Birds

The breeding success of obligate secondary cavity nesting birds, including most parrots, can be limited by the availability and quality of nest cavities. Habitat degradation can reduce the number of large cavity-containing trees. This reduction in available cavities can be exacerbated by destructive nest poaching practices, which leave cavities damaged and unusable. Yellow-shouldered Amazons Amazona barbadensis inhabit degraded dry-forest areas on the island of Bonaire (Caribbean Netherlands), and were suspected to be limited by the number of suitable nesting cavities. We compared two approaches to increasing the availability of nesting sites, measuring occupation rates of 10 nest boxes and 10 repaired natural cavities over three years. While none of the nest boxes were used, two of the restored cavities were occupied within five months of repair, and a third in the following year. Only one of the breeding attempts in restored cavities (33%) was successful, compared to the population average of 56%. Sample sizes are small, but restoring natural nest cavities led to a higher rate of uptake than nest boxes and was a considerably quicker and cheaper intervention. However the effectiveness of this intervention depends on the threat of poaching, and there is a risk that restoring poacher-damaged nests may attract breeding pairs away from safer cavities. 

During the HNLMS 'TYDEMAN' bathymetric expedition on the Saba Bank, April - May 1996, two observers spent 7 weeks on board and to collect data on the distribution of
seabirds, marine mammals, and human activities (fishing, shipping). The results show that the Saba Bank has a bird fauna that is relatively rich as compared with the surrounding seas, whilst the birds seem to be concentrated along the edges of the Bank. Observed cetaceans included three dolphin and one whale species. The bird and cetacean observations were made during a transitional season in which groups of animals are migrating into the area whilst others are migrating out.
Human activities included fishing (the distribution of fish pots was determined, and the activities of a few fishermen observed) and shipping. Especially the observation of large
tankers anchoring close to the edge of the Bank in areas where coral reefs occur, was identified as a threat.

The report presents the primary results of an opportunistic project which has yielded many rough but valuable data about the Saba Bank in April-May. These data are available
for future management of the Saba Bank. The preliminary elaboration of the data in this report confirm the importance of especially the edges of the the Saba Bank for birds and
suggest the Bank being a feeding area for populations that breed on the neighbouring islands. Together with the observations of different species of cetaceans, the results
confirm the idea that the Saba Bank has considerable importance or the marine biodiversity in the region of the leeward Antilles. The position of the Saba Bank, partly
within the territorial waters of the Netherlands Antilles but completely within the limits of a hypothetical Exclusive Economic Zone, offers a great promise that protection (and sustainable use) of these natural values can be legally effected.

Raw data of terrestrial bird observation on St.Eustatius by STENAPA. Observation include habitat, observer, plot, transect/point observation, species, number of individuals, heard/seen the bird, distance, etc.

Please contact STENAPA for more information.

BirdsCaribbean held its 20th international conference in Kingston Jamaica from 25 to 29 July 2015. The theme of the meeting was “Birds—Connecting Communities and Conservation”.

This news article was published in BioNews 17.

BioNews is produced by the Dutch Caribbean Nature Alliance and funded by the Ministry of Economic Affairs.

Predators can play an important role in shaping prey community structure and function through direct and indirect top-down effects. Bird predators in particular can decrease lower trophic level populations in a variety of habitats from terrestrial soils to coastal sediments. In the unique, high salinity salina habitats of Bonaire, NA top-down effects may be present as a result of the migratory bird community consuming epi- and infaunal organisms. In this study, I assessed the make-up of the bird community feeding in three salinas (Marina, Sorobon, City Shop) through morning and evening observations as well as the epi- and infaunal organisms of salina sediments through coring. The birds found to utilize the sediments of the salinas for feeding included flamingos, reddish egrets, great egrets, snowy egrets, great blue herons, plovers, and willets; different species richness per site. The coastal succulent, Sesuvium portulacastrum, and seagrass occupy the salinas from approximately 1%-8%. Snails were found in the sediments of all 3 locations (Sorobon 24.9 ± 7.6 m-2 , Marina & City shop 0.3 ± 0.58 m-2 ) and fiddler crabs (8.93 ± 4.05 m-2 ) were found only at the Marina site. In addition, I attempted to understand how the birds may structure infaunal communities through their feeding habits by using field-based feeding preference choice assays. Five plots, separated into four squares containing crabs, snails, plants, and a control (one per square), were placed at each of the three previously chosen monitoring locations. The plants and snails were not consumed in the experimental food assays, but approximately 90% of the crabs were consumed. The crab densities and percent plant coverage in the control plots remained constant to the original data collected, suggesting the feeding assay plots didn’t have an affect on the predators feeding. The presence of crabs at Marina and snails at Sorobon may be supported by the differences in sediment composition. Sediments at Marina were found to be composed of more coarser-grained particles versus the sediments at Sorobon which are more fine-grained particles. This may suggest that bottom-up effects may impact, shape the epi- and infaunal communities where potential predators are present.

This student research was retrieved from Physis: Journal of Marine Science V (Spring 2009)19: 14-19 from CIEE Bonaire.

Important Bird Areas of Curacao according to birdlife international.

A bird checklist is a snapshot in time. A checklist becomes outdated the moment a new species is registered. This checklist is based on seven sources that were cross checked. The oldest work used in this research dates back to 1983 and is from Professor Voous who presented 179 species of birds for Aruba back then. Of course, the number of species in subsequent lists increases with time. We also found that some authors had one or more observations than others did. Cross checking the sources has been a valuable instrument in the analysis process. From 2010 to date, 16 new observations for Aruba have been made. These have been added to the checklist, rendering the number of species observed at this time in Aruba at 252 species.
 

Documentation of significant avian sightings on Sint Eustatius between 19th November 2014 and 11th February 2015 by Steffan Walton, STENAPA. With no previous records, the sightings of Wilson’s Snipe Gallinago delicata and Rose-breasted Grosbeak Pheucticus ludovicianus are of particular interest.

In December 2009, we sampled 62 6-minute random-systematic counting points (k) to estimate the density and population size of yellow-shouldered parrots and brown-throated parakeets in a survey region (A) of 7,873 hectares, which covered the WashingtonSlaagbai National Park and forest, suburban, and agricultural areas between Brasil, Karpata, Dos Pos, Rincón, and Fontein. In March 2010, we sampled 104 points, covering a survey region of 17,000 hectares that included forest, urban, suburban, and agricultural areas in northern, central, and southern Bonaire....

Management Recommendations:

Expand the boundaries of the Washington Slagbaai National Park to include all the salts flats included in this monitoring program as well as their catchment areas in order to give adequate protection to the whole system of lagoons located in northwestern Bonaire.

Approach the Ramsar convection with the proposal to change the Ramsar designations of Salina Slagbaai and Salina Goto for one denomination that will include all the Salt flat in the system using the name of our Washington Slagbaai National Park.

Keep collecting data for the long term monitoring programs. It is fundamental for the proper management of our natural resources.

Hire more staff for the Natural and Historic Resources Unit of STINAPA Bonaire.

As resources and/or time become available, conduct scientific research for a better understanding of the ecological functions of the salt flat as a habitat for water birds.

As resources and/or time become available, start baseline research for a monitoring program for the nesting season of our resident waterbirds.

As resources and/or time become available, expand the monitoring program in order to include the salt flats in Central and South of Bonaire.

Improve this monitoring program by moving up to the next level through participation in the CWC (Caribbean Waterbird Census). This is an initiative taken by the SCSCB (Society of Conservation and Study of Caribbean Birds).