Since I can't post links - this is at snopes
Claim: Rice thrown to wish newly-wedded couples well can kill their fine feathered friends.
cautioned not to throw rice at the bride and groom, because the grain will prove harmful to the birds who swoop down
to eat it. The rice expands in those little birdy stomachs, causing our avian companions to explode, we're warned. Let's quit worrying about the birds. They'll be fine. Seagulls don't explode when they eat Alka-Seltzer; pigeons don't explode when they eat rice.
This response to a 1996 Ann Landers column in which she "informed" readers about the danger rice poses to birds just about says it all:
The USA Rice Federation in Houston has a message for advice columnist Ann Landers - straighten up and fly right when you talk about birds. In a recent column, Landers warned readers that throwing rice at weddings is Is that the premium bird seed? unhealthy for our feathered friends: "Please encourage the guests to throw rose petals instead of rice. Rice is not good for the birds."
"This silly myth pops up periodically, and it is absolutely unfounded," responded rice expert Mary Jo Cheesman at the USA Rice Federation. Many migrating ducks and geese depend on winter-flooded rice fields each year to fatten up and build strength for their return trek to northern nesting grounds.
Uncooked, milled rice is no more harmful to birds than rice in the field, Cheesman said. The Curator of Ornithology at the University of California at Berkeley agrees.
"It's a myth. There is no reason why birds, including small songbirds, can't eat rice," said Ned Johnson, a professor of biology at Berkeley who lectures frequently on the food and feeding of birds.
Many churchs and reception halls have rules prohibiting the throwing of confetti or rice. These rules work to keep the property clean so that the next happy couple doesn't get its send-off amid the leavings of the previous pair. Confetti is notoriously hard to clean up; not even vacuuming a lawn will return the grass to its pristine condition.
Rice poses a unique danger. Not to birds, though; to people. Scattered on a hard surface (such as the steps of a church or a dance floor) it puts anyone who walks across that surface at risk of taking a nasty spill. Far better to prohibit rice throwing at a wedding than to end up with an injured guest.
Don't do it for the birds, do it for the inlaws.
Barbara "slip covered" Mikkelson
Sightings: In The Simpsons episode of 14 May 2000, Bart is warned not to throw rice at Otto's wedding, lest he cause birds to explode. Also, in the 16 July 2001 episode of the TV soap opera Passions Charity told Tabitha that they don't throw rice at weddings anymore, stating this legend's premise as the reason. And in an episode of the TV sitcom Cybill ("Bachelor Party," original air date 6 January 1997), Holly (Ira's fiancée) dictates that rice won't be thrown at her wedding because it "makes pigeons explode."
Last updated: 25 July 2003
So, apparently, it's not possible for the seagulls to explode. I'm not sure how your husband picked up the corpses, when it's supposedly not possible.