Follows is a partial list of Gourd weights.

They are in order of weight, lightest to heaviest.

Please do NOT choose a gourd on weight alone. Many things should be considered when choosing what kind of gourd you want to offer your Purple Martins. Such as accessibility, safety from predators, entrance type, gourd wall transparency, ect

Heath (Carrol) gourds -7 ounces
BigBo gourd (ESTIMATE) - 20 ounces
Combo Plus with tunnel - 48.2 ounces*
BO11 Plus (with tunnel) - 48 ounces
BO11 (with ultimate tunnel) - 32 ounces
BO11 (NO tunnel) - 29 ounces

Natureline- 22 ounces
Troyer horizontal gourd - 24 ounces*
Troyer vertical gourd - 18 ounces *
Combo gourd - 25 ounces
Supergourd -32 ounces
Excluder gourd - 32 ounces