Keeping the Northern (Virginian) Cardinal, Cardinalis cardinalis, In Outdoor Aviaries – Part 1

Northern Cardinal

The northern cardinal is surely one of North America’s best loved birds – so much so that it is the state bird of 7 states here in the USA. As it is illegal to keep this species in the USA, it may surprise you to learn that it is a quite popular aviary bird in Europe. As a captive, the northern cardinal has much to recommend it – brilliant plumage, a fine song, hardiness (captive longevity exceeds 20 years) and an active and inquisitive nature.

Today I will give an overview of its care in captivity, so that you might get a different perspective on this common local species. If you are interested in keeping cardinals and other native birds, you may wish to become licensed by your home state as a wildlife rehabilitator. This license will allow you to care for injured birds and, in some cases, to maintain those that turn out to be un-releasable. My first experience with captive cardinals came about in this manner, and the lessons I learned proved invaluable. You can also easily observe cardinals in the wild, as they readily use bird feeders and can even be induced to feed from the hand.

The northern cardinal (sometimes called the “Virginian nightingale” in Europe) ranges throughout eastern and central North America and south to Belize. It favors suburban and park-like habitats and so responds well to human presence. In fact, the species is increasing both its range and population size in many areas (but declining, it seems, in California). In contrast to many other birds, female cardinals sing loudly from the nest, and with a song that is more complex than that of the male. It is believed that this is a form of communication with the male, but why such has evolved is not yet known.

The brilliant red plumage of the male, the intensity of which rivals that of any tropical bird, first attracted aviculturists to this species. During the breeding season, even the gray edges of the feathers disappear, enhancing the over-all brightness of the red color. Sadly, few take time to look closely at the females, which are generally described in books as “dull brown” or “tan”. But look carefully the next time you see one – most females, which vary greatly in pattern from one to another, are splashed with red, tan and green – resulting in a subtle beauty rivaling, in its own way, that of the male.

My experience with northern cardinals at home and in zoos has convinced me that they are best suited to outdoor enclosures. In addition to being quite active birds, those kept indoors invariably decline in color and condition. The carotenoids that lend this species its red color can only be acquired from dietary sources, and I expect that insects captured in outdoor aviaries may assist in this regard.

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Parrots and the Perils of Tropical Nights

African Gray Parrot
As mentioned in my recent article on this blog, providing pet birds with access to sunlight and fresh air is of great value to their well-being. A pair of yellow-fronted Amazon parrots, Amazona ochrocephala, kept at a research station on Tortuguero Island, Costa Rica, where I worked some years ago, seemed a perfect example of this. They spent their days climbing in 2 small trees and over the ropes stretched between them (their flight feathers were clipped). Active and inquisitive, they were in the peak of health and color. A large cage, door opened, hung in one of the trees. For a time, the birds’ owner had tried to herd them into the cage for the night, but had given up in the face of their stubborn refusal to cooperate.

One morning, we awoke to the gruesome discovery of a small pile of blood-spattered feathers below the birds’ roosting site – all that remained of the male. Tortuguero is home to a number of creatures, including ocelots, Leopardus pardalis, great horned owls, Bubo virginianus, and the unusual Linneaus’ false vampire bat, Vampyrum spectrum, that would be more than happy to snack on a plump parrot. Apparently, the dog that usually slept below the roost had gone “off duty”, and a nocturnal predator had made the most of the lapse in security. On the very next evening, with only the slightest of prodding, the female walked over into her cage and perched quietly while the door was secured – and, I’m told, she has done so each night since!


Providing the Proper Type and Amount of Light to Pet Birds

Those working with birds in zoological collections, commercial aviaries and poultry farms have long recognized that the behavior and health of the animals under their care seemed influenced by the quality and amount of light that they received. It many cases, breeding behavior and egg production also seemed linked to light in some way. Observant hobbyists also realize that parrots, canaries, finches and a host of other birds seem to do much better when exposed to natural sunlight. Perhaps you have noticed that birds housed in outdoor exhibits at zoos, or observed in the wild, seem more vigorous, active and brighter in color than individuals of the same species kept indoors?

Details concerning the specific needs of captive birds as regards light quality and quantity are still lacking in some respects, but a great deal has been learned. Much of this information has come as a byproduct of the exploding interest in captive reptiles, many of which fail to thrive if not provided with appropriate lighting regimes.

We now know that most commonly kept bird species rely upon ultraviolet light of a specific type (UVB with a wavelength of 295-310 nanometers) in order to synthesize Vitamin D (if experience with reptiles is any guide, nocturnal species such as owls and nightjars are likely able to obtain adequate amounts of Vitamin D from their diet). Exposure to UVB in this wavelength is also critical to normalization of the calcium/phosphorus ratio. Birds also sense ultraviolet light of another type, commonly known as UVA, as well as the colors red, green and blue (in this regard they are said to have tetrachromatic vision). UVA light provides the aforementioned colors, when viewed by birds, with a certain “tone” that we humans do not sense. Without UVA, birds will not see these colors properly, and their behavior and health will be negatively affected.
Most birds have the number of ways of assessing the quality and duration of the light to which they are exposed, and of conveying that information to the brain. Details concerning light quality are sensed by the retina and relayed to the pituitary gland. The Harderian Gland, locating near the eye, sends information concerning wavelength and photoperiod to the pineal gland. The pineal gland, thyroid gland and hypothalamus use this information to affect the functioning of other organs and of behavior in general. Insufficient or inappropriate levels of UVB or UVA, and daylight periods that are too long or to short, can lead to a host of problems in the functioning of these glands. So, if the quality of the light is not sufficient (i.e. “full spectrum”, or similar to that supplied by natural sunlight), critical glands will malfunction and will, in turn, negatively affect a number of important organs and processes.

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Hand Rearing Palm Cockatoos, Probosciger aterrimus – Part 2

Palm Cockatoo

To read the first part of this article, click here.
In reproductive biology as well, the palm cockatoo breaks with its close relatives. The male’s breeding display is the group’s most complex – flying high above the ground towards his mate, he raises his spectacular crest, deepens his cheek patch color, and calls loudly. They are the only cockatoos to build stick nests within their nest cavities – perhaps as a precaution against flooding – and their young are unique in hatching without down and in having such a long (to 160 days) nestling period. Even after all that time, young palm cockatoos fly poorly upon leaving the nest and are fed by their parents for an additional 6 weeks.

Strictly protected by the governments of New Guinea and Australia (and listed on Appendix I of CITES, The Committee on International Trade in Endangered Species), palm cockatoos were relatively unknown in American aviculture until quite recently. In fact, zoos here did not pay much attention to Psittacines in general – intelligent and gregarious, they need lots of room, stimulation and appropriate social groups and thus are difficult to provide for. After observing flocks of military macaws, Asa militaris, and other species, in the wild, I came to regard parrots and their relatives, in terms of their captive needs, as the “primates of the bird world”. Those of you who keep them as pets are no doubt familiar with their curiosity, and are fortunate in having a wide range of helpful products from which to choose when looking to keep them happy.

In 1983 the US Fish and Wildlife Service confiscated a large group of palm cockatoos, and placed them with various zoos and qualified private individuals. I was working in the Bronx Zoo’s bird department at the time, and learned that I would be assisting in the hand rearing of two chicks. Given the rarity of this species in captivity, I was excited by the opportunity to perhaps contribute to our understanding of its captive husbandry. The group eventually did quite well, and gave rise to a good percentage of the individuals in this country today.

The two chicks were at first fed (via syringe) around the clock, and thus required attention at all hours of the night. This quickly gave rise to their names – “OT” and “MOT”, signifying “Overtime” and “More Overtime”! Their helplessness (and the fattened pay checks they engendered) endeared the birds to their keepers. With barely any down feathers, they were at first kept at quite warm temperatures (92 F or so) in an incubator. Feather growth increased from age 3 weeks, when the temperature was reduced to 85F, and was complete when the birds were approximately 3 months old. The chicks’ face-patch color was variable even during their first weeks of life, although I cannot say what the changes meant. In common with most healthy nestlings, their feeding reaction was quite strong and, oddly, accompanied by much head bobbing.

In those days, formulas for hand-rearing cockatoos were not standardized, and the various zoos involved in the project experimented quite a bit. A dilute mix of Pedialite, monkey chow, baby cereal and fruit was common to most diets, and worked well (although not without some digestive upset). Today, both zoos and hobbyists have a number of fine products available, and hand-rearing success stories are more common. The chicks began pecking at solid food at 2 ½ – 3 months of age – I later learned that the timing of this milestones varies greatly among palm cockatoo chicks. Supplemental formula was given until the birds were approximately 4 months old and gaining weight consistently. They were later transferred to the World of Birds building, where their exhibit remains a major attraction.

I am happy to say that we learned quite a bit that has been of use to other bird keepers, hobbyists and their charges, and helped establish this magnificent species soundly in North American zoos and private collections.

Cockatoos and parrots are at once fascinating and challenging as pets – please share your own stories and forward any questions you might have.

You can see a video of a palm cockatoo at the Bronx Zoo (perhaps OT or MOT) below:

More information about the group of confiscated birds I referred to, and concerning parrot conservation in general, is available at:

Thank you. Until next time, Frank

Hand Rearing Palm Cockatoos, Probosciger aterrimus – Part 1

Palm Cockatoo
It is not easy for a single species to stand out among a group of birds as spectacular as the cockatoos, but the striking palm cockatoo does so quite handily. At nearly 30 inches in length and with a 30-inch wingspan, this giant among cockatoos approaches the hyacinth macaw, Andorhynchus hyacinthus, the largest of the world’s 350+ species of parrot-like birds, in size. Its jet black feathers are set off by powdery gray down and highlighted by brilliant red cheek patches. Adding to the air of imposing size, the head is topped by a crest of long feathers and the beak is massive. Today I would like to tell you about my involvement with the first large group of palm cockatoos brought into this country and to discuss some of this magnificent creature’s unique characteristics.

But first, if I may, a bit more about what distinguishes this bird from the approximately 20 other species belonging to the family Cacatuidae, the cockatoos (all of which are members of the order Psittaciformes, along with parrots, lories and macaws). Palm cockatoos, also known as black palm cockatoos or goliath aratoos, are the only tropical rain forest-adapted members of their family — the rest being more at home in dry, often sparsely vegetative habitats. They are native to northern Australia’s Cape York Peninsula, New Guinea, Aru Island and smaller neighboring islands. Three subspecies have been identified, with New Guinea’s P. a. goliath being the largest.

Although this bird is unique among cockatoos in many ways, perhaps its most distinguishing feature is tool use — a phenomenon quite rare among birds in general. Most likely as an adaptation to a thickly forested habitat where sound travels poorly, palm cockatoos beat sticks and large nuts against hollow trees when communicating with others of their kind. This behavior, known as “drumming”, is repeated anywhere from 2 to over 100 times, and creates quite a racket. In fact, “palms” seem prone to odd modes of self-expression — when frightened, rather than hissing in typical cockatoo fashion, they stamp their feet!

Palm cockatoos are also unusual in possessing bare patches on the cheeks. The skin on these patches varies in color from dull red to bright crimson, depending on the bird’s mood, stress level, health and other factors of which we are as yet unaware. The face patch can also be covered with feathers during communication displays. The maxillary, or upper beak, is twice the size of that of its largest relative (its genus name, Probosciger, alludes to the beak). Extraordinarily powerful, this impressive structure assists the bird in securing its diet of large nuts (in captivity, even Brazil nuts pose no problem), seeds, fruits and leaf buds. The lower beak meets the upper only at the tip, leaving the mouth always slightly open. Unlike other cockatoos, which forage in large flocks, “palms” feed singly, in pairs, or in groups of up to 7 in number. Pairs return to their territories in the evening, but roost separately.

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