by Fern Van Sant on 06 December
Avian reproductive behaviors observed in the wild......such as pair bonding, courtship regur...
The value of better understanding the basis and development of companion psittacine birds will be a new ability to intervene early in degenerative processes, possibly preventing them entirely.
It is likely that many common pet parrot behaviors, some of which may lead to serious degen-erative health conditions, are driven by reproductive hormones, often inadvertently triggered by com-mon and accepted practices of pet bird management. It may be that the unintended consequence of keeping companion parrots as treasured pets is, in many instances, profound and long term hormonal stress.
Many psittacine owners observe behaviors that range from cute to puzzling. These may in-clude intense bonding, constant egg laying, paper shredding, cavity seeking, loud vocalizations or fierce territoriality. In some instances, these behaviors may occur seasonally and have little impact on the bird's general health. In other cases, these behaviors progress from seasonal to year round and can have a very serious impact on the bird's health. Some of these behaviors, like protracted egg-laying, are obviously driven by reproductive hormones. A myriad of other behaviors, some subtle and some puzzling, may also be related to reproductive hormonal events.
An awareness of animals exhibiting behavior consistent with the "rites of spring" is one that most of us are very familiar with. Bunnies and bees, cows and horses, dogs and cats and birds dis-play familiar rites of courtship every year that are designed to lead to successful breeding and repro-duction. In the context of the natural world, these events ensure the continued populations of wild, farmed and pet species. It comes as no surprise to most of us that the drive to breed can be powerful and unrelenting.
There has been an alarming increase in the numbers of companion birds that continue to demonstrate specific sets of reproductive behaviors to the point of developing degenerative health conditions. Serious complications of ovulation such as yolk embolus stroke, yolk peritonitis, egg bind-ing, and prolapse are easily recognized as the result of reproductive dysfunction. (1,2) Other conditions, especially those that have been tacitly regarded as "behavioral" may indeed be the result of hormonal stresses induced by abundance of pet bird care. These may include specific patterns of feather pick-ing, feather barbering, feather loss or dermatitis. (3) Other conditions commonly seen that are likely related to these hormonal stresses are chronic anemia, skeletal bone changes and degenerative changes of abdominal musculature and cloacal tone. In addition to these problems, other medical conditions such as hepatic lipidosis, toxic ingestions due to chronic pica could be the result of chronic hormonal stress or dysfunction.
Most people who have had any experience with domestic pets like cats and dogs are familiar with the strong biologic drive to breed. Young adult dogs and cats may suddenly seem possessed, lose interest in their owners and begin to roam in search of a mate. Cat fights and roaming dogs are common examples of seasonally occurring hormonally driven behaviors. To curb these undesirable pet behaviors, reduce the risk of loss and trauma, and to stem the tide of unwanted litters, most own-ers spay and neuter their pets. Certainly, the changes in a pet's behavior after neutering can be dra-matic if the animal had already developed into a sexually mature individual.
Even knowing all of this, recognizing and understanding hormonally driven behaviors of our companion birds has been difficult and perplexing. In many cases pet parrots seem to be the perfect companion. They are adaptable, beautiful, social and some even talk. They like to share meals, play games, choose favorites, ride around on shoulders and many enjoy quiet cuddle time. But there is also the down side. Many companion birds scream loudly when an owner is otherwise occupied or out of the bird's line of sight. Some may start shredding at cage liners or any other material they can get. Some may become obsessed with finding dark places in closets or drawers. Some may loudly de-mand that owners hold and caress them constantly. Equipped with formidable beaks and ear piercing voices, it is easy to see how they get what they want. Couple this with the information given most new parrot owners that, without enough attention, the bird will become bored and pick its feathers, it is easy to see how we have arrived at this impasse.
Compounding this dilemma is the fact that the reproductive biology of the psittacine is very dif-ferent from most mammals. In fact most of what we assume to know about their reproductive biology we have learned from aviculturists breeding birds in captivity. With time, experience and investigation we are learning that most of what we thought and expected was in fact short sighted if not just outright wrong. Because companion parrots share so many attributes with humans, it is easy to assume that most of their biologic behaviors have a lot in common with ours. In fact, investigation and research support a very different and unique biologic strategy.
It is very likely that the answers to understanding and resolving these serious yet common conditions will be found in recognizing and defining the unique relationships between species and their native environment. In practice, it is possible to remedy and reverse many degenerative trends with modifications in the bird's routine and environment. Understanding and managing these events could potentially prevent serious degenerative conditions. In the process we will undoubtedly better understand psittacines in our care and be in a much better position to prevent both behavioral and medically degenerative processes.
It has been a naïve and unsatisfactory approach to regard companion parrots as a uniform group. Despite the physical characteristics that they share, a hooked beak, zygodactylic toes and a strong muscular tongue, the 332 species of the order Psittaciformes are organized into three distinct families that reflect a wide array of body types and adaptations. (4,5) Amazons and cockatoos are both parrots but they have few physical attributes and physiologic adaptations in common. Amazons are stocky parrots without powder or preen glands. They are usually green with vivid red, yellow and blue markings. They are known for hearty appetites and animated, often-feisty dispositions. Cockatoos are generally lighter birds that produce an abundance of powder down and usually have preen glands. Cockatoos are generally white or pink with highlights of yellow or orange and are famous for their sweet dispositions and their drive to chew. Cockatoos rarely develop obesity, even as sedentary well-fed pets. In contrast, Amazons often become so heavy with subcutaneous and intra-abdominal fat pads that they develop degenerative arthritic conditions and debilitating fatty liver conditions.
It should come as no surprise that these species share few attributes. They have evolved in ecosystems worlds apart. Over many hundreds of thousands of years these species have developed specific behaviors and physical characteristics that have allowed them to thrive in very different eco-systems.
A better understanding of these significant differences is facilitated by a quick review of the fossil record of psittacines. Although much of the ancient history of these birds is clearly hypothetical, psittacines are thought to derive from an ancient class of birds. It is considered likely that these birds have a more than 30 million year history and have their roots in the ancient landmass of Gondwa-naland. As the landmasses slowly drifted and the continents that we recognize today formed, the evo-lutionary processes that drove speciation slowly produced the three families of the order Psittacifor-mes that we now know. (5,6)
Of the 332 species known today, there are clear distinctions between psittacines based on geographical distribution. Neotropical species account for nearly two thirds of all psittacine species. These include, among others, Macaws, Amazons, Conures and Pionus. Although they appear at first glance to be a diverse group of birds, they share many physical and behavioral traits. In contrast are the 109 species from Australia, New Zealand and the Philippines. The incredible diversity of species demonstrated among these birds is thought to be due to the relatively long isolation of these geo-graphic areas across millennia as well as the absence of pressure from mammals. Only 34 species are found in Africa, India and South East Asia. (5,6,7)
If any single evolutionary tendency of these birds were to be singled out, it would have to be their flexibility to adapt to an impressive range of habitats. In order to understand the needs and be-haviors of our companion parrots, we have to acknowledge the power and uniqueness of their inextri-cable bond to their distinctive environments.
Many aspects of psittacine behavior not only fascinate people but also have been studied in depth. Psittacines have displayed an uncanny ability to mimic, learn, socialize and adapt. Certain be-haviors such as learning and talking have been extensively studied. (8,9,10) Behaviors pertinent to this discussion are those related to reproductive behavior. Although reproductive behaviors are at their basis both genetically determined and learned in nature, we are finding that our ignorance about nu-ances of the biology of most bird species in captivity is leading to serious degenerative health condi-tions and related behavioral difficulties that at times render a companion bird nearly impossible to live with.
One need look no farther than the classified ads of most newspapers or the waiting lists at par-rot rescue centers and sanctuaries to appreciate the point that incorporating psittacines into our homes and lives may not be as easy as we first thought. Our assumptions that these birds can easily be assimilated into a human flock and adjust successfully are proving to be naïve and unsettling. Compounding these errors is the fact that although in many instances these species were easy to breed in captivity, that ease may reflect the psittacines' ability to adapt to ideal breeding conditions and may have little to do with determining ways to allow them to thrive and enjoy sustainable health.
Before considering the unique ways that parrots have evolved in different parts of the world and how that impacts their behavior as pets, it is important to consider some basic principles of animal behavior.
If viewed from the perspective of simple behavioral biology, almost all behaviors observed in higher animals can be divided into reflexive, innate and learned. Whereas each of these types of be-havior is unique from a neurological perspective, most observed behaviors of intelligent species are a complex blend of all three types. (6,7,11)
Reflexive behaviors involve reactions to stimuli that result in a rapid withdrawal. The spinal cord and skeletal muscles mediate these reflexes. Innate behaviors, or "hardwired behaviors," are in-herited and genetically driven species-specific behaviors such as songs and nest design. These be-haviors are observed in individuals raised independently of conspecifics. Learned behaviors are those acquired by impressionable individuals. Included in these behaviors are imprinting, flying, food identi-fication and navigation.
Developing an understanding and appreciation for the complex behaviors observed in parrots in the wild will make possible a new perspective of the often quirky behaviors and personalities of companion birds. Acknowledging inherent genetically determined behaviors of different species will be a necessary first step in unraveling the puzzle of the intricately complicated behaviors observed in companion psittacines.
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Avian reproductive behaviors observed in the wild......such as pair bonding, courtship regurgitation, cavity seeking, nest building, territorial ag...