Tiritiri Matangi Research Articles

Monitoring of North Island fantail / pīwakawaka fantail (Rhipidura fuliginosa placabilis Bangs, 1921, Rhipiduridae) distribution on Tiritiri Matangi Island: using several spatial methods for processing volunteer data

The Aotearoa / New Zealand fantail / pīwakawaka (Rhipidura fuliginosa Sparrman, 1787, Rhipiduridae) is an iconic species and conspicuous in a range of habitats. However, island populations of the species are said to fluctuate dramatically. This project set out to investigate the population dynamics of the Te ika a Maui / North Island subspecies Rhipidura fuliginosa placabilis Bangs, 1921) on Tiritiri Matangi Island using a volunteer-based monitoring scheme. To achieve this goal we developed a pilot sampling grid and determined spatial distribution characteristics using several approaches including geostatistical tools in ArcMap, species distribution modelling and occupancy modelling. Fantail presence data was recorded twice a year by volunteers assigned to specific grids at different seasons for two years on Tiritiri Matangi Island. Recorded count data show distinctive differences between the sampling periods and different areas of the island. Significant hotspots as well as clustering of abundance show different patterns with significantly higher abundance and widespread distribution during May compared to November. Spatial analysis identified vegetation, particularly replanted areas, as influencing the fantail counts. Results of species distribution modelling showed areas of the island suitable for the species and occupancy models further described the seasonal spatial characteristics of fantail. The effort also highlights the importance of volunteers in providing bird count data to generate the knowledge base required for the management of an island sanctuary.

Do hihi lose access to supplemental feeders because of the presence of korimako?

ABSTRACT Supplemental feeding is now a ubiquitous and effective tool in the conservation management of wild populations. On Tiritiri Matangi Island, the persistence of the hihi (Notiomystis cincta) population depends on constant food supplementation. However, the more dominant korimako (Anthornis melanura) can also access these feeders. To understand whether korimako may be limiting hihi access to the feeders, we used an observational study to quantify the co-occurrences at feeders and potential for resource partitioning and competitive exclusion of males and females of both species. We measured hihi and korimako visits to sugar-water feeders and the frequency of territorial interactions during the non-breeding and breeding seasons. We found that male korimako were the most frequent visitors (116 ± 7 visits h−1), followed by male hihi (51 ± 3 visits h−1), female hihi (47 ± 3 visits h−1), then female korimako (6 ± 1 visits h−1). In general, visits positively correlated between each species and sex across months. Few intra- and interspecific aggressive interactions were observed in the non-breeding season and early breeding season. We found no evidence that hihi were being excluded from the supplemental feeders by korimako, potentially from the high visitation rates making territorial and aggressive interactions ineffectual.

Capturing the dynamics of small populations: A retrospective assessment using long-term data for an island reintroduction.

The art of population modelling is to incorporate factors essential for capturing a population's dynamics while otherwise keeping the model as simple as possible. However, it is unclear how optimal model complexity should be assessed, and whether this optimal complexity has been affected by recent advances in modelling methodology. This issue is particularly relevant to small populations because they are subject to complex dynamics but inferences about those dynamics are often constrained by small sample sizes. We fitted Bayesian hierarchical models to long-term data on vital rates (survival and reproduction) for the toutouwai Petroica longipes population reintroduced to Tiritiri Matangi, a 220-ha New Zealand island, and quantified the performance of those models in terms of their likelihood of replicating the observed population dynamics. These dynamics consisted of overall growth from 33 (±0.3) to 160 (±6) birds from 1992-2018, including recoveries following five harvest events for further reintroductions to other sites. We initially included all factors found to affect vital rates, which included inbreeding, post-release effects (PRE), density-dependence, sex, age and random annual variation, then progressively removed these factors. We also compared performance of models where data analysis and simulations were done simultaneously to those produced with the traditional two-step approach, where vital rates are estimated first then fed into a separate simulation model. Parametric uncertainty and demographic stochasticity were incorporated in all projections. The essential factors for replicating the population's dynamics were density-dependence in juvenile survival and PRE, i.e. initial depression of survival and reproduction in translocated birds. Inclusion of other factors reduced the precision of projections, and therefore the likelihood of matching observed dynamics. However, this reduction was modest when the modelling was done in an integrated framework. In contrast, projections were much less precise when done with a two-step modelling approach, and the cost of additional parameters was much higher under the two-step approach. These results suggest that minimization of complexity may be less important than accounting for covariances in parameter estimates, which is facilitated by integrating data analysis and population projections using Bayesian methods.

Using long-term data for a reintroduced population to empirically estimate future consequences of inbreeding.

Inbreeding depression is an important long-term threat to reintroduced populations. However, the strength of inbreeding depression is difficult to estimate in wild populations because pedigree data are inevitably incomplete and because good data are needed on survival and reproduction. Predicting future population consequences is especially difficult because this also requires projecting future inbreeding levels and their impacts on long-term population dynamics, which are subject to many uncertainties. We illustrate how such projections can be derived through Bayesian state-space modeling methods based on a 26-year data set for North Island Robins (Petroica longipes) reintroduced to Tiritiri Matangi Island in 1992. We used pedigree data to model increases in the average inbreeding level (F) over time based on kinship of possible breeding pairs and to estimate empirically Ne /N (effective/census population size). We used multiple imputation to model the unknown components of inbreeding coefficients, which allowed us to estimate effects of inbreeding on survival for all 1458 birds in the data set while modeling density dependence and environmental stochasticity. This modeling indicated that inbreeding reduced juvenile survival (1.83 lethal equivalents [SE 0.81]) and may have reduced subsequent adult survival (0.44 lethal equivalents [0.81]) but had no apparent effect on numbers of fledglings produced. Average inbreeding level increased to 0.10 (SE 0.001) as the population grew from 33 (0.3) to 160 (6) individuals over the 25 years, giving a ratio of 0.56 (0.01). Based on a model that also incorporated habitat regeneration, the population was projected to reach a maximum of 331-1144 birds (median 726) in 2130, then to begin a slow decline. Without inbreeding, the population would be expected stabilize at 887-1465 birds (median 1131). Such analysis, therefore, makes it possible to empirically derive the information needed for rational decisions about inbreeding management while accounting for multiple sources of uncertainty.

Seabirds as environmental indicators: foraging behaviour and ecophysiology of common diving petrels (Pelecanoides urinatrix) reflect local-scale differences in prey availability

Seabird foraging behaviour can reflect prey abundance at sea, and is influenced by stress hormone levels, thus providing a potential indicator of at-sea conditions. Using common diving petrels (Pelecanoides urinatrix, hereafter CDPs), a procellariform that preferentially forages on crustacean zooplankton, we sought to understand how spatially separate colonies responded behaviourally and physiologically to contrasting prey levels with a view to recruiting this species as an environmental indicator. In 2016, incubating CDPs from Tiritiri Matangi (− 36.59S; 174.88E, low levels of preferred prey) and Burgess (− 35.91S; 174.12E, high levels of preferred prey) Islands within the Hauraki Gulf, New Zealand, were tracked using GPS devices. We hypothesised that Tiritiri birds would exhibit greater foraging effort and higher stress hormone levels across the breeding season due to lower levels of available prey. Hidden Markov methods were used to model foraging effort, and prey trophic level (stable isotopes: δ13C and δ15N) and stress hormone levels (CORT) quantified in plasma samples. During incubation birds were spatially segregated when foraging. Tiritiri birds exerted more effort, chasing higher trophic level prey at larger distances from the colony, and had higher body weight and lower CORT than Burgess birds. However, bird CORT levels responded more to reproductive duties (peaking during chick rearing) as opposed to colony location, i.e. CORT was not consistently higher in Tiritiri birds. Although a snapshot, our findings illustrate the promise of integrating multiple parameters when recruiting seabirds as ocean indicators, resulting in improved resolution of future monitoring programmes based upon them.

Learning During Wildlife Tours in Protected Areas: Towards a Better Understanding of the Nature of Social Relations in Guided Tours

This article explores guided wildlife tours in Protected Areas (PAs) in the context of free-choice learning, social relations and environmental stewardship. Free-choice learning refers to people’s informal learning that occurs without requisite external assessment such as schools or workplaces. While the literature argues that guides on wildlife tours in PAs should make visitors aware of a set of achievable on and off-site actions the informal nature of such educational activities is difficult to measure. Research on guided tours on Tiritiri Matangi, New Zealand highlights the complex nature of social interaction between tour participants and the factors that impact on learning during a guided tour. The nature of the social relations that inform guide visitor interaction (GVI) is discussed in the context of Relations Model Theory and freechoice learning.

Little Adaptive Potential in a Threatened Passerine Bird

Threatened species face numerous threats, including future challenges triggered by global change. A possible way to cope with these challenges is through adaptive evolution, which requires adaptive potential. Adaptive potential is defined as the genetic variance needed to respond to selection and can be assessed either on adaptive traits or fitness [1]. However, a lack of high-quality data has made it difficult to rigorously test adaptive potential in threatened species, leading to controversy over its magnitude [1-3]. Here we assess the adaptive potential of a threatened New Zealand passerine (the hihi, Notiomystis cincta) based on two populations: (1) the sole remaining natural population, on the island of Te Hauturu-o-Toi, and (2) a reintroduced population with a long-term dataset (intensively monitored for 20 years) based on the island of Tiritiri Matangi. We use molecular information (reduced representation genome sequencing, on both populations), as well as long-term phenotypic and fitness data from the Tiritiri Matangi population, to find (1) a lack of molecular genetic diversity at a genome-wide level in both populations, (2) low heritability of traits under selection and (3) negligible additive genetic variance of fitness in the Tiritiri Matangi population. In combination, these results support a lack of adaptive potential in this threatened species. We discuss our findings within the context of other passerines and methods for assessing adaptive potential, as well as the impact of these results on conservation practice, for the hihi and species of conservation concern in general.

GPS telemetry for small seabirds: using hidden Markov models to infer foraging behaviour of Common Diving Petrels (Pelecanoides urinatrix urinatrix)

ABSTRACTCommon Diving Petrels (Pelecanoides urinatrix urinatrix) are distributed widely around coastal New Zealand and breed primarily on predator-free offshore islands. Despite their ubiquity, little is known of their at-sea foraging movement, as their small size and frequent diving behaviour have presented logistic challenges to obtaining high-resolution tracking data that reflect detailed movement patterns. We present the first attempt to collect detailed (5 min/fix) movement trajectories of Common Diving Petrels, using miniaturised global positioning system (GPS) loggers. Adult breeding Common Diving Petrels were tracked for single foraging trips from Tiritiri Matangi Island near Auckland, New Zealand. We applied a hidden Markov model to infer behavioural states from the movement data, and a kernel density estimation on the GPS fixes of area-restricted behaviour to characterise feeding hotspots. We found that Common Diving Petrels in the Hauraki Gulf are local foragers during their breeding season, and the model results indicated that foraging accounted for two-thirds of all behaviour states. At-sea foraging activities of the birds were concentrated in areas up to 30 km from their colony. Our findings reveal the utility of combining GPS tracking with behavioural models to infer the foraging behaviours and space-use patterns of small seabird taxa.

Female Song Rate and Structure Predict Reproductive Success in a Socially Monogamous Bird

Bird song is commonly regarded as a male trait that has evolved through sexual selection. However, recent research has prompted a re-evaluation of this view by demonstrating that female song is an ancestral and phylogenetically widespread trait. Species with female song provide opportunities to study selective pressures and mechanisms specific to females within the wider context of social competition. We investigated the relationship between reproductive success and female song performance in the New Zealand bellbird (Anthornis melanura), a passerine resident year round in New Zealand temperate forests. We monitored breeding behavior and song over three years on Tiritiri Matangi Island. Female bellbirds contributed significantly more towards parental care than males (solely incubating young and provisioning chicks at more than twice the rate of males). Female song rate in the vicinity of the nest was higher than that of males during incubation and chick-rearing stages but similar during early-nesting and post-breeding stages. Using GLMs, we found that female song rates during both incubation and chick-rearing stages strongly predicted the number of fledged chicks. However, male song rate and male and female chick provisioning rates had no effect on fledging success. Two measures of female song complexity (number of syllable types and the number of transitions between different syllable types) were also good predictors of breeding success (GLM on PC scores). In contrast, song duration, the total number of syllables, and the number of ‘stutter’ syllables per song were not correlated with fledging success. It is unclear why male song rate was not associated with reproductive success and we speculate that extra-pair paternity might play a role. While we have previously demonstrated that female bellbird song is important in intrasexual interactions, we clearly demonstrate here that female song predicts reproductive success. These results, with others, highlight the need for a change in how we view the significance of female secondary sexual traits; traits long underestimated due to a focus on male song.

Network analysis of wildlife translocations in New Zealand

AIMS: To identify network measures with relevance to disease spread in a network of movements derived from the Department of Conservation (DOC) translocation records from 1970 to mid-2014, and to identify conservation sites that should be prioritised for surveillance activities and improvements to data collection to make the best use of network analysis techniques in the future.METHODS: Data included the source and destination of translocated specimens, the species and the dates the translocations were expected to occur. The data were used to construct a directed, non-weighted network in which a translocation event represented a tie in the network. Network density, in-degree (movements entering a node of interest) and out-degree (movements leaving a node of interest) and reciprocity were calculated.RESULTS: The data analysed consisted of 692 unique translocations between 307 sites, with the majority (518; 73%) being for birds. The constructed network for bird, reptile and frog translocations comprised 260 nodes, with 34/260 (13%) having two-way movements and 47/260 (18%) non-reciprocal movements. The median degree score (sum of in- and out-degree) was two (min 0, max 36) with a mean of 3.5 in a right skewed distribution. Most sites acted as receivers or senders of consignments with only a few having both high in- and high out-degree, and thus had characteristics that made them sites of interest for surveillance activities. These included the National Wildlife Centre at Mount Bruce, Tiritiri Matangi Island and Te Kakahu (Chalky Island).CONCLUSIONS: The presence of linking sites that join larger clusters within the network creates the potential for rapid disease spread if a pathogen were to be introduced. The important sites that supply or receive specimens for translocations are already well recognised by those performing translocations in New Zealand, and this paper provides further information by quantifying their role within the network.

Emerging infectious disease or evidence of endemicity? A multi-season study of beak and feather disease virus in wild red-crowned parakeets (Cyanoramphus novaezelandiae).

Beak and feather disease virus (BFDV) is a single-stranded DNA virus that is the etiological agent of beak and feather disease in both wild and captive parrots. Given that BFDV is globally recognized as a conservation threat for wild parrots, between 2011-2013, red-crowned parakeets (Cyanoramphus novaezelandiae, n = 229), which are endemic to New Zealand, were captured in mist nets on Tiritiri Matangi Island and Hauturu-o-Toi/Little Barrier Island (LBI), New Zealand, for disease surveillance. Blood and feathers from all birds were tested by PCR for BFDV, and full genomes were recovered and sequenced. A subset of blood samples (n = 96) were tested for antibodies to BFDV by the haemagglutination inhibition (HI) test. A further 238 feather samples were obtained from red-crowned parakeets from three sites in the Wellington region of the North Island, and these were screened for BFDV. The DNA-based prevalence of BFDV infection determined on Tiritiri Matangi Island was 1.09% (CI 95 %, 0.1-3.9%); on Hauturu-o-Toi/LBI, 4.4% (95% CI, 0.5%-15.1%); on Kapiti Island, 3.4% (CI 95%, 1.1-7.8%); at the ZEALANDIA-Karori sanctuary, 1.6% (95% CI, 0-8.4%); and on Matiu-Somes Island, 0% (CI 95%, 0-12.3%). Seroprevalence for BFDV, indicating prior or current exposure, in the Tiritiri Matangi Island population, it was 2% (CI 95%, 0-10.1%), and in the Hauturu-o-Toi/LBI population was 14% (CI 95%, 5.3-27.9%). BFDV-positive birds showed no signs of clinical disease, with the exception of an individual bird obtained opportunistically from Shakespear Regional Park during the study period, which had classical signs of feather loss. Phylogenetic analysis of the 11 full genome sequences recovered from BFDV-positive red-crowned parakeets revealed evidence of ongoing viral flow between red-crowned parakeets and eastern rosellas (Platycercus eximius) in the Hauraki Gulf/Auckland region, with separate but closely related strains from the Wellington region of the North Island. This is the first study to report HI results for a New Zealand endemic parrot species, and the first epidemiological analysis of serial cross-sectional surveys in a BFDV-infected population of red-crowned parakeets in New Zealand. We postulate that although BFDV remains a threat to small, isolated or naïve populations of parrots globally, the low viral prevalence in this and other studies suggests that native parakeets in New Zealand may act as dead-end or spillover hosts.

Investigation of mortalities associated with Salmonella spp. infection in wildlife on Tiritiri Matangi Island in the Hauraki Gulf of New Zealand

CASE HISTORY: Salmonellosis was suspected as the cause of death in eight wild animals on Tiritiri Matangi Island, in the Hauraki Gulf of New Zealand, between November and September 2011, including three hihi (Notiomystis cincta), a tuatara (Sphenodon punctatus), a masked lapwing (Vanellus miles novaehollandiae), and a saddleback (Philesturnus carunculatus). An outbreak investigation to identify the source and distribution of infection was undertaken over the summer of 2011–2012. CLINICAL AND LABORATORY FINDINGS: Surveillance of five species of forest bird (n=165) in December 2011 returned a single positive result for Salmonella spp. Environmental sampling of 35 key water sources and hihi supplementary feeding stations conducted in December 2011 and March 2012 returned isolates of S. enterica subspecies houtenae and S. enterica serovar Saintpaul from a stream, a dam and a supplementary feeding station. The same serotypes were identified in tissue samples collected from post mortem specimens of the affected birds, and their similarity was confirmed by pulsed-field gel electrophoresis. DIAGNOSIS: Mortality in wildlife associated with infection with S. enterica subspecies houtenae and S. enterica serovar Saintpaul. CLINICAL RELEVANCE: This is the first detection of these Salmonella spp. from wild birds in New Zealand. Our study highlights how active surveillance in response to observed disease emergence (here mortalities) can provide important insight for risk assessment and management within populations of endangered species and inform risk assessment in translocation planning.

KNEMIDOKOPTINID (EPIDERMOPTIDAE: KNEMIDOKOPTINAE) MITE INFESTATION IN WILD RED-CROWNED PARAKEETS (CYANORAMPHUS NOVAEZELANDIAE): CORRELATIONS BETWEEN MACROSCOPIC AND MICROSCOPIC FINDINGS.

During a study on health and disease in Red-crowned Parakeets (Cyanoramphus novaezelandiae) on Tiritiri Matangi Island and Little Barrier Island (Hauturu-o-Toi) in New Zealand between 2011 and 2013, an outbreak of feather loss prompted the collection of skin biopsies (n = 135) under anesthesia from the head of captured birds. A subset of samples (n = 7) was frozen to obtain whole specimens for identification of ectoparasites. Mites (range 1-11) were observed in 79/135 (58.5%) skin biopsies, whereas feather loss was only found in 47/142 (33.1%) birds captured during the sampling period. Compact orthokeratotic hyperkeratosis and acanthosis were found in association with mites. Procnemidocoptes janssensi (Acari: Epidermoptidae, Knemidokoptinae) was identified from whole mites obtained from skin biopsies. We describe the presence, pathology, and stages of infestation for knemidokoptinid mange in a wild parrot population in New Zealand. Given the clinical and pathologic changes observed and poor knowledge of the parasite's New Zealand host and geographic distribution, further work is recommended for this and sympatric parrots, to understand relationships between the host, parasite, environment, and expression of disease. Results from this study reinforce the value of including biopsy samples for the investigation of skin disease in wild birds, particularly to link etiologic agents with pathologic changes.

Population genetic connectivity of an endemic New Zealand passerine after large‐scale local extirpations: a model of re‐colonization potential

Little is known about how a 70% loss of native forests has affected the genetic connectivity of remnant bird populations in New Zealand. We use the common and widely distributed New Zealand Bellbird Anthornis melanura as an indicator species of population connectivity for well‐flighted birds. Using eight microsatellite loci, we identified five main genetic populations in the North Island, South Island, sub‐Antarctic Auckland Islands and two small remnant island populations adjacent to a large region of avian extirpations in northern North Island. Only one remnant island population, on a 30‐year‐old conservation reserve at Tiritiri Matangi, displayed a clear signature of recent genetic bottleneck. The 7% migration rate at Tiritiri Matangi indicates that bottlenecks can be maintained despite habitat rehabilitation, possibly through behavioural barriers to gene flow. Adjacent to the same extirpation zone, Bellbirds on the Poor Knights Islands were found to have low genetic diversity and low re‐colonization potential. Two gaps concordant with deforestation patterns separated the Kapiti Coast of southern North Island from populations to both the north and the south. In summary, we identified linked avian habitats, as well as isolated and inbred populations and suggest that Bellbirds are good re‐colonizers. We emphasize the importance of genetic studies that assess animal dispersal among newly rehabilitated habitat patches.

EDITOR'S CHOICE: Saving the hihi under climate change: a case for assisted colonization

Summary Climate change is affecting the spatio‐temporal distribution of environmental conditions, forcing species to shift their range in response. Species not capable of dispersing naturally may benefit from conservation translocations. A key aspect of translocation planning is release site selection: under the 2012 IUCN guidelines for reintroductions and other conservation translocations, selected sites are expected to match the biotic and abiotic needs of the candidate species now and in the future. Here we present a methodological framework to identify optimal translocation sites under climate change. Our method is the first to explicitly combine statistical and predictive population modelling to understand the relationship between climate, climate change and population dynamics, in order to perform robust habitat suitability analyses for conservation decision‐making. We use the hihi Notiomystis cincta, a bird endemic to New Zealand, as a case study. We focus on the population of Tiritiri Matangi Island, which has been provided with ad libitum supplementary food since 1996. This offers the unique opportunity to study the direct impact of climate and future change in climatic conditions on a population free of confounding constraints. Climate is found to drive hihi population dynamics, even though they are not limited by the availability of food. Thus, despite the current management of the species, climate change remains a major threat to its long‐term persistence. Moreover, under predicted climate change for the country, hihi suitable habitat will shift southward: the two current largest hihi populations will face unsuitable climatic conditions in the coming decades, and habitat that was not part of the species' historical range may become suitable. Synthesis and applications. Assisted colonization is increasingly being considered as an adaptation tool for species threatened by climate change. Justifying the use of this extreme conservation action, however, requires robust evidence that it is necessary and clear guidance on where to translocate individuals of threatened populations. We show how both requirements can be met using habitat suitability modelling if knowledge of the relationship between climate, climate change and the species' population dynamics is systematically used to guide the modelling process.

Detection of Salmonella during the translocation of two endemic New Zealand lizard species within the Hauraki Gulf

Multiple species translocations to the same site are becoming common practice in New Zealand restoration programmes. With every new translocation, the risk of parasite transmission between populations can increase. The translocation of Hoplodactylus duvaucelii and Oligosoma smithi provided the opportunity to 1) test for Salmonella and Cryptosporidium occurrences; and 2) compare this Salmonella test prevalence with results from avian translocations at one release site, Tiritiri Matangi Island. Of the six reptile species tested, three skinks (O. aeneum, O. moco and O. smithi) and one gecko (Woodworthia maculatus) tested positive for Salmonella (n=274). This is the first record of Salmonella enterica subspecies IV 40:g,t:- in New Zealand reptiles. Test prevalences between reptiles and birds were similar, suggesting that Salmonella prevalence may be naturally low in the areas sampled.

Genetic consequences of a century of protection: serial founder events and survival of the little spotted kiwi (Apteryx owenii).

We present the outcome of a century of post-bottleneck isolation of a long-lived species, the little spotted kiwi (Apteryx owenii, LSK) and demonstrate that profound genetic consequences can result from protecting few individuals in isolation. LSK were saved from extinction by translocation of five birds from South Island, New Zealand to Kapiti Island 100 years ago. The Kapiti population now numbers some 1200 birds and provides founders for new populations. We used 15 microsatellite loci to compare genetic variation among Kapiti LSK and the populations of Red Mercury, Tiritiri Matangi and Long Islands that were founded with birds from Kapiti. Two LSK native to D'Urville Island were also placed on Long Island. We found extremely low genetic variation and signatures of acute and recent genetic bottleneck effects in all four populations, indicating that LSK have survived multiple genetic bottlenecks. The Long Island population appears to have arisen from a single mating pair from Kapiti, suggesting there is no genetic contribution from D'Urville birds among extant LSK. The Ne/NC ratio of Kapiti Island LSK (0.03) is exceptionally low for terrestrial vertebrates and suggests that genetic diversity might still be eroding in this population, despite its large census size.

Tuatara

Tuatara

Evidence of lizard predation by New Zealand kingfishers (Todiramphus sanctus vagans) and potential implications for threatened species translocations

Dietary analyses were carried out on four species of native birds on Tiritiri Matangi and Motuora Islands, New Zealand, between February 2007 and February 2008. We examined regurgitated pellets of kingfishers, moreporks and swamp harriers, and the faeces of pukeko. Remains of lizards were found in 88% and 43% of regurgitated kingfisher pellets on Tiritiri Matangi and Motuora, respectively. All remains belonged to one species, Oligosoma moco. No evidence of lizard predation was found for the other three bird species. Translocation of lizards to areas supporting a high abundance of kingfishers should take avian predation risk into account.

Losing anti‐predatory behaviour: A cost of translocation

AbstractTranslocation of endangered species to habitats where exotic predators have been removed is now a common conservation practice around the world. Many of these translocated populations have thrived, and they are often used as sources for the harvesting of individuals for translocations to sites where exotic predators still exist, albeit at reduced densities. This study investigates how isolation from exotic predators affects the ability of individuals to recognize such predators using the North Island robin (Petroica longipes) as a model. The study was carried out in three robin populations in the North Island, New Zealand: a translocated population on Tiritiri Matangi Island, where exotic mammalian predators are absent; a population reintroduced from Tiritiri Matangi Island to Wenderholm Regional Park, a mainland site where these mammals are controlled to low densities; and a mainland population at Benneydale where exotic predatory mammals are common. The response intensity of robins to a model stoat was high at Benneydale and low at Tiritiri Matangi and Wenderholm. This result indicates that isolation from mammalian predators on Tiritiri Matangi has suppressed the ability of North Island robins to recognize these predators. It is possible that the low predatory mammal densities at Wenderholm have reduced robin contact with stoats, therefore reduced the opportunity for robins to learn to recognize stoats. Thus, translocation of individuals from populations without predators to places where key predators still exist could be unsuccessful if translocated individuals fail to perform appropriate anti‐predator behaviours.