Thursday, November 22, 2012

The Conundrum about the Greater Vasa Hen’s Polyandry in Aviculture -- An Economical Solution!


The Greater Vasa Hen’s Breeding Behavior in Captive Scenarios

The purpose of this entry is to answer one question apropos of the coracopsis v. v. hen’s reproductive modalities that underpins a larger picture about her character, activities, habits, and feedings.  I sketch a picture that compares and collocates all three Greater Vasa species, i.e., c. vasa, c. comorensis, and c. drouhardi.  In the first section I emphasize the distinction between instinct and character staged within a constructed debate between Aristotle and Darwin. In the second, I identify a problem in the received opinion about the Vasa hen’s breeding behavior.  In the third, I resolve the problem in the second. 
The Greater Vasas are the largest of the African and Asian parrots, twenty inches long, and they are often said to resemble Australian parrots more than any other African species. Hence, when we talk about physical characteristics, the Vasa does not fit well with the other African parrots that one can group easily together (e.g., African greys, Jardines, poicephalus). The only shared characteristic they have with African pscittacines are behavioral or dispositional. This becomes difficult since we have only had them in the United States from the 1970s.[1]
  They, along with the Madagascar and red-faced lovebirds, both belonging to the genus agapornis, display sexual dimorphism.  Concepts like ‘sexual dimorphism’ seem hard to classify historically however much they are of importance for our account of Vasa hen reproductive behavior.[2]  
A fifteen week old Vasa chick by Marc Morrone,
Parrots of the World, Rockville Center, NY

I. Darwin and Aristotle on ‘instinct’ and ‘character’

A Philosophical & Historical Framework for Vasa Reproductive Behavior

In his History of Animals[3] Aristotle focuses on his thought that the biological capacities for food and reproduction constitute what unites all animals under a common genus in light of their status as necessary conditions for a mature animal’s active life.[4] From the assumption that an animal’s life activities can be divided into two acts (i.e., reproducing and eating), and within the context of this framework pivoted on procreation and feeding, Aristotle seeks out which activities are relevant to each animal by dint of what most essentially is at stake for animals in terms of how much of their activity concentrates on this two-part necessary interest.  I assume that Aristotle believes that their activities are mostly constituted by their character or disposition. Aristotle infers an animal’s ‘character’ from its observable behavioral modes.  How much of these behavioral modes are instinctual? How could we know, and with certainty, which, out of the plurality of theories on character disposition, could be the criteria for providing a materially adequate answer to this question? And if we were interested in applying this question to a specific organism, namely, the Greater Vasa parrot, how, within this Aristotelian framework, would we proceed? 
In Charles Darwin’s account of natural selection in his The Origin of Species he gleams with an idea that follows in Aristotle’s course of reasoning however much Aristotle’s thought is premature for Darwinian ‘instinct’. Darwin considers some conditions and criteria for attributing ‘instinct’ to animals.  I suggest that Darwin’s exploration here provides a foil to Aristotle’s view of animal character.

Darwin’s “Instinct”

Darwin emphasizes ‘instinct’ in animal behavior, in the eighth chapter titled ‘Instinct,’ by foregrounding the importance of ‘character’ in an instinctual state so that character does play a role in how populations survive over time. A population’s survival is, Darwin often reminds, constrained by environmental factors that modify and fix desirable features, that is, features, or elements, of the organism’s constitution that are responsive to change where change is suffered to benefit the species so that the species may thrive in futurity.
How does any of this Darwinian instinct concern Aristotle’s question? Aristotle’s syllogistic form of reasoning to an end may seem to be programmed into an organism’s identity.  For human beings we never chose to have the capacity to reason yet we can reason and thus actualize this capacity proper to our species.  The practical syllogism in this light may seem to constrain our heredity.  This constraint, one might further argue, is like an instinct insofar as we, just in virtue of our rational cognitive capacities, persist by way of reasoning toward a goal.  However, 'instinct' suggests for the contemporary reader and for readers of Darwin's era unconscious forces - Aristotle did not have the conceptual apparata for anything unconscious. These forces, Darwin insists, influence our deliberations in a way that Aristotle's picture of syllogistic practical reasoning forecloses.  The whole point of introducing a syllogistic model for human action is, for Aristotle, to suggest an actively thinking intellect that is not subject to any passive force whatsoever.  Since instincts suggest automatic expression, and Aristotle thinks that reasoning cannot arise haphazardly so as to come about without deliberation, he cannot hold instinct in his concept of animal character
Since I am pressed to fix the discussion about a specific organism, namely, the Vasa, I can only sketch out some preliminary thoughts, from anecdotal information, on why certain behaviors, proper to the Vasa’s characteristic disposition, appear in this pscittacine’s taxon. We need, and which is what Aristotle provides at HA VIII, a psychological account of animals to distinguish the Vasa’s activities from her characteristic life form given our sketched out framework apropos of how animals as such develop habits as such and how they feed on what they do as a result.
            Drawing from his experience as a biologist, Aristotle illustrates the elusive and central concept of character by suggesting that “certain traces of psychical qualities or attitudes” are observed not only in ourselves but in other animals similar to ourselves.  Such psychical qualities are natural capacities exercised by some mental apparatus. Agreeing with Aristotle's point that animals' "habits and modes of living ... vary according to their character and their food" (HA VIII.i.588A1ff), I will expound upon the Vasa parrot first by sketching out her animal character and her dietary needs; from here we can infer the Vasa's habits and life modalities and imagine how they fall in with her physical appearance. Aristotle’s thought is, as noted above, premature for Darwinian ‘instinct’, which considers some conditions and criteria that the earlier thinker could not have thought up, however much Darwin’s exploration provides a foil to Aristotle’s animal character.  In any case, the captive Vasa hen’s reproductive activity, her copulation and subsequent brooding, shows an answer to a more theoretical, comparatively historical, philosophical question when we ask whether it is necessary for her to behave as she would in the wild, as a polyandrous, promiscuous creature.
            Since I am asking about the necessity between the Vasa hen’s reproductive behavior among suitors and her chicks’ futurity and fitness, ‘instinct’ is of conceptual importance.  Is her polyandrous reproductive mode instinctual?  I.e., do they arise from unconscious forces within her?  And are her vocalizations to her male counterpart(s) necessary (or necessarily instinctual) in both captivity and in the wild?  These questions extend beyond what I can say - simply because parrot behavior, whether in the wild or in our homes, whether in a flighted aviary or in a single cage, is beyond overdetermined and far beyond our current understanding of parrot ethiology, ecology, sensory and perceptual and cognitive processes, et relata for the simple folk psychology of ‘unconscious forces’. Activities are mostly constituted by an animal’s character or disposition, character inferred from observed behavioral modes - at least for our Aristotle.  When the Vasa hen calls out in high pitch to a nearby favored suitor for food,[5] and we hear these same vocalizations each day and feel a connection between them and her food supply, we include the vocalization patterns within our concept of the Vasa hen’s disposition and behavioral capacities or range.

Physical Changes Supervenient on Reproductive Behavioral Modalities

Although physical changes (e.g., pigmentation) do not fall within either character disposition (i.e., the whole set of activities, including habits, abilities, capacities) or life activities (e.g., eating, reproducing) and life patterns (e.g., flight patterns, patterns of vocalizations) or even habits (e.g., burying her chicks under nest box materials[6]), the hen’s reproductive dispositional mode inheres in important physical characteristics within the breeding season[7] - about which we are inquiring. 
In the beginning of her reproductive cycle, her activity coincides with marked changes in her plumage, beak, and skin coloration.  Her variety of hues contains elements of blue in sunlight. More often, during the non-breeding season, she appears dark brown.  She also appears grey.  Either the brown or the grey appearance depends on which perspective the spectator views her, since she has more than sixty shades of grey and dark brown. When she is not breeding and out of season, her undertail-coverts stand gray and black streaks accompany them.  Her non-breeding primary remiges are also gray up to their outer edge. Unlike the c. v. drouhardi, a subspecies of the more general taxonomic genus, though both subspecies integrate in the eastern region of Madagascar, with the c. v.v.’s distribution moreso to the western segment, the c. v. v. has a slightly different coloration in her undertail coverts. The c. v. drouhardi has non-coverts that are grayish white, a lighter plumage than our hen has.[8]  When she is ready to breed, her head feathers disintegrate and she is left bald or with patches of baldness.  Her skin color soon becomes a saffron mustard yellow, a taxicab yellow - just imagine orange-yellow skin for your otherwise pasty pale skinned parrot![9] Her ceres and eye rings are naked and grey notwithstanding.   During the breeding season the beaks of both the male and female c. v. vasa become one-third wider. 
As for habits in captivity Vasa parrots do not appear to be one person birds nor do they seem to have problems with other Vasas.  Vasas are naturally gregarious and this is evidenced by their flocking behaviors in the wild.  Vasas tend to flock in congregations of three to eight.  Vasas tend to roost in communities and ornithologists report sightings of hundreds of birds in a single large tree. There are some advantages to considering a Vasa parrot over other parrots of its size. Unlike for most other parrots of the Vasa parrot’s size, Vasas do not seem to develop common psittacine behavioral problems (e.g., feather plucking, screaming).[10]  Vasas also produce considerably less dust and dander than do cockatoos and African greys. When kept as companion pets, the c. v. vasa has an affectionate affinity for its caretakers in a way similar to a cockatoo.[11]
The vocalizations of the c. v. vasa include whining and “peek-a-boo” like intonations.  Steve Garvin, proprietor of The Feather Tree, suggests that the Vasa parrot’s “natural voice is like a grouse or a donkey.” Both Vasa subspecies whistle in song in a way comparable to whistlings of the wild Cape parrot and African grey.[12]  Foster observes that the Vasa’s utterances do not reach the volume of an Amazon’s though the volume does topple that of a cockatiel. In addition, if an apartment dweller takes interest in the Vasa parrot for its lower volume range, one, Foster suggested to me, should assess by whom one’s apartment is flanked.  If one’s neighbors cannot tolerate noise, then one might want to consider a quieter avian companion.  Vasas, like most other African parrot species, can mimic sounds from their environment (e.g., microwaves, phones) - another shared behavioral character among Africans.  Vasas do not ululate in shrill pitch frequently but, when they do, it usually is a sign that they are nervous or afraid of some perceived object within their immediate surroundings. Vasas whistle in this way when either perched or in flight.[13] These vocalizations have a pitch higher during the three to four months surrounding the spring breeding season and it is usually the hen’s shrill cries rather than the cock’s, relates Garvin.

II. The Received Opinion about “Necessity” for Vasa Hen Promiscuity

Our hen, drab and ashen in her crow like semblance, with her long wings and non-graduated tail, her pronounced cere, is remarkable for her polyandrous reproductive modality in her homeland Madagascar.  But what about in aviculture, in breeding programs?   Celebrated accounts on the Vasa never fail to mention just how she needs, i.e., she could not have it otherwise, multiple cocks for her brood’s fitness and futurity.  These pundits do not seem to support what they have not argued for yet but assume - the relation, causal, as received opinion takes as dictum, between the hen’s demands from the plurality of suitors and her chicks’ fitness (past rearing and fledging, weeks one through six).  Her vocalizations, social behavior during and outside the breeding season, her antics before and while in heat, and her notorious breeding paradigm at home pushes many to consider her requirements for breeding in aviculture to match those in the wild.  If the goal in writing on Vasas is earmarked to equip the prospective investor, conservationist, breeder of the Greater Vasa - an important goal since deforestation of the sliver of land on the inlet proper to Madagascar’s Comoro Islands continues to prevail and the Vasas in captivity decrease exponentially (thanks partly to the global economic crisis), then this aim does not materialize properly and the aviculturist goal does not (and has not) come across with the success it sought to attain.  The Greater Vasa is also listed under CITES II as endangered - another sign that aviculturists should help reduce pressures on wild populations and part of doing this comes from thoroughly understanding how to get captive Vasas breeding (and why it is that they breed via the constructed and chosen paradigms).  The prospective Vasa husbandry enthusiast should at least have a minimalist picture of how the parrot can breed and carry on its species in both captivity and the wild.  If the Vasa needs three males to feed her nest chock full of neonates, then writers should emphasize this in their exhortations on how to set up the breeding paradigm. In what follows I cannot paint the entire picture of this paradigm.  Instead, I only have room to show what the received opinion has been and how to clarify its shape.  Why does it seem necessary to many writers on the Greater Vasa female's practice of neonatal care that she rely on her song - or what some call a loud shrill bleak cry, a demand for food for her babies from whichever male will serve her, she does not discriminate - to attract multiple males to aid her chickadees’ rapidly increasing crops and developing metabolizing structures.
In his observations in “Greater Vasa Parrot Breeding Survey”, Blynne suggests that a polyandrous “cage grouping, with the extra males, … shows promise for the future” (58).[14] His account, as Marc Morrone pointed out to me, is not scientific and this observation of his should not mislead the prospective breeder of Vasas to setup each hen with more than one male.  A Vasa hen in captivity does not need more than one male simply because a hen in the wild does in the case of both copulation and roosting. Blynn also suggests that development and fertility depend on the polyandrous behavior of the hen - “... [i]nfertile eggs in earlier years added extra males and they now produce yearly.” So, fertility somehow correlates with multiple males per hen.  “One greater female, two greater males and one lesser all placed in one cage in ’90.  Produced the first year.”  This does not mean, however, that adding more hens will yield this result each time.

III. Resolution - Polyandry in Captivity Need Not Be, However Possible, for The Six Weeks

Captive situations differ from wild ones in the case of food and feeding her very large chicks. More males are not necessary in captive situations, relates Morrone and Koloupos, because food and protection are abundant. Multiple suitors are not needed to insure the supply of food – human caretakers are.  Desborough told me that, in the wild, extra males likely provide food because one male will not be able to find enough.  After all, males must forage, which means travel a distance; so, finding just enough that will hold in his crop is a grave challenge, he must concentrate all his efforts and energies on this, as Aristotle said earlier, vital, if not most important, life activity.  If a hen has three or four babies in her nest,  her suitors must find quite a bit per feeding - and she demands that these suitors fill her babies’ crops.  And these cocks can be sure that they will have multiple feedings within that short six weeks (i.e., from hatching to fledging) since the chicks grow therein.  So, how much the male must work and how many males per hen depends on the hen’s clutch size.  And that is the answer to this present investigation.

IV. Conclusion

So, is it necessary (or not) in captivity that the Vasa hen rely on her song to attract multiple male Vasas, if she even needs multiple males? “Females with higher song rates attracted more males, and as a result received significantly more food,” reports Ekrstrom.[15]  Does the addition of more than one male determine her brood's weaning and fledging (i.e., come the six weeks)?  My exploration with several vasa breeders and the primary and secondary literature has convinced me that there is no necessity here, not forthe hen’s reproductive behavior – whether copulation or roosting – to involve either polyandry or promiscuity in captivity.  (Do note that Ekstrom studied wild populations of Vasas in western Madagascar, not Vasas in breeding programs for the sake of raising pet quality Vasas or Vasas within our palpable domain.) So, there is no necessity for polyandrous behavior to determine a successful outcome come the six weeks - at least not in captivity.   Does this mean that it might not work out for some scenarios?  Of course not.  Monica Vallair, who works for Texas breeder Lou Roberts, has her breeding Vasas set up one hen to two males.  We also cannot forget about Blynn’s success in 1990.  On the other hand, some scenarios work against this. Koloupos found aggression from Vasa hens when adding additional males.  In any case, my investigation into whether the Vasa hen needs one suitor for feeding and reproducing brings Aristotle’s inference not only to light but also down from the abstract world of philosophos to the very material and enchanting world of aviculture. 

ᙬᙩ Special thanks to Longo’s Aviaries, Milkwood Aviaries, Marc Morrone, Daniel Koloupos, Stephany Klein, Monica Vallair, Steve Garvin, and Laurella Desborough for insightful comments and support.


Works Cited

W.S. (1927). "Bangs on a New Parrot from Madagascar" in The Auk. 44 (2) 278-9

Doane, Bonnie Munro. (1991). The Parrot in Helath and Illness: An Owner’s Guide. New York: Howell Book House.

Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li.

Ekstrom, J.M, Burke, T.T., Randrianaiana, Le.L. & Birkhead, T.R. (2007). “Unusual Sex Roles in a Highly Promiscuous Parrot: The Greater Vasa Parrot Coracopsis vasa” in The International Journal of Avian Science, 149(2), pp. 313-20.
Forshaw, J.M. (1989). Parrots of the world. Princeton: Princeton University Press.

Juniper, T and M. Parr. (1998). A Guide to Parrots of the World. New Haven: Yale University Press.

Langrand, O. and I. Sinclair. (2003). Birds of the Indian Ocean Islands: Madagascar, Mauritius, Réunion, Rodrigues, Seychelles and the Comoros. Cape Town: Struik.

Moustaki, N. (2003). A New Owner's Guide to Lovebirds. Neptune City: T.F.H. Publications.

Peters, W.K.H. (1854) - Ngazidja (Grand Comoro), Mwali (Moheli) and Ndzuani (Anjouan) in Comoros.

R. Thorstrom and R. T. Watson (1997). “Avian inventory and key species of the Masoala Peninsula, Madagascar”. Bird Conservation International,7, pp 99­-115.



[1] Tracing the origins of Vasa importations proves tricky.  Morrone tells me that he first saw them in Canada back in 1980.  The internet grapevine has Connecticut breeder Timothee Grazee as the first importer of this parrot, but this is speculative. 
[2] Related concepts that are also tough can be seen in Ekstrom’s essay on Vasa promiscuity: “We describe sexual dimorphism, sexual promiscuity, copulation behaviour, parentage (using molecular markers) and the unusual singing behaviour of females, and discuss these different features to provide an overview of the Greater Vasa Parrot’s extraordinary mating system.”
[3] Hereafter ‘HA’.
[4] Cf. Arist. De An. II.iv.415A20ff
[5] Desborough remarks that her Vasa does not have “favored suitors” when she gives her cry for her nestlings’ food - “she doesn’t say, ‘hey, Jim, feed my babies’, and later ‘hey, Ed, my babies need to eat’, she does not, in other words, discriminate between males; she just cries out a blanket cry that is specific for feeding her chicks, not, on top of that, for particular suitors to feed her.”  Ekstrom’s paper, however, suggests that the more successful hens, at least in the wild, display higher song rates, which may, although Ekstrom does not show this in his paper, involve tailoring songs to specific males. Successful hens, in Ekstrom’s study, were those with larger clutches and with better overall health; as a result of how much higher their song rates were, these hens were fed better by males.
[6] See Bono, Lisa. A. “African Parrots  - Unique Behaviors of African Parrots” in Bird Talk  November 2011, p. 25: “Female vasa parrots tend to bury eggs and even chicks while they nest.  This is often a behavior reserved for reptiles and not seen in other species of parrots.”
[7] It is important to note that the breeding season is the spring usually around May to June. However, the pairs begin in a somewhat ‘instinctual’ way to prepare for this productive stretch of time as early as January.  Mate selection, Desborough informs, does not begin until April (earliest).  The season tapers off by August, completed by September (latest).
[8]Juniper, p. 146 (plate 63).
[9] Ekstrom’s observations of this sexual dimorphism in wild Vasas reveal the hen’s “taxicab mustard yellow” bald head period to be restricted to the chick-rearing weeks, not the later fledging weeks (p. 315). He compares the differences between the non-orange headed male Vasa with the female to show the dimorphism (316).
[10] Morrone insists, however, that the possibility of a plucker is a permanent one in captivity - “even pigeons and chickens pluck in captivity,” he urges.
[11] Interestingly, the Vasa parrot and the cockatoo - alongside the Keas - are born with hard beaks.  See Kawaldie https://sites.google.com/site/kawaldie/breedingbehavior.
[12] Forbes-Watson, pp. 114-115.
[13] Juniper, p. 146.
[14]"Lesser and Greater Vasa Parrots," reprinted from Bird Talk, Oct. 1992, Canadian Bird Symposium http://www.silvio-co.com/cps/articles/1992/1992blynn1.htm; my pagination is from The American Federation of Aviculture’s “Watchbird” (June/July 1993).
[15] p. 317

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