We are looking at putting in privacy hedge in our backyard. The location is Ontario in hardiness zone 4b. Looking at something evergreen, but would like it to attract birds. At the same time, we have a dog, so we don't want something that will have berries that would potentially be dangerous to our dog. The yard gets pretty good sun. We aren't looking at a tree hedge as such, just a good privacy hedge as a sound/neighbor barrier. Any help with ideas would be great. Hope I haven't been too longwinded with this. Thanks. (we used to have a mature tree in our back yard, but we lost it due to storm, hence something attracting birds, to hopefully keep them around now there's no mature tree at the moment.)
Try Arborvitae Thuja occidentalis. The seeds will attract Pine Siskins, etc., though it'll only produce good amounts of seed if you don't shear it closely, and the foliage is often used by other birds for nesting. Non-toxic, safe for the dog.
Eastern white cedar, if you have the room. White spruce can be trimmed as a hedge. Won't have much seed. If you are willing to compromise on the evergreen part cotoneaster makes a good 6-8 foot hedge. In winter its has enough twigs it's hard to see through. Lilac would also work, but you have to spend about 10 minutes per bush per year to maintain it. Pussywillow is another thick branchy shrub. Willows generally need hard pruning to maintain bushiness, otherwise they get leggy and open at the bottom. Dwarf cherries are a possibility, but the pits and leaves are somewhat poisonous. You have to eat significant quantities of both, and the seeds you have to crunch open to access the poison.