Arctic Exam 3
What is Traditional Ecological Knowledge (TEK)?
"A cumulative body of knowledge, practice, and belief, evolving by adaptive processes and handed down through generations by cultural transmission, about the relationship of living beings (including humans) with one another and with their environment" A wide range of techniques can be used to collect TEK.TEK can be complimentary to Western Science but also can be in conflict because a local perspective may differ from broader scientific perspective.US, Canada and Greenland -all moving towards using TEK more actively in management decisions for Arctic marine mammals. It contributes to local capacity by involving communities in research. 15 out of 19 subpopulations have co-management for polar bear harvest. But in each that does, the process, partners, timelines and legal framework varies In Greenland, Nunavut and Alaska there are frequent interview surveys of hunters for co-management purposes (TEK collection).
Narwhal basic facts
- About 14-16 feet long; tusk on males about 10 feet - 1,800 to 3,500 lbs, males larger than females - Specialized Arctic cetacean: deep diver, restricted diet and distribution - Hunted for subsistence in Greenland and Canada, rarely in US waters - One of the most ice-associated whales in the world - Most live in Baffin Bay (Baffin Bay pack ice) (Between Baffin Island (Canada) and West Greenland is home to 80% of the world's narwhals)
Polar bear dependence of sea ice
- All polar bear subpopulations are losing sea ice habitat - A 30% potential reduction has occurred in the global population of polar bears in the last ~35 years (with a probability of 70%). Results support listing polar bears as vulnerable on the International Union for the Conservation of Nature's (IUCN) Red List.
How will disturbance impact narwhals? Williams et al. Science
- Evidence suggests narwhals don't do well with disturbance -they have an unusual paradoxical fear response. - Heartbeats of most species when frightened or stressed tend to quicken. For narwhals, their heartbeats lower but they also swim away as fast as they can. Not the typical "fight and flight" or "hunker down like a scared rabbit". - May make increasing disturbance from ship traffic or resource extraction a real issue for narwhals.
Can polar bears adapt to an ice free environment?
- Evolutionary processes occur over generations - Species with long generation times have fewer opportunities to adapt to new selective pressures and higher risk of extinction than species with short generation times - Large long-lived species are therefore particularly vulnerable to extinction due to climatic change
Buzzes and high frequency broad band clicks
- First time narwhal acoustics has been studied with a sample rate up 500 kHz. Energy in high frequency narwhal clicks extends up to 200 kHz. - Frequencies this high have not been described previously for narwhals either due to the limitations of recording equipment or a priori sampling decisions. - The narwhal click is the most directional biosonar signal reported for any species to date. This may be an evolutionary advantage to reduce echoes from the water surface or sea ice surface.
Aerial surveys
- For abundance or how we estate the number of narwhales on the wintering grounds - 2% of the survey region is open water
What must be considered when flying offshore and spotting narwhal pods from the air?
- Ice conditions for helicopter and safety - Whale behavior and density - Lead size - Current weather and forecast weather - Fuel range - Sunset (darkness)
What are the three groups of Arctic humans and how log have each been in the Arctic?
- Indigenous People (Permanent or migratory residents; 20,000 years ago) - Vikings (lasted few hundred years) - Explorers (1-3 years)
How are polar bears studied?
- Location and immobilization of adult bears from helicopter 1.) Follow bear tracks in snow 2.) Locate bear 3.) Dart bear and immobilization - Immobilization of cubs by hand - Individual markings - Samples and measurements - Radiotelemetry - Drug amount varies on size of bear - Once immobilized, a series of body condition measures are taken (girth, length, weight) and samples (blood, fat, hair, nails all for pollution, isotope, and fatty acid studies) - They are marked with tattoo and plastic ear tags (lifetime markers) in some cases they are tagged with a satellite transmitter - Polar bears are marked so that they can be identified in the substinence hunt
There are 19 subpopulations of polar bears defined by:
- Mark-recapture - Satellite telemetry - Genetics
Narwhal hunt in greenland
- Meat and skin are consumed locally or distributed within Greenland. - Prior to 2005 unregulated: 700 /year - Now harvest is about 350/year w/ quotas - Historical exploitation low due to behavior - Shared stocks with Canada - Kayak hunting in Northwest Greenland - Summer: No motorized boats inside Qaanaaqfjord (NW Greenland) - Whales hunted with hand-thrown harpoon - Winter hunts -nets and open boats - Aging narwhals: The subsistence harvest offers an opportunity to sample whales
Why interview indigenous arctic peoples?
- Numbers and occurrence of animals - Climate change impacts - Effects on their catch & food resources - Human conflicts - Document what the hunters have observed for managers
Hybridization with brown bears
- Occur only in a few areas where the species overlap (to date only documented in Canada) -but could occur in Alaska and Russia Polar bears forced on to land for longer periods due to ice declines could result in more hybrids or from grizzly bears expanding their range, emerging from hibernation earlier, increasing in abundance, etc. Mixing of the species is not unique. (Ursus arctos×Ursus maritimus). We know they have interbred before. Physical traits are intermediate between polar bears and grizzly bear. Some second generation hybrids observed are ¾ grizzly and ¼ polar bear, meaning first generation hybrids can reproduce. Polar bear unique traits (living on sea ice, metabolizing fat) is likely lost.
Polar bear adaptations
- Polar bears are 2-3 times larger than Arctic grizzly bears (females up to 400 kg, males up to 800 kg) - Flat "pie shaped face" - Long, narrow "Roman nose" - Elevated eyes (adaptation to swimming?) -Narrower head -Longer neck (adaptation to seal holes) -Elongated skull also helps warm inhaled air (turbinate bones in nasal cavity) - Meticulously dry themselves by shaking and rolling (Fur will lose >90% of insulating properties when wet) - Overgrown hair around pads for added friction for walking on ice. Foot pad is sandpaper rough. - Exposed part of the eye is small -advantage in 24 h of daylight and helps avoid snow blindness - Polar bear: Short, curved, & sharp for snagging fleeing prey (compared to Grizzly claws: Long for digging and excavating roots)
Why not just eat berries?
- Polar bears cannot survive on a terrestrial diet. They need FAT Arctic char?: limited accessibility due to limited anadromy and predominant occurrence in streams too deep to facilitate efficient capture by polar bears Berries?: large interannual fluctuations in the availability of berries or competition with other frugivores; High energetic requirements associated with lengthy foraging times required to locate and consume sufficient fruit Data from populations document declines in biological indices over decades despite availability of terrestrially-based food resources
Senescence in narwhals
- Recent study of post-reproductive life spans of toothed whales suggest narwhals are among the few species that have a long period of reproductive senescence (females are no longer reproducing) - Older females likely aid other group members (grandmothers, 'late life helping') - Limited understanding and studies of narwhal social structure. Pods may be matrilineal (female-led) but largely unknown. - Difficulty of studying narwhals makes it hard to understand social structure - These post-reproductive life spans evolved independently at least three times in toothed whales
What changes in polar bear habitat have we observed?
- Total ice area (sq km) is decreasing - More open water (lower ice concentrations) - Increasing ice drift -more walking required - Shorter ice season and longer ice-free season (changes in the timing of when ice freezes up and ice breaks up) -means shorter time to feed
What are the difficulties in studying narwhals?
- Underwater, offshore, and in dense sea ice much of the year - Low surface profile = hard to observe - Cannot identify individuals
Arctic field research on narwhals consists of:
- summer field camps - set up 100ft x 30ft net in area with narwhals - keep watch in shifts until narwhal swims into net - 15 min to take samples and tag narwhal on dorsal ridge Results: - dives 4500 feet deep 15 to 20 times per day - winter is an important feeding period
Sea ice is the primary habitat for polar bears used for:
- travel - hunt - mate - maternity denning
Relationship of axillary girth and skull width
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The Vikings were only around for a few centuries and mysteriously disappeared by the 1500s. What are the four theories for their disappearance?
1.) Failure to adapt to using local food resources or hunting strategies (raised cows and pigs from Europe) 2.) Climate change: Cold periods were so harsh they could not survive (Little Ice Age) 3.) Loss of contact with Europe -and reduced demand for the goods they were selling -they possibly departed for home
What are the hypotheses on why cetaceans feed in winter?
1.) Reduced competition (no one else out on the pack ice) 2.) Reliable and predictable prey (stable and predictably Arctic benthos)
What are the hunting strategies polar bears use?
1.) Wander, detect, break into lairs in spring through the snow (Conducted in spring; Focus on fatty seal pups before weaning) 2.) "Still hunting" -Sit and wait motionless at a seal hole/lead and (80% of hunting is done this way. It minimizes energy expenditure and most still hunts are <1 hr long) 3.) "Stalking" - creep up on prey by moving slowly and steadily across ice or in water ("aquatic stalk")
Race to the north pole
April 6, 1909, American Robert Peary claimed to be the first person in recorded history to reach the North Pole (although whether he actually reached the Pole has been doubted... could have been off by 60 miles). Many other failed North Pole expeditions : Parry, Cook, Nansen (on the ship Fram).
Pollution and polar bears
As an apex predator largely feeding on seal fat, polar bears have been shown to accumulate high levels of a range of fat-soluble environmental pollutants Most pollution in the Arctic is transported northward by the large rivers, and on wind and in ocean currents that bring pollutants from southern latitudes. The most polluted polar bears in the world live in Northeast Greenland, the Barents Sea, and the Kara Sea because of global transport and deposition patterns. The overall impact of chemical pollutants on polar bear health and fitness is unknown. However, there could be long term effect son survival, immune system response, and reproductive hormone action. When combined with the stress from climate change impacts, the influence of pollutants can be magnified.
What drove the exploration of the Arctic?
As early as the 16th century Europe began to prosper and whalers traveled north into the Arctic for bowhead whales. Dutch, German, English and Scottish whalers in Atlantic. Americans in the Atlantic (Baffin Bay, Davis Strait) and Pacific (Bering Sea).. The quest for Arctic Marine Vertebrates drove the exploration of the Arctic! It also decimated populations of bowhead whales around the Arctic -brought many to near extinction.
Age estimation in narwhals
Aspartic and racemization (AAR) technique: - Amino acid - L- and D-form - Racemization rate (kAsp) - Initial D/L value (D/L) - Used for narwhals since they have no teeth besides tusk which is hard to use for aging Traditional method: Count growth layers in teeth
Franklin's Expedition
British voyage led by Captain Sir John Franklin departed England in 1845 aboard two ships: HMS Erebusand HMS Terror. The two ships became icebound in the Canadian Arctic. The entire expedition, 129 men including Franklin, was lost. A disastrous expedition -ships were stuck in the sea ice & abandoned -over 90 search parties were deployed. Evidence of graves on remote islands, evidence for dispersal from the ship to Inuit encampments where pots with boiled human remains were observed. The Erebus was located under the sea ice in 2014, the Terror in 2016. Inuit traditional knowledge played a critical role in locating Erebus-oral testimony recorded by missions in the 1850s and 1860s spoke of a large ship sinking in Queen Maud Gulf, narrowing the search area.
What is the chain of change?
Climate warming --> altered sea ice --> less food --> lower body condition --> fewer and smaller cubs --> lower cub survival --> population decline
Co-management(or Cooperative management)
Co-management is local to regional-scale institutional arrangements that are intended to share some measure of control and authority for decisions about resources(wildlife, fisheries, lands, protected areas, and water) between governments and resource users. Co-management agreements among indigenous people, federal & state agencies, and other stakeholders a way of dealing with natural resource conflicts in a participatory and equitable manner. It comes down to respectfully working together across cultures. Usually involves an agreed-upon management plan for the conservation and the enforcement of rights. How this works is highly variable across nations and within national borders. Co-management requires equal power relationships between partners, understanding of indigenous people, and the acceptance of Traditional Ecological Knowledge (TEK)* as a legitimate knowledge system. *Sometimes referred to as "local knowledge" or "local ecological knowledge" (LEK).
Human and polar bear interactions
Conflicts between humans and bears are inevitable in areas where both reside. •The level and number of conflicts is increasing, and in some areas are correlated with a change in distribution of polar bears due to climate warming. As increasing local populations, tourists and employees in resource extraction inhabit the Arctic, there will be increased interactions across the range of polar bears. Human-bear interactions have the potential to increase direct human-caused mortality. To reduce these polar bears are trapped or relocated (Expensive and time-intensive. Does not occur everywhere. In many places problem bears are shot dead.)
Climate change impacts on narwhals
Direct: -Loss of sea ice habitat - Increased predation by killer whales with more ice-free seasons (only some parts of the Arctic) - Increased disturbance from anthropogenic activates (shipping, seismic exploration, etc.) Indirect: - Shifts in ocean temperatures, ecosystem/prey -but how will it impact them
Erik the Red
Erik the Red and other Vikings (or Norsemen) reached Greenland in 900 AD (probably sent there in exile for committing a murder).They returned to Europe with stories of a new island rich, fruitful and ripe for settlement called "Green-land" (a bit of an overblown assessment). The Icelandic sagas say that 25 ships left Iceland with Erik the Red in 985, and that only 14 of them arrived safely in Greenland
Subsistence hunt of polar bears
For thousands of years, polar bears were hunted using traditional methods occurring at sustainable levels (no rifles); however, concerns over large numbers of polar bears sport hunted and harvested commercially from the 1700s to the mid-1900s. Hunting in US Chukchi seas occurs from from airplanes while hunting in Svalbard is done with automated bait stations (did not need to be present to shoot the bear) 1973 Agreement on the Conservation of Polar bears and subsequent conservation efforts and actions have been taken by the range States (Canada, Greenland, Norway, Russia and the United States), polar bears are still found in much of their historic range. - a binding agreement to jointly manage polar bear populations for conservation Russia and Norway have not hunted polar bears since 1956 and 1957 (illegal hunting by indigenous people), while Canada, the United States and Greenland are the only range States that currently allow hunting of polar bears for subsistence purposes. On average, 735 bears are killed annually from a global population of ~25,000 bears. This is approximately three to four percent of the global population.
Hyperphagia
Gorge when food is plentiful and store energy
How is the proportion of indigenous populations different in the Greenland vs. Russia?
Greenland is almost entirely Inuit and has the only parliament in the world composed entirely of Indigenous people vs. Russia is a massive area if the Arctic with a small fraction of Indigenous peoples.
Vikings in Greenland
Had two settlements in Greenland (SW Greenland).At their height, had a population of between 2,000 and 10,000 people. Carried on a trade in ivory from walrus tusks with Europe, as well as exporting rope, sheep, seals and cattle hides. They depended on Iceland and Norway for iron tools, wood, and religious and social contacts. Vikings sold narwhal tusks as "unicorn horns" to Europeans. They bartered with the Inuit. A dirty secret, kept for hundreds of years, because narwhals rarely swim south. The last written record of the Norse Greenlanders is of a marriage, in 1408, in Hvalsey church—which still stands today in SW Greenland. The best-preserved of the Norse buildings of that period.
Future of polar bears
If climatic warming continues, the future is grim for polar bears. But It's not too late! - There is a lot of uncertainty. - There is regional and temporal variation. - Predicted declines are based on "business as usual" greenhouse gas emissions. If climatic warming can be slowed or reversed, the sea ice will persist. Last "refuge" for polar bears will likely be Canadian high Arctic and North Greenland where the last of the multi-year ice is expected exist.
How does ice impact Arctic living?
In Greenland, 81% of the surface is covered by ice. Ice cap: 1550 miles long, 620 miles wide, 9000 ft thick. This means not many areas for humans to settle and difficult to migrate along the coast. In Greenland, ALL villages are coastal.
Cannibalism in polar bears
Intraspecific killing of one polar bear by another has long been known by Inuit and scientists. Mostly focused on cubs and subadults and on land during the ice-free season. Stirlingand Ross (2011) report three instances of intraspecific killing and cannibalism of young polar bears by adult males in good condition on the sea ice in Svalbard in summer and autumn. This could be do to food stress related to declining sea-ice conditions.
Why does the mitochondrial DNA suggest a much more recent origin for polar bears?
It's not necessarily evidence of origin, but possibly of interbreeding between polar bears and brown bears long after they evolved, perhaps when the polar bears were driven to land because of sea ice loss during interglacials. Mitochondrial DNA tells the story of the female line only. The longer evolutionary timeline with nuclear DNA implies polar bears' adaptation to climate change in the past was a slow process. Means the speed of change now poses threats. However, it also indicates successful survival through two previous warm intervals between ice ages (as evidence polar bears can deal with reduced ice and other environmental shifts)
Polar bear reproduction
Maternity dens are built in fall and the pregnant female waits. Cubs are born in January inside the maternity den. Cubs and mom emerge in March/April timed with the peak in sea ice extent and the birth of ringed seal pups. They have delayed implantation in spring. Pregnant females do not eat until they return to the sea ice in the spring. They must rely on their fat reserves during the winter months. Pregnant females must double their weight before entering their den. They have relatively slow population growth (2.5 years to weaning) and they are relatively long lived (24 - 28 years).
Narwhal scientific name
Monodon monoceros
Narwhal family
Monodondidae (one of two species in this family with beluga whales)
Narwhal tusk
Narwhal tusks were sold as "unicorn horns" to Europeans by Vikings. Vikings made good money on their dirty secret, kept for hundreds of years, because narwhals rarely swim south! Until the 19th century, belief in unicorns was widespread among historians, alchemists, writers, poets, naturalists, physicians, and theologians. In 1638, along comes Ole Worm who defended his dissertation before the merchants of Copenhagen. He proposed the controversial and explosive hypothesis: "Unicorns may well be myth, whereas narwhals fact." Since then, there have been a sum total of 4 doctoral dissertations devoted to the narwhal. "In the male narwhal one alone of the upper teeth is developed into the well-known, spirally-twisted, so called horn....When the males are provided with weapons which the females do not possess, there can hardly be a doubt that they...have been acquired through sexual selection." It is not used for spearing fish, breaking sea ice, or fighting. A positive correlation between the size of male narwhal's tusks and the mass of their testicles. Tusks evolved as an "honest signal" or visible feature of reproductive status and fertility. Only applies to mature males, not juveniles, so it has a critical role in mating. Narwhal body size and tusk length show steep scaling -it is a sexually selected trait. Larger males -longer tusks. 40-60% of males have broken tusks
How are narwhal subpopulations separated?
Narwhals occur in separate summering subpopulations Subpopulations are functionally distinct in summer but genetically similar (very low genetic diversity). They overlap in winter between subpopulations.
Last Ice Area (LIA)
New research out last month suggests LIA could be more vulnerable to disappearing than previously thought. Ice arches (multiyear sea ice areas) are breaking down and it could flush the system of ice. Much more work needs to be done to understand this and integrate it into future projections for polar bears.
Do polar bears hibernate?
No true hibernation, but may rest in an area for weeks (or build and rest in shelter/maternity dens)
Polar bear prey and diet
Participate in optimal foraging (exploit patches with energy greater than the rest of the environment). Fatty tissue is advantageous so they eat meals high in fat. They can eat up to 20% of mass in a single meal. Pregnant females take in almost all of their dietary intake from April -June. and then can fast for up to 8 months and produce 1-3 cubs. Ringed seal = 50 sticks of butter Bearded seal = 300 sticks of butter
Grizzly vs. polar bear cub size
Polar bear: Mean litter size< 2 cubs. Born < 1 lb. Mostly nurse the first year but quickly switch to seals. With mother 2.5 years Grizzly bear: 3 cubs
How did polar bears evolve?
Polar bears and brown bears are sister species with distinct physiological and behavioral adaptations that have been evolving along different trajectories for around 500,000 years. Polar bears evolved into a behaviorally, physiologically, and morphologically distinct lineage adapted to life on Arctic ice, with very little species-level genetic diversity. Brown bears, alternatively, live in nearly every habitat type across the northern hemisphere and are genomically diverse. Published estimates of the time of divergence between brown bears and polar bears using genetic data range from 150 thousand to 4-5 million years ago. Mitochondrial DNA indicates polar bears split from brown bears ~150,000 years ago. Nuclear DNA indicates polar bears split from brown bears 600,000 years ago (polar bears are older and more genetical unique) . The Hailer et al. 2012 and Liu et al. 2014 findings using nuclear DNA suggest the cold adapted polar bear is about five times older than previously thought based on mitochondrial DNA (study in 2010), and may have had more time to adapt to Arctic conditions than recently assumed.
Polar bear swimming
Polar bears are good swimmers and divers -they are marine mammals! They can easily swim for 100 miles. Swimming is increasing in some areas with loss of sea ice.
Kane Basin (KB) population
Previously inhabited a mix of multi-year and annual sea ice. One of the most northerly subpopulations in the world. KB is moving from multiyear ice to a seasonally ice-free region because of climate change. More open water, longer open periods and thinner sea ice. Bears in the LIA show transient benefits of thinner ice -better body condition, no changes in reproduction. But this is temporary. ---------------------------------------------------------------------------------------------------------
Diet studies
Stomach contents from subsistence harvest Summer: - <15% fresh remains Polar cod and Arctic cod. Many empty stomachs Fall and Winter: - 100% fresh remains Greenland halibut and Gonatus squid. No empty stomachs
Subsistence hunters
Subsistence hunters are keen observers of their surroundings. They are naturalists and pass down information about what they see..
Inuit people
The Inuit people are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Greenland, Canada, the US and eastern Siberia. The Inuit languages are classified in Eskimo-Aleut family. They have been traditionally been fishers/hunters. They hunt whales, walrus, caribou, seals, polar bears, muskoxen and seabirds Their diet is high in protein and very high in fat - traditionally, Inuit consumed on average of 75% of their daily energy intake from fat. It is not possible to cultivate plants for food in most of the Arctic, traditionally gathered grasses, tubers, roots, stems, berries, and seaweed. They also get vitamin C from mattak (skin and blubber) of whales, which is also a very good source of heat. A vast area of different hunting technologies is used to gather their food (dog sled, kayak, etc.).
When was the Northwest passage conquered?
The NW passage was not completely conquered by sea until 1906 (by Norwegian explorer Roald Amundsen). It took 3-years in a converted 47-ton herring boat Gjøawith 6 people.
Who is better studied: narwhal or beluga and why?
The beluga is far better studied than the narwhal, partially because it's easier
Arctic human history
The first people to populate the Arctic regions of North American and Greenland were a group who moved into the area from Siberia across the Bering Sea land bridge around 3,000 BC. They lived in isolation for almost 4,000 years before disappearing. These were referred to as the "Paleo-Eskimo/Dorset" people. We do not know why these people disappeared (violence, disease, some other factor, etc.). These peoples were placed with the "Thule People", who had developed larger boats more advanced weapons and the ability to hunt whales. There is genetic evidence that modern Inuit people are descended from the Thule and not the Paleo-Eskimo groups.
Inuit in Greenland
The prehistory of Greenland is a story of repeated waves of Paleo-Eskimo immigration from the islands north of the North American mainland. Because of Greenland's remoteness and climate, survival was difficult. One culture succeeded another as groups died out and were replaced by new immigrants. The current inhabitants of Greenland came from decedents that arrived about 12,000 years ago. The Danes colonized Greenland in the 1700s to try and establish contact with the (lost) Vikings. Missionary Hans Egede established a mission with the Inuit. and was credited with establishing Greenland's capital (Nuuk). This was the start of Danish "Home Rule" over Greenland where he largely converted traditional Inuit society into a more "Westernized" culture over several hundred years. In many areas, traditions are still used in modern times, though technology has made Inuit more efficient.
Narwhal reproduction
They breed in late winter, early spring on northward migration. They give birth 11 months later. One calf every 3 years
Scavenging by polar bears
Whale carcasses from natural mortality events or human-sourced subsidies can be used by polar bears as a source of food. They are predictable in some parts of the Arctic but not available everywhere and can offer a huge supply of energy during ice-free seasons.
Optimal foraging
exploit patches with energy
Demography of indigenous people is based on...
linguistic groups
Mattak
skin and blubber of whales