Now, scientists are looking at the rhino’s estrogen levels and see that they have higher levels than they normally would after being pregnant. So with that they look at what may cause this. They actually looked at the rhino’s diet and the levels of estrogen in the food they’re given in captivity. There are plants that exhibit estrogen in them and rhinos are also herbivores. Now, alfalfa is one of these plants that rhinos are actually given as a part of their diet. The grasses they eat contain 20% of alfalfa and the pellets given to them have 33% of it in them. Another plant that rhinos are given that contain this estrogenic compound is soy. So this could actually be why these rhinos are not reproducing! It’s sad to think that in an attempt to help the rhinos we’re actually not being successful.
Christopher Tubbs, Phillip Hartig, Mary Cardon, Nicole Varga and Matthew Milnes. "Activation of Southern White Rhinoceros (Ceratotherium Simum Simum) Estrogen Receptors by Phytoestrogens: Potential Role in the Reproductive Failure of Captive-Born Females?" Endrocrinology. The Endocrine Society, 17 Jan. 2012. Web. 24 Oct. 2012. <http://endo.endojournals.org/content/153/3/1444.abstract>.
