Elk in Study Area (IMAGE) University of Calgary Caption Elk in the southern Alberta study area that was the subject of Tyler Muhly and Marco Musiani's research article 'Humans strengthen bottom-up effects and weaken trophic cascades in a terrestrial food web. Credit Marco Musiani. University of Calgary Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.