Iron nanowires with a square cross section are grown by pulsed electrodeposition within a newly developed nanochannel template that allows for easy characterization. Measurements of the magnetoresistance as a function of magnetic field and temperature are performed within a large parameter window allowing for the investigation of the magnonic contribution to the magnetoresistance of electrodeposited iron nanowires. Values for the temperature dependent magnon stiffness D(T) are extracted: D(T) = D-0 (1 - d(1)T(2)) = 365(1 - 4.4 x 10(-6) .T-2 . K-2) meV angstrom(2). (C) 2015 WILEY-VCH Verlag GmbH \& Co. KGaA, Weinheim