Okavango Nest Box Project

The Okavango Nest Box Project (ONBP) aims to look at the ecology of Meyer's Parrots in the Okavango Delta as a cavity nesting bird species in particular, as well as to research cavity nesting bird species in general - with an overall look at the availability and preference of nest cavities as a keystone for ecological processes of the species. The project includes all cavity nesting bird species using nest boxes. The data collected will be used to develop a strategy that will protect the species and the community in which it lives in the future.

Another aim of this project is to look at whether nest boxes can be successfully used to substitute the removal of old-growth timber and woodland habitat. This is especially important during these times when cavity nesters are threatened by increasing deforestation due to logging and burning. To this end, the project will assess both nest box preferences and breeding biology of bird species that make use of cavities in which to nest.

Other threats such as ectoparasites and predation will be investigated to determine how much of a limiting factor they are. The use of nest boxes and natural cavities by different species will be compared to see if a conservation plan for cavity nesting bird species can be developed.

The Okavango Nest Box Project is part of the larger Meyer's Parrot Project and will last two years; it is hoped that the research will provide data for both projects.

Study Area
The location of this study is Vundumtiki Island in the Kwedi Concession (NG22/23) in the Okavango Delta. The reason for this is that there is a large population of Meyer's Parrot and other cavity nesting bird species in this area, with 25 active Meyer's Parrot nest sites identified in the area, as well as the desired vegetation and habitat type. The Kwedi Concession has a total area of 960 square kilometres, and includes all wetland categories (perennial swamp, seasonal swamp, seasonally inundated grassland, intermittently inundated grassland and rainwater seepage pans) and all dry land categories (woodland, savannah, grassland, forbland).

Project Details
- To determine which nest box design is preferred by which cavity nesting bird species and supports the highest fledging rates in the wild;
- Determine the seasonal nesting habitat preferences of the different cavity nesters using the nest boxes;
- Develop a breeding calendar for the different cavity nesters using the nest boxes;
- Record nest site attendance by adults during 12-hour nest observations;
- Record nest site temperature before, during and after incubation and fledging in the nest boxes;
- Sample ectoparasites in the nest boxes and natural cavities;
- Crop analysis of the nestlings to determine nutritional requirements in the wild;
- Record hatching sequence, egg size, and hatchling growth rate through daily inspection of active nest boxes;
- Determine the impact of predation on different species;
- Determine the impact of competition with bees on cavity nesting species; and
- Develop a conservation plan to accommodate all cavity nesting species represented in the fieldwork.

To achieve these objectives, several experiments will take place. Estimates of natural cavities will be obtained, and 30 wooden nest boxes, 105 PVC nest boxes and 45 palm trunk sections will be put up in dead or damaged Knobthorn or Leadwood trees in various ecotones and biomes, including riverine forest. Climate, temperature, humidity and other data will be recorded at each daily and nest boxes inspected.

During nesting season eggs will be measured, ectoparasites collected, behaviour observed and five breeding pairs will be radio-tagged to be tracked and monitored. Blood samples from adult birds will be collected for later analysis.