One of the things I typically ask potential customers is “do you have any birds now?” If they do not, I try to convince them to get two. Wild psittacines live together in large flocks or small family groups. They are not mentally designed to live alone and when you have a single bird, even if you spend a lot of time with it, there are going to be times when you’re not around- work, school, weddings, vacations, running errands. When you make yourself your parrot’s only source of social interaction, you unintentionally set it up to have a stressful life. Toys can keep birds busy, but they only do so much and they don’t satisfy any of the bird’s social needs. When a bird has to rely on humans to be its only flock, it will scream when they are out of the room (contact calling, a bird version of “where are you?!”) and can develop stereotypies (purposeless, repetitive behaviors like pacing or plucking). Stereotypies are an indicator of poor animal welfare.
I have kept birds for 27 years. In my professional opinion, a bird housed in a large aviary with a flock of its own kind is far more psychologically healthy than a single bird kept in a pet cage with a zillion toys. Aviary birds have the benefit of exercise, flight, and socialization. The research agrees with me. A UC Davis study found that: “Paired parrots used their enrichments more, and spent less time screaming, less time preening, and less time inactive than singly housed parrots. . . . Isosexual pair housing resulted in a more active and diverse behavioral repertoire, eliminated the development of stereotypy and reduced fear responses to novel objects without imparting significant risk of illness and injury or jeopardizing the ability of parrots to relate positively with humans. Thus, it appears that pair housing can significantly improve environmental quality and positively affect the welfare of captive parrots.”

Access to conspecifics, flight, and foraging are all excellent methods of enrichment.
Many people are concerned that if they have more than one bird their bird won’t love them anymore, or that they won’t have as deep a bond. The latter is true, but context is important. When humans speak of bonding to their parrots or being chosen by their parrots, they think of their parrot as their “baby” and themselves as a parent or caretaker. That is not how the parrot sees it. When a parrot bonds to a person they see the human as a mate. This can lead to all kinds of behavior problems when the parrot’s sexual advances are rebuffed or intentionally squashed. It can lead to aggression when the human prefers their spouse, or shows affection to their child. It definitely leads to stress, as mates are typically not apart during the day unless one is incubating eggs. It’s not a psychologically healthy relationship and it’s unfair to the bird. However, if the bird has a mate (same sex is fine!) you won’t see the same issues. (Please note: a mirror is NOT a substitute for a real bird and can be detrimental).
Will the bird still be tame once it has a companion? Yes! Birds still enjoy interacting with humans even if they have a buddy. You can see evidence of this every time I walk into my aviary:

Vita and her mate.
The relationship won’t be less, it will just be different. You will be someone they enjoy spending time with. Do people stop loving their parents or siblings every time they enter a romantic relationship? Do they love their spouse less because they had a child? Their child less because they had another? No. Love is not a finite resource. People (and birds) can have multiple healthy, loving relationships that are all somewhat different. Each relationship has its own dynamic and fulfills various needs.
To me the ideal is that birds be raised and housed with their own kind from the start- if you’re buying a baby bird, get two. If you do not wish to breed I recommend a same sex pair. Even a mature solo bird that prefers humans can benefit from having a buddy. They don’t have to be housed together, be the same species, or even particularly like one another. They just have to be kept in the same room within sight of one another. My pets ten years ago were my Goffin cockatoo, Loki, and a mitred conure, Verde. They disliked one another. When I first started having children I had little time for my birds. I’m sure Loki and Verde missed me, but they never developed any psychological issues from lack of human contact. In fact, over time I saw their poop piles move towards each other’s cages. When Verde passed away Loki immediately began to scream more. I gave her as much attention as I could but it didn’t really die down until I got her a replacement buddy (my pionus, Lando).
This is something very serious to consider: Birds are long-lived and regardless of how much time you have now, there will always be a point (or more likely, many points) in your life when you just won’t have as much time as you’d like to spend with your birds. These periods are temporary, yet many people rehome their birds anyway, mistakenly believing it is the best interest of their bird. A bird with a companion is easily able to weather these patches of reduced attention, where a solo bird will feel isolated and forgotten and start to show it by screaming, plucking, or otherwise acting out.
If you are on the fence about getting a second bird, know that your concern is quite common, but the best thing for birds in the long run is to have access to other feathered friends. It will reduce their stress, frustration, contact calls, and help alleviate boredom. It will also reduce your urge to rehome unnecessarily when you find you suddenly have a life event that takes a majority of your time.
Copyright 2018 by Karen Trinkaus. May not be reprinted without author’s permission.