Illustration by Aina Bonner


Welcome to AVIENIGMA. This is a personal blog of Josep Antoni Alcover and the views expressed here are not those of my employer (the Institut Mediterrani d’Estudis Avançats – Consejo Superior de Investigaciones Científicas and Universitat de les Illes Balears, Mallorca). They are mine and solely mine. I would like to thank my Institute for the facilities provided for the use of the material preserved in its scientific collection. The mistakes that can be made in this blog are exclusively mine. I apologize and ask for understanding for possible errors.

I hope you will enjoy my queries, their “solutions”, as well as my occasional meanderings.


The initial photographs of this blog have been made available to us by Sebastià Torrens (; and Juanjo Enseñat ( The question mark that accompanies these lines and the challenges has been prepared by Aina Bonner ( Xisca Comas, Carme Alcover, Miquel Rayó, Laia Pubill, Alejandro Valenzuela, Pau and Maebh Manning and Pedro Serrano have contributed in different ways to improve the presentation of this blog. Thanks a lot!!!!

Ornithological challenges blog

Informal ornithological questionnaire, enigmas, anecdotes, curiosities and other questions about the extant dinosaurs

The name of this blog, AVIENIGMA, refers to “enigmas” about birds. It has nothing to do with grandparents (“avis”, in Catalan). It is an ornithological blog that was born as a WhatsApp-group during the first phase of the corona-lockdown. It was conceived as a kind of entertainment, a “divertimento”, addressed to a very small group of about 15 friend ornithologists, people who are very enthusiastic and full of knowledge and curiosity on birds. Mostly, amateurs; a few, professionals. It was a way to keep in touch while we were trying stimulate our neurons and learn, all of us, more about birds.

Click to continue reading the presentation

For me, the development of the challenges during the corona-lockdown has been very stimulating and I learned a lot, not only from what I had to read, with pleasure, to elaborate the challenges, but also from the knowledge, opinions and views of those who participated. The “Ornithologic Questionnaire” in the WhatsApp phase had its limitations, and it came to an end with the “35th challenge”.


With this blog I want to rescue the work done, give it some continuity, and make it more extensive than it was through the primitive WhatsApp-group. Within this rescue, I will start by repeating the challenges posted in the WhatsApp phase, while the answers, the “solutions to the challenges”, will be here more elaborate than in the WhatsApp messages. In some way, this is an invitation to the birding community to do an immersion in the bird’s world.


The dynamics of this questionnaire will be to pose a biweekly challenge to those who want to answer it. As a rule, this challenge will be presented on Monday. Responses / comments will be collected in a section that will be not always visible to participants. I will present my “solution” and comments the next Monday, and I will present a new challenge next Monday. So, challenges and answers will be presented alternatively every Monday. I hope you will have fun!


In the answers, I will present not only my comments, but also the bibliography on which I based them. I want to encourage readers to turn to this bibliography to expand their knowledge. Sometimes I will present an illustration from the bibliography consulted. If it is not available in Open Access I will present it with a watermark, which will refer the reader to the consultation of the original work, respecting copyright.


This blog not only has an ornithological function. It also wants to have a cultural function, for the promotion and dissemination of ornithology in Catalan. To this end, it has been sent to the mailing lists of the ornithological societies of the Catalan cultural area, but also to other ornithological societies of the Spanish State. Obviously, it is open to everyone.