Post by Eaglehawk on Jan 10, 2020 3:59:10 GMT
African Grey Parrot - Psittacus erithacus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Psittaciformes
Family: Psittacidae
Genus: Psittacus
Species: Psittacus erithacus
The African grey parrot (Psittacus erithacus) is an Old World parrot in the family Psittacidae. This article describes the Congo African grey parrot. The Timneh parrot (Psittacus timneh) has been split into a distinct species.
Description
The African grey parrot is a medium-sized, predominantly grey, black-billed parrot which weighs 400 g, with a length of 33 cm and an average wingspan of 46–52 cm. The Congo subspecies is a lighter grey, with darker grey over the head and both wings, while the head and body feathers have a slight white edge to them. The tail feathers are red. The Timneh subspecies is a darker gray and has a dark maroon colored tail as well as having a portion of their beak being light pink in color. Due to artificial selection by parrot breeders, some Congo African grey parrots are partially or completely red. Both sexes appear similar. The coloration of juveniles is similar to that of adults, but the eye is typically dark grey to black, in comparison to the yellow irises around dark eyes of the adult birds. The undertail coverts are also tinged with grey. The adults weigh between 418 and 526 grams.
African grey parrots may live for 40–60 years in captivity, although their mean lifespan in the wild appears to be shorter at about 23 years.
Distribution and habitat
The African grey parrot is native to equatorial Africa, including Angola, Cameroon, Congo, Côte d'Ivoire, Ghana, Kenya, and Uganda. The species is found inside a range from Kenya to the eastern part of the Ivory Coast. Between 120,100 and 259,000 Timneh African gray parrots remain worldwide. Current estimates for the global population of Congo African grey parrots are uncertain and range from 0.63 to 13 million birds. Populations are decreasing worldwide. The species seems to favor dense forests, but can also be found at forest edges and in more open vegetation types (gallery and savanna forests).
Range of the Congo African Grey Parrot
A population study published in 2015 found that the species had been ″virtually eliminated″ from Ghana with numbers declining 90 to 99% since 1992. They were found in only 10 of 42 forested areas, and in three roosts that once held between 700 and 1200 birds each, now had only 18 in total. Local people mainly blamed the pet trade, and the felling of timber for the decline. Populations are thought to be stable in Cameroon, and in the Congo an estimated 15,000 are taken every year for the pet trade, from the eastern part of the country. The annual quota is 5,000.
Behavior and ecology
Breeding
African grey parrots are monogamous breeders which nest in tree cavities. Each couple of parrots needs its own tree to nest. The hen lays three to five eggs, which she incubates for 30 days while being fed by her mate. The adults defend their nesting sites. Both parents help take care of the chicks until they can go off on their own. African grey parrot chicks require feeding and care from their parents in the nest. The parents take care of them until four or five weeks after they are fledged. Young leave the nest at the age of 12 weeks. Little is known about the courtship behavior of this species in the wild. They weigh between 12 and 14 g at hatching and between 372 and 526 g when they leave their parents.
Diet
They are mostly frugivorous; most of their diet consists of fruit, nuts, and seeds. The species prefers oil palm fruit and also eat flowers and tree bark, as well as insects and snails. In the wild, the African grey is partly a ground feeder. In captivity, it can eat sunflower seeds, bird pellets, a variety of fruits such as pears, orange, pomegranate, apple, and banana, and vegetables such as carrots, cooked sweet potato, celery, fresh kale, peas, and green beans. They also need a source of calcium.
Conservation
The natural predators for this species include as palm-nut vultures, as well as a number of raptors; monkeys target eggs and the young for food. African grey parrots in captivity have been observed to be susceptible to fungal infections, bacterial infections, nutritional insufficiency, malignant tumors, psittacine beak and feather disease, tapeworms, and blood-worms.
Humans are by far the largest threat to wild African grey populations. Between 1994 and 2003, over 359,000 African grey parrots were traded on the international market. Around 21% of the population of the wild birds are being harvested every year. Mortality rates are extremely high after they are captured until they reach market, ranging from 60 to 66%. Mortality among imported birds is high. This bird is also hunted for its meat and for its parts are used in traditional medicines. As a result of the extensive harvest of wild birds, in addition to habitat loss, this species is believed to be undergoing a rapid decline in the wild and has therefore been rated as vulnerable by the IUCN.
In October 2016, the Convention on the International Trade of Endangered Fauna and Flora (CITES) extended the highest level of protection to African greys by listing the species under appendix 1, which bans global and domestic trade in the species.
Relationship to humans
The species is common in captivity and is regularly kept by humans as a companion parrot, prized for its ability to mimic human speech, which makes it one of the most popular avian pets. They are notorious for mimicking noises around their environment and using them tirelessly. While they are highly intelligent birds, they need enrichment and attention in captivity or they can become distressed; feather plucking is a common symptom. However, they may be prone to behavioural problems due to their sensitive nature.
African greys are also highly intelligent, having been shown to perform at the cognitive level of a 4– to 6-year-old child in some tasks. New experiments have shown that African greys can learn number sequences and can associate human voices with those humans' faces. Most notably, Dr Irene Pepperberg's work with Alex the parrot showed his ability to learn over 100 words, differentiating between objects, colors, materials, and shapes.
Prosocial and tolerant parrots help others to obtain food
by Max Planck Society
In the behavioral experiments, the parrots receive metal tags, which they can then exchange for food. Credit: Comparative Cognition Group
Parrots are considered extraordinarily clever animals. Alex, the famous Harvard-based African grey parrot, communicated with a vocabulary of more than 500 human words, could answer questions and classify objects spontaneously. Scientists from the Max-Planck-Institute for Ornithology based at the research station outpost for parrot comparative cognition in the Loro Parque in Tenerife, Spain, have shown that parrots exhibit a high level of social intelligence and cooperativeness. They readily help others, even when there is no immediate opportunity for reciprocation. Moreover, they reciprocate received favours and do not appear jealous, if conspecifics obtain a better reward than themselves. This further supports that they have evolved a level of intelligence comparable to that of great apes, crows and dolphins.
In the laboratory in the Max-Planck-outpost research station for comparative cognition run in collaboration with the Loro Parque Fundación, in Puerto de la Cruz, Tenerife, the African grey parrot Bella obtains a few metal tokens from a human experimenter. She has learnt to exchange those tokens with one of the scientists for her favorite food. But there is a problem—the exchange hole in her testing chamber through which the exchange occurs has been blocked.
In the neighboring test chamber her friend Kimmi is waiting. Her exchange hole for the token exchange is open. However, Bella notices that Kimmi is lacking any tokens. What is he going to do?
Indeed, the parrot female picks up token after token and passes them over to Kimmi though an opening in the wall separating the two neighbouring chambers. The latter, seemingly pleased, accepts those gifts and readily exchanges them against treats. Bella in the meantime, rather relaxed, observes how Kimmi benefits from her generosity, without knowing that at a later point in time, the other may return the favor.
If a bird does not receive a tag, the neighbor often passes on its own and thus forgoes its own reward. Credit: Comparative Cognition Group
Helping partners
According to the most recent scientific findings, other than humans, only some great apes species behave similarly selfless towards unrelated individuals in comparable studies. In contrast, all other species tested so far in did not seem to pay attention to the wellbeing of conspecifics. They either behaved indifferently or even selfishly in comparable test situations. "Our parrots indeed seem to have grasped that another individual requires their help in order to achieve a goal," says Désirée Brucks, first author of the study. If Kimmi's exchange hole was blocked too, however Bella did not bother to pass over tokens. The African grey parrots therefore appear to recognize exactly when a conspecific actually benefits from their help and when it would not.
In a second study, the same parrots proved their general 'prosocial attitude,' i.e. their willingness to help and capacity to attend to the wellbeing of others. Besides, they showed the ability to reciprocate the other's previous actions, following a 'tit-for-tat' strategy, which is seen as an important prerequisite for the evolution of cooperation. In the experiment, the birds had to decide between two types of tokens. One of them rewarded just the subject, whereas the other token provided food to both the subject and its neighbor. "Initially the parrots chose randomly, without paying any attention to the wellbeing of their neighbor," explains Anastasia Krasheninnikova, first author of this study. "As soon as the parrots were tested alternatingly with their neighbor, they very rapidly learned to choose the token that benefited both birds."
No jealousy if others get better treatments
Furthermore, the research team has shown in a third recent study that parrots apparently are not jealous if a conspecific receives a better payoff for the same work performance than themselves, or has to work less hard for the same payoff. "At first, this finding came as a surprise, given that a "sense of fairness" is considered a prerequisite for the evolution of cooperation," says Auguste von Bayern, the leader of the comparative cognition research group. If you are able to detect when somebody is cheating upon you, you can react and switch to a fairer and thus better cooperation partner.
Whereas the parrots remained easygoing, primates, for example, do not put up with such an unequal treatment but show clear signs of anger and at some point boycott the unfair game. Possibly, the explanation for this is that parrots tend to be life-long monogamous, i.e. they remain pair-bonded with a single partner throughout their lives, whereas primates typically maintain affiliative relationships and/or coalitions with several partners in parallel and switch partners often as new opportunities arise.
"Given that parrots are so closely bonded with a single individual and thus so mutually interdependent, it does not make any difference if one of them gets a better pay-off once in a while. What counts is that together, they function as a unit that can achieve much more than each of them on their own (in addition to raising their joint offspring). This is probably why parrots are much more tolerant towards unequal treatment than species that are not long-term monogamous, while still being excellent cooperators," explains Auguste von Bayern.
phys.org/news/2020-01-prosocial-tolerant-parrots-food.html
Journal Reference:
Désirée Brucks, Auguste M.P. von Bayern. Parrots Voluntarily Help Each Other to Obtain Food Rewards. Current Biology, 2020; DOI: 10.1016/j.cub.2019.11.030
More information: Parrots voluntarily help each other to obtain food rewards, Current Biology (2020).
Summary
Helping others to obtain benefits, even at a cost to oneself, poses an evolutionary puzzle. While kin selection explains such “selfless” acts among relatives, only reciprocity (paying back received favors) entails fitness benefits for unrelated individuals. So far, experimental evidence for both prosocial helping (providing voluntary assistance for achieving an action-based goal) and reciprocity has been reported in a few mammals but no avian species. In order to gain insights into the evolutionary origins of these behaviors, the capacity of non-mammalian species for prosociality and for reciprocity needs to be investigated. We tested two parrot species in an instrumental-helping paradigm involving “token transfer.” Here, actors could provide tokens to their neighbor, who could exchange them with an experimenter for food. To verify whether the parrots understood the task’s contingencies, we systematically varied the presence of a partner and the possibility for exchange. We found that African grey parrots voluntarily and spontaneously transferred tokens to conspecific partners, whereas significantly fewer transfers occurred in the control conditions. Transfers were affected by the strength of the dyads’ affiliation and partially by the receivers’ attention-getting behaviors. Furthermore, the birds reciprocated the help once the roles were reversed. Blue-headed macaws, in contrast, transferred hardly any tokens. Species differences in social tolerance might explain this discrepancy. These findings show that instrumental helping based on a prosocial attitude, accompanied but potentially not sustained by reciprocity, is present in parrots, suggesting that this capacity evolved convergently in this avian group and mammals.
www.cell.com/current-biology/fulltext/S0960-9822(19)31469-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982219314691%3Fshowall%3Dtrue
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Psittaciformes
Family: Psittacidae
Genus: Psittacus
Species: Psittacus erithacus
The African grey parrot (Psittacus erithacus) is an Old World parrot in the family Psittacidae. This article describes the Congo African grey parrot. The Timneh parrot (Psittacus timneh) has been split into a distinct species.
Description
The African grey parrot is a medium-sized, predominantly grey, black-billed parrot which weighs 400 g, with a length of 33 cm and an average wingspan of 46–52 cm. The Congo subspecies is a lighter grey, with darker grey over the head and both wings, while the head and body feathers have a slight white edge to them. The tail feathers are red. The Timneh subspecies is a darker gray and has a dark maroon colored tail as well as having a portion of their beak being light pink in color. Due to artificial selection by parrot breeders, some Congo African grey parrots are partially or completely red. Both sexes appear similar. The coloration of juveniles is similar to that of adults, but the eye is typically dark grey to black, in comparison to the yellow irises around dark eyes of the adult birds. The undertail coverts are also tinged with grey. The adults weigh between 418 and 526 grams.
African grey parrots may live for 40–60 years in captivity, although their mean lifespan in the wild appears to be shorter at about 23 years.
Distribution and habitat
The African grey parrot is native to equatorial Africa, including Angola, Cameroon, Congo, Côte d'Ivoire, Ghana, Kenya, and Uganda. The species is found inside a range from Kenya to the eastern part of the Ivory Coast. Between 120,100 and 259,000 Timneh African gray parrots remain worldwide. Current estimates for the global population of Congo African grey parrots are uncertain and range from 0.63 to 13 million birds. Populations are decreasing worldwide. The species seems to favor dense forests, but can also be found at forest edges and in more open vegetation types (gallery and savanna forests).
Range of the Congo African Grey Parrot
A population study published in 2015 found that the species had been ″virtually eliminated″ from Ghana with numbers declining 90 to 99% since 1992. They were found in only 10 of 42 forested areas, and in three roosts that once held between 700 and 1200 birds each, now had only 18 in total. Local people mainly blamed the pet trade, and the felling of timber for the decline. Populations are thought to be stable in Cameroon, and in the Congo an estimated 15,000 are taken every year for the pet trade, from the eastern part of the country. The annual quota is 5,000.
Behavior and ecology
Breeding
African grey parrots are monogamous breeders which nest in tree cavities. Each couple of parrots needs its own tree to nest. The hen lays three to five eggs, which she incubates for 30 days while being fed by her mate. The adults defend their nesting sites. Both parents help take care of the chicks until they can go off on their own. African grey parrot chicks require feeding and care from their parents in the nest. The parents take care of them until four or five weeks after they are fledged. Young leave the nest at the age of 12 weeks. Little is known about the courtship behavior of this species in the wild. They weigh between 12 and 14 g at hatching and between 372 and 526 g when they leave their parents.
Diet
They are mostly frugivorous; most of their diet consists of fruit, nuts, and seeds. The species prefers oil palm fruit and also eat flowers and tree bark, as well as insects and snails. In the wild, the African grey is partly a ground feeder. In captivity, it can eat sunflower seeds, bird pellets, a variety of fruits such as pears, orange, pomegranate, apple, and banana, and vegetables such as carrots, cooked sweet potato, celery, fresh kale, peas, and green beans. They also need a source of calcium.
Conservation
The natural predators for this species include as palm-nut vultures, as well as a number of raptors; monkeys target eggs and the young for food. African grey parrots in captivity have been observed to be susceptible to fungal infections, bacterial infections, nutritional insufficiency, malignant tumors, psittacine beak and feather disease, tapeworms, and blood-worms.
Humans are by far the largest threat to wild African grey populations. Between 1994 and 2003, over 359,000 African grey parrots were traded on the international market. Around 21% of the population of the wild birds are being harvested every year. Mortality rates are extremely high after they are captured until they reach market, ranging from 60 to 66%. Mortality among imported birds is high. This bird is also hunted for its meat and for its parts are used in traditional medicines. As a result of the extensive harvest of wild birds, in addition to habitat loss, this species is believed to be undergoing a rapid decline in the wild and has therefore been rated as vulnerable by the IUCN.
In October 2016, the Convention on the International Trade of Endangered Fauna and Flora (CITES) extended the highest level of protection to African greys by listing the species under appendix 1, which bans global and domestic trade in the species.
Relationship to humans
The species is common in captivity and is regularly kept by humans as a companion parrot, prized for its ability to mimic human speech, which makes it one of the most popular avian pets. They are notorious for mimicking noises around their environment and using them tirelessly. While they are highly intelligent birds, they need enrichment and attention in captivity or they can become distressed; feather plucking is a common symptom. However, they may be prone to behavioural problems due to their sensitive nature.
African greys are also highly intelligent, having been shown to perform at the cognitive level of a 4– to 6-year-old child in some tasks. New experiments have shown that African greys can learn number sequences and can associate human voices with those humans' faces. Most notably, Dr Irene Pepperberg's work with Alex the parrot showed his ability to learn over 100 words, differentiating between objects, colors, materials, and shapes.
Prosocial and tolerant parrots help others to obtain food
by Max Planck Society
In the behavioral experiments, the parrots receive metal tags, which they can then exchange for food. Credit: Comparative Cognition Group
Parrots are considered extraordinarily clever animals. Alex, the famous Harvard-based African grey parrot, communicated with a vocabulary of more than 500 human words, could answer questions and classify objects spontaneously. Scientists from the Max-Planck-Institute for Ornithology based at the research station outpost for parrot comparative cognition in the Loro Parque in Tenerife, Spain, have shown that parrots exhibit a high level of social intelligence and cooperativeness. They readily help others, even when there is no immediate opportunity for reciprocation. Moreover, they reciprocate received favours and do not appear jealous, if conspecifics obtain a better reward than themselves. This further supports that they have evolved a level of intelligence comparable to that of great apes, crows and dolphins.
In the laboratory in the Max-Planck-outpost research station for comparative cognition run in collaboration with the Loro Parque Fundación, in Puerto de la Cruz, Tenerife, the African grey parrot Bella obtains a few metal tokens from a human experimenter. She has learnt to exchange those tokens with one of the scientists for her favorite food. But there is a problem—the exchange hole in her testing chamber through which the exchange occurs has been blocked.
In the neighboring test chamber her friend Kimmi is waiting. Her exchange hole for the token exchange is open. However, Bella notices that Kimmi is lacking any tokens. What is he going to do?
Indeed, the parrot female picks up token after token and passes them over to Kimmi though an opening in the wall separating the two neighbouring chambers. The latter, seemingly pleased, accepts those gifts and readily exchanges them against treats. Bella in the meantime, rather relaxed, observes how Kimmi benefits from her generosity, without knowing that at a later point in time, the other may return the favor.
If a bird does not receive a tag, the neighbor often passes on its own and thus forgoes its own reward. Credit: Comparative Cognition Group
Helping partners
According to the most recent scientific findings, other than humans, only some great apes species behave similarly selfless towards unrelated individuals in comparable studies. In contrast, all other species tested so far in did not seem to pay attention to the wellbeing of conspecifics. They either behaved indifferently or even selfishly in comparable test situations. "Our parrots indeed seem to have grasped that another individual requires their help in order to achieve a goal," says Désirée Brucks, first author of the study. If Kimmi's exchange hole was blocked too, however Bella did not bother to pass over tokens. The African grey parrots therefore appear to recognize exactly when a conspecific actually benefits from their help and when it would not.
In a second study, the same parrots proved their general 'prosocial attitude,' i.e. their willingness to help and capacity to attend to the wellbeing of others. Besides, they showed the ability to reciprocate the other's previous actions, following a 'tit-for-tat' strategy, which is seen as an important prerequisite for the evolution of cooperation. In the experiment, the birds had to decide between two types of tokens. One of them rewarded just the subject, whereas the other token provided food to both the subject and its neighbor. "Initially the parrots chose randomly, without paying any attention to the wellbeing of their neighbor," explains Anastasia Krasheninnikova, first author of this study. "As soon as the parrots were tested alternatingly with their neighbor, they very rapidly learned to choose the token that benefited both birds."
No jealousy if others get better treatments
Furthermore, the research team has shown in a third recent study that parrots apparently are not jealous if a conspecific receives a better payoff for the same work performance than themselves, or has to work less hard for the same payoff. "At first, this finding came as a surprise, given that a "sense of fairness" is considered a prerequisite for the evolution of cooperation," says Auguste von Bayern, the leader of the comparative cognition research group. If you are able to detect when somebody is cheating upon you, you can react and switch to a fairer and thus better cooperation partner.
Whereas the parrots remained easygoing, primates, for example, do not put up with such an unequal treatment but show clear signs of anger and at some point boycott the unfair game. Possibly, the explanation for this is that parrots tend to be life-long monogamous, i.e. they remain pair-bonded with a single partner throughout their lives, whereas primates typically maintain affiliative relationships and/or coalitions with several partners in parallel and switch partners often as new opportunities arise.
"Given that parrots are so closely bonded with a single individual and thus so mutually interdependent, it does not make any difference if one of them gets a better pay-off once in a while. What counts is that together, they function as a unit that can achieve much more than each of them on their own (in addition to raising their joint offspring). This is probably why parrots are much more tolerant towards unequal treatment than species that are not long-term monogamous, while still being excellent cooperators," explains Auguste von Bayern.
phys.org/news/2020-01-prosocial-tolerant-parrots-food.html
Journal Reference:
Désirée Brucks, Auguste M.P. von Bayern. Parrots Voluntarily Help Each Other to Obtain Food Rewards. Current Biology, 2020; DOI: 10.1016/j.cub.2019.11.030
More information: Parrots voluntarily help each other to obtain food rewards, Current Biology (2020).
Summary
Helping others to obtain benefits, even at a cost to oneself, poses an evolutionary puzzle. While kin selection explains such “selfless” acts among relatives, only reciprocity (paying back received favors) entails fitness benefits for unrelated individuals. So far, experimental evidence for both prosocial helping (providing voluntary assistance for achieving an action-based goal) and reciprocity has been reported in a few mammals but no avian species. In order to gain insights into the evolutionary origins of these behaviors, the capacity of non-mammalian species for prosociality and for reciprocity needs to be investigated. We tested two parrot species in an instrumental-helping paradigm involving “token transfer.” Here, actors could provide tokens to their neighbor, who could exchange them with an experimenter for food. To verify whether the parrots understood the task’s contingencies, we systematically varied the presence of a partner and the possibility for exchange. We found that African grey parrots voluntarily and spontaneously transferred tokens to conspecific partners, whereas significantly fewer transfers occurred in the control conditions. Transfers were affected by the strength of the dyads’ affiliation and partially by the receivers’ attention-getting behaviors. Furthermore, the birds reciprocated the help once the roles were reversed. Blue-headed macaws, in contrast, transferred hardly any tokens. Species differences in social tolerance might explain this discrepancy. These findings show that instrumental helping based on a prosocial attitude, accompanied but potentially not sustained by reciprocity, is present in parrots, suggesting that this capacity evolved convergently in this avian group and mammals.
www.cell.com/current-biology/fulltext/S0960-9822(19)31469-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982219314691%3Fshowall%3Dtrue