“…For example , Felsman, 1981;Aptekar, 1988;Valverde and Lusk, 1989;Lusk, Peralta & Vest, 1989;Connolly, 1990;Glauser, 1990;Lucchini, 1993aLucchini, , 1993bLucchini, , 1994aLucchini, , 1994band Green, 1997. Work on a more global level includes Agnelli, 1986, Boyden, 1991and Ennew, 1994.…”