Thanks everybody. I did some searching for common repelants for lettuce feasting insects and came up with garlic and pepper as commonly being effective. I may also look into using BT, though I'd prefer to stick with stuff I have around my house while I can. I do think it's some sort of insect, I still havent been able to observe anything though. I feel like if it were some sort of rodent there would be some kind of trace left behind, a whole or disturbance in my netting, footprints, trampled seedlings, something, none of which I've observed. It's not the whole plant that's being eaten, just the two leaves of the seedling with the stalk left there still standing, which quickly dies with no photosynthetic surface. I'm going to keep applying a garlic and pepper spray every 3-5 days and see how that works. Since I applied it Saturday I havent noticed a significant decline in the # of seedlings, so perhaps it's having some effect.

The only thing I was able to make out was the kookaburra...

I spend a lot of time IDing hawks and still find this one challenging. I see you're in the Pacific NW? Please correct me if I interpreted that incorrectly. A very important part of bird IDing is to know the location. This is a juvenile hawk which makes IDing difficult without seeing the full front and the tail. The massiveness of this bird, along with the thick legs and huge talons (and bill) indicate this is not a Cooper's Hawk. But I cannot rule out the Accipiter genus here. I cannot see the tail. Back to that in a sec..... As for Buteos, Western Red-tailed Hawks are usually more marked than their Eastern counterpart and this bird is quite heavily marked down the front side. Perhaps too much for a Red-tailed Hawk (they usually have a white upper chest, not streaked). The front markings could reflect a Red-shouldered Hawk juvenile, but I don't see the upperwing barring that is indicative of a Red-shouldered (and are they even in your range?). My readings say no. Back to the Accipiters..... a 1st year Northern Goshawk is a possibility in your range. I would expect to see less of a solid brown upperwing, though, as the juvie Goshawks have a lot of white mixed in with their brown upperparts and also usually have a pronounced white supercilium above the eye. A Cooper's Hawk (smaller, too small- also would have lighter plumage in the head and back. This bird is dark brown). It's not a falcon at all..... Ferruginous Hawks do not show much streaking, even as youngsters..... Rough-legged Hawks just don't look like that at all and have feathered tarsi...... The best I can do off this photo is juvenile Red-tailed Hawk, but I don't like those upper chest streaks for a Red-tailed. Since I cannot fully rule out a first year Northern Goshawk from this photo, I'd say it's one of the two. It just looks too bulky to be a Coop. If I could see the tail I could ID it.

Well the flower form eliminates Mulberry and Crab Apple. Both cherry and almond are Prunus species so my suggestion still stands. It will not show fruit until the flowers are pollinated. And the seeds are the pits inside the fruit. When it leafs out perhaps you could show us a picture of a leaf or two.