What kind of mattress suits you best for a good
night’s sleep? Is it the spring kind, or foam, or maybe air or water, or even
one that has hexagonal cells called a honeycomb base. If it is the latter, you
are sharing this honeycomb experience with the Red-tailed Amazon (Amazona
brasiliensis) except that, in the case of the parrot, it is real honeycomb.
This has been observed in a long-running project of the Brazilian NGO, the
Society for Wildlife Research and Environmental Education (SPVS), for the
conservation of this species throughout its coastal distribution in south-east
Brazil, especially in the State of Paraná. The Loro Parque Fundación finances
this project, and since 1995 has supported activities for the study and
protection of this species.
The Red-tailed Amazons nest in forest of the low-lying
islands and neighbouring coastal plains, where they face diverse challenges to
reproduce successfully. One of those challenges is that suitable nest cavities,
both natural and artificial, can become colonised by introduced aggressive
Africanized honeybees (Apis mellifera). While the bees are in residence
the parrots are excluded, but after the bees vacate a nest, the parrots return
to use the cavity again in the following breeding season. Pieces of broken
honeycomb piled-up on the cavity floor, although not the usual substrate, do
not deter the breeding amazons. Indeed, one can imagine that the body heat from
the chicks (and brooding female) gradually softens the honeycomb in a way
somewhat akin to a natural memory foam!
Unfortunately, the occupation of artificial nests by Africanized
honeybees has increased in the past year, despite efforts to keep them in
check. One initiative, which has been in progress for several years, is to
train and support people from local communities in the Red-tailed Amazon
breeding zone to keep native species of bees. The objectives include to help
the native bees sustain healthy populations, and to provide local people with
an additional source of income from the sale of honey, which in turn gives them
an incentive to help protect the forest. The native bee species most favoured
for honey production is the Yellow jataí (Tetragonisca angustula).
During the 2019/2020 breeding season in Paraná, the
lowest number of hatchings of Red-tailed Amazons in the last ten years was
recorded. A total of 105 cavities suitable for forming nests were monitored, of
which 74 eventually had breeding activity. A total of 155 eggs were laid, from
which 69 (44.5%) chicks hatched. Of those, only 15 (21.8%) successfully fledged.
On the south coast of São Paulo State, 23 suitable nest cavities were
monitored, with only five of them showing breeding activity. In those, nine
eggs were laid, seven chicks hatched and five of them successfully fledged. The
poor results are surprising, the numbers being 34% lower than those recorded for
the previous breeding season, and similar to the results prior to the installation
of artificial nests from 2003.
The SPVS researchers postulate that natural predators,
human interference and climate change could all have influenced the reproductive
output. Predation was higher, and climate changes took temperatures to
extremes, increasing the possibility of diseases and decreasing the food
supply. Even with the research team in place to monitor the breeding areas,
cases of theft of parrot chicks for illegal sale are still recorded, especially
on the coast of São Paulo, as well as illegal felling of trees used by the amazons
for nesting. The project has witnessed an increase in the Red-tailed Amazon
from perhaps less than 2,500 in the mid-1990s to almost 10,000 nowadays, and it
has been removed from the IUCN Red List as a threatened species. However, the
presence of the threats shows the prudence of continued monitoring. In 2019, the
Red-tailed Amazon annual census recorded approximately 9,365 individuals, with
about 80% of the population concentrated in Paraná.
The monitoring of the nests can be arduous. Not only is the forest dense with mosquitos during the breeding season, every nest tree must be climbed several times during the season using all the expected safe climbing paraphernalia. After so many years, the field team is hardened to it, and knows it must continue. However, the project is now testing a new method of nest monitoring using technology: it is using drones to search for new breeding sites and to verify occupied tree cavities. In the municipality of Cananéia, in one of the breeding sites with nests already mapped by the project team, testing of the utility of a drone to verify the occupation of the tree cavities, by means of taking photographs inside the cavities, has been conducted. Drone use is likely to become more versatile and sophisticated, but from the testing done so far, the project team have proven that the type of tree cavity available in the Queen palm (Syagrus romanzoffiana), with the cavity opening upwards, is the most effective for drone monitoring. In addition, it has been found that the sparser the vegetation, such as in forest clearings, the better is the guidance of the drone for nest cavity search and verification.
Author: David Waugh, Correspondent, Loro Parque Fundación
Photos Credit: title, 1, 3-10 – SPVS; 2 – Rafael de Rivera/SPVS