Flat but wide tree/shrub/bush?

[SunshineAndSoil]

Things that I'm looking for:
1. Shorter than 25 feet
2. Branches close to ground
3. Medium to fast growth
4. Wider than 15 feet
5. Evergreen
6. Not poisonous to animals

The thing that I want it for is to provide something for poultry to hide under from hawks.

 

[Tetters]

How about Cotoneaster horizontalis or similar intertwined with a strong growing rambling rose - the framework for a rose can be horizontal as well as upright. Add in an evergreen climber like Hedera. Stick some Eleagnus ebbingei in too maybe for good measure.
We used this kind of mix to protect an area where the feeders were for very small birds. They were bothered by a sparrow hawk that pestered daily. It worked! The thorns on the rose were definitely a good deterrent.

 

[cpp gardener]

Skip the ivy (invasive exotic) and choose any Cotoneaster or Pyracantha and that sounds like a good idea.

 

[Tetters]

I`m not sure what kinds of Ivy you have in the USA , and whilst the arboreal type of the plant can get very big and possibly troublesome if not looked after, many of the smaller cultivars we use here can be invaluable for evergreen cover - especially for the smaller birds. An example of these is ''ice cream''

shown here, and goldheart

Any basic gardener should easily be able to keep these in check.

Failing that - and as an afterthought, there's always chicken wire.