The Green Gazette

Hi everyone,

This is my video on apex predators, specifically looking at the affects of the reintroduction of the Gray Wolf into Yellowstone National Park

https://www.youtube.com/watch?v=YzuyDMQWr_A 

This is all the resources I used to create the video “the wolves of Yellowstone”, links to the articles are included. There is much more information out there and this is a good starting point if you want to know more. There is also the Yellowstone wolf project website and this is the link:- https://www.yellowstone.org/wolf-project/

And this website has annual reports on the project if you want to check that out as well. https://www.nps.gov/yell/learn/nature/wolf-reports.htm

Finding the wild wolves of Yellowstone by The Greater Yellowstone Coalition

http://greateryellowstone.org/blog/2018/11/30/finding-the-wild-wolves-of-yellowstone?gclid=CjwKCAjw7LX0BRBiEiwA__gNw4uiv6RxgPIBAg5fSBOiMXT_urf9FhueBItc2IHD064QEijZvlQjTBoCYvEQAvD_BwE

Throughout the 1800s wolves were eradicated from much of the US continent, including Yellowstone national park by the early 1900s.

1970s saw the introduction of the Endangered species act which recognised the moral and legal obligation to prevent human-caused extinction of other species.

Reintroduction of the grey wolf into Yellowstone national park in 1995:

The greater Yellowstone ecosystem contains the large intact landscapes and massive herds of elk wolves need to thrive.

Creating a living laboratory in ehich scientists could study the return of the long lost apex predator. (Greater Yellowstone Coalition, 2018)

An introduction to Conservation Biology by Primack & Sher, 2016

Their interactions with herbivores like elk are changing rivers in some areas but are less pronounced impacts in other areas

 Aims to restore the equilibrium of predators, herbivores and plants that existed prior to human intervention in the region

Changes in habitat selection by Elk after reintroduction.

Top predators/ Keystone species 

 Keystone species effect the organisation of the community to a far greater degree that we would predict if we only considered their numbers. (Primack & Sher, 2016)

“the loss of keystone species will lead to losses of numerous other species as well” (Primack & Sher, 2016)

“the elimination of even a small number of individual predators may result in dramatic changes in vegetation and a great loss in biodiversity” (Primack & Sher, 2016)

https://www.britannica.com/science/trophic-cascade

Trophic cascade- an ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling. (Britannica, n.d)

https://www.nps.gov/yell/learn/nature/wolves.htm

prey mostly on Elk (90%) during winter,

Elk kills benefit other species- ravens, magpies, eagles and coyotes eat left overs)

1995 to 200 in early winter, elk calves made up 50% of the wolves diet while bull elk made up 25% this ratio reversed in 2001 to 2007, indicating changes in vulnerability and availability (National Park Service,)

Trophic cascades in Yellowstone: The first 15 years after wolf reintroduction Biological Conservation

Volume 145, Issue 1, January 2012, Pages 205-213

https://www.sciencedirect.com/science/article/pii/S0006320711004046

Riparian vegetation recovery in Yellowstone: The first two decades after wolf reintroduction, Biological Conservation, Volume 198, June 2016, p93-103 https://doi.org/10.1016/j.biocon.2016.03.031

(these two articles are where I got the information in the section below)

Changes in Elk behaviour

Before wolf reintroduction Elk numbers were 15,000 plus and after reintroduction by 2010 numbers were down to 6100 approx.

Aspen browsing areas decreased from 100% to as little as 4% in some areas.

 Meaning the elk were changing their eating behaviours staying away from areas that made them an easy target or that were difficult to get away from.

 This resulted in a change in average heights of the aspen trees. Before wolf reintroduction the average height was 40cm and in 2006 the average was 230cm. and the browsing height of elk is approx. 200cm. (trophic cascades in Yellowstone).

During the seven decades of gray wolf absence in Yellowstone National Park intensive browsing by Rocky Mountain elk suppressed the growth of young deciduous woody plants within the parks northern ungulate winter.

24 assessments of these woody plants in riparian areas have been published all but two of these studies found increases in plant height, stem diameter, stem establishment, canopy cover or recruitment.

(I didn’t end up writing anything up about the beavers, but these are the articles I used to find that information)

https://bioone.org/journals/Northwest-Science/volume-86/issue-4/046.086.0404/The-History-and-Current-Status-and-Distribution-of-Beavers-in/10.3955/046.086.0404.full

Why Beavers Love Wolves by Gerry Bishop, Ranger Rick Jul 2004 vol. 38 Issue 7, p16-19 (I don’t have a link for this one as it was in my universities library and therefore not accessible to anyone not attending my uni).

I hope you enjoyed this video and found it interesting, If you have any suggestions of topics you would like to know more about please let me know!

 Thanks,