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HOCHSTETTER'S  FROG

(Leiopelma hochstetteri):

A study of it's Habitat in Native and Pine Forests In the

Breynderwyn Hills, Northland

Lorna Douglas

November 1997

An independent Research Project as Part of a Diploma of Environmental Management, Northland Polytechnic, Whangarei.

Abstract:

The endemic frog species ( Leiopelma hochstetteri) has been identified as at risk from damage  to its habitat, with populations in Northland being seen as particularly vulnerable.

This study compared habitat parameters in native (control) streams with those of streams in a catchment within an established pine forest (pinus radiata) owned by Carter Holt Harvey(CHH) The habitats of streams in the CHH catchment where no frogs were found were compared to those where frogs were found.  The parameters studied included vegetation type, canopy density, localised frog sites, stream width etc.

The most obvious correlation was that where pines were close to the stream flow (ie<10m) no frogs were found.  This may have as much to do with the geography and past land use history as with the pines themselves, although the effects of pine litter in the water ought to be considered.

It was noted that the severe floods experienced during the latter part of this study had more of an impact (eg fallen trees, slips and silt) on the pine catchments than the native control catchments.  It is thus recommended that future plantings of P. radiata are confined to at least 10m from the stream of any known L.Hochstetteri habitat, to minimise effects of silt and debris.

Other data collected were used to determine population structure.  This data suggested  a younger , establishment type populations from data collected in previous years, the differences may be only temporary and/or significant.

It is suggested that, not withstanding the limitations of this study, the information gained will be useful baseline data for future more detailed study.

Some areas identified specifically for further study include biological monitoring of streams, the effects of pine litter in streams , and more detailed habitat parameters .  Also suggested is the trial of artificial cover objects in this area because of the possible shortage of suitable shelter sites for the frogs (Peter Anderson, pers. comm.).

CONTENTS:

         Abstract

         Contents

1.0    Introductions

2.0     Methods

2.1     General

2.2      Transects

2.3      Population Features

2.4     Stream Catchment Features

2.5     Light

3.0.    RESULTS

3.1     General

3.2     Rainfall

3.3     Density

3.4      Population structure

3.5     Habitat

3.5.1   Stream Width

3.5.2   Catchment slope & upstream gradient

3.5.3  Light

3.6      Vegetation

3.6.1  Canopy

3.6.2  Vegetation type

3.6.3  Pines

4.0    Discussion

4.1    Introduction

4.2    Population structure

4.3    Behaviour

4.4    Effects of Pines

4.5    Flood damage

4.6    Conclusion

5.0    Recommendations

        Acknowledgments

        Bibliography

        Appendices

( The complete copy of this document is available to read by contacting Vince Kerr Ph. 4303850 ex 789)

Copyright©1998Department of Environmental Management