(a) General requirements. Primary enclosures must be designed and constructed of suitable materials so that they are structurally sound. The primary enclosures must be kept in good repair.

1. (1) Primary enclosures must be constructed and maintained so that they:

   1. (i) Have no sharp points or edges that could injure the birds;
   2. (ii) Protect the birds from injury;
   3. (iii) Contain the birds securely;
   4. (iv) Restrict other animals from entering the enclosure;
   5. (v) Ensure that birds have the option to remain dry and clean;
   6. (vi) Provide shelter and protection for each bird from climatic and environmental conditions that may be detrimental to its health and well-being;
   7. (vii) Provide sufficient shade to comfortably shelter all birds housed in the primary enclosure at one time, including low ranking birds that are maintained in social groupings that form dominance hierarchies;
   8. (viii) Provide all the birds with easy and convenient access to clean food and potable water;
   9. (ix) Ensure that all surfaces in contact with the birds may be readily cleaned and/or sanitized in accordance with § 3.158 or be replaced when worn or soiled; and
   10. (x) Have floors that are constructed in a manner that protects the birds' feet and legs from injury. If flooring material is suspended, it must be sufficiently taut to prevent excessive sagging under the bird's weight. If substrate is used in the primary enclosure, the substrate must be clean and made of a suitably absorbent material that is safe and nontoxic to the birds.
2. (2) Furniture-type objects, such as perches and other objects that enrich a bird's environment, must be species-appropriate and be designed, constructed, and maintained so as to prevent harm to the bird. If the enclosure houses birds that rest by perching, there must be perches available that are appropriate to the age and species of birds housed therein and a sufficient number of perches of appropriate size, shape, strength, texture, and placement to comfortably hold all the birds in the primary enclosure at the same time, including birds that are ranked low in a dominance hierarchy.
3. (3) Primary enclosures that are adjacent to one another or that share a common side with another enclosure must be suitably screened from each other or kept at a sufficient distance apart in order to prevent injury of the occupants due to predation, territorial disputes, or aggression.

(b) Space requirements. Primary enclosures must be constructed and maintained so as to allow each bird to make normal postural and social adjustments, such as dust-bathing and foraging, with adequate freedom of movement and freedom to escape from aggression demonstrated by other animals. Both part-time and full-time attending veterinarians at a facility must consult with the facility to ensure that the space in all enclosures housing birds is adequate and allows for normal postural and social adjustments. Inadequate space may be indicated by evidence of malnutrition, poor condition, debility, stress, or abnormal behavior patterns. The normal postural and social adjustments of a bird may be restricted:

1. (1) When the attending veterinarian determines that making species-typical postural or social adjustments, such as dust-bathing, foraging, or running, would be detrimental to the bird's good health and well-being. The attending veterinarian must document the reason and recommended duration for the restriction and make such records available for review by an APHIS inspector.

2. (2) When the birds are tethered in accordance with current professionally accepted standards. Birds must not be tethered unless:

   1. (i) It is appropriate for the species of bird;
   2. (ii) It will not cause harm to the birds;
   3. (iii) The birds are maintained on perches appropriate for the species and age of the bird while tethered;
   4. (iv) The birds have sufficient space to fully extend their wings without obstruction; and
   5. (v) The tether does not entangle the birds.
3. (3) When dealers, exhibitors, and research facilities breed or intend to breed their birds, such birds must be provided with structures and/or materials that meet the reproductive needs of the species during the appropriate season or time periods. A sufficient number of structures and materials must be provided to meet the needs of all breeding birds in an enclosure and to minimize aggression.
4. (4) Birds intended for breeding, sale, in need of medical care, exhibited in traveling exhibits, or traveling for other reasons must be kept in enclosures that, at minimum, meet the individual specific space, safety, bedding, perch, and physical environment (including, but not limited to, temperature, humidity, sun and wind exposure) requirements for transport enclosures as specified in § 3.162. At all other times, birds must be housed in enclosures that meet the space requirements of this section.