Coulter Pine

I think with most Pine cones the scales that conceal the papery seeds are closed whilst the cone still has moisture in it and open when dry to let the seeds be well dispersed by the wind. When they get wet they swell and close again to avoid falling during rains as the wet seeds will not carry well even if its windy. Some have larger seeds that are dispersed by birds and squirrels too and in these cases need to be broken into. The birds that do this are pretty well equipped for the job.. as far as I'm aware Crossbills beaks are shaped to prise open things like pine cone scales. It would be nice toknow which birds are most likely to do the business. In the third group the cones are serotinous, or open in response to an environmental trigger. I had to look up Pinus coulteri and along with a number of other Cali. native Pinus the cones open when there's a fire. I think the scales are glued shut with resin, which melts when temps are high enough allowing them to open. Such events usually clear a lot of the parent trees and perhaps more significantly other vegetation less equipped to deal with fire, which ensures enough light and moisture for a mass germination of a new generation to colonise the land! Pretty cool huh? It's an integral part of a number of ecosystems worldwide that need a burn from time to time in order to stay healthy. The study that I looked at showed the importance of rodent carrying seeds away from parent trees & stashing them after they fall to the ground: http://www.jstor.org/pss/20146478

Tentative ID Emma as this is the only Pine I know that fits the bill but there may be another sp with big cones. These ones would actually be at the smaller end of its monster cone potential -my favourite common name for Pinus coulteri tree is 'The Widowmaker' !