Guard dog suggestions?

[Beakrr]

I have about two dozen birds. I have confirmed sightings of foxes, possums, raccoons, hawks, and roaming dogs on my property. They have taken 20 birds over 2 years. It’ll be calm for weeks and weeks and then there will be a massacre.

I have 4.75 acres.

I have a dog that stays out. She’s a cocker spaniel/heeled mix. She’s old and arthritic, so she doesn’t protect much.

Can anyone recommend a guard dog that
1. Doesn’t roam
2. Isn’t 100 lbs
3. Won’t eat the mailman/UPS guy if left out all day when I’m not home.
4. Does leave giant piles of you-know-what

I was interested in a Great Pyrenees until I saw one in person. They are too big.

I look forward to your recommendations. Google doesn’t have many good ones.

 

[50-45-1]

Australien shepherd , great dogs. Get a pup and let your older dog teach him the ropes.
Our old dog Momo (passed now), taught our 2 existing dogs in this way and they are terrific. Miki is Austrlien cattle dog/border collie mix.
And our 2 year old Zip, is australien shepherd/pit bull mix.
Medium sized dogs, very fast and agile, smart and obedient.
Picture of Zip sitting on his favorite stump, looking down the hill where preditors like to sneek in.

 

[Folly's place]

Your immediate and least expensive fix is properly set up electric fencing! Premier1supplies.com, and Howard E are great resources for help in this.
You will need fencing for any dog too.
Raising the perfect dog or dogs takes time, and breed may not be the most important issue. Medium or small will get killed by other dogs or coyotes, Long haired dogs overheat easily in hot climates and take more coat care, and short haired dogs won't be warm in snow.
Guard dogs guard! This likely includes stray humans, as delivery people and maybe children.
Livestock guard type breeds still take training, especially because non of them were meant to guard chickens. Doable, but think months or years of training.
Centrarchid uses pointer types, some folks use labs, some find mixes from the shelter just perfect. My Chesapeakes did great, but were fenced and lived indoors. The chickens have a safe coop and run, and free range sometimes, and sometime have losses due to that.
You could Invisible Fence your property, or use electrified poultry netting for your flock, or some combination of these things too.
Mary