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Wednesday, August 25, 2010

The Cliff Parakeet Subspecies of the Quaker Parakeet

This is an excerpt from an article written by Donald Brightsmith that was published in Bird Talk Magazine.
article source: http://vtpb-www2.cvm.tamu.edu/brightsmith/Monk%20Parakeets.htm 

What is a Cliff Parakeet anyhow?

Most experts list four different subspecies of Quakers. If you are curious about what subspecies you may have and want to know where it came from, check sidebar 1. It is uncertain calita and cotorra are really different enough to be called subspecies, but the others are significantly different from each other and are thought to be good subspecies. In fact the Nigel Collar in his chapter on Parrots for the Handbook of Birds of the World considers M. m. luchsi so different from the other subspecies that he calls it a different species, the Cliff Parakeet. This form has a very small range in the wild, occupying only a small number of valleys in central Bolivia. Some birds were exported from Bolivia so it is possible that some pet birds in the US belong to this species. If you or anyone you know has one of these, it would be great if you could find another Cliff Parakeet owner and breed this form which is undoubtedly very rare in captivity.

Nesting: Apartments built to suit.

The most characteristic thing about wild Quakers is their nest. They are the only parrots in the world where colonies cooperate to build a stick nest. Each pair builds its own nesting chamber out of sticks. Thorny sticks are the preferred building material as they are thought to stick together better and help deter predators. Each nesting area consisting of an entrance, usually located on the bottom of the nest and facing down to help deter predators. The entrance leads to a short tunnel that widens in to a porch where the birds can turn around and pair members can pass each other during nest visits. This porch then opens in to a large globular chamber where the birds lay their eggs and raise the young. Some pairs will go out on their own and nest in isolated nests but most nests are group affairs containing 2-20 chambers where multiple pairs nest at the same time. In exceptional cases the nests can get quite impressive. One nest on a tower in Argentina contained over 200 different nesting chambers and probably weighed in excess of 2,600 lbs!

These massive structures are usually constructed in tall isolated trees and artificial structures like telephone poles, towers, silos, buildings and even fire escapes. These massive structures on tall isolated structures are a conspicuous part of the landscape and do not go unnoticed by their animal neighbors. In Connecticut a Great-horned Owl nested right on top of a huge Quaker nest, and the Quakers continued nesting right underneath their large and dangerous guest. In other instances the interactions between Quakers and their guests are less amicable. Starlings and House Sparrows often try to occupy chambers in the Quaker nests. But the Quaker’s don’t take kindly to this and can usually drive away the unwanted squatters. In one instance a House Sparrow was found dead after a prolonged squabble with Quakers over a nest site. In Argentina the tables are sometimes turned on the birds. The Spot-winged Falconet is a particularly unwelcome visitor as it hunts both adult and young Quakers and then even usurps the nest to raise their own young. These falconets prefer to take over isolated nests with only one compartment giving the Quakers more reason to nest in a colony.

Quakers are not always the innocent victims in cases of nest takeovers; they are known to do their fair share of squatting as well. In Florida they have been found nesting in the lower levels of Osprey nests. In South America the practice is even more widespread. In a study in Argentina Jessica Eberhard found that over half of the Quaker nests were remodeled nests of the Brown Cacholote (10-inch long, jay-like birds that also make large stick nests up to 7 ft. across). Jessica suggests a that the Quakers’ nest building behavior may have evolved first as a habit of using, or stealing, the nests of other birds; then as the ability to fix dilapidated nests; then finally the birds evolved the ability to build their own nests.

Whatever the way it evolved, these impressive nests may just be the key to their current success both in South America and the US. These nests free the birds from dependence on the naturally occurring tree cavities that limit the populations of so many other parrots worldwide. The parakeets just need sticks and any tall sturdy structure. These nests also provide another unexpected advantage. They keep the birds warm. Quaker Parakeets sleep in their nests year round and temperatures inside these nests remain significantly warmer than the winter air outside. This may help explain how Quakers survived winters in Chicago where the temperature dropped as low as -27° F. The Quakers are not the only parrots that knew the trick of staying inside in the coldest weather. The Carolina Parakeet, which also occurred as far north as the Chicago area, was reported to have kept warm on the coldest nights by roosting in large groups inside hollow trees

The nest is not the only key to the Quaker’s cold tolerance. Experiments have shown that the birds have a great ability to tolerate temperature extremes. At 17° F healthy Quakers showed no signs of hypothermia. The birds also showed a great deal of heat tolerance as well. At 111° F the birds were still easily able to control their body temperature.

[Note the birds in these experiments were in a controlled laboratory setting with no wind and no direct sun, the author does not suggest that you expose your birds to such extremes of temperature without careful consideration]. The birds kept cool not by sweating like we do, but by opening their beaks and panting much like a dog.

The wonderful nests of these parakeets are not without a down side. The fact that they are occupied year round provides nest parasites with a steady food supply. In South America nests are inhabited by two different blood-sucking parasites: a kissing bug (Triatoma platensis) and a cimid bug (Psiticimex uritui). The cimid bug is completely dependant on Quakers and is found only in the nests of these parakeets. Large nests may contain thousands of these parasites. The desire to escape hoards of parasites may help explain why as many as 50% of the pairs switch nests every year and why some birds may go off and start new nests on their own, even when other colonies are available nearby.

Even when the pairs decide to switch nests they don’t go very far. In fact Quakers seem to be homebodies for the most part. When adults switch nests between years they choose a new site on average about 550 yards away. The furthest such move recorded was only about half a mile. Young of most birds are known to nest long distances from where they were raised. In the parrots that have been studied, most young go on average over 10 miles before settling down to nest, but not the stay-at-home Quakers. On average they locate their nests only a quarter mile from where they were raised. This low rate of dispersal is particularly surprising because they may travel as far as 15 miles from the nest to gather food. The incredibly low rate of dispersal is thought to be a major reason why the species has not spread explosively across the US as officials from agriculture departments nationwide once feared.

Food, agriculture and eradication: Are Quakers the demons they are made out to be?

Wild Quakers in the wild eat a mixture of seeds, buds, fruits, nuts and flowers. In South America they prefer thistle and grass seeds. Perching on a grass stem to eat the seeds can be rather challenging for a bird the size and weight of a Quaker. To get around this problem the birds have been seen hovering and plucking the seed heads off these plants then carrying them off to sturdier perches to eat. Quakers also eat the fruits of palms and other native trees. In Chicago the birds eat a variety of different items including weeds like plantain and dandelion; buds from elm, birch, ash and maple trees; fruits like mulberries, apples, and crabapples; berries from holly and juniper and seed from birdfeeders. In Chicago it is thought that without the food from residential bird feeders the species would not be able to survive because almost all of their food comes from these sources in the winter. This may not be the case in Connecticut where there is a greater abundance of winter foods available

It is the Quaker’s reputation for raiding agricultural crops that has brought them in to the greatest conflict with man. In South America the species is known to eat corn, sunflower, sorghum, peaches and pears. This taste for commercially valuable crops has led to their persecution both in South America and the US. In South America the species has been persecuted for over 150 years. Argentineans have used a wide variety of methods to control the populations. They shoot the birds, burn the nests, snare adults at favorite perches, net birds and put out poisoned baits. Even putting bounties on the birds and exporting thousands for the pet trade has not reduced their populations significantly. From 1958 – 1960 in one province in Argentina bounty was paid on 427,206 Quakers killed by local citizens. This is over twice as many as the number listed on US importation records. Yet the populations continue to increase, showing that these campaigns are ineffective. The failure of these campaigns is due to a misunderstandig of the biology of the species. A large proportion of the individuals do not breed each year. So as breeders are killed, non-breeders usually step in and take their place. This means that as much as 30-50% of the population may need to be killed off before the number of breeders is reduced.

In the US the US Fish and Wildlife Service began an eradication campaign in 1973 to help control the potential spread of Quakers in the US. 163 birds were killed, mostly in New York, New Jersey, Virginia, and California but within a few years the campaign faded out without having eradicated the species. Today fifteen states regulate or ban the ownership and transport of the species (see Bird Talk January 2000) because of the supposed threat they pose to agriculture.

How serious a threat are Quakers to agriculture? This is the $1,000 question and with most such questions the answer is unknown. In Argentina they definitely do eat crops and have caused damage. Unfortunately there has never been any independent measure of the financial impact this has had on farmers, so the only figures come from the farmers themselves and are considered less than reliable. The effects on fruit orchards are considered negligible and for grain crops the effects are unknown. In the US all populations of the species are confined to urban and suburban areas and the only potentially valuable crops they are reported feeding on are apples and mulberries. In fact Spreyer and Bucher list no complaints from farmers in their paper, not even in Florida where the species is the most abundant and tropical fruit orchards occur close to major Quaker population centers like Miami. Given that this species require a variety of fruits and seeds available year round, their current restriction to urban and suburban habitats, and their sedentary nature it seems that their potential for causing great damage to US agriculture is minimal.

For more information on Quaker Parakeets please see Spreyer, M. F. and E. H. Butcher 1998. Monk Parakeet (Myiopsitta monachus). In The Birds of North America, No. 322 (A. Poole and F. Gill, eds.). the Birds of North America, Inc. Philadelphia, PA. Available at most larger libraries.

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