Grizzly-Polar Bear Hybrid!

An interesting impact of northward migration! Polar bears and grizzly bears are a close enough match of DNA to mate but under normal circumstances they would never interact in the wild. However, the first hybrid has been found in the wild - and the most likely cause of this is climate driven as grizzly bears move northwards!

References:

http://news.nationalgeographic.com/news/2006/05/polar-bears_2.html

The Real Story

Species all over the world are moving northwards and upwards in order to reach colder climates to live in. To put it simply, climate change is real and happening - whether caused by humans or natural processes, it has warmed the planet by approximately 0.8C in the last century (NASA - [1]). Within this time period, over 2,000 species have moved significantly northward or upward (i.e. tree ranges have shifted up mountains) in order to reach their optimum conditions to live [2]. As their original habitats become warmer, species can no longer survive due to increased temperatures or in some cases lack of food as their sources of prey have moved north. In either case, the ultimate consequence is to move northward to colder conditions and prey sources. However, for many species this is difficult as they could be slow ground movers as opposed to species such as birds and butterflies. I will cover the obstacles many species have to overcome in order to migrate north in another blog.

References:

[1] http://www.nasa.gov/vision/earth/environment/2005_warmest.html

[2] Parmesan et al 1999, 'Poleward shifts in geographical ranges of butterfly species associated with regional warming', Nature, 399, 579 - 583

Guillemots facing extinction?

To begin my blog I want to start off with something simple - a short video from the National Geographic. It shows the impact global warming has had on the polar regions, witnessed by a man who goes there every year to count the population of guillemots. The three main points the video makes are:

1. Reduction in pack ice has decreased the number of Arctic cod which the guillemots feed on.

2. A general increase in the area has led to an increase in other birds which increases the competition for the small number of Arctic cod left.

3. Polar bears are left stranded in this area due to pack ice reduction and so have begun to eat a large number of guillemots.

These are just a few impacts of global climate change. The fact is, in the last decade more than 2000 species are thought to be moving north at a rate of 15 feet per day to escape the increase in temperatures due to global warming [1]. In this blog I will be looking at different species that have successfully migrated north, and those that are at risk of extinction due to habitat fragmentation and physical boundaries such as oceans that prevent this movement. I will look at past examples of species migration and how we can learn from these to predict the bleak future of our bio-diverse planet.



References:

[1] http://news.discovery.com/animals/animals-migrating-north-global-warming-110818.html