Evolution, Vol. 54, No. 3. (2000), pp. 998-1010.
Journal of Evolutionary Biology, Vol. 8, No. 4. (1995), pp. 463-479.
Journal of Evolutionary Biology, Vol. 21, No. 3. (2008), pp. 651-657.
Behavioural Processes, Vol. 8, No. 1. (March 1983), pp. 91-96.
Animal Behaviour, Vol. In Press, Corrected Proof
Animal Behaviour, Vol. 37, No. Part 4. (April 1989), pp. 600-609.
Animal Behaviour, Vol. 73, No. 4. (April 2007), pp. 661-669.
AUK, Vol. 123, No. 4. (October 2006), pp. 991-1003.
Proceedings of the Royal Society B: Biological Sciences, Vol. 273, No. 1600. (7 October 2006), pp. 2559-2564.
Proceedings of the Royal Society B: Biological Sciences, Vol. 274, No. 1621. (2007), pp. 2035-2040.
Biology Letters, Vol. 4, No. 3. (23 June 2008), pp. 240-242.
Animal Behaviour, Vol. 76, No. 3. (September 2008), pp. 521-528.
Animal Behaviour, Vol. 29, No. 1. (February 1981), pp. 114-125.
Journal of The Royal Society Interface, Vol. 5, No. 24. (6 July 2008), pp. 691-703.
Annals of the New York Academy of Sciences, Vol. 1016, No. Behavioral Neurobiology of Birdsong. (2004), pp. 611-627.
Amer. Zool., Vol. 38, No. 1. (1 February 1998), pp. 179-190.
Trends in Ecology & Evolution, Vol. 11, No. 9. (September 1996), pp. 358-360.
Animal Behaviour, Vol. 25, No. Part 2. (May 1977), pp. 475-478.
Trends in Ecology & Evolution, Vol. 17, No. 3. (1 March 2002), pp. 133-141.
Behavioral Ecology, Vol. 16, No. 3. (May 2005), pp. 580-591.
Animal Behaviour, Vol. 70, No. 6. (December 2005), pp. 1265-1271.
Ethology, Vol. 107, No. 3. (2001), pp. 201-216.
Behavioral Ecology and Sociobiology, Vol. 55, No. 4. (1 February 2004), pp. 341-348.
Animal Behaviour, Vol. 75, No. 2. (February 2008), pp. 489-500.
Ethology, Vol. 112, No. 10. (October 2006), pp. 984-992.
Oecologia, Vol. 157, No. 3. (September 2008), pp. 545-551.