Prof. Franz Bogner starts research trip 40 years late

Prof. Dr. Franz Bogner, now Professor of Didactics of Biology at the University of Bayreuth, wrote his doctoral thesis on neurobiology at the University of Regensburg. However, the topic had changed in the course of his doctorate; actually, he had wanted to deal with the foraging plants of monarch butterflies, whose toxins chemically protect the caterpillars for life. "Supply chain problems of the chemical aromatic substances eventually forced me to switch my doctoral thesis to an African butterfly that is also chemically protected," Bogner says.

But monarch butterflies never let Bogner go. Now, in February 2022, he is in Mexico, finally in the butterflies' legendary overwintering habitat. Since the doctoral thesis, countless other projects had intervened, especially the change of subject from chemical ecology to didactics: "Even getting there from Arizona is still a major undertaking." As a visiting professor at the University of Arizona, however, Prof. Bogner is now closer than he was in Bayreuth. "Seeing the spectacle of millions of butterflies in such a confined area is mind-blowing. In Mexico's Sierra Nevada, millions of butterflies overwinter, i.e. the entire population of North America east of the Rocky Mountains, crowded together on just a few hundred hectares of space," Bogner notes enthusiastically. "The phenomenal thing is that, in November, the great-grandchildren of the butterflies will return, having started their journey north in March. So how do they know their destination?" Thank goodness protected areas have been designated in the meantime, some even with World Heritage Biosphere Reserve status.

What at first glance appears in a romantic, glorified tinge is, however, jarring on closer inspection. "Although the monarch butterfly has hardly any predators due to its perfect chemical protection, we nevertheless have to fear considerably for its winter quarters a good 50 years after their scientific discovery, and wonder whether there are still another 50 years to go," says Bogner. The impressive pictures of millions of animals hanging in dense clusters on the trees is deceptive. "Like many insects, the monarch is hugely endangered; there are serious estimates that the monarch population has shrunk by up to 90% in the last 50 years." In the USA, it is mainly threatened by large-scale industrial farming with its massive use of insecticides, which leaves no room for the special forage plants; while in Mexico, it is mainly illegal logging that gnaws away at the hibernation areas. "Although various protected areas have been designated in the meantime, they are far too small and not easy to protect," explains Bogner. Illegal logging is too lucrative to stop it completely. "However, it was shocking TV footage showing the sawing down of butterfly-laden trees that first built up public pressure for the designation of small protected areas."

The current reason for the trip is therefore to establish cooperation project with environmental educators from the University of Guanajuato in order to raise awareness for the protection of this unique natural phenomenon through tailor-made youth work. In the long term, democratic majorities are needed for sustainable nature conservation; and inspirational educational work could be the cornerstone for this.