Nah, this is the '
Off Topic Board', we can talk about just about anything here... except for politics, definitely not politics!
As for the pellet gun, that might be a viable option in your part of the World, and would be even here, if only we were another few km's out of town!

But because we're now in a 'township zone', shooting is 'legally' not allowed unless you're an authorised 'Animal Control Officer' - and our local Council has just one of them!

Besides, if I used a 'quiet' gun of any sort, I could certainly keep them off the lawn, but only if I guarded it
every minute of the day, 24/7 (they've even come onto the lawn while I've been sitting on the front verandah dictating this, just a few metres away, and they come back within minutes of being chased away!

) but whatever way I might kill them, then I'd hafta be able to dispose of the bodies in a way that wouldn't reveal that they died from any projectile, and by my earlier 'estimation' that mean there'd be waaay too many carcasses to burn, bury, or dispose of otherwise in a way that doesn't draw unwanted attention! I can't put anything more into the ground in the back yard, too many b...

We're not allowed to burn (and they stink when you burn them anyway) and if I put any more in the tip &/or garbage, 'people' will ask even more pointed questions than they do already!
Here in Oz, any projectile weapon falls into the same category, including slings, slingshots, bows & arrows, crossbows, spears, spear guns, whatever, even an air powered 'spud gun' shooting tiny organic pellets! Mind you, I do wonder if I'd get away with using one of those small 'modified bicycle pump' style spud guns shooting 'pellets' of poisoned carrots or wheat grains?! That'd really just be poisoning them, wouldn't it?

Probably wouldn't get away with it tho, cos it's still a 'projectile'.
I've considered the higher fence, &/or using wire mesh instead of bird netting, but I already got a warning from our local Council about the bird netting, cos we aren't allowed to have any 'fences or fence like' structures in front of the house due to encumbrances - apparently, anything like that in front of the house clearly has to be a temporary structure that gets removed daily! So a higher wire fence
might be doable and may be my only viable option, but it'll be a pain to put up and take down every day!
That ^ is also something that might work well where you are, and it
used to work here too, but not where we are now 'in town'! There's very few non-domestic dogs or cats around here, any animal that isn't registered is actively 'removed' or 'culled' on a regular basis; and all the registered/domesticated animals have curfews and fairly stringent over-night controls imposed. Domestic cats aren't allowed outside
at all unless they're in a fully enclosed (including overhead) wire run; and cos it's now a town, dogs need to be supervised and under control at all times. So any cats or dogs loose on the streets at night fairly rapidly become 'former' cats or dogs. And because the Wetlands just down the road from us is a Wildlife & Native Bird Sanctuary, we get very regular sweeps from the local Animal Control Officer, but he's just not running over or shooting enough rabbits when he does a sweep!
There's been a very active 'Fox Eradication Program' in the area too, so we don't have too many of them around any more, altho there is one aging dog fox known to be around the place and still eluding 'capture' (with a high velocity lead injection!) - I guess he might get slower as he gets fatter, but that'll probably just mean he gets shot sooner rather than later!?! As for hawks & eagles, they tend to keep away from the built up areas, and outside of those, they're so well fed now that the Wildlife Protection mob are often out picking them up off the roadsides and taking them to shelters until they digest enough/lose enough weight to be able to fly again!! No joke! We've got Whistling Kites here that are growing bigger'n most of the hawks, and the hawks that are almost as big as Wedge Tail Eagles - there's probably going to be a population boom in all of them soon, cos they're all so well fed!

That might help with the rabbit problem, altho by then, the rabbit numbers will probably be so much greater that it's an un-winnable battle, and there won't be anything green left by then anyway!
Snakes, we've got plenty of them, and they too, are already so well fed that they can't eat any more and almost can't be bothered to get out of people's way! That'll mean a population boom of them soon too, but I doubt it'll make much impact on the rabbit population growth - and that'll probably mean a snake eradication program; which will likely lead to a boom in the rat & mouse population and another eradication program, and... Ah, you get the picture!
I'll try the Cayenne pepper, it's a possibility, but then, given the limited & short term success of the rodent/bird repellent spray (which is a capsaicum/chilli/pepper based product) I doubt it'll work for too long - worth a shot tho, and cheaper than the spray!

And if that doesn't work, I guess that if I want to keep a green lawn out front, I'll be putting up and taking down wire netting fences every day for the foreseeable future!