Monthly Archives: October 2012

Tracking narwhals – October 2012

From the field, General,

Visit the WWF narwhal tracker
October 22
With so much latent heat still in the water column, the Arctic sea ice is slow in reforming again this autumn. Our 4 narwhal with radio transmitters still working are moving fairly slowly SE along the North Baffin coastlines. Only the inner reaches of Eclipse and Tremblay Sounds, Milne Inlet etc have started freezing, and there are large expanses of open water well to the north still. I wouldn’t expect our 4 whales to really start moving fast to the wintering areas until the temperatures drop substantially. Pond Inlet air temperatures this week are still in the zero to -10C range, quite warm still, really!
October 10
Now that people are mainly back at their homes, labs and offices, we can start sharing the summary results and weekly updates from the August narwhal tagging work WWF was proud to be able to support in the north Baffin region!
This August was a very different one from 2011 – local say that this was “the summer that never came”! The narwhal were there certainly, in Tremblay Sound and areas near Pond Inlet and Arctic Bay, but they certainly behaved very differently, as the windy, rainy, and gray weather dominated every single day it seemed.
In the 2 weeks we were there we caught 5 narwhal, and fitted them with Argos satellite radios – one seems to have malfunctioned or fallen off within the first few weeks, so we display the weekly updates now on the adjacent map, for the 4 animals (2 are males, and 2 are females). This year we’re able to give a small profile of the individual animal – sex, length, and even a nice mugshot/the radio when fitted.
Although there were far fewer bird species than in the same period last august around the Tremblay Sound camp, the daily rain/deluge this year was great news for plant life – many species that hadn’t flowered in 2011 august camp were carpeting the low tundra ‘garden’ beside our camp this august. We were also treated to almost daily visits by up to 4 polar bears and 5 arctic foxes, and a few narwhal carcasses along the coast provided much welcomed food for these bears and probably other scavenging foxes.
Right now, we know that narwhal 01 (tag #115959, a 4.4m male) moved quickly west into Admiralty Inlet, after tagging in mid-August, and remained there for September. It seems now to be slowly edging eastwards, catching up with the other 3 animals, heading east before the winter sea-ice starts forming fast from the shoreline outwards. In early October now, the region now has routine sub-zero temperatures, with overnight lows at -10C or lower, so sea ice will start to reappear soon., and we can expect the narwhal to keep heading steadily along their continental shelf migration corridors towards the wintering areas, where they will feed at much greater depths for much of the winter.

Climate change shapes polar bears’ past… and future

General, Polar bears,

© Eric V. Regehr / USGS


Change… Following on the well-traveled path of the Greek philosopher Heraclitus and others since, Isaac Asimov once said:
“It is change, continuing change, inevitable change that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be…”
Alternatively – change is the only constant.
The planet we call home has been changing since it all began some four billion years ago. From the formation of our current atmosphere to the position, shape, and size of the continents that support us, change has indeed been a constant. Therefore, while the world is certainly a very different place today than it was say a thousand years ago, the questions that haunt us now have to do more with the rate, magnitude, and drivers of that change. Answers to those questions are providing some troubling, if not alarming, data regarding human driven changes. Some scientists have even coined a new term for our current era: the anthropocene: the time when human activities became the dominant drivers of key global systems and biodiversity.
Nowhere are these questions more acute, and the transformative affects more apparent than in the Arctic, a region that is warming at more than twice the global average. The face of that change for many is the iconic polar bear. A warming Arctic is rapidly eroding the very sea ice that polar bears need to be- well- to be polar bears as we know them today. While polar bears have clearly survived warming events in the past, there is no reason to infer the bears we have today will be as fortunate. A host of scientific research has clearly laid out those concerns and the measurable impacts of warming to date on some management units like Western Hudson Bay. However, some new observations of hybrid bears in the wild and fresh data on polar bear genetics have some people asking questions.
First, let’s look at the important recent genetic study (overview | original study) that resets our collective understanding of bear evolution and relatedness. This paper was several years in the works and required the collaboration of many scientists from around the world. It will not be the last word on polar bear evolution, but it provides a significant new dataset and several new hypotheses that reshape our understanding of this species. The essence of this first full look into the polar bear genome is that they split from a common bear ancestor with brown bears much longer ago than currently thought (up to 4.5 MYA) and that the two are sister species that have interbred historically. Polar bears likely co-evolved with brown bears, but did not evolve fromthem as previously thought. Researches also theorize that past changes in climate likely brought these two species into closer proximity that allowed for this hybridization. While some of their genes may carry on through cross breeding, there is no reason to believe the animals we know as polar bears would endure.
Genetic data also suggest that polar bears occur in much smaller numbers today than in prehistory. There is also no evidence that early polar bears resemble the highly specialized animals we know today. These historical population estimates appear to track changes in climate, showing a long-term decline in numbers since the last ice age. One result of this decline is that polar bears likely possess far less genetic diversity today than they had historically, making them more vulnerable to recent and projected changes.
At the end of the day, whether polar bears are 150,000 years old or 5 million, in the face of current persistent and rapid climate warming, the world around them (and us) will be unlike anything they have experienced by the end of this century, if not earlier.