NWT Barren-ground Caribou (Rangifer taradus groenlandicus)
Barren Ground Caribou Management Strategy for the NWT 2011 - 2015
Description:
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Barren-ground caribou adult males stand about 110 cm high at the shoulder. They weigh up to 140 kg in the fall when they are in their prime, and drop down to about 100 kg in November after a month of mating activity.
Caribou have long legs that end in large, broad, sharp-edged hooves. This helps them dig craters through ice and snow to feed during the winter months. Their hooves also provide good support and traction when traveling over snow, ice or muskeg. In winter, the fleshy pads between their hooves shrink and the hair between their toes forms tufts that cover the pads to protect them from touching the frozen ground. Caribou are one of the few mammals adapted to feed and digest lichens. They are also the only species in which both males and females grow antlers. |
Distribution
In the NWT, barren-ground caribou range over the taiga forests and tundra of the mainland. They have the widest distribution and are by far the most abundant subspecies of caribou in the NWT. There are several distinct barren-ground caribou herds in the NWT:
Tuktoyaktuk Peninsula herd
Cape Bathurst herd
Porcupine
Bluenose-West herd
Bluenose-East herd
Bathurst herd
Beverly - Ahiak herd
Qamanirjuaq herd
In March and April, barren-ground caribou begin to migrate from their southerly used areas northwards. Individuals band together, each small group joining another, until long lines of caribou are moving steadily to their calving grounds, which may be as far as 700 km away. Calving grounds are often located in high, rocky areas, where there is little shelter from wind and driving snow. If the spring snow melt is late and plants have not yet begun to grow, cows can feed on lichens on the rocky slopes. If spring arrives early or on time, cows can fee on cotton-grass flower buds and green sedge leaves.
Pregnant cows lead the way and their urgency to reach traditional calving grounds. Even if calves are born along the way, they may be left behind as the cows continue on with the herd. Bulls and immature caribou lag behind the cows and do not go all the way to the calving grounds. They slowly graze their way northward following the retreating snow line, eating the nutritious new leaves sprouting on the sedges and willows, and wait for the cows to return with the new calves.
When calving is over, cows and calves slowly begin their long trek back toward the winter range. The cows meet up with the bulls that have continued to drift north. In an attempt to reduce the intense disturbance caused by mosquitores, warble flies and nose-bot flies, caribou form dense groups or "post-calving aggregations" that can number in the tens of thousands.
Barren-ground caribou cows return to the same general area to calve each year and the herds are named after those calving areas. Only since the 1990s has research started to show that barren-ground caribou can be grouped into discrete herds that calve in different calving grounds.
Management
The number of animals in a caribou herd naturally fluctuates over time. This interval or cycle lasts about 30 years for some herds, but may be longer for other herds. The goal of caribou management is to manage human activities so we do not cause herds to decline to the point where people do not have enough caribou, or the herds are unable to recover from natural declines.
Management of barren-ground caribou in the NWT is a collaborative process with governments, co-management boards, Aboriginal governments and organizations, and communities located on the ranges of herds working together. While some NWT barren-ground caribou herds are shared with neighbouring jurisdictions, co-management processes that have been established under land claim agreements in the Inuvialuit, Gwich'in, Sahtu and Tlicho settlement areas provide direction and advice to governments on management of caribou and their habitat using traditional and scientific knowledge. These boards are: Wildlife Management Advisory Council (NWT) (WMAC NWT) (Inuvialuit); Gwich'in Renewable Resources Board (GRRB) (Gwich'in); Sahtu Renewable Resources Board (SRRB) (Sahtu); and Wek'eezhii Renewable Resources Board (WRRB) (Tlicho). In addition, three caribou management boards have been established through inter-jurisdictional agreements. The Porcupine Caribou Management Board (PCMB), the International Porcupine Caribou Board (IPCB) and the Beverly and Qamanirjuaq Caribou Management Board (BQCMB).
Knowledge of caribou numbers is important for management, but exact counts are neither possible nor necessary. Estimates of the number of pregnant cows on the calving ground can be used to tell whether a herd is stable, declining or increasing. However, calving ground estimates provide only an approximation of the total herd size because bulls do not migrate onto the calving grounds. Other surveys use aerial photography either during or after calving to estimate herd size.
Caribou declines were generally widespread in the NWT in the early 2000s. The Cape Bathurst and Bluenose-West herds have been stable since 2006, in large part due to harvest management actions and better calf recruitment. Results from the 2010 surveys indicate the Pocupine and Bluenose-East herds have increased, while the Bathurst herd may have stabilized, in part due to harvest management actions and improved calf recruitment. However, other NWT herds (Tuktoyaktuk Peninsula, Beverly and Ahiak) have yet to recover.
A five-year barren-ground caribou management strategy (2006-2010) resulted in an increased investment by the GNWT and its partners to take action to help stabilize declining herds, and intensify the collection of information needed to make wise management decisions.
Actions are still needed to support the recovery of all barren-ground caribou herds to levels that benefit all residents. A 2011-2015 NWT barren-ground caribou management strategy, Caribou Forever - Our Heritage, Our Responsibility, was built from the 2006-2010 version and previous management planning initiatives recommended by co-management partners, Aboriginal governments, caribou management boards and NWT communities.
To ensure barren-ground caribou remain to sustain present and future generations, the 2011-2015 strategy focuses on:
- Engaging partners;
- Ensuring appropriate information is available for management decisions;
- Managing impacts of key factors on caribou herds;
- Informing the public about their role; and
- Maximizing benefits.
Continued advice and direction from co-management partners and Aboriginal governments are critical in defining specific actions needed for each herd.
Everyone has a role to play in the management of barren-ground caribou.
About Caribou Collaring
Since 1996, movements of barren-ground caribou cows have been tracked using satellite collars. Cows are collared during the winter and their movements are tracked by satellite throughout the year. The collars help us study seasonal range distribution, measure annual variations in rut and calving locations, and determine spring and fall migration routes.
How the cows are collared
Biologists use a helicopter to locate caribou as they migrate onto the tundra. Once a group of caribou is located, a net is fired from the helicopter to capture one of the animals.
Within seven minutes of capture, the caribou is collared and released back into the herd. The caribous eyes are covered during the collaring to help reduce stress during handling. This procedure requires no drugs and places the animal in very little danger.
Each collar is programmed to fall off the animal at a specified time. Once dropped to the ground, a satellite signal is used to locate the collar so it can be reused in future studies.
How caribou are tracked
The satellite collars turn on for six hours every five days. During this time, the transmitters send signals out into the atmosphere.
Four of the many satellites circling the Earth can pick up the signals from the collars. Each of these satellites passes within range of the collar transmitter at almost the same local time each day. If a collar is turned on while the satellite is sweeping that area for transmissions, the satellite picks up the signals and relays them to ground stations for processing. Our caribou data are relayed to one of the two ground stations in the United States.
The ground stations process the signals into longitude and latitude locations by measuring the Doppler shift on the transmitter signals. The Doppler effect is the change in frequency of the signal when a source of transmission (collar) and an observer (satellite) are in motion relative to each other. The ground station then emails the data to the caribou biologist.
During the six hours the collar is turned on, many location readings may be sent to the biologist from the ground station. The biologist plots maps according to the most accurate longitude and latitude signals sent from the collar. In ideal transmitting conditions, the accuracy of the coordinates can range from within 150 meters to up to 1,000 meters from the actual location of the caribou.
Important Links:
Taking Care of Caribou - A Draft Management Plan for the Cape Bathurst, Bluenose-West and Bluenose-East Barren Ground Caribou HerdsPorcupine Caribou Management Board
Porcupine Caribou Management Board
WRRB Recommendation Report to Revised Joint Proposal on Caribou Management in Wek'eezhii
Updated: 16 April 2013