Before purchasing birds, it is a good idea to visit some  bird  gardens, zoos and private aviaries to look at their healthy specimens.   Compare the different types and observe their behaviourclosely.
The choice of dealer is most important when buying birds.  Check  up on as many different sources as possible, as pet stores vary   tremendously in the quality and selection of birds on offer. Do try to  takes  much time as possible over this. It is often better to wait a  little longer for  the birds of your choice, rather than to buy inferior  stock. It may also be  possible too brain birds from experienced  fanciers who wish to sell their  surplus stock. There are some basic  points to search for when trying to select healthy  birds: 
1. Make sure the bird is not sitting huddled up with  feathers puffed out. 
2. Ensure that the eyes are clear and open, showing no signs  of a watery discharge. 
3. Check the vent to make sure it is clean and unsoiled. It  should not appear the damp. 
4. Make sure that the legs and feet are undamaged and toe  nails are intact. 
5. Examine the nostrils to see that they’re clear and free  from discharge. 
6. Feel the breast bone of larger birds to see that there is  a fair amount of flesh on the breast.
Do not worry unduly about the appearance of the plumage.  Molting  bird soften look quite scruffy, as do those that are feather plucked or   have had wings clipped by dealers or exporters. Feathers soon grow  again and a  bath often makes bird look much better. The only point to  remember when  purchasing a moult-in bird is that its general health may  be little under par  and extra nourishment may be required.
When trying to choose a true pair of birds of a species  where no  sexual differences are visible or described, it is avis-able to   purchase several birds and allow them to pair up. This usually results  in at  least one true pair and the surplus may then be sold or  exchanged.
When purchasing birds, note that very healthy specimens  often  sit balanced ionone foot while perching or roosting. This is usually a   good sign, although some healthy birds resolutely perch on both feet. A  bird  that is seen to be busily preening its feathers is generally a fit  bird,  interested in its appearance and in reasonable health. If a bird  is at the  feeding dish, look for signs of a healthy appetite. Avoid a  bird that appears  to be gorging itself on grit. Too much grit indicates  a poor or sluggish  digestion. In general, choose a bird which appears  fairly lively and interested  in its surroundings.
Keep new birds in separate cages in the bird room or shelter  for  a short period before releasing them into an outside aviary. Remember  to  acclimatize birds that are to live outside. They should not be  transferred from  an indoor site to an immediate drop in temperature,  although this need not be a  problem if the weather is warm or if the  bird has come from another outside  location.
When choosing birds it is important to select only those  which  can live together in harmony. Incompatible birds fight over favorite   perching spots, nesting sites and feeding dishes. Unhappy birds refuse  to breed  and, in extreme cases, severe injuries, such as damaged toes  or the loss of an eye  can be caused, particularly amongst the parrot  like species.
It must be emphasis Ed that these groups are a guide only —   always remember that there are individual birds who may have aggressive   tendencies. Watch out for bullies and isolate individuals where  necessary. It  is often better to sell such a bird, rather than to wait  and hope it may change  its ways. Sometimes, however, the addition of  another dominant type may alter  the situation.
It is a good idea for the novice bird keeper to start his   collection with seed-eaters, possibly moving on to the more difficult  soft hill  species at a later stage. The most easily managed species of  seedeaters are the  Zebra Finch, Bengalese and many of the small  waxbills. Australian Grass  finches, while relatively easy to care for,  may need extra warmth .Budgerigars,  cockatiels and small arrangements,  such as Bourke's Parakeet, are every simple  to care for.
Where parrot like birds are concerned, very few species may  be  kept together. Try to house any of the lovebird species in mixed  collection.  They may look small and beautiful, but their sharp, curved  beaks can be lethal.  They should only be kept in pairs in individual  housing. The Fischer's Lovebird  is the only species which may safely be  kept in a colony of its own breed.  Never put lovebirds in with finches  for they will certainly attack. The same  warning applies to all the  small species of parrot, such parakeets conjures and  all the  nectar-feedingparrakeets.
The size of the aviary has a considerable influence on the   success of mixing various species. Birds are always less tolerant of one   another in a small enclose-sure than in a larger area, as they are  territorial  creatures who like to claim the largest spot for  themselves.
Smaller birds are content with a smaller area for their own   preserve than the larger species. Breeding pairs must be allotted more  space  than single species. If there is very little space available,  consider keeping  only single cock birds of individual species. In this  way, it is possible to  house a colorful collection of attractive birds  without risk of fighting. Sonic  birds prefer densely planted aviaries,  which provide the best cover forest  building and privacy for the more  timid and shy birds. If keeping birds such as  the Chinese Painted Quail  and other ground species, take care not to tread on  their eggs or  young.
Providing several roosting spots, nest-in sites and feeding   dishes prevents arguments between birds. Too few roost-in spots or  nesting  sites in the accommodation means fighting can break out even  amongst the most  placid birds. Nest boxes arid baskets should be placed  as far apart as possible  and evenly distributed around the quarters.
When introducing new birds of any kind to a mixed  collection, it  is useful to provide an extra place for the new birds to feed,  so that  they do not interfere with the usual feeding routine.
 It is quite easy to keep birds of similar size and habits   together. If a smaller types introduced to the collection it is likely  to be  bullied, likewise if a larger type is brought in it often tries  to dominate thirst.
In their natural state, birds operate a pecking order': the   stronger dominate and rule the weaker. This order is often observed in a   captive collection and when newcomer is introduced it is certainly  noticed.  Such encounters are best kept toad minimum and should he  watched closely. In a  few days the normal order should be restored.  Large omnivorous birds and insect eating  species should only be kept  together when they are of similar size, strength  and habit.