Tag: eagle

Did Neanderthals honour the raven?

A new discovery by archaeologists in Crimea is providing evidence that ancient Neanderthals had a high cognitive and artistic ability. That evidence is the carved leg bone of a raven also raising the question (not actually included in the archaeologist’s paper) does the relationship between human and raven go back to a period between 38,000 and 43,000 years ago?

For more than a century, archaeologists have debated the question of just how smart the Neanderthals, the species that preceded what archaeologists now call “Modern Humans” into Europe and west Asia and there is increasing evidence of Neanderthal intelligence.

The raven bone fragment  which has been dated between 38,000 and 43,000 years ago, was found at the Zaskalnaya VI site in Crimea. It is described in to a study by Ana Majkic at the Universite de Bordeaux and colleagues, A decorated raven bone from the Zaskalnaya VI (Kolosovskaya) Neanderthal site, Crimea. published in the open access journal, PLOS ONE on March 29, 2017. 

The site in the Crimea was once a campsite in a river gully.

Location of Neanderthal campsite in a river gully in what is now Crimea. (PLOS1)

The radius bone fragment has seven notches. Microscopic analysis of the notches indicate that they were produced by the to-and-fro movement of a lithic (stone) cutting edge and that two notches were added to fill in the gap left between previously cut notches, probably to increase the visual consistency of the pattern.

The study worked to duplicate and test the work of the Neanderthal crafts person by examining sets of notches cut by nine modern experimenters on the leg bones domestic turkeys shows that the variations recorded on the Zaskalnaya set are comparable to experimental sets made with the aim of producing similar, parallel, equidistant notches.

A raven on the dock at Masset, Haida Gwaii, June 2016. (Robin Rowland/Northwest Coast Energy News)

The object represents the first instance of a bird bone from a Neanderthal site bearing modifications that cannot be explained as the result of butchery activities.

That means the argument that bone notches are symbolic argument can be built on direct evidence.

The respect that British Columbia and Alaska First Nations have for the raven is found in countless legends and stories. Other cultures have honoured the raven including the Celtics who believed the raven was symbol of war, the Vikings and Greeks where the raven was a messenger of the gods, to name just a few.

The discovery of the raven bone in a Neanderthal cave may mean that the relationship with the raven is much more ancient than previously believed.

The paper says evidence of burials, collection of rare items, production of engraved and perforated objects, personal ornaments, pigment use, and the extraction of bird  feathers and claws support the notion that Neanderthals engaged in symbolical behavior, independently from the influence of anatomically modern humans.

Neanderthal burials of infants, children, and adults have been reported at several sites throughout Europe and the Near East, some of which are associated with grave goods. Pigment use among Neanderthals dates back as far as between 200,000 to 250,000 years ago. Pigment use became a more widespread practice about 60,000 years ago.

A string of new discoveries have shown that Neanderthals regularly exploited birds. The activities conducted by Neanderthals that may reflect their involvement in symbolic activities have been found in Italy, in caves in Gibraltar, nine sites in France and one Croatia.

Those discoveries indicate that cut-marks and scraping marks on upper limb bones mean that feathers were purposely detached from the wings of seven different bird species, including the common raven and the red-billed chough (a red beaked and red legged crow that is sacred in Wales and Cornwall). Others were the white-tailed and golden eagles, two species of vulture, and an unidentified raptor.

The study says that removal of feathers and claws is interpreted as proof that these objects were used as personal ornaments by Neanderthalsm the study says.  Feathers and claws do not survive archaeologically. So far, no clear modifications for suspending or threading the claws were found so far on bird talons, so up until now this was considered circumstantial evidence.

On the left is the notched raven bone from Zaskalnaya VI Neanderthal site, Crimea. center: experimental notching of a turkey bone; right: sequences of experimentally made notches compared to those from Zaskalnaya VI. (Francesco d’Errico)

As for the raven bone found in Crimea, the scientists say it is more probable that the Neanderthal took the decision of adding notches two and six, after completing the first set and realizing that its production left two gaps.

Two reasons may account for this action. The craftsman may have considered that, if made for functional reasons, i.e. to facilitate the grip of the object, the notches of the first set were not frequent and numerous enough to fulfill that function. Alternatively, he/she may have considered, irrespective of the possible functional reason behind the production of the
notches, that it was important to add two notches in order to create a visually more regular and consistent pattern.

The archaeologists conclude the artistic hypothesis more probable because adding the two very small and superficial notches added virtually nothing to the gripping power of the object`s surface.

The results of the study pinpoint that a clear effort has been put to reach the goal of producing not just random but instead equidistant notches, that would have been perceived as regularly spaced. This implies that the resulting pattern could have conveyed an information, not directly linked to the object function, communicating to the user, and likely other members of the Neanderthal group. In this respect the sequential notches on the ZSK raven bone represent the first case of bird bone use by Neanderthal for which a symbolic function can be argued on direct rather than circumstantial evidence.

Letting salmon escape from nets could benefit grizzly bears and even the fishers, study says

Grizzly eating a salmon
A grizzly bear eats a salmon. A new study says managers must consider the value of salmon to the entire ecosystem. (Jennifer Allan)

A new study suggests that the health of the grizzly bear population is also a strong indicator of the health of Pacific salmon—and perhaps surprisingly, allowing grizzlies to consume more salmon will, in the long term, lead to more, not less, salmon.

The study, led by Taal Levi, of the University of California at Santa Cruz and colleagues from Canada, suggests that allowing some more Pacific salmon to escape the nets of the fishing industry and thus spawn in coastal streams would not not only benefit the natural environment, including grizzly bears, but could also eventually lead to more salmon in the ocean. Thus there would be larger salmon harvests in the long term—a win-win for ecosystems and humans.

The article, “Using Grizzly Bears to Assess Harvest-Ecosystem Tradeoffs in Salmon Fisheries,” was published April 10 in the online, open-access journal PLoS Biology. In the study  Levi and his co-authors investigate how increasing “escapement”—the number of salmon that escape fishing nets to enter streams and spawn—can improve the natural environment.

“Salmon are an essential resource that propagates through not only marine but also creek and terrestrial food webs,” said lead author Levi, an environmental studies Ph.D. candidate at UCSC, specializing in conservation biology and wildlife ecology.

Salmon fisheries in the northwest Pacific are generally well managed, Levi said. Managers determine how much salmon to allocate to spawning and how much to harvest. Fish are counted as they enter the coastal streams. However, there is concern that humans are harvesting too many salmon and leaving too little for the ecosystem. To assess this, the team focused on the relationship between grizzly bears and salmon. Taal and his colleagues first used data to find a relationship between how much salmon were available to eighteen grizzly bear populations, and what percentage of their diet was made up of salmon.

The study looked at Bristol Bay, Alaska, the Chilko and Quesnel regions of the Fraser River watershed and Rivers Inlet on the Inside Passage, just northeast of northern Vancouver Island.
The study says adult wild salmon are “critical” to ocean, river and terrestrial ecosystems. As well as humans, salmon are eaten by orcas, salmon sharks, pinnipeds (seals and sea lions). On land, salmon are eaten by black and grizzly bears, eagles and ravens.

Because the grizzly is the “terminal predator” the study says “if there are enough salmon to sustain healthy bear densities, we reason there should be sufficient salmon numbers to sustain populations of earlier salmon-life history predatory such as seabirds, pinnipeds and sharks.”
As is well known in the northwest, the study says “bears are dominant species mediating the flow of salmon-derived nutrients from the ocean to the terrestrial ecosystem. After capturing salmon in estuaries and streams grizzly bears typically move to land to consume each fish, distributing carcass remains to vertebrate and invertebrate scavengers up to several hundred metres from waterways.”

“We asked, is it enough for the ecosystem? What would happen if you increase escapement—the number of fish being released? We found that in most cases, bears, fishers, and ecosystems would mutually benefit,” Levi said.

The problem, the study says, is that fisheries management have a narrow view of their role, what the study calls “single-species management,” concentrating on salmon and not the wider ecosystem. “Currently,” the study says, under single-species management, fisheries commonly intercept more than 50 per cent of in bound salmon that would otherwise be available to bears and the terrestrial and aquatic ecosystems they support.”

The relationship between salmon and bears is basic, Levi said. “Bears are salmon-consuming machines. Give them more salmon and they will consume more—and importantly, they will occur at higher densities. So, letting more salmon spawn and be available to bears helps not only bears but also the ecosystems they nourish when they distribute the uneaten remains of salmon.”

When salmon are plentiful in coastal streams, bears won’t eat as much of an individual fish, preferring the nutrient-rich brains and eggs and casting aside the remainder to feed other animals and fertilize the land. In contrast, when salmon are scarce, bears eat more of a fish. Less discarded salmon enters the surrounding ecosystem to enrich downstream life, and a richer stream life means a better environment for salmon.

In four out of the six study systems, allowing more salmon to spawn will not only help bears and the terrestrial landscape but would also lead to more salmon in the ocean. More salmon in the ocean means larger harvests, which in turn benefits fishers. However, in two of the systems, helping bears would hurt fisheries. In these cases, the researchers estimated the potential financial cost—they looked at two salmon runs on the Fraser River, B.C., and predicted an economic cost of about $500,000 to $700,000 annually. This cost to the human economy could help support locally threatened grizzly bear populations, they argue.

While these fisheries are certified as sustainable by the Marine Stewardship Council (MSC), the researchers suggest that the MSC principle that fisheries have minimal ecosystem impact might not be satisfied if the fishery is contributing to grizzly bear conservation problems.
The researchers believe the same analysis can be used to evaluate fisheries around the world and help managers make more informed decisions to balance economic and ecological outcomes.

 

What do grizzlies eat in northwestern BC ?

The current study and previous studies track the grizzly’s diet by studying the nitrogen and carbon istopes in grizzly hair. In one study in the early part of this decade, the BC Ministry of the Environment used guard hairs from “passive hair snags” as well as samples from bears killed by hunters or conservation officers.

The 2005 study says “Guard hairs are grown between late spring and fall, thus integrating the diet over much of the active season of temperate-dwelling bears.” Analysis of the isotopes can show what the bears ate over the season.

The study identified four elements in the grizzly diet across British Columbia, Alaska, Yukon and the Northwest Territories: plants, “marine-derived nutrients” mostly salmon, meat (primarily from ungulates such as moose) and in inland areas, kockanee salmon.

As could be expected, grizzly salmon consumption is highest in coastal areas. Males generally consume more salmon than females, likely because a mother grizzly may avoid taking salmon if there is danger to the cubs from males. The further inland a grizzly is found, salmon is a lesser factor in the bear’s diet. In Arctic regions, grizzlies can feed on arctic char, whales, seals and barren-ground caribou.

So what do local grizzlies eat? (excerpts from the 2005 study, Major components of grizzly bear diet across North America,  National Research Council Research Press  published March 28, 2006)

Map of grizzly diet and salmon
Grizzly consumption of salmon on the northwest coast (NRC)

North Coast 54.54 N 128.90 W (north and west of Kitimat)
Plants 33 per cent Salmon 67 per cent

Mid Coast 52.50 N 127.40 W (between Bella Bella and Ocean Falls)
Plants 58 per cent Salmon 42 per cent

Upper Skeena Nass 56.80 N 128.80 W
Plants 71 per cent Salmon 5 per cent Meat 13 per cent

Bulkley Lakes 54.10 N 127.10 W
Plants 63 per cent Salmon 6 per cent Meat 16 per cent Kokanee 15 per cent

Cranberry 55.40 N 128.40 W (near Kiwancool)

Plants 30 per cent Salmon 17 per cent Meat 40 per cent Kokanee 13 per cent

Khutzeymateen 54.68 N 129.86 W (near Prince Rupert)
Plants 22 per cent salmon 78 per cent

 

###

Other authors of the 2010 study are Chris Darimont, UCSC, Misty MacDuffee Raincoast Conservation Foundation, Denny Island, BC; Marc Mangel, Paul Paquet, UCSC and University of Calgary, Christopher Wilmers, USCC
Funding: This work was funded by an NSF GRF and Cota-Robles Fellowship (TL), a NSERC IRDF (CTD), the Wilburforce and McLean Foundations, and Patagonia. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

2005 study by Garth Mowat Aurora Research  Crescent Valley BC and  Douglas Heard BC Ministry of the Environment, Nelson