Grizzly Bears

Scientists classify any North American subspecies of the brown bear as a grizzly bear – although they’ve actually assigned them the name of a “North American Brown Bear”. However it was first given the name of the Grizzly bear due to its characteristic long, ‘grizzly’ hair. Characteristically, they’re very solitary, active animals. They gather once a year for the “great salmon run”- where they gather at rivers to catch the mass migration of salmon. These bears have one of the lowest reproduction rates across the whole of North America. This is due to many reasons, one being that they reach sexual maturity at around 5 years old – a lot later than most land mammals in North America. When they do reproduce, a female bear produces on average 2 cubs a litter. Once the cubs leave or are killed, the female might not produce a second litter for perhaps 2 or 3 years later.

Surprisingly, Grizzly Bears play a huge ecological role; they have mutualistic relationships with some plants, spreading their seeds. The bears actually help by increasing species diversity in the plants on the forest floor.

Reindeers | #SciSparksAdvent

For obvious reasons - reindeers are mostly known for their link to Santa Claus and make the ideal sleigh pullers. Aside from Christmas, they're more usually seen during their mammoth Arctic migration -  during this, North American herds may travel for more than 5,000km.
Reindeers are also the only kind of deer where both males and females sport antlers, although they still can reach epic proportions in male reindeers.


Throughout the year, Reindeer mostly eat grass but they also take a fancy to virtually any other plant. In the winter - they often eat 'Reindeer lichen', moss and fungi. They are also very sociable creatures, living in groups of 10-100 groups.


As far as breeding is concerned, they mate in October and have a pregnancy of 230 days and give birth in May or June. When they do so, they only give birth to one baby who becomes fully mature at 2 years old. In the wild, they live to between 12 and 15 years old, although some live until they're 20.

Like many animals, they're hunted and have been hunted since the stone age. In northern regions in particular, they eat the meat and use the fur, skin, antlers and bones for various products. The reindeer was first domesticated around 3,000 years ago in Siberia and Scandinavia. Since then, they've been used for transport and pulling sleds. Because they can live in very cold climates - this makes them the ideal animals for the job.  

Our 21st Century World

We now see the world through different eyes. Whether it's global warming and the Europe-wide thunderstorms or the middle-eastern crisis. Whatever it is... we can't help but look at our world through different eyes. So today, I thought as part of the Summer of Science I'd put a collection of my favorite pictures of Earth together. 

And no, this picture hasn't been photoshopped!! 

Just for good measure - one of the coolest astronaut selfies!


Follow the rest of my #SummerofScience and me on Twitter @Sci_Sparks. Don’t forget to download my charity eBook, Science Bites: A Short Tour of the Universe HERE. 

How do the northern lights form?

The aurora borealis (the Northern Lights) and the aurora australis (the Southern Lights) have always been on people's wish list to visit, but how they actually form is a mystery to many people.   Both of the auroras surrounding the north and South Pole occur when highly charged electrons from solar wind (see next post) interact with elements within our atmosphere. These particular solar winds can be up to speeds of 1 million miles per hour! They then reach earth some 40 hours since leaving the sun. They follow the lines of the magnetic field (much like you would see on a diagram). The solar winds then flow through the earths magnetosphere, this is a teardrop shaped area of highly charged electrical fields.

When the electrons enter the earth's paper  atmosphere they come across atoms of oxygen and nitrogen at altitudes from 20 to 200 miles above the earth's surface. The colour of the aurora depends on which atom is struck and the altitude at which this happens. 

• Green - oxygen, up to 150 miles in altitude
• Red - oxygen, above 150 miles in altitude
• Blue - nitrogen, up to 60 miles in altitude
• Purple/violet - nitrogen, above 60 miles in altitude

The magnetic and electrical forces react with each other, which creates the "shifting" combinations of colours and patterns, some people might say that the auroras "dance". The auroras then move along with the atmospheric currents, which can be as high as 50,000 volts. To put this into context circuit breakers in your home start working when the current reaches 120 volts. 

The northern or southern lights generally happen along the "auroral ovals", these are at the centre of the magnetic poles and they roughly coincide with the Arctic and Antarctic circles. They can however, appear further south when there is alot of sunspots, these occur in a rough 11 year cycle the last happened in 2011/12 where many people enjoyed the northern lights outside their normal range.