by Fern Van Sant on 06 December
Avian reproductive behaviors observed in the wild......such as pair bonding, courtship regur...
Once an understanding of the role of parrots in nature is developed, it becomes possible to look at many of the quirky behaviors they exhibit in an entirely new light. It is often difficult for compan-ion bird owners to realize that the way a parrot becomes a household member and part of the "flock" is likely due more to the bird's adaptation skills than a reflection of a great home provided. It can re-quire a huge leap of faith to view the devotion and longing that many bonded pets display as some-thing to be concerned about. This is the underlying cause for a number of serious degenerative medi-cal conditions in companion birds.
Most Americans have become all too familiar with so-called "conditions of abundance" that have predisposed us to higher cancer risks, obesity, heart disease and diabetes. Generally these conditions are the result of the physiologic stresses induced by too much good food and too little ex-ercise. As a genetically diverse population, we see different people affected in different ways by a similar lifestyle. Recent research strongly supports an underlying genetic basis to the ways certain individuals develop degenerative medical conditions. Doctors tell us that the body can only respond in a limited number of ways to a vast array of conditions. When viewing the range and relative severity of medical conditions in pet parrots, it becomes apparent that a similar phenomenon is occurring.
Conditions of abundance have had severe impact on feral animal populations as well. In California's Monterey Peninsula, "Please Don't Feed the Animals" signs were commonly ignored in the early 1990s to the point that population explosions among several species resulted in territorial "squeeze-outs." Eventually, ground squirrels displaced rats, which expanded into raccoon territory, driving rac-coons into attics and basements. Not only was the threat of disease nearly out of control, but in-stances of raccoon attacks on domestic pets increased dramatically.
Returning to the comparison of Amazon parrots and cockatoos, dramatic differences appear in the way these very different species respond to the relative abundance of life as a pet. The incidence of obesity in Amazon parrots maintained on a seed diet was noted in the early 1980s. The tendency to obesity was so serious that hepatic lipidosis with subsequent liver failure was not an uncommon find-ing. As domestic breeding gained in popularity and endoscopic sexing was routinely performed, it was often noted that the ovary was often obscured by abdominal fat. Many female Amazons were found to have mature but abnormal ovarian structures. As these conditions typically translated into breeding failures, experienced aviculturists quickly learned to control body weight by controlling available calo-ries. Umbrella Cockatoos (Cacatua alba) responded to the same conditions of a seed diet by produc-ing many eggs and many young. It seemed for a while that anyone with a pair of cockatoos was in-stantly an accomplished breeder. With abundant calories, a mate and an available nest box, these females produced and produced and then, sadly but often, died.
As emphasis shifted to companion birds as treasured pets, these same tendencies were commonly seen but poorly understood. Many female Amazons developed sets of behaviors that in-cluded constant posturing, cavity seeking, shredding of any available material and intense bonding with their owners. Over time, these birds often started barbering their feathers, clipping off primaries, secondaries and contours. Many developed specific patterns of feather loss involving the feathers of their legs, patagiums and trunks. A tendency towards dermatitis in areas of feather loss was noted. Most of these birds carried obvious subcutaneous fat deposits. Many began showing signs of an epi-sodic seasonal event but those progressed to year round signs. Female Umbrella Cockatoos, many sold to naïve owners as the cuddliest parrot, demonstrated their physiologic stress in a very different way. Many Umbrella Cockatoos have demanded - and received - an inordinate amount of physical affection. Many showed signs of sexual behaviors early. Over time many became chronic egg layers. Cloacal prolapse and hernias of abdominal wall muscles were commonly seen. Patterns of feather loss, failure to molt and even self-mutilation became common clinical entities. Some birds failed to ovulate but demonstrated orgasmic like shaking in response to their owners' attention. These birds often began to show chronic degenerative changes that ranged from feather loss to self-mutilation.
As veterinary medicine for birds progressed, the metabolic hazards of a seed diet were elucidated. Formulated diets were introduced that dramatically changed the way companion birds were being fed. An unintended consequence of better nutrition for many birds has been an increase in these so called behavioral problems. As the population of companion parrots became healthier and the risks of infec-tious disease minimized, conditions of abundance became epidemic.
Hormonal therapies like leuprolide actate (Lupron ®, TAP Pharmacutical) and human chorionic gonandatropin (HCG) were frequently offered as a remedy to many commonly seen medical com-plaints. The response was staggering. It seemed that almost everything was responsive to therapies that temporarily decreased the reproductive drive. Most owners, however, found the therapeutic re-sponse to these remedies dramatic but short lived. (21,22) This temporary response is due in part to the formulation of Lupron® as a limited time treatment. Equally important is the usual failure to identify, understand and effectively correct the environmental conditions triggering the abnormal chronic re-productive drives.
Recent years have brought the dawning of a new awareness about deep-seated underlying processes that led us to this epidemic of hormonally driven degenerative conditions. Researchers at several universities published findings that certain environmental circumstances resulted in the in-ducement of hormonal cascades of reproduction. Millam demonstrated that cockatiels were very pho-toperiod responsive. (23) He also was able to show that the process of cavity exploration and develop-ment resulted in peak levels of testosterone production in Orange-winged Amazon parrots (Amazona amazonica). (18)
Despite the nearly incomprehensible success of parrots as pets in the last 25 years, we have been plagued by a lack of information about these birds. Their role in nature and their biology were never thought to be terribly important or pertinent to their lives as pets. They have blended so well into our homes, adapting quickly to new diets and new surroundings, that their natural history seemed to start at the pet store or at the breeders. Cockatoos, Amazons, macaws and conures were lumped into the nondescript group of pet parrots. Budgerigars were sold by the tens of thousands at dime stores. Cockatiels became very popular as family pets. Companion birds were sold as the perfect low main-tenance pet. Usually sold as juveniles, parrots seemed like tractable animals. As juveniles look like adults after several months, most new owners anticipated the sweet, easygoing nature of their new bird to last. Many owners were stunned as their bird quickly developed into a loud often-challenging young adult.
Just as staggering is the hard learned insight that caring for a pet bird in the manner proposed by industry and breeders will usually translate into troublesome, hormonally driven events. It turns out that if you furnish your cockatoo with the physical affection it craves, as the breeders and pet stores have typically instructed, you would typically induce a pattern of degenerative hormonal responses. Without understanding the biology of the species and the relative importance of each phase of matu-ration and development, our companion birds will remain an enigma. Viewed from the perspective of their innate adaptations, with a new respect for the uniqueness of each species and habitat, we can successfully unravel and perhaps prevent these so called degenerative conditions of abundance.
The Umbrella Cockatoo is a sterling example of this. Imported in large numbers in the 1980s from In-donesia, these birds were easily tamed. They responded so quickly to touch and food treats that they were often used in taming demonstrations. They were also found to be very prolific when offered a steady food supply, a mate and a nest box. The young were sold to adoring new owners that lavished them with physical attention. Many were sold as unweaned babies so new owners could be assured of a bonded pet. In some cases it worked, but all too often young birds that failed to wean and pets that couldn't bear to be away from their owners marred the process. Birds are equipped with voices and beaks that turn humans into compliant servants. So, what the bird wanted the bird usually got. Unfortunately, these indulgences appear to wreak more havoc than benign neglect.
Veterinarians have long been puzzled by mature male Umbrella Cockatoos that exhibit signs of tenesmus and straining, apparently as a misguided juvenile begging behavior. These actions can result in severe damage to pelvic architecture and subsequent painful persistent cloacal prolapse. Reviewing the history of these birds reveals a common underlying theme. Birds that range in age from two to 15 years are effectively unweaned. They demand and receive soft, warm food as a regular event. This condition has long been thought by many veterinarians to be a hormonally driven event but our ability to define the physiologic mechanisms has been hampered by our limited understanding of normal development.
Despite this, a general review of the biology of the species can clearly define how at odds pet bird care can be from what nature designed. Most psittacine species fledge and become independent members of the flock within a year. Larger species may receive assistance from parents or other adults for a bit longer but fledging, flying and self-feeding are essential for survival. Physical contact is important in the nest and lavished on young birds. As young adults join the flock, most are driven by a need to sharpen foraging and flying skills. Most flocks are characterized by a discipline that maintains a critical distance between individuals while flying, feeding and roosting. In most cases, physical con-tact is reserved for courting and breeding.
When this information is contrasted to conditions of pet bird care, the sharp contrast of tradi-tions becomes immediately apparent. As stewards of a huge population of psittacines kept as pets, it is incumbent on us to re-educate ourselves about the adaptations of each species. Without this edu-cation, sustainable health and quality of life will be essential elements missing from the lives of our companion birds. The old adage of "you can't fool Mother Nature" certainly applies here.
The clinical implications of feather picking have been the focus of a great deal of attention by avian veterinarians, parrot behaviorists and bird owners. Of course there is no single predisposing cause but rather a very complex mesh of genetic, environmental and medical factors. Several clinical presentations of feather loss seem to regularly occur in concert with hormonally driven behaviors. In many instances reversal of hormonal drives will be followed by regrowth of health skin and feathers. In principle it follows that chronic reproductive behaviors are hormonally driven. In nature parrots are "turned on" to breed by a set of well-defined environmental factors including seasonal changes, abun-dant food, available mates and available cavities. As pets, the conditions of abundant food, bonded owners, comfortable cages and considerable physical contact seem to initiate breeding behaviors that become long term drives. Without the naturally occurring environmental pressure of dwindling food supplies, changing conditions, and competition for resources that limit breeding behavior in wild popu-lations, breeding behaviors and hormonal drives persist unchecked. When these behaviors continue in an unrelenting fashion, the physiologic occurrences timed to occur during non-breeding season do not occur. Molting and breeding occur as mutually exclusive events in the lives of most birds. As both events are physically taxing, the timing of them is important. Large Psittacines have been observed to have a one or two year molt cycle synchronized with gonadal cycles. Large parrots reproducing year-round in avicultural situations have been noted to not molt in the same manner as non-breeding or free living conspecifics. (24) Delayed molts and failure to molt are common complaints of pet parrot owners. Also common are sets of clinical signs that that have been observed to occur in companion parrots showing chronic breeding behavior. These clinical signs have been noted to be fairly specific to different groups of birds.
Mature bonded female Amazon parrots commonly demonstrate chronic breeding behaviors such as posturing, shredding and cavity seeking. Birds with these signs are typically well nourished and often obese. Feather loss over the trunk, legs, back and patagium are common. Many seem pu-ritic. New growth is sparse and often removed by the bird as pinfeathers erupt. Environmental changes are less rewarding in these birds as the owner has become the bonded mate and the cage has become the perceived nest. Endoscopic exams of these birds usually reveal a mature but abnor-mal ovary. Lacking is the usual cascade of developing oocytes. Instead, a solitary, mature follicle is usually found. Lupron® therapy usually falls short. Successful therapy can be achieved with weight loss. Individual birds seem to have a weight threshold under which the behaviors cease. This clinical recommendation is supported by observations of wild Amazons that describe a weight increase trig-gered by food availability and male super-feeding preceding ovulation.
Female macaws may demonstrate cavity seeking and protracted egg laying. These conditions can be addressed by removing the perceived nest. Lupron® is a very useful therapeutic tool. A less common but very significant presentation in bonded female macaws is an inflammatory process of the medial leg. These birds exhibit agitation and foot stomping. Close exam of the medial vascular pattern of the legs will usually reveal dilation and inflammation of the vessels. The legs are often hot. This condition may develop into a crusty dermatitis. Therapeutic Lupron® coupled with HCG and a non-steroidal anti-inflammatory are helpful. Discontinuing any warm food is imperative as that practice seems very capable of mimicking mate regurgitation and inciting hormonal stimulation.
Male Amazon parrots have been observed to demonstrate seasonal aggression, territorial dis-plays and recurring focal inflammatory lesions of the feet. These conditions can be successfully treated with Lupron® and HCG. Cool water baths to the legs are helpful.
Examining the cooling mechanisms of parrots, primarily the skin and vessels of the legs and patagiums, may provide insights into clinical presentations. Thermoregulation is obviously a critical component of successful incubation. Hormonal regulation of vascular channels is well defined in mammalian and avian physiology and could be assumed to be a critical factor here.
African Grey Parrots frequently demonstrate signs of breeding behavior. These events seem to be less of a seasonal nature and can occur year-round especially when there is a bonded owner. Warm food and abundant food will often trigger regurgitation behaviors. Commonly coupled with these behaviors is feather picking of the trunk and legs. Control of calories, especially rich simple carbohy-drates like pasta and cookies, is very helpful. Of serious consequence is the tendency of African Grey parrots to develop severe non-responsive dermatitis of the patagium. When closely monitored, these conditions appear to start with the loss of down and contours of the wing web. Superficial vessels usually appear dilated. If allowed to continue, secondary opportunistic yeast and bacterial infections may develop. Control of chronic dermatitis can be difficult, but early intervention and environmental and behavioral corrections that focus on decreasing hormonal stimulation are usually successful.
Considering the critical distance observed between African Grey parrots in the wild and in aviary situations, the role of physical affection demonstrated by frequent petting and body contact with an owner should be considered when addressing protracted breeding behavior and hormonal feather-picking in these birds.
Three species of companion cockatoos commonly demonstrate clinically significant changes that may relate to hormonally driven behaviors. Umbrella Cockatoos, Moluccan Cockatoos (Cacatua moluccensis) and Goffin's Cockatoos (Cacatua goffini) are frequently presented for feather loss, feather picking and dermatitis. These conditions are commonly seen in female birds that demonstrate chronic breeding behaviors. Female cockatoos are commonly handled and cuddled by adoring own-ers. Lavishing physical attention to the bird's head, crest, and trunk usually elicits posturing and often orgasmic like shuddering. In many cases these birds exhibit these behaviors for years. Clinical im-pressions of these birds seem to reveal a progressive and serious pattern of degenerative changes including dermatitis, loss of cloacal tone and anemia. The availability of an estrogen panel assay at the University of Tennessee Clinical Endocrinology Service made possible quantification of hormonal levels in these species. Elevated estradiol levels correlated well with clinical distress. Therapeutic Lu-pron®, HCG and a concerted change in the birds' environment results in dramatic recovery.
It now seems very likely that the role of intense physical contact, so typical in cockatoo pets, is capable of eliciting hormonal responses. These hormonal responses can start early and continue pro-gressively for years. The perception that no amount of attention is ever enough for the social cockatoo has been difficult to overcome. The missing piece of information, critical to the sustainable health of these birds, is the naturally occurring environmental conditions that serve to make these behaviors seasonal rather than constant. In the case of the Goffin's Cockatoo, seasonal shifts in the Tanimbar Islands are dramatic. As the island is located in the geographical rain-shadow of Australia, there is a distinct periodicity to rainfall. Nine months of the year bring regular rainfall and abundant water. For three months of the year rainfall amounts drop precipitously. Inherent in this pattern is an environ-mental shift that is not conducive to reproduction and challenging for survival. As pets, these condi-tions, or seasonal stresses, never occur and breeding behaviors continue in an unrelenting fashion. Further investigation into the ranges of other cockatoos will hopefully provide valuable insights useful for our companion cockatoos.
Male Moluccan Cockatoos, particularly those that have endured sedentary life and seed diets for 10 or more years, have a high incidence of self-mutilation over the sternum. Considered a behav-ioral problem by many or the result of abject boredom, perhaps this should instead be investigated as a physiologic event. Building on the experience of successful clinical intervention of these cases where life style changes including diet and exercise have been used in concert with Lupron® and symptomatic medicine, it might be possible to hypothesize underlying factors involving vascular changes, tissue perfusion dependent on physical conditioning and even chronic hormonal stress.
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Avian reproductive behaviors observed in the wild......such as pair bonding, courtship regurgitation, cavity seeking, nest building, territorial ag...