Muskox – I’m a Survivor!

Muskox – I’m a Survivor!

Muskox – I’m a Survivor!

4 minute read – 

The muskox is an adaptable animal. In the face of climate change a generalist diet with a slow metabolism helped this species survive through the last ice age and to today while other megafauna, like woolly mammoths, went extinct.

During Beringia there were two types of muskox present on the extensive grassland biome – Ovibos moschatus, the tundra muskox that roams today, and Bootherium bombifrons, the helmeted muskox. 

The helmeted muskox did not survive the Pleistocene even though it was endemic to North America and had a wider range than its relative, the tundra muskox. If you could imagine this Beringian muskox was taller and more slender than those of the living tundra muskox and its wider range spanned an area from Texas all the way to Alaska. Like many of the horn and antler bearing animals of this era it was all about BIG, oversized, dramatic displays for sexual selection. The helmeted muskox had longer deeper skulls that supported higher and more flaring horns than the tundra muskox. But, size didn’t get selected as most important for survival in this dramatically changing and climatically unstable landscape. It seems not only was smaller horns preferred through evolution but overall body size too – the less compact nature of this muskox might have played a role in its extinction along with many other large herbivorous mammals of its’ time.  

The tundra muskox crossed the Bering land bridge from Eurasia into North America about 100,000 years ago. A more focused range and smaller size as well as thicker coat than that of the Bootherium, the Ovibos remains a resident of the Arctic landscape to this day. What’s pretty incredible is that these muskox have changed, genetically, very little since their days on the Mammoth Steppe. The muskox of today’s Arctic Archipelago are however much less genetically diverse than those that lived during the last Ice Age which suggests they were not completely unscathed during this time of climatic instability. Significant population and geographical range shrinkage restricted the tundra muskox to Greenland and much of the western Northern American Arctic populations are reintroductions from those limited genetics. The two types of muskox of the late Pleistocene did not mix genetically and the reduction of both species, including the extinction of the helmeted muskox, seem to exclude humans as a driving force behind these population dynamics into the Holocene.

Ovibos moschatus, the tundra muskox, was able to ride the waves of climate change over tens of thousands of years. Their adaptability to variability, including climate and thus vegetation quantity and quality, fostered this large Ice Age mammal to survive a formidable narrow niche of the Arctic biome to present day. What might the future hold for the muskox?

Photo credit L. Caskenette

Resources:

Thanks to Dr. Grant Zazula for taking the time share incredible insights into the past, into Beringia with the YWP crew! 

Ancient DNA analyses exclude humans as the driving force behind late Pleistocene musk ox (Ovibos moschatus) population dynamics. Paula F. Camposa, Eske Willersleva, Andrei Sherb, Ludovic Orlandoc, Erik Axelssona, Alexei Tikhonovd, Kim Aaris-Sørensena, Alex D. Greenwoode, Ralf-Dietrich Kahlkef, Pavel Kosintsevg, Tatiana Krakhmalnayah, Tatyana Kuznetsovai, Philippe Lemeyj, Ross MacPheek, Christopher A. Norrisl, Kieran Shepherdm, Marc A. Suchardn, Grant D. Zazulao, Beth Shapirop, and M. Thomas P. Gilberta.

Musk ox (Ovibos moschatus) of the mammoth steppe: tracing palaeodietary and palaeoenvironmental changes over the last 50,000 years using carbon and nitrogen isotopic analysis Maanasa Raghavan,, Gonçalo Espregueira Themudo, Colin I. Smith, Grant Zazula, Paula F. Campos

Tundra Muskox

Helemeted Muskox

Lindsay Caskenette

Lindsay Caskenette

Manager of Visitor Services

Lindsay joined the Wildlife Preserve team March 2014. Originally from Ontario, she came to the Yukon in search of new adventures and new career challenges. Lindsay holds a degree in Environmental Studies with honours from Wilfrid Laurier University and brings with her a strong passion to share what nature, animals and the environment can teach us.

867-456-7400
lindsay@yukonwildlife.ca

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I Wish I Was as Tough as a Chickadee!

I Wish I Was as Tough as a Chickadee!

I Wish I Was as Tough as a Chickadee!

6 minute read – Banner image photo credit: Syd Cannings, iNaturalist

Gram for gram, there are few creatures in the North that have the endurance, temerity and constitution equal to a Boreal Chickadee. An iconic small bird of the north, this species lives its entire life in the Boreal forest and does not migrate to warmer southern climates in the winter months. Chickadees have adapted to not only survive, but to thrive in harsh winter conditions known across this northern biome.

For hundreds of thousands of years Boreal Chickadees, a cousin of the Black-capped varieties, has called the upper lands of North America home. It is believed to have crossed the Bering land bridge from present-day Russia into North America, very much like the first humans and many animal species to arrive in the Americas.

A secret to the Chickadee’s success is its work ethic where much of the summer is spent gathering and storing food, in the form of insects and their larva; seeds of many varieties and fat often gathered from animal carcases killed by much larger predators. Chickadees are frequent participants in cleaning up the remains of other animals as they can eat and digest just about anything organic.

They cache their winter larder in the bark and crevasses of trees, in tree cavities and roots, rock faces and structures. They demonstrate a very reliable memory for where they hid these morsels as some weeks later they return and consume them, often retrieved from beneath snow cover.1https://www.hww.ca/en/wildlife/birds/chickadee.html

A very social bird, the Boreal Chickadee is often found in the company of its cousins the Black-capped variety, Nuthatches, Pine Siskins, Red Polls, Kinglets and other regular visitors to bird feeders in the back yard. Their cheerful call is very recognizable and can often be heard following an insect hatch when their food gathering activities stimulate greater activity.

It is believed that Boreal Chickadees mate for life with the pair remaining together all year. The nest site is often a hole in a tree, either a natural cavity or old woodpecker hole; chickadees may also excavate their own site or enlarge an existing hole. The nest site is usually low, within twelve feet above the ground. Both male and female help with excavation, but only the female builds the nest inside. Nest has a foundation of moss, bark strips, lichens, topped with: feathers, plant seed fluff and the fur and hair shed by local animals. In human occupied locations, nests have been found to contain clothes dryer lint, threads and strings and similar items useful for the purpose.

This is a Boreal Chickadee’s cousin, the Blackcapped Chickadee making a nest in the spring of 2020. Watch the Wild Spring Adventures video for the action of this busy bird and other spring happenings at the Preserve. 

After breeding, the hen will lay up to nine eggs in a single clutch. These are white, with fine reddish brown dots often concentrated at the egg’s larger end. Only the female sits to incubate the eggs which take between ten and fifteen days to hatch. The male captures food and brings it to the brooding female during incubation. The female stays with the young and broods them much of the time at first, while the male continues to bring food. Growing quickly and developing flight feathers within a week of hatching, the young leave nest at about 20 days.

As summer concludes and the fall winds blow through the trees, Chickadees put on fresh, heavier plumage. And their feathers are more dense than most birds’, creating a comfy down parka for the chickadee. And most impressive, the chickadees adapt to deep cold by lowering their body temperature at night from 42 degrees Celsius to just 29.5 degrees. In this way, the birds conserve their stores of insulating fat as their metabolism slows. They fluff their feathers up so they truly look like little balls of fluff capturing more body heat within the airspace created within their feathery parka.

An average Boreal Chickadee weighs only a third of an ounce and its body size – without all the fluffy feathers – is about as big as an adult human’s thumb. It truly is remarkable how a creature this small and delicate can endure the harsh frigid cold of a six-month Yukon winter.

Each year the local Yukon Bird Club does several outtings and observations including a the winter seasonal Christmas Bird Count across the Territory – several variety of chickadee are noted to withstand Yukon winters! It’s an excellent citizen science engagement that contributes to a North American wide bird monitoring and conservation program. The Preserve boasts an array of species for bird lovers year-round but especially in Spring migration and throughout summer.

Annual Spring bird walk at the Yukon Wildlife Preserve.
Photo Credit: Jake Paleczny. 

Doug Caldwell

Doug Caldwell

Wildlife Interpreter

Doug is one of the Interpretive Wildlife Guides here at the Preserve. An avid angler and hunter he has a broad knowledge of Yukon’s wilderness and the creatures that live here. With a focus on the young visitors to the Preserve, Doug takes the extra time to help our guests to better appreciate the many wonders of the animal kingdom here in the Yukon.

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