on most arthropod communities,
their ecological roles, and their potential response to
global warming. Arthropods are known to be highly responsive
to temperature and their growth and reproduction are limited
to a very narrow window of favorable climatic conditions
in the Arctic. This generates a short-lived peak in abundance
and activity over the summer.
On Bylot Island, many species of insectivorous birds depend on
arthropods to survive and breed successfully. It is critical and
challenging for these birds to synchronize their hatch dates with
the narrow peak in arthropod availability, which occurs in mid-summer.
Climate changes will very likely affect the timing and magnitude
of this peak. Potential effects of these changes on arctic insectivore
populations are unknown and we are currently trying to document
the adaptability of insectivores to their rapidly changing breeding
environment (see shorebirds).
Since 2005, temporal and spatial variation in arthropod abundance
is monitored in order to acquire information on factors affecting
their populations and to better understand their interactions
with insectivorous birds.
Traps specially designed to capture ground dwelling arthropods
and low flying insects are used to track arthropod communities
in mesic and wetland habitats.
From 2005 to 2007, many spiders and mites were collected along
with representatives of 33 families of insects. The insects collected
were mostly flies, some sawflies and a few beetles. For a complete
list of arthropods present on Bylot Island, take a look at our
Peak of Arthropod Activity
Arthropod abundance peaked at similar dates in 2005 (14 July)
and 2006 (12 July). Mean daily temperature clearly had an effect
on the number of arthropods collected over the summer.