FINCH COMPATIBILITY

Many reasons exist that would explain why an established pair of finches (or any species) might stop getting along with each other. To make sense of this change in behavior, consider two things: the importance of mate selection, and the effects of stress on paired finches.

Finches select mates carefully and often have strong preferences about their partners. Although there is still much to learn about how birds select mates, it is clear that a major element of mate selection is assessing potential partners for their ability to raise offspring successfully, because birds form pairs for the purpose of raising young. For instance, in some species, males with more elaborate plumage or more brightly colored feathers have the best chance of winning females; in other species, males with more complex songs or more vigorous flight displays attract mates more easily. In each of these examples --- fine plumage, complex song and vigorous flight --- a male's health, stamina, experience and skill is advertised to potential partners, who then use this information to judge a male's ability to help raise young.

However, mate selection is not always easy for us to understand. For example, after I released four new female silverbills into a flight, my single males all courted the same female. Although I could see no difference in the females, clearly the male silverbills did! The point is that captive finches do have opinions about which mates they want.

In the wild, of course, there are no forced pairings. Wild finches select their own mates. Whenever possible, do the same in captivity: Allow finches to select their own partners, which increases their chances for compatibility and contentment. Unfortuately, when finches are arbitrarily paired by us, chances for incompatibility increase. However, because most finches need companionship, they accept the partners that are provided.

If members of a pair are not particularly compatible, the probability increases that the birds will squabble and be less tolerant of each other. Incompatibility also leads to poor breeding results, often because the birds do not cooperate effectively. If the opportunity arises, dissatisfied parners may also "divorce" their mates by driving their mates away or by taking new mates.

Divorces, which occur even in established, compatible pairs, have been reported for birds in captivity and in the wild. In fact, divorce is well documented among captive zebra finches, which do sometimes outgrow their devotion to their mates. Consequently, it is possible that your squabbling finches would benefit from being repaired with new mates --- perhaps your finches did not select each other as mates and were never very compatible.

However, before separating your partners, be sure that the birds are really incompatible, not just stressed. Like people, birds often become quarrelsome with their mates when conditions are stressful. In many cases, harmony returns to the relationship when the stress is removed. Consider that before breaking up the pair.

When exposed to continuous stress, finches --- even happily paired finches --- can become hostile to their mates. Stress results when birds are housed in cages that are too small or crowded. Stress also develops when birds are kept in a noisy environment that lacks security. For instance, frequent interruptions, disturbances or loud noises make birds nervous and frustrated. Eventually, finches may vent their frustrations on their partners. Similar reactions can occur when threatening or noisy additions are made to the household (such as a new cat, dog, hookbill, family member or loud machine).

Breeding failures also produce frustration, which may result in mate comflict. In some cases, one member of a pair enters breeding condition earlier than its mate. When the unwilling partner fails to show an interest in nesting, it may be attacked by its impatient partner, which has gotten angry with a mate that is not fulfilling its obligation to help raise young.

Other problems contribute to breeding failures, including clutches of infertile eggs. Equally, fertile eggs can be damaged by long toenails or disturbances that suddenly cause parents to panic while on the nest. Repeated disturbances, of course, make parents nervous and may lead to abandonment of eggs or nestlings.

Regardless of the reason for breeding failures, poor breeding success leads to mutual dissatisfaction and often results in mate conflict or divorce. In fact, chances for divorce increase with breeding failures. This is well documented in the wild, but also occurs in captivity (among captive birds that have the opportunity to divorce their mates). Since birds form pairs in order to raise young, it is no surprise that breeding failures contribute to divorce.

To ensure optimal mate compatibility, the environment needs to be comfortable and free of stress. Before separating your birds and giving them new partners, try improving their environment by moving the cage to a better (quieter, more secure) location or, if needed, by acquiring a larger cage (at least 30 inches in length). If housed with other finches, try giving the pair a separate cage. Be sure the cage offers security in the form of cover (plant cover or a partial cage cover). Add cover near the nesting site, and offer a fresh, new nest and nesting material, which will allow your birds to go through all the rituals associated with breeding. (Courtship displays, nest building and related ritual behaviors help establish, maintain and strengthen pair bonds.) If these measures do not stop the quibbling, look for new mates for your birds.