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DOC wants your opinion on Whitebait Management

DOC wants your opinion on Whitebait Management - closes 7 January 2019

This process isn’t a consultation and no decisions will be taken from it at this stage, but what you say and the information gathered is important to shape what happens next. Their survey here will take 2 -5 minutes to complete, depending on how much additional information you wish to provide.

NZ dotterels spotted at Waikanae

NZ dotterels seen and photographed on Friday by Waikanae Estuary

Care Group Secretary, Pam Stapleton. Female on left, male on right

New species of diving petrel discovered by 2016 CRT scholarship recipient

Johannes Fischer, our 2016 scholarship recipient, discovered that the South Georgian Diving Petrels he studied for nesting behaviour (see paper), were not quite the same as the South Georgian Diving Petrels in other parts of the world.

A subsequent study found that there were enough differences between the birds to declare the Codfish Island ones a separate species. The new species was named Pelecanoides whenuahouensis sp. nov. Read the full paper.

Coastal lizards of New Zealand

By Moniqua Nelson-Tunley from Waikato Regional Council

New Zealand’s lizards are often described as our forgotten fauna. They are often overlooked in conservation projects because they are more cryptic (harder to find) than native birds- but they are also more diverse and threatened than our native birds. There are currently 105 species of native skink and gecko, some of which haven’t been formally described yet (new species are being discovered on an almost yearly basis). Only nine of these species are considered “Not Threatened”, leaving 96 species (91% of our lizard fauna) at risk or threatened with extinction.

One species, the cobble skink, was discovered less than 10 years ago and the entire population (only 40 animals) is held in captivity because their coastal habitat was destroyed. The cobble skink was abundant along a discrete patch of boulder beach coastline near Westport. In the 10 years since it’s discovery, the species rapidly declined until the last population was trapped between the Granity pub and the Tasman sea on an eroding piece of beach. The future for this species is bleak unless its habitat is restored and the species returned to the wild.

But it’s not all doom and gloom. Thanks to restoration and pest animal control, a few lizard species are beginning to recover. There have been a number of successful projects where pest control (or eradication when possible) combined with restoring native vegetation has resulted in increasing lizard populations. The key things to keep in mind when restoring habitat for any animal are; what do they eat (food sources), what eats them (predators), and where do they hide (refuges).

There are mountains of evidence about the impact pest mammals have on native wildlife. You are probably familiar with the war on rats, possums and mustelids, but mice and hedgehogs are also major lizard predators. Rats and mice are possibly the worst of the bunch because they affect all levels of the ecosystem, eating seeds, eggs, chicks, invertebrates and lizards.

Being ectothermic (cold blooded) makes lizards especially vulnerable because if a predator finds them during winter they don’t have the energy to run away. Smaller lizards can hide in small cracks and crevices where only a mouse can reach them, but the larger lizards aren’t so lucky. All of our larger skink and gecko species are either safe in predator-free reserves, or rapidly declining due to predation. On pest-free offshore islands the lizard populations increase exponentially. Pest suppression on the mainland also results in native species recovery, but the control needs to be long-term in order to keep the pest numbers low.

It can be difficult to control pest animals in a dune environment due to the high level of public use and interest in the area. Early engagement of the community and signage to inform visitors can go a long way to getting support for pest control in amenity areas. Another way to yield benefits for the coast is to encourage adjacent landowners to control rats on their properties- no-one wants a rat nesting in their roof! The self-resetting trap technology (by Goodnature) is very convenient for non-resident landowners. With the huge enthusiasm for Predator Free NZ, now’s a great time to start a pest control group.

I’m sure you are all aware that the iconic green pastures of New Zealand were once vast wetlands and forests. Hopefully you are also aware that the destruction of New Zealand’s natural environment is ongoing. Coastal environments are no exception, and in fact are often more heavily impacted by human modification than most other ecosystems. Your dune restoration projects are helping turn the tide (figuratively speaking) of coastal ecosystem loss in New Zealand. The best action you can do to help protect coastal lizard populations is to continue the good work you are already doing- plant a variety of native species in and around your dunes, rocky shores, boulder beaches and coastal forests. Lizards eat small invertebrates (like sand hoppers, flies and moths), nectar and small fruit. In dunes, planting flowering and fruiting plants like sand coprosma and pimelea provides a great food source for lizards, as well as attracting insects. Knobby club rush (wiwi) and muehlenbeckia within backdunes provides dense foliage which makes great lizard habitat. Geckos love licking nectar from pohutukawa and flax flowers.

Another activity you might already be intuitively doing is planting to connect nearby patches of existing habitat. This is extremely valuable for lizards and other small animals. Imagine how hard it is for a 5cm skink to run across 2000m of sand to colonise a new dune. By planting between existing vegetation, you are creating dispersal corridors that make it much more likely that the little skink will succeed in finding a new home.

Does your coastal restoration project conduct beach clean-ups? Removing plastic and other rubbish from the beach is a great idea, but natural detritus like driftwood and seaweed can be an asset. Placing driftwood and seaweed in the dune system (while minimising squashed plants) creates refuges for lizards to escape from predators as well as somewhere to hibernate in cold weather. Natural detritus also serves other purposes- it is a source of food for native sand scarab larvae (they look like a huhu grub) and other invertebrates, it slows the wind, allowing sand and seeds to collect in the lee and providing nursery-like conditions for seeds to germinate. When the logs and seaweed eventually break down they provide natural fertilizer for dune plants.

So hopefully by now I’ve convinced you that our lizards are precious and need protection, but also that there are easy things you can do to help protect our native lizards. You are probably already doing some of the things I’ve mentioned above – thanks! Have a go at a few of my suggestions that you aren’t already undertaking.

  • Plant a variety of native plants- plant diversity supports animal diversity.
  • If removing driftwood and seaweed from the beach, place above the high-tide line within the vegetation.
  • Connect nearby patches of vegetation by planting in between.
  • Set up a pest control program on your coast and work with neighbours to expand the area where pests are supressed.

Read more here:

Cobble skink: http://www.radionz.co.nz/national/programmes/afternoons/audio/201804032/critter-of-the-week and https://www.theguardian.com/environment/radical-conservation/2017/jun/01/new-species-discovered-behind-a-pub-then-saved-from-extinction

Conservation status of New Zealand reptiles, 2015. Department of Conservation. http://www.doc.govt.nz/Documents/science-and-technical/nztcs17entire.pdf

Goodnature self-resetting traps

https://www.goodnature.co.nz/

A broad range of pest control options

https://www.traps.co.nz/

Predator free NZ- getting started

http://predatorfreenz.org/get-started/

South Georgian Diving Petrels - Student Update

Ecology, breeding biology and conservation status of the South Georgian Diving Petrels (Pelecanoides georgicus) on Codfish Island (Whenua Hou), New Zealand

 Johannes H. Fischer, School of Biological Sciences, Victoria University of Wellington

 The South Georgian Diving Petrel (Pelecanoides georgicus;SGDP hereafter) is a burrow-breeding Procellariiformes with a circumpolar distribution across the southern oceans and is currently considered “Least Concern” by the IUCN. In New Zealand, however, the SGDP has declined steeply due to a combination of predation by introduced species and habitat destruction. Subsequently the species became extinct on the South Island, Stewart Island, Auckland Islands and Chatham Islands. The only remaining New Zealand breeding population persists in the dunes of the Sealers Bay, Codfish Island (Whenua Hou), with a population size of 150 adults at most. Therefore, the species is considered “Threatened - Nationally Critical” by the New Zealand Threat Classification System. As this highly-threatened population is the only New Zealand Procellariiformes that specializes in breeding in coastal dunes, the Coastal Restoration Trust of New Zealand supported my research project aimed at better understanding the threats and population trends of the SGDP on Codfish Island. The proposed aims of this study were:

  • Continued assessment of nest site characteristics critical to the SGDP on Codfish Island
  • Assessment of population dynamics and trends of the SGDP on Codfish Island
  • Assessment of the breeding biology of the SGDP on Codfish Island

Analysis of explanatory variables that potentially affect nest site selection in SGDPs on Codfish Island using a theoretic information criterion (AICC) showed that their nesting habitat are mobile, steep, north-eastern (seaward) facing dunes no further than 20 m from the sea. In addition, the interactions between the distance to the sea and physical aspects of the dunes, as well as the interaction between plant cover and the physical aspects of the dunes proved important. Surprisingly nest site selection by SGDPs is not dictated by the presence of invasive plant species (as opposed to the indications given by preliminary results), nor by the presence of conspecifics, Common Diving Petrels (P. urinatrix; CDP), or Sooty Shearwaters (Puffinus griseus). However, four burrows showing changes in occupancy suggest that CDPs may directly compete for burrow sites with SGDPs. More importantly, the preferred nesting habitat thus renders this Nationally Critical species extremely vulnerable to effects from stochastic events (e.g., storms and storm surges) during the breeding season. These results have been written up as a formal publication.

During the 2015/2016 breeding season, 60 SGDPs were banded and these individually recognizable birds presented a unique opportunity to assess population dynamics of this species. Therefore, continued banding and recapture efforts have become a priority during the 2016/2017 breeding season. During the first field trip of the 2016/2017 breeding season (late September to early October 2016), an additional 47 SGDPs were banded. Furthermore, 31 SGDPs were recaptured (21 from 2015/2016 breeding season, 3 from 2008/2009, 4 from 2004/2005 and 1 from 2003/2004). This data will form a solid foundation for a detailed study aimed at understanding the population dynamics and trends in the SGDP. Banding and recapture efforts will continue in upcoming field trips and breeding seasons to further compile the data.

The third aim, the assessment of the breeding biology of the SGDP on Codfish Island, is crucial to enable the continued existence of this species. Unfortunately, it was not possible to deploy the required study equipment (study burrows) during the first field trip due to logistical and bureaucratic constraints. Preliminary data on the breeding biology were collected during the first field trip (by assessing body condition of birds in the hand) and these data suggest prospecting to start in September, while incubation appears to start in the first week of October. Future attempts to place study burrows are currently being considered, as well as a study trial to assess the effects of study burrows on brood-chamber conditions (e.g., temperature and humidity).

In conclusion, the smooth progress of the analysis of the nest site selection of the SGDP on Codfish Island will enable more fine-tuned conservation strategies in the future. The first SGDP field trip of the 2016/2017 breeding season was a remarkable success in terms of capture-mark-recapture efforts. In addition, future field trips may enable the study of the breeding biology of this Nationally Critical species. I am thus very grateful for the support received from the Coastal Restoration Trust of New Zealand to further our understanding of a species in such desperate need of conservation management.