Current monitoring of Himalayan thar (Hemitragus jemlahicus) populations in New Zealand involves a technique based on repeated observations by different, experienced observers. The method gives no measure of error and hence does nor allow for statistical comparison of repeated surveys. We outline a faster and cheaper technique that enables statistical comparison between surveys based on mark-recapture theory.
Monitoring the effect of management in rangelands is an integral part of the process of adaptive management. An understanding of how individual species react to management has two major benefits. Firstly, monitoring, can be simplified by avoiding species which are reacting mostly to other influences, and secondly the abundance of species can be interpreted in a meaningful way for assessing the influence of previous management.
The success of studies of change in South Island tussock grasslands can be assessed indirectly by the form in which their results are presented-scientific paper, institutional bulletin, popular publication, conference proceedings, unpublished report, or not at all. Studies often fall short of their potential to increase understanding of the effects of natural processes or management: the results of many simply never reach either the authority that commissioned them or the public in general.
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 P
Quantitative and qualitative studies of understorey regeneration in a mature kohekohe-taraire dominated forest remnant were undertaken before and after the extensive replanting and species reintroduction programme on Tiritiri Matangi, a northern New Zealand island. The changes in regeneration patterns of taraire and kohekohe within this remnant before the restoration programme, and twenty years later, are described.
Tiritiri Matangi Island is one of the oldest community-driven island restoration projects in New Zealand. While great effort has been directed towards recovery of vegetation and avian communities since the 1980s, restoration of the island’s reptile fauna has not been initiated until early 2000s. Tiritiri Matangi supports only three remnant reptile species, which is considerably low given the island’s size and geographic location. In recognition of this and the importance of reptiles in ecosystem function, translocations of several reptile species have been undertaken.
Designing robust monitoring programmes for cryptic species is particularly difficult. Not detecting a species does not necessarily mean that it is absent from the sampling area. A conclusion of absence made in error can lead to misguided inferences about distribution, colonisation and local extinction estimates, which in turn affects where and how conservation actions are undertaken. It is therefore important to investigate monitoring techniques that reduce the non-detection rate of cryptic species.
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.
The five-minute bird count (5MBC) method was developed in New Zealand in the early 1970s by the DSIR for monitoring forest birds. The method has been undertaken consistently for nearly 40 years leading to a large resource of counts (over 200 000).
In 2007 The Nature Conservancy (TNC) undertook an intensive ungulate control programme throughout three of its preserves on the Hawaiian islands of Maui and Moloka'i, with one aim being to reduce feral pig numbers to zero or near zero. The preserves were divided into manageable zones and over a 2 to 5 month period hunted from the ground with dogs in a series of up to four sweeps across the zones. More focussed hunting followed at sites with evidence of survivors. We used the data collected by the hunters to evaluate the efficacy of the control programme.