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    Post-release survival and productivity of oiled little blue penguins (Eudyptula minor) rehabilitated after the 2011 C/V Rena oil spill : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Palmerston North, New Zealand
    (Massey University, 2014) Sievwright, Karin Amy
    There is ongoing global debate about the effectiveness and conservation value of rehabilitating oiled wildlife, with post-rehabilitation monitoring of released individuals being required to evaluate the medium- and long-term effectiveness of the rehabilitation process. This study provides the first assessment of the efficacy of the oil-rehabilitation process used in New Zealand by monitoring the post-release survival and productivity of little blue penguins (Eudyptula minor) that were oiled and subsequently rehabilitated following the 2011 C/V Rena oil spill in Tauranga, New Zealand. This study was enabled as all rehabilitated penguins were tagged with passive integrated transponders (PIT-tags/micro-chips) before release, as were similar numbers of non-oiled control penguins from within the local area around the same time. This enabled survival and productivity to be compared between rehabilitated and non-oiled penguins. Surveys for the presence of marked penguins were made in 18 of the 23 months following the release of rehabilitated penguins at three study sites (Mount Maunganui/Mauao, Leisure Island/Moturiki, and Rabbit Island/Motuotau). Mark-recapture analyses indicated that survival rates of rehabilitated penguins were comparable to those of control penguins. However, survival was reduced for both groups in the first six months following rehabilitation/micro-chipping. Survival probabilities increased thereafter and were high and reasonably constant over time. Probabilities estimated are likely to represent minima as by the end of the study an asymptote of first-time re-sightings of control and rehabilitated penguins was yet to be reached. Survival was not influenced by selected variables including oiling degree, admission and release body mass index, packed cell volume, total protein levels, blood glucose levels, and captive duration. This work also found that rehabilitated penguins were heavier than control penguins upon release and during the subsequent two months, however following the moult and post-moult foraging period masses reduced and thereafter were similar to those of control penguins. The behaviour of individual penguins was also recorded during surveys; rehabilitated penguins were more likely to stay (not move) when approached during surveys and were more docile than control penguins when handled. Breeding monitoring found that productivity of rehabilitated penguins was somewhat reduced in the year after the spill. The timing and duration of egg laying, clutch sizes and pre-fledging chick masses were similar between rehabilitated pairs (pairs including at least one rehabilitated penguin) and control pairs (pairs including two control penguins), whereas hatching, fledging and egg success were lower in rehabilitated pairs; however, only hatching success was significantly reduced. Despite these reductions, hatching, fledging and egg success rates of rehabilitated pairs were within ranges reported for other little blue penguin colonies in Australia and New Zealand. These findings suggest that the oil-rehabilitation process used during the C/V Rena oil spill was reasonably effective at treating and reversing most negative effects of oil-contamination on the post-release survival and productivity of rehabilitated penguins. This demonstrates the general effectiveness of the rehabilitation process used to treat oiled little blue penguins in New Zealand and justifies, with on-going improvement and adaption of treatments and techniques used, the continued practise of oiled wildlife rehabilitation in New Zealand.
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    The foraging ecology of Little Penguin (Eudyptula minor) on Tiritiri Matangi Island : a thesis submitted in partial fulfilment of the requirements of Master of Science in Conservation Biology, Massey University, Auckland
    (Massey University, 2011) McKenzie, Fiona Rea Katrine
    Little Penguins (Eudyptula minor) are the smallest penguin in the world. They have a distribution ranging from south-western Australia, through to New Zealand and the Chatham Islands. Some populations in Australia and the South Island of New Zealand have been the subject of considerable research, but there has been less undertaken on populations in the northern half of New Zealand. The Department of Conservation however, are concerned about their status and have list the northern populations as ‘At Risk – Declining’ in the New Zealand Thread Classification System. As part of a new longitudinal study on Little Penguins (LP) resident on Tiritiri Matangi Island, Hauraki Gulf, New Zealand this study focussed on their foraging behaviour and breeding success over 2010 and 2011. Two new biogeochemical techniques were used in this study to examine LP diet from tissue samples. Stable isotope analysis of LP blood, feathers and potential prey species established the trophic level of the LP (calibrated from a captive feeding trial) and was able to determine both temporal and spatial shifts in trophic level over a 12 month period. These shifts may indicate changes in prey type or abundance, however more research is required to determine this. Fatty acid signature analysis of potential prey and LP adipose found similarities that suggest the prey types were likely included in the LP diet, but sample sizes were small and again further research is required. Abundance of potential prey species within the local Hauraki Gulf region were extrapolated from commercial catches of bait fish statistics and foraging ranges from were proxied from previous studies. It was determined that commercial fishing is unlikely to impact the LP at this time. A third emerging technology, GPS tracking dataloggers, was proposed to track the penguins across the breeding and non-breeding seasons to determine where they foraged, how far they ranged and how this changed seasonally. Unfortunately, equipment failures resulted in no tracks being recorded. Breeding success recorded for 5 years was extremely variable however, for one year at least, it was apparent that a significant absence of preferred prey may be linked to a devastatingly poor year for rearing chicks. Top predators such as seabirds, including penguins, are a model bioindicator for the health of their local marine environment i.e. a seabird population that breeds well and is in good body condition likely indicates there is abundant food and clean water. Conversely a sea bird population that is declining in size or experiences poor recruitment, may be an indication that prey is absent or that waters are polluted. With the local North Island LP populations potentially already in decline, it is important to continue to monitor aspects of their breeding and foraging in the coming years – not only for the benefit of the penguins, but for the wider conservation of the Hauraki Gulf Marine Park.
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    The effect of conservation management on Little Blue Penguins (Eudyptula minor) on North Island, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Conservation Biology at Massey University, Auckland, New Zealand
    (Massey University, 2009) Lowe, Mark Ian
    This study aimed to fill a gap in research, particularly on the size of breeding populations of Little Blue Penguins in the North Auckland area, while also providing recommendations for the conservation management of Little Blue Penguins. Three sites North of Auckland were used for the majority of this study; Tawharanui North, Tawharanui South and Goat Island The abundance and nest density of Little Blue Penguins was estimated for the three sites north of Auckland. All three sites had a very low nest density: 0.0096 nests/100m2 at Goat Island, 0.0064 nests/100m2 at Tawharanui North and 0.0048 nests/100m2 at Tawharanui South. Abundance showed a similar trend, with Goat Island having the highest average number of birds coming ashore over the year (2.25 birds per night), followed by Tawharanui North (1.81 birds per night) and finally Tawharanui South (1.19 birds per night). Habitat surveys were conducted at the three sites and differences in habitat structure were found between all three. Tawharanui North was predominantly sand and flax and Tawharanui South was predominantly pebbles and scrub, while Goat Island displayed mostly sand with no vegetation. The results suggested that grass and boulders make up the Little Blue Penguins‘ preferred nesting habitat and it was predicted that sites containing more of this habitat type would have higher nest densities and abundance, although small sample sizes prevented this from being validated statistically. The nest success was calculated, again for the three sites, using the Mayfield method. The key results showed that the incubation period was associated with the lowest success rate of any of the nesting stages observed. Success rates for the incubation stage at the three sites fell between 0.11 and 0.66, success rates for the guard stage fell between 0.74 and 1.00, and success rates for the post-guard stage fell between 0.62 and 1.00. Findings also revealed that nest success was greater at the two Tawharanui sites (where similar rates of nest success were observed) than at the Goat Island site The number of carcasses recovered was recorded as follows: Goat Island, 0.67 birds/km; Tawharanui North, 0.63 birds/km; and Tawharanui South, 0.43 birds/km. There was no statistically significant difference between the rates of carcass recovery and the study site, nor was there a statistically significant difference between the rates of carcass recovery and the season. The rates of carcass recovery were also determined to be lower than historically found for these sites. As an aside to the rest of this study the acute stress response of Little Blue Penguins to pit tag and metal flipper band application was assessed through measuring corticosterone levels in the blood of the birds. The results showed that implantation of a pit tag produced a significantly greater acute stress response than banding with the traditional metal flipper bands. This study makes recommendations regarding the study and conservation of Little Blue Penguins. These recommendations are found throughout this thesis; however, key recommendations are repeated here for convenience.  Re-assess density and abundance measures for the Tawharanui and Goat Island sites in 5 to 10 years time  Research what makes a particular habitat type more preferable than another for Little Blue Penguins  Place nesting boxes around the Tawharanui coast to increase suitable nesting habitat  Carry out ongoing carcass recovery observations and necropsies on penguin populations in Auckland to better understand the causes of mortality  Engage in further study regarding both the acute and chronic stress levels induced by different identification techniques  Engage in further study into possible alternatives to both pit tags and metal bands for penguin identification  Protect Little Blue Penguins from predators on the mainland where possible