A few weeks back, I spent the day tagging along and navigating the bush with Sara Bombaci. Sara is a conservation biologist and Ph.D student at Colorado State University. She is in New Zealand studying the implication that fenced mainland island sanctuaries (such as Rotokare) have for bird communities and seed dispersal. Unfortunately for me, I only knew about Sara's visit on her last day here, but she filled me about what she had been doing during her time at Rotokare.
Sara previously had erected cameras in fruiting trees to observe bird feeding habits and set up nets to catch bird poo, which would hopefully contain seeds. During my time with her, Sara was conducting bird counts at algorithm-generated locations around the sanctuary, at about 200m apart. During these bird counts, she listened and watched carefully to note all the birds she saw or heard, their approximate location and distance from her. She will then enter this information into an algorithm to give an estimate of the total number of birds in the sanctuary. The algorithm recognises that when the observer is close to the bird, the data is likely to be more accurate than when the bird is a long way away. Some birds are also more likely to flee in human presence (e.g. the kereru) and some are more likely to seek out humans (e.g. the robin), so Sarah notes down bird movements as she moves around the bush.
The data she collects will be compared with data from similar near-by areas of bush with no fence. After my time with Sara, she was heading to other similar sanctuaries to Rotkare, to collecting in her monitoring devices and carry out more bird counts. I look forward to hearing about her findings.