We live in a very biodiverse region. More than 120 of the species that call our region home are endangered, threatened or of conservation concern. Other species are of interest because of their interactions with humans. Metro Vancouver strives to inventory and conserve habitat for these species and develops specific management plans where appropriate.
While beavers themselves do not pose a significant problem, their work often does. They raise the level of their dam to enlarge their pond, expanding their access to a supply of trees and other resources. This can result in flooding of roads and properties outside the park boundary. Installing a pond-leveler keeps the pond below the flood point, allowing the beavers to continue living in the park, but reducing disruption to their neighbours. Also, the trees beavers cut for their food and shelter provide important habitat to other park animals. Trees in these areas are wrapped with wire or other materials to protect them and the habitat they provide.
Western Hemlock Looper
An outbreak of western hemlock looper is taking place in Metro Vancouver. Visitors to regional parks such as Capilano River, Lynn Headwaters and Belcarra may notice an abundance of little brown moths as well as damaged (brown) conifer trees. The western hemlock looper is a native species; and the outbreak is part of a natural cycle that happens every 11 to 15 years. The moths lay eggs, which hatch into larvae. Those larvae eat conifer needles – especially those of western hemlocks.
Common Questions About Western Hemlock Looper
How long will the outbreak last?
Outbreaks typically last three to four years. We are in year two of the current outbreak. How extensive and how long the outbreak lasts depends on weather and other environmental factors.
Which trees are being affected?
The western hemlock looper prefers western hemlocks, but will also eat other conifer species such as Douglas-fir, Sitka spruce and amabilis fir. Deciduous trees such as bigleaf maple and red alder, as well as other forest understory plants may also be affected when caterpillar populations are high.
Are the dead or dying trees a hazard?
Conifer trees typically take years of decay before they become weak enough to be hazardous. Trees in proximity to trails and other public areas in regional parks are monitored by certified hazard tree assessors and will be removed when there may be a hazard present.
What is the impact to forest health?
Outbreaks like these are an important component of ecosystem dynamics and essential in recharging the ecosystem. New openings in the forest allow young trees to emerge and understory vegetation to grow lush. Dead trees eventually fall down and their nutrients are recycled into the forest floor.
Is there any upside to the outbreak?
The caterpillars and moths provide food for a range of animal species that are found in regional parks. At night, bats gobble up the moths. During the day, numerous bird species feed on the moths, As well, when moths fall into streams, rivers and ponds, they are eaten by fish.
When moths fall on the ground, they’re eaten by salamanders, frogs, mice, shrews and a host of invertebrates such as centipedes and millipedes.
Also, the dead trees that result from the outbreak provide new habitat in the form of snags for wildlife such as woodpeckers, owls and flying squirrels.
Will there be an increase in wildfire risk as a result of the dead trees?
It will depend on how severe the outbreak is and how many dead trees there are. Once the outbreak is over, Metro Vancouver will assess the forested areas along the wildland urban interface (where residential areas meet the forest) to determine the risk and mitigate the risk as needed.
Metro Vancouver coordinates the delivery of a mosquito control program on behalf of the region. The current focus is on control of nuisance mosquitoes at the larval stage. Services are provided to the following participating municipalities:
- The City of Coquitlam
- The City of Maple Ridge
- The City of Pitt Meadows
- The City of Surrey
- The Township of Langley
To learn more about mosquito management, visit our service provider's website:
Morrow BioScience Ltd.
For information about this program or to report mosquito related concerns, please call the Mosquito Hotline at 604-432-6228.