A pair of Amazona vittata. the puertorican amazon calling from a tree near their nest

It has been an unusually rainy 24 of February.  Normally this month is one of the driest ones of the year.  But the arrival of a cold front ushered non stop rain and drizzle that has lasted the whole day.  In some parts of the island the rain has set records that had stood since the 1940's.  It has been a rainy and cloudy afternoon.  Every afternoon, I do a round to check the captive breeding pairs.  I do this every day during the breeding season, at a specific time.  The captive parrots become habituated to my presence and are not alarmed when I go by.   Some wild birds have territories inside the aviary and they also become habituated to my presence.   This pair is perching in a tree near to where their nest is located.  You can hear their calls and also the calls of other parrots who are near.  Their calls serve to mark their territory and to warn other birds away.   There was another pair who had a territory close to that of this pair.  The male of that pair died.  In an unusual turn of events, this pair tolerates the female in their territory rather than chasing her away as they do with other birds.  You can see the widowed female arrive after second 18 of the video.  The male is a captive bird that was released a few years back, you can see the antena of his radio transmitter.  The is lacking a few feathers from the top of his head, probably he lost them in a territorial fight.

A puertorican parrot displaying to others of its flock.

Sometimes the puertorican parrots will open partially open their wings when they are displaying to other birds.  My guess is that they do so to make themselves look bigger.  This wing opening is often accompanied with bowing, and a side to side motion.  This particular bird was displaying in front of two other birds who were licking the sap that oozed from a broken banana leave.

When resting among the foliage, the green color of the puerto rican parrot, Amazona vittata, serves as a great camouflage

The puerto rican parrot is one of the Amazons with the the least color aside from green.  When resting or hiding among the vegetation it is very hard to see.  These two parrots were photographed just after sun down.  As you can see by the retracted foot inside the plumage of the left parrots, it is quite at home and relaxed in the tree stump.  The left parrot vocalizing loudly, something they do at sundown and at sunrise.  The bird to the left has a radio transmitter.

Periquito espléndido (Neophema splendida), nativo de los desiertos de Australia

The largest flock I have seen to date of Puerto Rican parrots (Amazona vittata) in the Rio Abajo forest.

Since the first releases of the Puerto Rican parrot in the Rio Abajo forest, it has become almost commonplace to see, in certain parts of the forest, small flocks foraging or roosting.  These flocks can vary in size, but in my experience, 20 to 30 birds together has been the upper range for these groups.  Sometimes I walk in the forest to enjoy the clear afternoons that follow the thunderstorms of that start after noon and to see if I can catch a glimpse of the wild birds. 

Seeing PR parrots fly over the forest, during these walks, is always an inspiring sight.   Today, as I was walking around the forest just before nightfall I saw a flock sitting on a leafless tree.  The moment I saw the group of birds I was thrilled.  It was clear this was a very large group for the species.   From the photos I took I can count 45 birds on the tree.   I took several photos but since light was falling quickly and the birds kept moving, this one probably has the most birds together.   In my knowledge this is the largest flock ever documented on a photo.

I could not help but recall an article that I read many years ago, in which the authors said “…we personally doubt the current population exceeds 50 individuals and may even be much smaller.  We predict that Puerto Rico is about to lose another of its native birds.”¹  I am happy to say that thank to the work of many, many highly dedicated people, this is one prophecy that didn’t come to pass.   Of course our work is not done yet, but as this photo attest, we are on our way.

Recher Harry F, and  Recher, Judy T.  1996.  A contribution to the knowledge of the avifauna of the Sierra de Luquillo, Puerto Rico.  Caribbean Journal of Science.  Sept-Dec. 1966

Puerto Rican parrots, Amazona vittata, in captivity feeding on Sierra palm (Prestoea montana) fruits.

Brian Ramos, Piel Jonas Banchs, Ana Estrella, Jong Piel Banchs

Planting sierra palm

Although the diet the parrots receive in captivity is designed to furnish all their nutritional needs, from time to time we add seeds, fruits and leaves gathered from the forest to the parrot's food.  These foods collected from the wild fulfill an important role in the wellbeing of the parrots in captivity. 

Wild collected fruits, seeds, and leaves play a role as environmental enrichment for the birds in captivity, as they offer the opportunity to manipulate and feed on food that is different in size, shape and texture from the standard captive pellet diet.   Because we put the whole inflorescence with the fruits inside the cage, the birds get to interact with the food in a way that is similar with what would happen in the wild.  In simpler terms, environmental enrichment is a way of saying these food help relieve the boredom of the parrots.

Puerto Rican parrots relish eating the fruits of various species of palms.  Although sierra palm is a favorite, they also eat royal palm (Roystonea borinquena) and corozo palm (Attalea aculeata).  In the El Yunque forest the puerto rican parrots favor the sierra palm to the point that it is said that its breeding season is influenced by the availability of sierra palm seeds. 

The staff of the Puerto Rican parrot project collects these wild fruits from the forest around the aviary.  This means that when the birds are released they are quite familiar with the foods available in the forest.  In the Rio Abajo forest, sierra palm Prestonea montana is an uncommon plant we don’t feed the birds with them frequently.  In place of sierra palm we feed the birds royal palm fruits.

Aside from caring for the birds in captivity and monitoring the birds in the wild, the puerto rican parrot project staff works in a variety of endeavors of which the general public is generally not aware, one of these is improving the habitat by planting a variety of trees the parrot use as food. In the past decade the aviary staff has planted, among others, hundreds of seedlings of sierra palm, corozo palm and even the endemic manaca palms (Calyptronomas rivalis), in the aviary and nearby areas.

A Puerto Rican parrot, Amazona vittata, feeding on the fruit of the guava tree Psidium guajava

Those that keep Amazons in captivity are quite familiar with the messy feeding habits of these birds.  It is not rare for an Amazon to take a tiny bite of a piece of fruit and then drop the rest on the floor of the cage.    The birds behave the same way in the wild.  However sometimes, if the mood strikes them, these birds will take a piece of food and manipulate it with surprising delicacy and dexterity.

Some years ago I was able to photograph a Puerto Rican parrot in the wild eating a fruit from a guava tree Psidium guajaba.  Holding the fruit firmly with one leg, the parrot first cut a groove around the middle of the fruit to expose the pulp.  Then it proceeded to consume the fruit slowly and deliberately.  After it had finished the top half it ate the bottom half.   The fact that nothing disturbed this bird during its feeding bout is probably the reason that it ate almost all the fruit.  Birds that feel even slightly alarmed will immediately drop any food they are eating.

Wlid guava Psidium guajava, is a common tree in the Rio Abajo forest, particularly in disturbed areas.  When the local trees are fruiting, the Rio Abajo staff sometimes collects the fruit and gives it to the captive birds.  The captive birds not only relish the fruits but will also eat the leaves and sometimes will also strip the bark of branches after all the fruits and leaves have been eaten.

Some comments on the changes in brightness of certain colors of the tail feathers of the Puerto Rican parrot as you look at them from different perspectives.

top view

Reverse view

Side angle view

front angle view

Of all the species in the psittacine genus Amazona, the puertorican parrot, Amazona vittata is the least colorful.¹  Aside from a limited amount of red in the forehead, and the white skin patches around the eye, the rest of the body is covered with green feathers.  On a perching PR parrot there is little color besides green to be seen, the turquoise and black of the wings, the blue, red and yellow areas on the tail are all kept well hidden.  The reason for such lack of color is probably the need to be as cryptic as possible to avoid attracting the attention of predators.

The PR parrot brightest colors are in the forehead and in the tail feathers.   The red band in the forehead varies widely in width, length and shape.  Generally males have a wider red band than females, but not always.  Perhaps the best example of the variability of the forehead color in the species is the pair of PR parrots currently on exhibition on the Juan A. Rivero Zoo at Mayaguez. The male has a single tiny red feather in his forehead, the female has a red band wider and larger than almost all females, so one on first sight could easily be fooled into thinking she is the male and vise versa.

Very few people are familiar with the color in the tail feathers of the PR parrots.  The reason is that because they can only be sighted when the parrots fan their tails, a normally brief occurrence, they are essentially invisible to the casual observer.     But even if an observer happened to be at the right place and time to see a bird with its tail fanned, from a distance the colors are barely visible and unremarkable when compared even with even modestly colorful species, such as the hispaniolan amazon (Amazona ventralis).

In the aviary the birds interact in many ways during the day.  Some of these interactions involve body language, on occasions this includes tail fanning which is normally accompanied by vocalizations and sometimes bowing and wing cupping.   The birds can do these displays as parts of being aggressive and also for other reasons which are not necessarily so easy to discern.   Except when we are selecting breeding pairs from the flock, or are concerned about a bird being bullied, we don’t pay much attention to these displays. 

About a decade ago, when I was standing next to her breeding cage, a female known as Ann, did a bowing and tail fanning display standing in front of me on the wire floor of the cage,  very close to my face, this is, to this day, an uncommon event (by the way, Ann and her mate, Pepe, used to be among the tamest and sweetest birds in the aviary, but as they grew older they became more and more intolerant of people around their breeding cage, now as they are getting close to the two decade mark in their lives, when breeding, they are hideously aggressive and among the most fierce of our pairs, but I digress).

When this event happened, it was morning and sunlight was coming from my back and hitting the parrot head on.  When Ann did her display, for a brief moment, her green color became brighter the way a mirror becomes brighter when the sun hits it at just the right angle.  I was intrigued by this but given that I had many other concerns at the time, filed it in the back of my mind for future reference.  Early this year I found some a shed tail feather and decided to photograph it to record how light reflected from it.

The feathers that are the last ones at the sides of the tail are different from the other tail feather and any other feather.  They are asymmetrical and one of their sides is blue.  I found that the blue of these feathers changes in brightness and you look at it from different perspectives.  If you look at the feather from an angle of 90 degrees from top looking down at the top side, the color is not particularly bright.  But as one changes the perspective, the blue becomes brighter and brighter as one approaches the horizontal plane.  If one looks at the feather in the orientation that it would have if a parrot was displaying standing in front of you the blue becomes almost mirror-like in its brightness.  You can see how the blue changes in the photos.  

What is the meaning of this change of color?  The birds have a different color perception system than us, with four receptor cell types.   Personally, I don’t know how the eyes the parrot’s perceives the changes in color that my mammal brain reports to me.   My own guess would be that if the feathers undergo changes in color and brightness as a result of the birds fanning and bowing, it may be that those changes play a role in courting displays, alternatively it also could be important in aggressive interactions.   It has been shown that budgerigar females favor males whose face feathers display fluorescence.²   For the moment, from a strictly scientific point of view, I can’t say with any certainty what the brightness changes means for the parrots.   For all I know it could be an artifact of perspective or of my own perception.   Nevertheless I find it an intriguing phenomenon. I don’t foresee the program exploring this matter as we have worked hard to keep our birds from getting imprinted with humans and breeding pairs are not fond of either people or photographic cameras.

¹Low, R. 1984. Endangered parrots

²Proc Biol Sci. 2001 Nov 7;268(1482):2273-9.

Ultraviolet vision, fluorescence and mate choice in a parrot, the budgerigar Melopsittacus undulatus.

Puertorican parrots eating west indian tree fern stems

The Puerto Rican parrot (Amazona vittata) is known to eat the leaves, fruits or seeds of more than forty species of plants.  In the Rio Abajo forest the parrots sometimes consume the stems of the fronds of the tree ferns of the genus Cyathea.   The effect of the parrots’ activity is to completely defoliate the ferns.  The parrots consume all stems, from very young ones that are starting to unfurl to the oldest ones.    The ferns eventually produce new leaves and recuperate fully from the parrots foraging activities.    The birds don’t eat the whole frond, just parts of the stems.    I find the fact that the parrots were using the tree fern stems as food remarkable given that the birds that have been  released into the wild since the reintroduction program began were given a wide variety of wild leaves, fruits and seeds before the release, but not tree fern fronds.    

Amazona ventralis, the hispaniolan parrot, in flight

This photo shows particularly well the belly area of a hispaniolan parrot.  The colors of the belly of the hispaniolan parrot can be used, along with other things, to ID this species.  One of the most distictive characteristics of the hispaniolan parrot is its white forehead.  The blue patches just behind the eyes are also useful to identify this species.  But it is the combined observation of the various traits that can give you the best confidence that you have correctly identifed this species.  In this photo you can see the white forehead, the blue patch behind the eye, the red patches in front of the legs and the red tail feathers.  This bird was photographed in one of the Rio Abajo aviary flight cages.  Hispaniolan parrots are used here as foster parent to eggs and chicks of the Puerto Rican parrot.  They are not for sale.  A selected few of these birds stay in the project their entire life where they receive exactly same care as the PR parrots.  Because the hispanionan parrots on ocasion are allowed to raise their own chicks, we produce a small number of birds of this species.  Some of the chicks stay in the program, most are sent to the Dominican Republic where a number of them have been released into the wild in El Parque del Este.  The USFWS sometimes keeps a few in the Iguaca aviary hispaniolan flock.

Here you can see the flight feathers.  The flight feathers are black and navy blue.  The colors of the flight feathers of the hispaniolan parrots is different from the color of the same feathers in the PR parrot.  In the PR parrot the flight feathers are turquoise.  This photo is of Ivan.  He if flying in the Rio Abajo bird hospital room.  Sometimes birds have to be hospitalized for a few days to receive treatments.  If they are alone in the hospital they can become depressed.  Ivan was born in May 2012, I plan to use him as a companion parrot to birds in the hospital.  Ivan is relaxed among humans and is familiar with the inside of office and the hospital.  I hope his generally unstressed demeanor among humans will be reassuring to birds in the hospital.  I have to add that infectious diseases are extremely rare in the RA aviary, almost all the birds that end up in the hospital do so because they need treatment for accidents or scrapes due to fighting .  After a few days of antibiotics they are sent back to their cages none worse for the wear.  In the case of a suspicion of an infectious disease we have a separate quarantine building that is used for this cases. 

Puertorrican parrot goes bananas about its bathtime

This is a male of the species Amazona vittata vittata, the Puerto Rican parrot.  These birds greatly enjoy getting baths.  In the wild when it rains after a spell of dry weather the parrots become very excited and vocalize powerfully as they get wet under the rain.  In captivity the cages are designed so that the  birds can take baths whenever it rains, however a few will also eagerly seek getting wet under the water we use to clean cages.  From time to time we indulge them and allow them to frolick under the water stream.  As you can see in the video the bird is unabashedly enjoying the water.  These parrots are highly intelligent and we try, as much as it is possible in captivity, to enrich their enviroment with things they like. 

I want to make clear that this animal trusts me a great deal, birds that don't have a trusting relationship with their owners or keepers will not behave this way, some may even feel threatened when their cage is cleaned.  If you want to give your birds a bath like these make sure that the bird doesn't feels threatened, is in a familiar enviroment and that it can get away from the water stream at any time if it chooses to do so.

This particular male has been particularly fecund and a number of his offspring have been released into the wild as part of a program to reintroduce the species to parts of it former habitat where it has beene extinct since the early twenty century.

Amazona vittata, laparoscopic examination of their internal organs to check their state of health

This is a normal ovary of a mature female, the white irregular patch to the left marks the spot where an egg was released

A healthy testicle

A spent fibrous ovary of an old Amazona ventralis, the owner of this ovary is reproductively senecent

A liver with yellow spots of uncertain etiology 

Lymari (USFWS), Jafet Velez (USFWS), Brian Ramos (DRNA)

Dr. Antonio Rivera the veterinarian that conducted the laparoscopic examinations

A bird ready for the procedure, note the laparoscopic probe  which is the wand like apparatus on the doctor;s hand

The view of the body cavity of the parrot on real time on the computer screen

The first sign that bird is coming out of anesthezia is when they open their eyes, as you can see this bird is not amused

A hispaniolan parrot just removed from the anesthezia apparatus

During the course of the year we test our birds for various diseases, give them physical examinations and do a variety of blood tests on the flock.  Also we evaluate carefully each breeding pair performance during the breeding season.  Usually all these things put together give us a pretty good idea of what to expect from our birds and the state of their health.  But in some cases what exactly is the reason for a bird not breeding is not clear from blood examinations and physical tests.  Then we use a laparoscopic apparatus to see into the bird.

The laparoscopic apparatus is an electronic device that allows us to see inside the bird by using a flexible tube that acts as a camera to capture images of the internal organs.  Since the tube is fairly thin the incision needed is small, more like a hole than a cut.  The flexible tube has fiber optics that bring light inside the animal and allows us to see the internal organs live in a computer screen.  At times we have added a tiny probe that can clip diminutive bits of tissues of interest.  This procedure can be done with very little loss of blood by the animal and after it is finished the birds can get back to their cages and normal routine after a few hours of observation.

The birds are anesthetized using isoflourane.  The flow of the anesthetic is carefully metered to insure that the bird has the proper level of anesthesia.  Unfortunately the level of anesthesia needed to put the birds to sleep is not too far from the level that can kill them.  That means that during the whole operation there is one person paying very close attention to the bird vital signs.  In case a bird stops breathing we have ways to rescue it.  Thankfully, because the staff has a fair amount of experience on treating birds we have never lost one to anesthesia.  We anesthetize the birds because the parrots in our flock object in the strongest terms possible to being handled and will happily put one or a dozen vicious bites in the hand that feeds them.  Our parrots are familiar with medical tests and abhor them wholeheartedly.

Once the bird is safely anesthetized an area on its left side is cleaned and a cut of about one centimeter is made on the skin and muscles.  Through this cut a hole is made into the body cavity and the laparoscopic apparatus is threaded into the body.  Usually the lungs, heart, liver, kidney and gonads are checked for appearance and everything is described, if any abnormality is noted a photo is taken.  Relevant aspects of the bird life history are discussed before each individual laparoscopic examination.   The doctor checks the organs and makes his evaluation and recommendations.  The probe is extracted and the cut sutured.

After the operation the birds are carefully monitored to see that they recuperate successfully from anesthesia.  We all can remember what happened to Michael Jackson because his doctor put him under deep anesthesia and then left him all alone to do some errands.  The birds recuperate fairly quickly from the anesthesia and after they open their eyes and stand on their feet we can confidently say that they won’t unexpectedly croak on us.

I want to thank the USFWS for lending us the laparoscopy machine and for the help of their skilled personnel to give support to Dr, Rivera during the procedure.  I want to thank Jafet Velez (USFWS), Lymari (USFWS), Brian Ramos DRNA) and Dr. Antonio Rivera.

Puerto Rican parrot twilight behavior, sleeping clumped in a bunch.

This is the only photo of this behavior ever taken, you can see a parrot ready to fly away at the bottom

As the leader of the captive propagation program of the Puerto Rican parrot I spend time, probably than anyone on its right mind should, observing parrot behavior. I also read the notes of previous aviculturists about the parrot’s behavior in captivity to look for context for my observations. But there is a gap in the information about this parrot’s behavior, there’s an absolute absence of writings on what the parrots do after dark. In fact most people seem to assume that as soon as night falls the parrots go to sleep and that’s that. To say the truth this inference is largely true, however in the period of twilight before complete darkness the parrots do things that have been missed, as far as I can tell, by other observers.


The reason for missing these behaviors is very simple, after the daily work shift ends the personnel goes to their houses, to do errands, to take a nap, to eat, and hanging around the parrot cages is the last thing in (including me) anyone’s mind. But one day I noted that the period of twilight was marked by an inordinate amount of calls coming from a relatively small area in the cage, the calls denoted intense socialization at a time that I had always assumed the birds were setting down to sleep. This piqued my curiosity and I decided to see what was happening.

What I found is that sometimes, instead of sitting on the many perches on the cage, the parrots will cluster together to sleep in the wire forming a mass that resembles a grape bunch. I have never read this reported, and it doesn’t seem like they sleep in this way in the wild. The birds arrange themselves in a very tight bunch, literally side by side in a degree of intimate contact that I would have thought inconceivable between adult parrots that are not pair bonded. The forming of the bunch is accompanied by much squawking and I suspect this is caused by birds jostling each other for position on the bunch. I have never set out to watch the formation of the bunch since this would probably disrupt its formation but I have on rare occasions witnessed its dissolution. Also most of our flight cages have, by design but this is a matter for another post, odd asymmetrical shapes that limit line-of –sight viewing.  What I found most interesting about this clumping behavior is that the PR parrots, which can be quite picky with who they associate during the day, seem to lose their selectivity as night falls and join together in relative amicability and closeness that they don't show during the day.

I suspect the birds clump as a form of protection from predators. I make this inference because of what happens when the clump is disturbed. When the birds are startled the clump explodes like a grenade with birds flying in all directions. I have just a single photo of this clumping, it was taken when I had to feed the flock very early before dawn because we were doing some special work with the wild birds and I wanted the captive birds to be all fed by first light in the morning. In the photo you can see only part of the clump as a number of the birds had flown away the moment they detected movement near the cage. Nevertheless the photo shows the way the birds arrange themselves on the wire. Previously I always thought that only mated pairs slept this way.

It is unclear what triggers this behavior as some birds are quite content to sleep in perches.  For the moment being this behavior remains a curiosity observed from time to time.

Puerto Rican parrot, Amazona vittata, a smile of hope

One of the ten most endangered species of parrot in the world, the PR parrot is the focus of an intense effort to restore its populations. A formerly extremely abundant bird whose population was counted in the hundred of thousands if not in millions, it s wild population suffered a catastrophic decline and dwindled to 13 in the 1970's due to habitat loss and other causes. Now there are about 280 individuals and two wild populations, including a new one in the Karst region of Puerto Rico that has about twenty birds. I post this photo to invite you to think of all the species that are in jeopardy due to habitat destruction and unwise resource exploitation. Some of endangered species are superbly adapted to their enviroment but have great trouble dealing with highly unnatural pressures such as being captured for the pet market (one of the reasons for the decline of the PR parrot). I have dedicated my life to save these extraordinary creatures which are profoundly emotive, very independent and a true nightmare to breed in captivity.

There are various posts in this blog about dufferent aspects of the life and biology of Amazona vittata both in captivity and in the wild.

Para informacion en Espanol con respecto a la reproduccion en cautiverio de esta cotorra en el Aviario de Rio Abajo, puede buscar en:bc.inter.edu/focus/a4_n2/valentin_delarosa.pdf