 Males are generally larger than females and have longer bills . The smallest species is the brown pelican , small individuals of which can be no more than 2 @.@ 75 kg ( 6 @.@ 1 lb ) and 1 @.@ 06 m ( 3 @.@ 5 ft ) long , with a wingspan of as little as 1 @.@ 83 m ( 6 @.@ 0 ft ) . The largest is believed to be the Dalmatian , at up to 15 kg ( 33 lb ) and 1 @.@ 83 m ( 6 @.@ 0 ft ) in length , with a maximum wingspan of 3 m ( 9 @.@ 8 ft ) . The Australian pelican 's bill may grow up to 0 @.@ 5 m ( 1 @.@ 6 ft ) long in large males , the longest of any bird . 
