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Contents: Calving Update 2008 Meet our newest caribou How many of the satellite collared cows had calves? Download the memorandum by Jason Caikoski of the Alaska Department of Fish and
Game
During the winter of 2007–2008, seventy-three percent of satellite collared caribou (n = 15) wintered in the southern foothills of the Brooks Range between the Coleen the Junjik Rivers, Alaska, from mid October through February. Caribou were concentrated around Arctic Village between the Sheenjek and East Fork Chandalar River. Four of 15 satellite collared caribou wintered in the Ogilvie Basin, Upper Miner and Upper Whitestone River drainages in central Yukon from mid October through March.
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The annual calving survey was conducted using an ADF&G chartered Piper Super Cub on 1, 2, and 3 June 2008. Arctic National Wildlife Refuge (ANWR) staff conducted additional radio tracking flights on 28 and 30 May and 2 June to determine radiocollar distribution for the calving survey. Seventy-six radiocollared cows ages 2 years and older were observed during flights on 1-3 June. Parturition rate (percent of cows that were pregnant or had given birth) was 79% for cows 4 years of age or older (n = 63) and is slightly below average.. On 1 and 2 June, 64% (n = 25) and 57% (n = 28) of parturient cows were observed with calves, respectively. Most calves appeared to be 1-2 days old based on size and mobility. Thus, the peak of calving was probably on the 29 or 30 May, which is slightly earlier than normal. |
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During the 1-3 June calving flights, 25 radiocollared cows were located in ANWR, Alaska, and 51 were located in Ivvavik National Park, Yukon. No radiocollared cows were located in the 1002 area. Extent of calving occurred from the Aichilik River to the Babbage River and was concentrated around the Clarence River
Post-calving flights were conducted on 23, 24, and 25 June to estimate calf survival and the proportion of cows accompanied by calves (Figure 2). At this time, 64 radiocollared cows were observed including 61 of 76 cows observed in early June. Strong wind turbulence in the mountains prevented late June observations of 15 cows that were observed with calves (n = 6) or were judged to be pregnant (n = 5) or barren (n = 4) in early June. Post calving survival, estimated from cows observed with calves in early June whose dams were observed in late June was 92% which is above average. The late June calf : cow ratio was 59 % which is slightly below average. |
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From the 23 to 25 June, most of the herd was distributed between the Kongukut and Hulahula Rivers, Alaska, at elevations from 2500-5000 feet. Radiocollared cows were among loosely aggregated groups except for a considerable concentration observed in the Okpilak River drainage that contained 58% of located radiocollars. Two of fifteen satellite collared cows and 15% of radiocollared cows were located in the Firth drainage near Mountain Creek, Yukon. Fifteen of 20 radiocollared bulls were also located and most were in the Jago River drainage (not depicted in figure 2) and segregated from cows. Two bulls were transmitting a mortality signal; one in the upper Egaksrak River and one in the upper East Fork Chandalar River.
Cool weather in the mountains and an apparent lack of insects prevented adequate aggregations for a photocensus. We continued to monitor the PCH with satellite collars for two weeks following post calving flights. By late June and early July, most of the herd moved south across the Continental Divide and into the upper Sheenjek River drainage. Three attempts were made to radiotrack and monitor the status for a photocensus on the south side of the Brooks Range. However, thunderstorms and a low cloud ceiling prevented flights. The next attempt at a photocensus will be after calving in 2009. This past year there have been two new Porcupine Caribou that have been added to the Satellite program. As mentioned in the April 2008 update, a new satellite collar was deployed on a caribou cow wintering near Arctic Village in March. While we were trying to decide who should name this caribou, a 6-year old girl from a school in England wrote to tell us that she had been reading a book about caribou which she really enjoyed. She had found this website and was hoping that her class could name a new caribou. This seemed like a splendid idea! Her class thought long and hard on a suitable name, before deciding to call the caribou Margaret after the name of their school which is St. Margaret's Preparatory School. We are all pleased to see that "Margaret" had a calf this year! The second caribou which was added to the program had been followed for a number of years already. In March 2002, a Porcupine Caribou cow was captured where she was wintering in the Ogilvie Basin and fitted with a conventional radio collar. Between 2002 and June of 2007 this caribou was relocated at various times of the year with the Porcupine Caribou Herd. During the late summer flight of 2007, she was not heard, and was missing throughout the fall, winter and spring of 2007 - 2008. In early June, this caribou was finally relocated amongst many other Central Arctic caribou on their calving grounds. This is not a new phenomenon - we have had other radio collared caribou that have "switched" herds in the past. It was decided that she should be fitted with a satellite collar so that we can monitor her movements more closely, and see if she remains with the Central Arctic Caribou Herd or returns to the Porcupine Herd. On July 2nd, she was recaptured and a satellite collar was deployed. Considering that this caribou appears to be a bit of a wanderer, it was decided that she would be named "Tramp". For more information on the history of the caribou involved in this program, click here. Use your browser BACK button to return to this page. How many of the satellite collared cows had calves? Fourteen caribou cows were monitored by satellite tracking at 2-day intervals between May 17 and July 8. One additional satellite collar was deployed July 2. The table below summarizes calving success of the satellite collared caribou.
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Below is a summary of all caribou and information on whether or not they calved the past 11 years.
Note: -- means that the caribou was not located
If you have any questions, please contact:
Dorothy Cooley or Martin Kienzler
Regional Management
Box 600
Dawson City, YT
Y0B 1G0
Phone (867) 993 6461
Fax (867) 993 6548
Email dorothy.cooley@gov.yk.ca or
martin.kienzler@gov.yk.ca
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