I have had the immense pleasure of having had two lorikeets in my life (though not at the same time!), both of them tiny purple crowned lorikeets, a rooster called Sludge back in the 1990’s, and more recently my Princess Lilly Pilly whom we tragically lost in January 2022. I think when most people think about lorikeets they may have the larger rainbow, yellow bibbed or chattering varies in mind. I can really only speak about the Australian species, as I have not experienced the Asiatic species myself so cannot speak to their temperament.
Lorikeets in generally are just that much more challenging to keep. Rainbow lorikeets are not for the faint of heart. They are all cuddly, sweet, goofy birds as babies, but when they grow up and those hormones take hold – BAM – everything changes overnight. Rainbows in the wild live in very large and socially complex flocks with very distinct hierarchies, and they are not above a bit of violence in sorting the social order out. This can translate to you as their flock member in the home, many is the story I’ve read of rainbow owners who claim they cannot go near their previously sweet baby without wearing thick clothing, gloves, hats to protect delicate ears and eye goggles to prevent serious injury. There will of course be exceptions to this, but these are traits that are hard-wired into them over billions of years of evolution and are not easily trained out of them, if they can be ever. Even my tiny purple crowned Princess turned into a murderous banshee for six months of the year in her breeding season, and would continually launch violent attacks at my hands and face from sun-up to sundown for half of the year! This was nothing she or I could do anything about, it was just the way her behaviour and urge to breed was so hormonally and chemically hard-wired and it manifested itself in mad, manic and violent behaviours for half the year, every year!
I don’t know how readily available a smaller species might be to you, such as a musk or a scaly breasted lorikeet. They are not as big and colourful as the Rainbows, but they are just as full of personality but are WAY easier to handle than a big mature aggressive Rainbow. Personally, as much as I love them, I wouldn’t have a Rainbow, I know many do, but for me they're just a bit above my skill set. I knew a lady years ago who had been a sweet baby, but that turned very violent indeed upon sexual maturity, so she thought the solution was to go get him a little friend. BIG mistake, she just ended up having TWO very violent birds who then stuck with their own species and wanted nothing to do with her! They are also not birds who do well stuck in a cage for any length of time while you, for example, go to work all day, and they should not be housed in the same cage as another bird for “company”, as this can lead to fights and injuries, most likely to the other poor hapless bird. Rainbow lorikeet beaks are very strong and can inflict a lot of damage, sometimes requiring lips or eyelids to be stitched back together, and they can make puncture wounds up to 1 centimetre deep!
Diet isn’t that much of a drama really. Lories do not (or should not) eat seeds. Rather should be fed a wet nectar mixture (generally a dry powder mixed with water to make a thin slurry), and this should be left with them for no more than about 3 or 4 hours, depending on how hot the weather is, because it will spoil and need to be replaced after that time. My Lilly would get wet mix for her breakfast, and then I’d replace it with straight dry nectar powder for the rest of the day. Cleanliness is everything, water bowls should be kept on the opposite side of the cage to prevent fouling as they will fling their food into it. Ideally you want to change the water part way through the day anyway because if they can find a way to foul their water, they’ll do it! In a domestic setting, it’s best to feed leafy green vegetables and only feed very minimal fruit. There’s a lot of sugar already in that wet nectar mix, and being in captivity they do not need the extra sugar found in fruit, inevitably their not as active in captivity as they are in the wild and don’t burn that sugar off so it can lead to or exacerbate those already troublesome behavioural problems. Some people will try to convince you to buy nectar pellets for lorikeets but I (and British ornithologist and lory fancier Rosemary Low) do not recommend them. They are too dry and a completely unnatural food made for human convenience to try to curtail that notorious liquid poop, with little thought given to how they affect the bird. It would be like spending your whole life with constipation – lorikeets have evolved their whole gastro-intestinal tract towards a liquid diet and therefore liquid poop is just a fact of life that you need to accept if you want to own a lorikeet.
It's your choice of course, but if you are considering having one, my advice would be try for one of the smaller species if available. Also maybe try to go for a rooster, as they don’t have the reproductive issues that were such a massive problem for my Lilly, and that ultimately claimed her life when she was far too young. But even though she was vicious and violent and as mad as a cut snake (as we say in Australia) I loved my little Princess, so as long as you are aware of the potential issues going in and are not under the illusion that that sweet baby will necessarily remain that way forever, you’ve got a much better chance of being able to make your relationship work, and if you do get one please let me know! I wish you all the very best of luck