Caribou / reindeer

Photo: Carsten Egevang
Photo: Carsten Egevang
Figure 1: Locations of the 12 caribou / reindeer herds along the west coast of Greenland. Numbers 1 to 11 are wild populations, while 12 is the Isortoq semi-domestic reindeer husbandry district.
Figure 1: Locations of the 12 caribou / reindeer herds along the west coast of Greenland. Numbers 1 to 11 are wild populations, while 12 is the Isortoq semi-domestic reindeer husbandry district.

Rangifer tarandus spp.

Biology

The west and northwest coast of Greenland are home to both indigenous wild caribou and feral semi-domestic reindeer. Greenland's east coast has neither. Both the feral semi-domestic reindeer and the muskoxen are recent additions to West Greenland, 1952 and 1963-65 respectively. Caribou and reindeer are of the same genus and species, Rangifer tarandus, and are differentiated only by sub-species. Aside from some differences, e.g., physiological, behavioural and morphological, the feral reindeer are similar to their Greenland cousins.

Distribution

We recognize 12 populations of caribou / reindeer along the west coast of Greenland (Figure 1), whose boundaries correspond to hunting regions, and whose interactions are limited owing to topographical barriers. Recently Rangifer have been found re-inhabiting the Tuttulissuaq peninsula (Cape Seddon, ca. 75°N) at the southern end of Melville Bay. A special subspecies of caribou, R. t. eogroenlandicus, once inhabited the northeast coast of Greenland, however, these became extinct over 100 years ago at the end of the 1800's. A catastrophic stochastic weather event is assumed the probable cause. Semi-domestic reindeer were first introduced to Greenland in 1952. These animals came by ship from Finmark in the north of Norway, and were released deep inside the Godthåbsfjord at Itivnera near the town of Kapisillit. The Kapisillit reindeer have successfully multiplied into thousands, and today we suspect that they constitute much of the Ameralik population. Subsequently several further introductions occurred in which animals captured at Kapisillit were taken elsewhere. Status Survey data shows that caribou / reindeer abundance among the populations inhabiting West Greenland have been high for at least the past decade. Harvest data strongly suggests that caribou numbers have been high since the 1970's. Meanwhile, harvest and trade statistics since 1721 indicate that caribou numbers in West Greenland have been through at least two major population "Boom & Crash" cycles, which suggests we can expect such cycles to reoccur. Currently the Kangerlussuaq-Sisimiut (KS) herd density is ca. 7 caribou/km2 on core winter range. This density can negatively affect the carrying capacity of the range, specifically in the face of catastrophic stochastic events, e.g., severe thaw-freeze and icing events or deep snows. The historical crashes were abrupt and reduced caribou numbers to "nothing". Caribou numbers always recovered, although this took the better part of a century or more. Despite open harvests and long hunting seasons over the past decade, the largest herd (KS) remains untouched in high abundance. The Akia-Maniitsoq AM herd is the second largest and seems in slow decline, and only the Ameralik was successfully reduced through harvest to the target density of ca. 1 caribou/km2. The key may be an areas' accessibility for hunters. KS and AM offer limited accessibility to their large inland areas, in contrast to Ameralik. How much longer high caribou abundance may be sustained is unknown.

12 populations of caribou / reindeer in West Greenland

The list of the 12 populations of caribou /reindeer is arranged in order from north to south with their relative status. The first 11 are wild indigenous caribou, feral reindeer or a mixture of both. All are managed under wildlife for sustainable hunter harvest. The 12th, Isortoq, is a semi-domestic reindeer husbandry district and managed under agriculture. Additionally, and immediately south of Isortoq is Tuttutooq (Tugtutooq), an island with ca. 200-300 semi-domestic reindeer under husbandry.

The populations are as follows:

1) Inglefield/Pruhoe Land - 1999 estimated at 2300, current number unknown

2) Olrik Fjord - current number unknown, includes feral reindeer and possibly genetic mix with caribou

3) Nuussuaq Halvø - 2002 minimum count 1164, current number unknown, includes indigenous caribou and feral reindeer, genetic mixing possible

4) Naternaq - current number unknown, only indigenous caribou

5) Kangerlussuaq-Sisimiut (KS) - relatively stable, high density, 2010 revised estimate at ca. 58,900 (90% CI: 43,300 - 79,000) only indigenous caribou

6) Akia-Maniitsoq (AM) - slow decline, 2010 revised estimate at ca. 14,300 (90% CI: 10,300 - 18,800) caribou, includes indigenous caribou and feral reindeer, and documented genetic mix

7) Ameralik - relatively stable since 2006, the 2012 estimate was ca. 11,700 (90% CI: 8,500 - 16,000), population includes documented genetic mix of caribou with feral reindeer

8) Qeqertarsuatsiaat (QEQ) - relatively stable, the 2012 estimate was ca. 4,800 (90% CI: 3,400 - 6,800), population includes indigenous caribou and feral reindeer, genetic mixing possible

9) Qassit - 2000 minimum count 196, current number unknown

10) Neria - 2000 minimum count 332, current number unknown

11) Ivittuut - recent arrival of feral reindeer from Isortoq reindeer herding district, small groups totaling 93 reindeer were observed near seashores in June 2015

12) Isortoq - semi-domestic reindeer district, July 2015 post-calving pre-slaughter minimum count was 1781, post-slaughter winter 2015/2016 herd size ca 1200 reindeer. Tuttutooq current number unknown.

The largest Rangifer populations occur along the south west coast of Greenland. The largest is the KS, followed by the AM, the Ameralik and QEQ. Aerial surveys for abundance and herd structure are carried out on these top four. For greater details see Greenland Institute of Natural Resources technical reports 42, 46, 48, 61, 67 and 78

Figure 2. Survey observer, Hans Mølgaard, Sisimiut hunting officer. Photo: C. Cuyler
Figure 2. Survey observer, Hans Mølgaard, Sisimiut hunting officer. Photo: C. Cuyler

Monitoring

Abundance surveys

Abundance monitoring is done by helicopter survey about every 5th year. These are carried out by scientists from the Greenland Institute for Natural Resources with assistance from hunting officers and local hunters (Figure 2). Only the four major West Greenland herds are surveyed. These include the KS, AM, Ameralik and QEQ herds. Results include estimates of abundance, herd structure and distribution.

Harvest monitoring

Annual harvest monitoring of the 11 Greenland caribou/reindeer populations is achieved through hunter reports from local hunters. Information on hunter reports includes the location, sex, age (calf, juvenile, adult) and rump fat depth of each caribou. If a cow, whether she had a calf-at-heel is also requested. This data may provide information about trends within each herd, however, recent analyses illustrated widespread inaccuracies in the fat depth and age data. In 1995 all jawbones from the harvest were collected and used to examine sex, age and body size of harvested animals. Differences in jawbone length in animals of the same age reflect differences in range quality, quantity and availability, i.e., when the animal was young. The total number of caribou harvested annually in Greenland, all herds combined, is available (in Danish or Greenlandic) from the Greenland Self Rule's website for the Department of Fisheries, Hunting and Agriculture.

Research

Health and body condition

Intensive scientific monitoring of cow body size / condition, health and reproduction using CARMA protocols is performed about every decade on the two largest herds in West Greenland, the Kangerlussuaq-Sisimiut (KS) and the Akia-Maniitsoq (AM). Intensive scientific monitoring was done in 1996, 1997, 2008 and 2009. These are exclusively cow collections, although calves-at-heel may also be taken. The health and body condition of cows are major determinants of calf recruitment and future trends in herd abundance, and therefore vital to caribou management in Greenland.

Akia-Maniitsoq (AM) and Kangerlussuaq-Sisimiut (KS)

We collected 41 caribou cows and 6 calves from the AM in 2008, and 40 caribou cows and 10 calves from KS in 2009. Initial data collected included; date, location, elevation, sex, age classification (calf, sub-adult (<3-years) or adult) and the presence, absence and condition of antlers, calf-at-heel, milk in udders or calf antlers and gross body measurements. A photo record for each animal was kept. Important parameters included body, bone, fat and organ weights and measurements, tooth wear, and body condition score. Samples collected included blood, muscle, liver, kidney, urine, rumen contents, bone marrow, bone (mandible, metatarsus), ovaries, foetal tissues, feces, abomasums, small intestine contents, milk, and hair. We checked for a variety of parasites including protozoa, nematodes, tapeworms, flukes and flies. Information and further data from the study is still under analysis and will be published afterwards.

Figure 3. Satellite collared female, Akia-Maniitsoq herd. Photo: C. Cuyler.
Figure 3. Satellite collared female, Akia-Maniitsoq herd. Photo: C. Cuyler.

Satellite collaring

In 1997 eight caribou cows in the Akia-Nordlandet region of the Akia-Maniitsoq caribou population were captured and equipped with satellite collars. Two years of data made clear that some cows were stationary with annual movements of ca. 10 km along elevation gradients, while others were migratory with annual movements of up to a maximum of 170 km between winter and calving ranges. All movements appeared to be individual rather than synchronized as an aggregated herd. Regardless, before calving pregnant females moved to areas close to the Greenland Ice Cap, or to high elevations. In May 2008, 40 caribou cows from the Akia-Maniitsoq population were equipped with satellite collars (Fig. 3). The information obtained is still under analysis.

Figure 4. Bot larvae located deep in the caribou’s throat. Photo: B. White
Figure 4. Bot larvae located deep in the caribou’s throat. Photo: B. White
Figure 5. Warbles. Photo: B. White
Figure 5. Warbles. Photo: B. White

Parasites - Warbles and Bots

The warbles and bots have a yearly life cycle. Briefly, in winter they live as larvae inside their caribou / reindeer host, they exit in May-June to pupate for ca. 41-47 days, and by July and August the adult flies are ready to mate and start the process again. Warble and bot flies look alike. The adult flies do not eat, but just mate and then find a caribou / reindeer for their larvae. The presence of warble and bot flies can make for some spectacular avoidance behavior among caribou, i.e., they panic, especially if it is a bot fly. The bot fly female injects live larvae into the caribou's nose. These larvae wriggle about in the nasal passages and finally end up in the throat where they anchor themselves by 'hooks' in the throat pouches (Fig. 4). In contrast, warbles lay their eggs on caribou hairs, these eggs hatch after a few days and crawl down the hair to penetrate the skin and live inside the caribou for about three months before encapsulating under the skin along the back and boring their breathing holes through the skin. The skins of caribou taken in mid-winter are often full of fat warble larvae (Fig. 5). However, by August-September the warble larvae are long gone leaving only the scars. Warbles can be ca. 3 cm long when they leave their host. When skinning an autumn caught caribou, hunters can see the holes, or scars of healed holes, on the inside of the skin especially along the back where warble larvae lived the previous winter. The bot larvae are harder to detect because they overwinter in the caribou's throat. Come May-June they crawl out the nasal passages or are coughed out by the infected caribou.

Updated 01.14.2016