Dear listers and colleagues, WHO: I am a PhD student reviewing the concept of density dependent (DD) in ecology, under supervision of Corey Bradshaw and Barry Brook at the University of Adelaide (South Australia). REQUEST: I am gathering an audience of respondents to a fairly simple questionnaire dealing with regulation of population size and demographic density dependent (DD) feedbacks. The results of the questionnaire will be incorporated in a manuscript in which I am reviewing the use of DD across taxa and ecosystems in the ecological literature (1980-present). AIM: Given that many authors have stated that a main cause of the regulation debate has been terminology, my goal is not to produce new definitions (which would do nothing but add more unnecessary rhetoric to the debate), but to assess the degree of consensus in the conceptualization of DD and of related terms. QUESTIONNAIRE DESIGN: a list of closed questions on 4 topics. It should take you not more than 20 min. to complete. HOW: If you are interested in filling the questionnaire, please send me an e-mail (to me not to the list). Questionnaires will be distributed next week and would need to be completed within 1 week from reception. IMPORTANT NOTE: Please the survey is directed to people who have some empirical/theoretical experience in demographic studies and is aware of the regulation/limitation paradigms as initiated by John Nicholson versus Herbert Andrewartha in the 1930s or followed by authors like Alan Berryman, Charles Krebs, Robert May, Anthony Sinclair or Peter Turchin in the last two decades. Looking forward to hearing from you, and many thanks for your time on this request. Sincerely, Salva Salvador Herrando-Pérez School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Australia Office phone: +61 8 8303 5254 / Office fax: +61 8 8303 4347 / Mobile phone: +61 406049010 https://www.adelaide.edu.au/directory/salvador.herrando-perez / salvador.herrando-perez@adelaide.edu.au