Showing posts with label aviary. Show all posts
Showing posts with label aviary. Show all posts

Saturday, October 12, 2013

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

Wednesday, January 12, 2011

Amazona vittata, The Puertorican parrot, roosting behavior in the wild





Branch used by several parrots to roost, note the way the leaves and smaller branches have been stripped away
There are seventeen parrots in this photo, it was taken just after dawn, at the moment the first sun rays were stricking the tops of the trees

A branch used by a single pair, see how they have stripped the branch of leaves for a considerable lenght.  They sleep together at the very tip of the branch.

Part of one of the largest flocks of this species since the 1950's, there are twenty two birds in the photo, the flock was composed of thirty two birds.
The birds continue circling and calling and sometimes fly around almost until it is too dark to see
In this unique photo you can see a pair at night

The birds have excellent hearing, and probably have a small degree of night vision.
The Rio Abajo wild flock spends the day foraging in the forest, usually in small flocks of a few birds, but during the months of July to December in the evening they tend to form a large flock that sleeps in a single roosting area.  This is related to their breeding cycle, during the breeding season, which lasts from January to July in the RA forest, the birds become more aggressive, territorial and less likely to form large groups.  Once the chicks fledge the parents aggression toward other birds lessens to a considerable degree and they become much more social.
The roosting flock assembles in the evening and the way they choose which tree they will roost is very noisy and interesting.  First the birds start arriving at an area where several trees are used to sleep.  As the birds arrive they start calling and interacting with the other birds.  Then they start flying back and forth between the different trees singly and in small groups.
The impression I get is that they are going through a process of ascertaining where is the larger concentration of parrots, sort of a popularity vote between the different roosting spots.    As nightfall starts the groups in flight become bigger and bigger until at times the whole flock is in the air at the same time.  Just as it is getting too dark to see the flock finally settles in a single spot with all, or nearly all the birds in a fairly small part of the tree.
The parrots keep calling and squabbling for some time after it is dark but eventually they fall silent.  The parrots are not passive users of the roosting trees, they modify favorite sleeping branches by removing leaves for at times a considerable length of the branch.  Then they sleep near or at the very tip of the denuded branch.  MY guess is that this is an anti-predator measure but this is just speculation as any place where the parrots spend a considerable amount of time eventually becomes denuded of leaves and quite wretched looking due to their proclivity to chew with their powerful bills anything that is at hand nearby when they are perched in a spot.
The flock wakes up early but generally doesn’t leave their roost until the rays of the sun start striking the top of the tallest trees.  Then they might take flight in a single large and very noisy group that lands again after circling over the roost a few times.  After this the birds start slowly going their own way in small groups away from the roosting area.
If you happen to run into one of these roosting areas during a hike in the forest I would ask that you please don’t disturb the birds.  If the parrots are disturbed they will flee the area and abandon the roosting tree.  In the nineties the whole PR parrot population that used to live around the area of the old aviary high near El Yunque peak relocated to the west part of the forest near el Verde.   The suspicion of the project scientists is that the birds fled the area they formerly used because they were alarmed and disturbed when military exercises were staged on the forest.  I can’t blame them, I would have moved too.

Monday, January 10, 2011

Working on an artificial nest used by a wild pair of Amazona vittata, the Puerto Rican parrot




Ivan Llerandi Roman the leader of the wild release project, note all the equipment hanging from Ivan's utility belt

Gustavo Olivieri

An artificial nest high up in a tree

A wild female turning the eggs, they turn the eggs over every fifteen minutes on average

A baby that has just hatched is gently cupped under the wing by the female, you can see the part of the egg shell under the head of the female.  You can see the head of the newly hatched baby near the center of the photo.
Eddie Velez

The top part of the cage in the photo is about twenty feet all.
One of the more secretive aspects of the parrot project is the work that is done with the wild nests.  The reason for the secrecy is to protect the nests from unwanted human intervention which can, sad to say, include the theft of the nestlings for sale.  Unfortunately even well meaning people can cause a nest to fail if they try to approach it when the parrots are nesting.    Therefore the work of the people that manage the nests in the wild is practically unknown by the general public.  Another problem that affects the recognition of the achievements of the field workers in the area of nest management is that most of this work takes place deep in forested areas where the conditions generally are not conductive for good photography.  As a result this work is rarely documented and even more rarely described on print.  The need for artificial nests in the wild is due to the fact that for centuries and all the way up to the middle of the twenty century the main fuel for the island was wood.  As a result there was severe deforestation on many parts of the island and even on places where the forest now appears in a reasonably good health old trees are few and far between.  Also at the start of the twenty century there was a forestry theory that deemed old, hole ridden, mature trees less desirable than young trees which were still growing vigorously.  As a result in some forest areas old trees were cut down to encourage new growth. 
But in 2009 and 2010 we had the unexpected opportunity to document the work in a nest in a tree inside the aviary.  It has to be noted that the wild release staff pretty unhappy with the location of this nest.  Its location inside the aviary grounds raised all sort of issues about unintended disturbance of the breeders during our daily work at the aviary.  But they had to submit to the will of the parrot pair that signaled they wanted to nest in this particular area, and that was that.  The pair that chose this nest is the one whose male is known by the nickname “Scarface”.   The “Scarface” pair had been haunting the area around the aviary for a couple of years and had rejected or ignored all the nests that were offered in other areas.  For some reason known only to them, the pair decided that they wanted to nest inside the aviary.  Those that are old hands at the PR parrot project know that this is a startling, unheard of situation as wild nests in the east part of the island in the Luquillo mountains are in rugged, hard to get locations, well away from human habitation and the possibility of human disturbance.    But the silver lining in this particular case is that secrecy is not needed as the nest is closely, and jealously,  guarded by the staff.  The way we adapted to the presence of the breeding pair and the tolerance they showed for our rhythm of work helped bring a collective sigh of relief from everybody as from historical reports we know that Puertorican parrots nests have been abandoned over disturbances that other bird species would have ignored.
The tree where the artificial nest is located has to be prepared to receive the nest and fitted with the necessary infrastructure that allows maintenance and checking of the nest.  This particular nest has a close circuit camera that operates in the infrared region of the spectrum, this allows us to check the birds without disturbing their nesting activities.
The photos posted shows work done is 2009 and 2010.  Working with wild nests demands stamina, impressive upper level strength and the ability to work while hanging from ropes in leg and butt numbing positions.  Obviously a lack of fear of height is a must in this kind of work, you will notice that there is a large vanilla orchid on top of the nest, I have never climbed there to check that orchid out.
The nest needs to be fitted with wooden entrances to allow the birds to gnaw on the wood of the entrance, an important part of their nest choosing/preparing procedure.   The nest is also checked periodically during the breeding season to see the condition of the eggs and chicks and to band the chicks.
 To our great happiness the clutch in the nest was incubated flawlessly by the female.  The pair raised two healthy babies than on due time fledged from the nest.  I had the opportunity to observe closely and in unparalleled comfort (in relation to the experience of watching  other nests wild nests both in El Yunque and Rio Abajo) the whole breeding cycle.
I hope these photos give you an idea of the strenuous nature of this little known aspect of our work that is as crucial for the survival of the population at the Rio Abajo forest as the more widely publicized aspects of iur operation.  I would ask of all of you that if you come across a parrot nest in the wild, please do not, under any condition, try to climb the tree or disturb the parrots in any way, this will only make our work much, much harder and may make the parrots abandon the area altogether.   Another reason not to climb up to the nest is the very real possibility of falling from the tree.  Finding someone with its neck broken from a fall who has died sloooowly while being eaten alive by fire ants, centipedes and eyeball and brain gouging beetles would probably leave us inconsolable for about ten seconds after which we would have to make arrangements to drag the body out of the forest, notify the next of kin and present a nomination for a Darwin award on behalf of the dumb-as-a-doorknob deceased.
I want to add that if we notice anyone disturbing the parrots on their nesting areas we will call the local police, notify the federal government, the vigilantes of the DNER and I will personally call their mothers to tell them in no uncertain terms what horribly inconsiderate children they have.   So far we have had absolutely no problems with anyone bothering the parrots or their nests and we hope it stays this way.