Many restoration projects aim to increase populations of native fauna and flora, but benefits to the ecological interactions between species are unknown. The restoration of bird pollination services to Fuchsia excorticata (tree fuchsia) was examined at Maungatautari, in the Waikato Region, New Zealand. At Maungatautari, a pest-exclusion fence encloses ~3400 ha of native forest, within which most mammalian pests were eradicated between 2004 and 2007.
Five-minute bird counts were made on Rangitoto Island in 1998 and 1999, 8 and 9 years after the start, and 1 and 2 years after the completion of a 7-year programme that resulted in eradication of the introduced brushtail possum (Trichosurus vulpecula) and brushtailed rock wallaby (Petrogale penicillata). These were compared with counts made in 1990 (immediately before the start of the programme), to assess whether bird species diversity and abundance had increased as a result of the eradications. The number of bird species detected in 1998/99 was similar to 1990.
Native kanuka (Kunzea ericoides) and adventive gorse (Ulex europaeus) stands aged 10-14 years, and not grazed by domestic stock, were studied near Nelson, New Zealand. The aim was to determine their use by introduced small mammals, and native and adventive birds, and the effects of these animals on seed rain and seedling dynamics as factors influencing vegetation succession. Seed traps were established where they could catch only bird-dispersed or wind-blown seed, and seedling emergence and growth were monitored.
Bird populations were monitored for one year (October 1990- October 1991) to determine whether the 1080 poison used to eradicate possums and wallabies on Rangitoto Island had had any detrimental effects on them. There was no significant decline in bird numbers recorded immediately after poisoning, with four species increasing in abundance (P <0.001). Twelve months after the operation the abundance of four species had increased significantly (P <0.001).
[Abstract of a paper read at the Ecological Society Conference, 1983.]
Monthly five-minute bird counts were made for two years between 1981 and 1983 to identify birds present in forest zones from sea level to 1000 metres altitude in podocarp-hardwood forest near Franz Josef Glacier, South Westland.
The ecological restoration of Tiritiri Matangi Island is a community-driven initiative that has captured the interest of the international conservation movement. Ecological restoration commonly focuses on the establishment and maintenance of functioning indigenous ecosystems through the control or eradication of invasive weeds and animal pests, indigenous species translocations, and habitat enhancement, including revegetation. Revegetation of indigenous plant communities provides an opportunity to kick-start natural processes and facilitate succession towards a diverse ecosystem.
To make sense of how nature is responding to an increasingly rapidly changing world, a lot of species distribution and abundance data are needed. To infer population trends, these data ideally need to be collected in a standardised, repeatable manner that includes ‘absence’ data on species sought for but not found. If many people, even just professional ecologists and postgraduate students, are to record biodiversity frequently in their daily lives, a convenient method that meets these requirements is needed.
We used the distance detection function from five-minute point counts entirely within large woody vegetation patches to derive a method of truncating counts of birds detected close to the observer to estimate their relative abundance in small habitat patches. Our method trades off loss of information by truncation of bird sightings at successively larger distances from the observer to reduce sampling bias. Truncation of counts to include detections within 10 m of the observer gave similar absolute density as distance methods for the six most abundant native and six introduced species.
Urbanisation is a significant and increasing threat to biodiversity at the global scale. To maintain and restore urban biodiversity, local communities and organisations need information about how to modify green spaces to enhance species populations. ‘Citizen science’ initiatives monitoring the success of restoration activities also require simple and robust tools to collect meaningful data. Using an urban monitoring study of the bellbird (Anthornis melanura), we offer advice and guidance on best practice for such monitoring schemes.
We evaluated the accuracy and precision of three population estimation methods (mark–resight, distance sampling and five-minute bird counts) for two populations of South Island robin (Petroica australis australis) of known size in the Eglinton Valley, Fiordland, over 5 years (March and August, 2005–2009). The performance of these population estimators was compared to known robin abundance derived from simultaneous territory mapping of individually marked birds.