Factors Affecting Reproductive Success

We have compiled a brief check list of factors related to husbandry, medical, physical or behavioral implications that can be easily assessed when troubleshooting infertility in birds. Proper assessment of the egg development: are the eggs really clear or could they have DIS (died in shell) in the first days of incubation? A necropsy should be done on every egg that fails to hatch, even if the egg appears clear when it is candled.

• Is the pair properly sexed? Gender is the most common cause of reproductive failure.
• Has a complete physical exam been done on the pair prior to the breeding season, to eliminate debilitating health conditions? Cloacal papillomas & other localized infections surrounding the cloaca could inhibit the pair to properly copulate.
• Do you offer a varied and balanced diet? Obesity: consider dieting overweight birds.
• Nutritional deficiencies: diet should be carefully analysed and deficiencies should be corrected such as hypovitaminosis ADE, low calcium levels and low caloric intake.
• Is the drinking water provided always fresh?
• Have the nails been trimmed too short? Is bumble-foot, feet deformities or toe amputations preventing the pair to maintain a stable position during copulation?
• Are the perches adequate? Are they not too slippery, unstable or malpositioned?
• Do you provide fresh branches to encourage mating behaviour and nest construction? Refer to a toxic plant list to provide safe tree species and non-pesticide treated branches.
• Can you identify certain disturbances surrounding your aviary that could be disrupting their mating behaviour & activity? Disturbances induced by humans, other birds, vermin and other animal species?
• Do your enclosures provide a safe, stress free environment? Is there ample space to allow exercise and territorial behaviour?
• Are the nest dimensions, materials & substrate used adequate for this species?
• Is the nest stable or can vibrations be observed when the pair is moving in it?
• Does the nest box entrance to the cavity allow sufficient privacy, and security? Can the pair chew the entrance and mark their cavity?
• Do you routinely inspect the nests? Sporadic and invasive inspections are not recommended, especially when done exclusively during the breeding season.
• Egg candling: proper candling equipment and handling technique should allow you to evaluate fertility and monitor developmental stages with minimal manipulation. Eggs should not be manipulated at the early stages of development.
• Is the lighting (natural and artificial) provided adequate?
• Are indoor installations equipped with a timer to insure desired light cycle? Lengthen photoperiods promote LH secretion (the primary reproductive hormone).
• Do you gradually alter the climate (temperature, humidity and lighting) to stimulate the breeding activity? Excessive environmental temperature and humidity can decrease reproductive activity (temperature exceeding 27 ̊C = thermal stress).
• Has the microclimate of the nest been evaluated or recorded? Metal nests can contribute to excessive temperature within the nest, rendering it inhospitable for the pair & perilous for the eggs.
• Can a video monitoring system be installed? This could give you additional insight as to their actual reproductive activities, behaviour & aviary disturbances.

If the reproductive activity fails to be successful following a thorough evaluation of the pair, consider repairing the birds. Consult your avian veterinarian for the possibility of performing an endoscopic evaluation of the male and female reproductive tract. We recommend that you save this check list, and use it as a work sheet when evaluating each breeding pair. Evaluating each pair individually is recommended, versus trying to assess the colony as a whole.

Josee Bermingham AHT