Why are blackbirds digging the garden

In all the years I have been gardening and feeding birds this is the first year that the blackbirds have decided to dig up everything in sight.  The garden looks a complete mess after a couple of days, bark mulch all over the paths, bulbs and plants dug up and left laying around, it's a constant battle putting it all back and very cold too.  Has anyone else experienced this.  It has always happened but not to the extent of this year. I love the birds to bits but they are trying my patience this winter.

Jobird, we love the blackbirds but have always referred to the as "The Hooligans".  This tossing around of bark mulch whilst searching for food sounds like normal behaviour to me.  Got to say they've never dug bulbs up - the squirrel usually sees to that .  

Just saving you a job

Your soil must be easier digging than I'm used to Jobird. The blackbirds sling mulches  but the bulbs are in some pretty solid soil

They are just looking for something tasty to eat,annoying but that's the joy of wildlife,and they will eat all those pesky snails and slugs.

I have to say, I kept finding several bulbs and flowers damaged in the way. I eventually found out that it was squirels who were looking for food and random acorns they had buried earlier in the season, 2 of my large planters had to be re-done. Maybe if you are able to put some food out that they like they might stop searching for their natural food.

I feed the birds and put out plenty of sultanas, chopped apple and oats for the blackbirds, but I can't provide what's best for them - worms - they have to find those themselves, and they do.  

I love to watch the blackbirds rootling around in my borders for worms - it means my soil must be in pretty good heart.  After all, sweeping some bark mulch back off the path every few days isn't really that onerous is it?  Far better than starving birds IMHO.

As for digging up plants and bulbs  unless  your bulbs are planted far too shallowly, or you've seen a blackbird with a trowel under his wing, it's unlikely to be them - far more likely to be pesky grey squirrels - plant your bulbs deep and in  'bags' made of small mesh chicken wire' - that'll stop the little blighters.

My blackbirds dig through my compost bins & they can fairly shift a sizable amount in a short time!!  They love snacking on my worms.  Pity they didn't like the slugs so much.  The birds did a rubbish job on them last year.  If humans ate them I could have raised 3 sets of triplets out of my garden alone!