I prefer Leatherwings for pets because they hunt vermin and can be sheared for leather.
I also always bring at least one Golden Goose for the gold bars. Praying for soft metals also provides gold sometimes.
My carpenter knocks out a few beds, tables, and chairs, then starts making the parts for the Guildhall.
In my current game, I've created a mason, smith, farmer, merchant, fisherdwarf, and craftsdwarf before the first caravan showed up.
Good point about the golden goose being used to mint coins, I hadn't thought of that. Praying for soft metal will also make silver and platinum show up sometimes, which is nice. I disagree on leatherwings. You get 1 piece of leather a year from them, and I can have raised 2-7 moleweasles in that time which I can then butcher for meat, turn the blood into trade goods/weapons via armok or turn it into bloodwine, use the bones and skull for drink, hell, I could use the meat for special plants but theres a 20% chance only of it turning into plants so I won't.
Anyone got a list of poisons that you can make/aquire and coat your weapons with?
Leatherwings are shearable four times a year.
- 1 breeding set will produce 8 leather per year.
- no need for nest boxes or egg management to insure they are giving birth.
- female is able to hunt vermin instead of sitting on an egg for a season. (useful for Studding)
- Maturity of one year.
- I'm swimming in meat, bones, and blood from standard hunting.
- As far as I know, leather goods are worth more for trade.
Just be sure to plant some Hide Roots in the spring to make the oil.
I guess I'm just pro-leatherwing. 
Okay, leatherwings versus any birds except the kavernkeet (eggs+wool just too good to pass up, domestic cloth production is just shitty to set up with harder farming so you want to get cloth anyway you can) leatherwing wins hand down. Leatherwing versus horned turtle is more difficult to assess. Leatherwings cost less, they also hunt vermin, give leather quater annually. Horned turtle lays 1-5 eggs quarter annually, take two years to mature, and give shells upon butchering, in case of that one fucking strange mood. You know the one. Prepared food>leather trade. Try trading a barrel of prepared food sometime. You can actually buy out a caravan filled with more food then you just traded them for, plus seeds. there is almost little reason to trade anything else that aren't insanely valuable goods. I stopped bringing stone crafters with me on embark because prepared food. So leatherwings versus horned turtles: personal opinion. I get shit all from hunting to be honest, I just don't have very many wild animals appear, I do bring a hunter in the beginning because I can easily swap him to my first marksdwarf after the initial 10 or so animals that are on the map are hunted and my first migration wave shows up, so I can see how the leather can be an asset. However, needing oil to make it better is a bit...annoying. I don't like farming. Not to mention it takes a while to turn that leather in to useful goods, whereas I can turn eggs into prepared food in a single step.
Now, leatherwing versus moleweasel? Moleweasel wins, hands down. The fact taht leatherwings hunt vermin: Moot point. So do moleweasels. Moleweasels grow larger then leatherwings, in the same time span. moleweasels have a litter size of 4-7. That means they always give birth to anywhere from between 4 to 7 new moleweasels. Also, im pretty sure they have skin in their butching returns due to this line in the raws: [PLUS_TISSUE_LAYER:SKIN:BY_CATEGORY:THROAT] meaning they also produce leather. Assuming the minimum litter size, butchering them after they grow to full size in 1 year, I get: 4 pieces of leather. In 1 year, you also get 4 pieces of leather. I get more meat, I have a chance of getting MORE then 4 pieces of leather, etc. If you could train leatherwings the way you can train hawks, you might have a case, but when it comes to moleweasels versus leatherwings, moleweasels win. it seems a golden goose, moleweasels, a few horned turtles and kavernkeets are the ideal pet layout. alternatively drop the kavernkeets and add some dogs to wartrain. You can't pull off both a golden goose and mastiffs with a 1274 point embark and still be able to fit in enough stuff to have a successful fortress.
Honestly you could just request dogs/mastiffs/kavernkeets from your mountainhomes liason though.
Nest boxes cost a few pieces of wood/stone. not exactly something that isn't in plentiful supply (unless you're on a glacier), and what you call egg management I call a door and a single tile of digging for the nest box. assign nestbox to bird, wait for bird to be inside, lock door. Bird's dont need a pasture to graze so they won't starve.
