Last year Marc Champagne published an article in Sign Systems Studies in which he refers to my 2003 article "Umwelt ethics". This is the complete reference:
Champagne, Marc 2011. Axiomatizing umwelt normativity [25-26, 57 – Tønnessen 2003: 287]. Sign Systems Studies 39.1: 9-59.
Excerpt (Champagne's footnote no. 31):
Tønnessen (2003: 287) remarks that Uexküll never discussed "whether attribution of moral status to animals is possible within a Kantian framework".
The context is (here presented as fragment only) the following sentence: "Whereas in Kant's philosophy we find epistemological solipsism coupled with an assignment of ethical primacy to the Other (Kant countenancing other minds in practice but not in theory),31 ..."