YELLOW-SHOULDERED AMAZON PARROT

BrokenWing Chronicles
YELLOW-SHOULDERED AMAZON PARROT
(Amazona barbadensis)

he Yellow-shouldered Amazon Parrot is a medium sized parrot with a short tail. As is typical of the Amazona genus A. barbadensis is mostly green with colourful head, wing, thigh, and tail feathers. The extent of this colouration varies between individuals. The subspecies A. barbadensis rothschildi is described as having less yellow on the head and bend of wing. The validity of this classification however, is much disputed. After examination of skins from all parts of the geographical range Low (1981) concluded the subspecies classification was not valid. More recently genetic analysis of a limited number of birds has been conducted concluding that there is no significant genetic variation between sub populations (Sanz & Grajal 1998).

Habitat loss and alteration have had a negative affect on this species, but the most significant pressure they have faced, and continue to face, is poaching. Trade in parrots for the local market has a long history and keeping a pet parrot is very traditional in this region. On Bonaire in particular poaching has been so intense that there are actually more A. barbadensis in captivity than in the wild. This species is classified as vulnerable on the IUCN Red list and listed as an Appendix 1 species by CITES (Snyder et al. 2000).

Amazona barbadensis generally inhabit a dry xerophytic thorny scrub. Mangroves may be used during the nesting periods, particularly on Margarita. In this harsh environment, seasonal drought and the subsequent low food availability can have a significant effect on population numbers. On Bonaire there have been drought periods when large numbers of A. barbadensis have starved despite the efforts of islanders to provide food for these birds (Voous 1983). Less intense dry periods may have a negative effect on reproductive output as well as other natural factors such as predation and parasitism.


3. Current Status


The total wild population size for this species is not known, however, it is probably no more than 5000 (Sanz & Grajal 1998) and possibly less than 4000. One difficulty in estimating the number of A. barbadensis is that they occur in several isolated populations, these includes two separate mainland populations in northern coastal areas of Venezuela, the Venezuelan islands of Margarita and Blanquilla and the Dutch Antilles islands of Bonaire and Curaçao. The Yellow-shouldered Amazon also formerly occurred on Aruba. Unfortunately this population was exterminated due to being considered a crop pest and consequently they were considered extinct from the island by the 1950s (Voous 1983). Interestingly, despite its location between Aruba and Bonaire there are no historic records of this species on Curaçao. The population that is currently found on Curaçao is introduced and the birds are believed to have originated from mainland Venezuela and Bonaire (E. Newton verbally).

Little has been reported on the status of the mainland Venezuelan populations. The western state of Falcón is estimated to hold between 400-700 individuals (Snyder et al. 2000). The number of A. barbadensis found in the western state of Lara is unknown. There are two eastern states of mainland Venezuela where A. barbadensis are found. These are Anzoátegui and Sucre. There does not appear to have been an estimate of the number of A. barbadensis in this region. The Island Resource Foundation reports that even within the eastern and western mainland populations, groups of A. barbadensis are “local and disjunct”.

Since 1989 the Venezuelan islands of Margarita and Blanquilla have received conservation attention from the Venezuelan NGO, Provita. The number of A. barbadensis on Margarita is reported to have increased dramatically as a result of this work. In 1989 the population estimate was of 800 individuals. Only 7 years later in 1996, the estimate was 1900 individuals (Snyder et al. 2000). The population on the small island of Blanquilla is believed to between 80 to 100 birds.

Several population size estimates have been made on Bonaire for A. barbadensis during the last 20 years (Reijns and Van der Salm 1981, Mellink and Molina 1984, Joordens 1987, Van Helmond and Wijsman 1992, and Scholtens 2001). These suggest that the population has fluctuated between 100 and 500 individuals. The current estimate is between 350 and 500 birds. There has not been a formal count of the number of introduced Yellow-shouldered Amazon parrots on Curaçao.


4. Previous work and current situation specific to Bonaire


On Bonaire the local name for the Yellow-shouldered Amazon Parrot is Lora. For convenience I will use this name for the remainder of the report.

Since 1980 several scientists have visited Bonaire to estimate the Lora’s population size. Unfortunately, there has been little continuity or development of methodology by these researchers. In recent years regular annual counts have been developed and coordinated by members of STINAPA (the non-governmental National Parks Agency) and DROB (the governmental department for Planning and Resource Management). The situation has therefore improved, as there is now some continuity between the counts. Each year volunteer observers participate and their involvement serves to raise awareness within the community. I learnt of only one earlier study (Mellink and Molina 1985) that had investigated the reproductive biology of the Lora on Bonaire. I will refer to this study in greater detail below.

The Lora of Bonaire are one of the many species that have been the focus of a pride campaign. Working with STINAPA, Enit Schulzen and then later Janneke van Gerwen, promoted the Lora through T-shirts, posters, stickers and many activities including puppet shows and costumes. This has worked well and there is certainly a level of awareness within the community. Efforts should be made to continue and develop this work in order to educate the island’s children about their wildlife.

On Bonaire the Lora have been protected by law since 1952. Unfortunately, this protection has not been enforced and approximately 1 in 6 homes keep a pet Lora. Additionally, there are many homes that have pet parrots such as macaws and other amazon parrots originating from Venezuela. In 2002 efforts were made to begin the enforcement of the Lora’s protected status. An island wide amnesty was held whereby owners of captive Lora could register their birds and have them legalised. All registered birds were banded with a unique numbered steel ring (Montanus 2003). If a person is now found with an unbanded Lora they face a relatively large fine and the confiscation of their pet. The possibility of having confiscated birds necessitated the construction of a place to house them. An aviary (approximately 3x8x3metres) has been built at the island’s Ministry of Agriculture field site where daily care will be easy to provide.

The World Parrot Trust (WPT) was involved with the registration campaign. Ruud Vonk of the Benelux WPT group coordinated a shipment of “Happy Healthy Parrot” information leaflets in Dutch which were given to each owner during the banding work. WPT also negotiated for the rings to be purchased at a discounted price.


5. Feeding notes and Distribution


The north of Bonaire forms the majority of the Lora’s natural habitat which includes the vegetation categories mixed evergreen-deciduous thorn woodland, succulent evergreen shrubland and sclerophyllous evergreen shrubland (Web site of the Netherlands Antilles Government). In contrast, the parrots do not visit the salt flats that cover the southern third of the island. In the central area of the island the natural habitat has been significantly reduced in favour of mixed planted/cultivated crops and presently this appears to offer relatively poor foraging for the Lora.

The Lora population has to respond to seasonal variations in food availability. Sustained dry seasons are common and it appears that during these periods the wild Lora have difficulty obtaining adequate food from the remaining natural habitat. At these times it is now normal to find many parrots foraging in and around the residential areas of Kralendijk and Rincon (Map 1). The Lora have shown that they can adapt and exploit the available exotic fruit from cultivated trees.

Public Opinions

Generally, it would appear that visiting Lora are welcomed and people are sympathetic to their cause. Boi Anton, island historian and editor of the Papiemento newspaper Extra highlighted the conflict that can occur in some cases between poorer fruit growing members of the community and foraging Lora. Despite this important issue I observed only one garden (in the village of Sobi Rincon) where the fruit of a cultivated Papaya tree (Carica papaya) were protected, a measure presumably taken to keep inquisitive Lora away. Crop raiding parrots and their potential persecution are difficult yet potentially important topics for Lora conservation. On two separate occasions, both in residential areas, I observed an individual Lora that had clearly sustained an injury. The first was during a morning roost watch (30.5.03); the bird was very lethargic, had difficulty moving around and appeared to have a bloodied wing. The second occasion (8.8.03) was in Rincon where I saw another bird with a bloodied wing. Both of these birds may have had lucky escapes from the few Crested Caracara (Polyborus plancus) that are present on the island. They may equally however, have been targeted by an unhappy landowner. Clearly, protecting the Lora from persecution of this kind would be extremely difficult which highlights the importance of continuing and developing education efforts.

There have been several significant droughts on Bonaire where large numbers of Lora have starved. In the prolonged drought of February to June 1978, an estimated 200 Lora were reported to have died, despite the efforts of STINAPA board members who organised the provision of imported mangos for the wild birds (Voous 1983). In anticipation of future droughts the group Save de Loras was formed. This NGO holds funds for the sole purpose of importing food for wild Lora in the event of a future drought. Thankfully they have not been called upon frequently.

Introduced donkeys and goats are present throughout the island and on several occasions I noticed wild pigs around Dos Pos and Keteldal. As the donkeys are considered a quirky tourist attraction but are also the primary danger to road users and raid waste bins there is mixed public opinion regarding them. The goats are eaten by local people and as a result are considered by some to be important for the human population. These species represent a pending ecological disaster for Bonaire. Thankfully efforts are being made to exclude them from the national park and a “Donkey Safari Park” is being created. The introduced Troupial (Icterus icterus) is a common bird found throughout the vegetated areas of Bonaire. This species feeds on a variety of foods including fruits preferred by the Lora. The abundance of Troupials may represent a major food resource limitation for the Lora.

Feeding on Cactus

Voous (1983) lists nearly 30 different food items (mostly fruits and seeds) that wild Lora have been observed eating. Throughout Bonaire there is an abundance of tall candle cacti of which there are three species. Voous does not mention the cactus fruit, which the Lora certainly eat. He does however, suggest that the wild Lora eat the juicy upper shoots of only one species of the candle cacti, the Kadushi (Subpilocereus repandus). During this year’s visit no attempt was made to create a complete list of all feeding observations. Where Lora were feeding on candle cacti however, notes were recorded and observations of Lora feeding directly from both Kadushi and Datu cacti (Ritterocereus griseus) were made.

Rainfall

The total precipitation recorded for 2003 up to and including September at the Hato weather station, (Bonaire Web Cams) was 105mm. The Netherlands Antilles Meteorological Service provides climatic data summarised from the last 30 years. Their data is collected from the Flamingo airport, 5km south of the Hato station. Both of these stations are on the West Coast. Comparing the monthly precipitation data for the same period indicates that in 2003 (up to and including September) there was 56% less precipitation than average. This is despite the relatively heavy rain in July 2003 (55mm) that was 51% more than average for the month. All other months in 2003 from January to September received less than average precipitation.

During May, June and the first weeks of July it was possible to observe groups of Lora in most areas of Kralendijk. It would appear that these birds were able to achieve greater foraging success from various town gardens than in their natural habitat in the north of the island. The apparent low availability of natural food would almost certainly be related to dry spring months. On July 10th 8mm of rain fell and a further 40mm fell on July 12th. The other 7mm of rain fell on 4 other days during the month. These rains had a dramatic effect on the habitat. It is logical to believe that this in turn brought about the considerable reduction of Lora presence in Kralendijk.

Read the rest here
http://www.mina.vomil.an/Pubs/Williams-LoraReport2003.htm