Individual study: Further results of the provisioning of nest boxes for scarlet macaws Ara macao in Tambopata Nature Reserve, Madre de Dios, Peru
Brightsmith D. & Figari A. (2003) Ecologia reproductiva y uso de colpas de guacamayos en Madre de Dios (English title: Breeding ecology and the use of clay licks by macaws in Madre de Dios).
Most macaw populations in tropical forest are endangered, due primarily as a result of hunting, habitat loss and collection for the pet trade. As part of the Macaw Tambopata Project in Peru, a PVC and wooden nest box strategy was developed between 1989 and 1993 to combat the loss of available nesting cavities in the wild (for summaries please see: www.conservationevidence.com/ViewEntry.asp?ID=206 and www.conservationevidence.com/ViewEntry.asp?ID=207). This strategy aimed to offer an alternative to natural nesting sites which are increasingly scarce as a result of selective logging.
As a continuation of these conservation efforts further results of research carried out between 1999 and 2003 have been reported that assesses the relative success of different types of nest boxes, relative to natural cavities, used by scarlet macaws Ara macao.
Study area: The scarlet macaw nest box provision study was carried out in Tambopata Research Center (TRC), a research centre open to tourists, on the bank of the Rã Tambopata, Tambopata Province, Department of Madre de Dios, south-east Peru.
Nest monitoring: Nest boxes and natural cavities were monitored to check the number of eggs, number of chicks, and the presence of hatching eggs and/or egg predation. Chicks were weighed and measured to assess growth until they were fully fledged.
Parental care: Attention patterns in the nest by adults and changes in this pattern during the nesting season were documented. Observations were made between 05:00 h and 17:30 h with the registering of weather conditions, parent arrivals and departures, warning calls, and interaction among nesting adults, potential predators and other macaws.
Nest monitoring: A total of 32 nest boxes and natural cavities were monitored during the breeding season of 2002-2003 (November 2002 to April 2003). Eighteen of these were nest boxes (14 PVC and 4 wooden) and 14 were natural tree cavities.
Fourteen of the nest boxes (13 PVC and 1 wooden) were occupied by scarlet macaw pairs. Ten of these contained eggs (9 PVC and 1 wooden); in six (5 PVC and 1 wooded) at least one egg hatched and in four (4 PVC and 0 wooden) at least one individual fledged. Four of natural cavities contained eggs; in three at least one egg hatched and in three at least one individual fledged.
Combining these results with results from past nesting seasons (1999-2001), hatching rate for natural cavities, PVC nest boxes and wooden nest boxes were 65%, 41% and 80%, respectively. However, the results for wooden nest boxes might not be reliable due to the small sample size (an average of 5 wooden boxes were available/nesting season). Chick survival rates for the three types of nests were very similar (76%, 76% and 75% for natural cavities, PVC and wooden nest boxes, respectively)
Parental care: During the breeding season of 2002-2003, 38 observation days were made for 12 nests: 15, 11 and 10 observations were made for nests with (i) eggs, with (ii) one chick and with (iii) two chicks, respectively. Combining these results with those from the two previous nesting seasons, the average number of visits to nests for which parents fed two chicks was 0.86 ± 0.50 visits/h (N = 4) and the average number of visits to nests for which parents fed only one chick was 0.6 ± 0.19 (N = 4). Rain reduced the frequency of visits from 1.03 visits/h to 0.38 visits/h.
Conclusions and discussion: Hatching rate for PVC nest boxes was lower than for natural cavities. This could be explained by greater daily temperature fluctuations (reaching higher temperatures) inside the PVC nest boxes than natural cavities. Humidity was lower inside PVC nest boxes. Temperature and humidity also fluctuated more in wooden nest boxes than in natural cavities but this fluctuation did not seem to affect the hatching rate. Further investigation is needed to resolve any ambiguity of these results.
Note: If using or referring to this published study, please quote the original paper. This Spanish language paper has been translated and summarized for Conservation Evidence.