Female Weddell seals (Leptonychotes weddellii) display a mixed capital-income breeding strategy, losing up to 40

Attaching cameras to marine mammals allows for first-hand observation of underwater behaviours that may otherwise go unseen. While studying the foraging behaviour of 26 lactating Weddell seals ( Leptonychotes weddellii ) in Erebus Bay during the austral spring of 2018 and 2019, we witnessed three adults and one pup investigating the cavities of Rossellidae glass sponges, with one seal visibly chewing when she removed her head from the sponge. To our knowledge, this is the first report of such behaviour. While the prey item was not identifiable, some Trematomus fish (a known Weddell seal prey) use glass sponges for shelter and in which to lay their eggs. Three of the four sponge foraging observations occurred around 13:00 (NZDT). Two of the three sponge foraging adults had higher-than-average reproductive rates, and the greatest number of previous pups of any seal in our study population, each having ten pups in 12 years. This is far higher than the study population average of three previous pups (± 2.6 SD). This novel foraging strategy may have evolved in response to changes in prey availability, and could offer an evolutionary advantage to some individuals that exploit prey resources that others may not. Our observations offer new insight into the foraging behaviours of one of the world’s most studied marine mammals. Further research on the social aspects of Weddell seal behaviour may increase our understanding of the extent and mechanisms of behavioural transfer between conspecifics. Research into the specific foraging behaviour of especially successful or experienced breeders is also warranted.

Hypervirulent Klebsiella pneumoniae infection causes significant mortality of endangered New Zealand sea lion pups at Enderby Island, Auckland Islands. Gross necropsy and histopathology findings are well reported, but little is known about the clinical course of disease in affected pups. To determine factors feasible as clinical screening tools for hypervirulent K. pneumoniae in live pups, 150 pups over two field seasons (2016-18) were recruited shortly after birth for a prospective cohort study. A randomised controlled clinical treatment trial with the anthelmintic ivermectin was conducted concurrently and risk factor data and biological samples were collected approximately fortnightly. Treatment with ivermectin has been demonstrated to reduce the risk of hypervirulent K. pneumoniae mortality in pups, so effects on clinical parameters between the treated and control cohorts were also investigated. A broader sample of pups were monitored for clinical signs to investigate the course of disease in affected pups. Clinical signs, haematology and oral and rectal swabs to detect gastrointestinal carriage of hypervirulent K. pneumoniae were not useful for detection of disease prior to death. Of those pups that died due to hypervirulent K. pneumoniae, only 26.1% (18/69) had any clinical signs prior, likely a reflection of the peracute course of disease. On comparison of haematological parameters between ivermectin-treated and control pups, significantly lower total plasma protein and higher eosinophil counts were seen in control versus treated pups, however standard length as a surrogate for age was a more important influence on parameters overall than ivermectin treatment. This study also highlighted a cohort of pups with severe clinical signs suggestive of hypervirulent K. pneumoniae infection were lost to follow up at the end of the monitored season, which could be contributing to cryptic juvenile mortality.

Septicaemia due to hypervirulent (HV) Klebsiella pneumoniae is the leading cause of neonatal pup mortality in endangered New Zealand sea lions ( Phocarctos hookeri ) at Enderby Island, in the New Zealand sub-Antarctic. Accounting for approximately 60% of annual pup mortality at this site following an epizootic event in 2001–02, HV K. pneumoniae is also emerging worldwide as a significant community-acquired human pathogen. To facilitate efficient direct mitigation to reduce pup mortality, a case-control study and prospective cohort study were conducted to identify risk factors amenable to active management. Additionally, to investigate impacts of hookworm ( Uncinaria spp.), a nested treatment trial with the anthelmintic ivermectin was undertaken concurrently. During two austral summer field seasons (2016–2018), 698 pups were captured for treatment trial recruitment and the collection of morphometric measurements, biological samples and risk factor data. Gastrointestinal carriage of the virulent phenotype of K. pneumoniae was a consistent risk factor, while ivermectin treatment and higher body condition index consistently reduced risk of HV K. pneumoniae mortality. Significantly fewer ivermectin-treated pups were found dead (24.1% control, 11.1% treatment), with a trend towards a higher proportion of HV K. pneumoniae deaths amongst the control group. This study provides evidence to support ivermectin treatment as a pup mortality mitigation strategy in New Zealand sea lions at Enderby Island. If applied to larger colonies where HV K. pneumoniae and hookworm impact pup survival, this intervention could have population-scale benefits for this endangered species. Further work is required to understand how ivermectin prevents HV K. pneumoniae septicaemia, but removal of hookworms before intestinal mucosal damage occurs could limit systemic spread of virulent bacteria from the gastrointestinal tract.

Translocation of Tasmanian devils (Sarcophilus harrisii) is a common strategy for recovery of the species as carried out by the Save the Tasmanian Devil Program. Dasyurids including the endangered Tasmanian devil are well known to asymptomatically harbour the zoonotic bacteria Salmonella enterica in their intestinal tracts. Testing for Salmonella is a routine component of pretranslocation health testing, so a statewide microbiological survey of captive and wild devils was implemented in order to understand prevalence and common Salmonella serotypes, and inform decision-making when positive cultures are identified. This preliminary study identified a significantly higher proportion of Salmonella isolations in wild compared with captive devils. Mississippi and Typhimurium were the most common serotypes, followed by Lexington, Bovismorbificans, Kottbus and Amsterdam. Given the common finding of Salmonella in wild devils and the range of serotypes involved, in addition to numerous isolations in domestic species and humans, it is unlikely that the release of small numbers of captive devils to the wild in Tasmania poses a significant risk to the destination ecosystem. Ongoing monitoring of devils is required as the stress of acclimatisation could predispose devils to clinical disease. Appropriate personal protective attire is pertinent to protect personnel handling animals from this zoonotic infection.

Abstract ContextSeabirds were the most common taxa captured alive as part of the oiled wildlife response to the grounding of the container vessel MV Rena in the Bay of Plenty, New Zealand. AimsTo describe the management of seabirds during the spill response, to outline the common problems encountered and to make recommendations for future responses. MethodsSeabirds were collected from 7 October 2011 to 14 January 2012. They were stabilised and underwent pretreatment, washing and rinsing procedures to remove oil, followed by swimming physiotherapy to restore waterproofing and long-term housing in outdoor aviaries. The birds were released in batches close to the original sites of capture once the wild habitat was cleaned. Key results428 live seabirds were admitted. There were two temporal peaks in admissions associated with the ship grounding and when the ship broke up. The majority of live birds were little penguins (Eudyptula minor; 394/428, 92%). Most seabirds admitted (393/428, 91.8%) were contaminated with heavy fuel oil, with the remainder (35/428, 8.2%) found unoiled but starving and/or exhausted or with injuries. Little penguins had lower mortality during rehabilitation (28/394, 7.1%) than other seabird species combined (27/34, 79.4%). Seabirds in poorer body condition on arrival had higher mortality, and unoiled birds were also more likely to die than oiled birds. In oiled little penguins, the degree of oiling on the plumage ranged from 1 to 100%, but mortality was not significantly associated with the degree of oiling (P=0.887). Pododermatitis affected 66% of little penguins. The most common causes of death (n=45) included weakness, anaemia and hypothermia in oiled seabirds (16/45, 35.6%), and starvation and weakness in unoiled seabirds (14/45, 31.1%). ConclusionsTotal survival to release was 87.1%, primarily influenced by the species involved and the body condition of the birds on arrival. Unoiled seabirds had higher mortality rates than oiled seabirds. ImplicationsOiled wildlife can be rehabilitated with good success, even when heavily oiled, or to a lesser extent, when found in poor body condition. More work is needed to refine species-specific rehabilitation protocols for seabirds, especially for those being admitted in emaciated body condition.

The New Zealand sea lion is an endangered species endemic to New Zealand. While causes of death are well described for pups of this species, mortality in adults is poorly characterised. This study investigated causes of death in 136 New Zealand sea lions in two different populations: a major breeding site on remote, uninhabited Enderby Island in the sub-Antarctic, and a slowly increasing recolonising population on the inhabited mainland. For animals with at least a partial diagnostic investigation (n = 112), the most frequently diagnosed causes of mortality were infectious disease (41/112; 37%), particularly tuberculosis due to M. pinnipedii (20/112; 18%), and conspecific trauma (27/112; 24%). Anthropogenic trauma was an important cause of death in mainland sea lions (9/33; 26%). Deliberate anthropogenic mortality has previously been identified as the greatest potential threat to population recovery for mainland sea lions, and as human and pinniped populations increase, managing interactions between these species will become increasingly important.

BACKGROUND:Devil facial tumour disease (DFTD) is a contagious cancer causing marked population declines in wild Tasmanian devils. In response to this threat, a captive insurance population has been established. This study investigated causes of death in captive Tasmanian devils.METHODS:Clinical and laboratory records of captive Tasmanian devils held in seven Tasmanian captive facilities were analysed for cause of death or severe morbidity requiring euthanasia.RESULTS:Neoplasia was found to be the most common cause of mortality/severe morbidity, accounting for 27/63 of deaths. Cutaneous lymphoma was the most frequently observed tumour (10/27), at a higher incidence than previously reported. The most common cause of severe morbidity, following neoplasia, was leucoencephalomyelopathy, which caused severe, progressive hindlimb paresis and ataxia.CONCLUSION:Neoplasia, specifically cutaneous lymphoma, and degenerative neurological conditions are the most frequent causes of death in captive Tasmanian devils in Tasmania. Further work to determine the aetiologies of these conditions, as well as effective treatments, would be valuable.

New Zealand sea lions (Phocarctos hookeri) are an endemic and endangered species. Pup mortality at Enderby Island (50.5°S, 166.28°E) in the New Zealand sub-Antarctic has been well studied, with subsequent investigations yielding more intricate detail of the causes of mortality, as new diagnostic methods become available. Klebsiella pneumoniae was first reported in 2001-02 at this site, causing a pup mortality epizootic and is now known to be present at several colonies. This bacterium is a common mucosal commensal of humans and animals, however the agent found in pups at necropsy is a hypervirulent strain, readily recognised in microbial culture as being hypermucoviscous. Infection causes septicaemia with a common syndrome of subsequent meningitis and polyarthritis. This investigation uses histopathology and microbiology, with new modalities such as matrix assisted laser desorption/ionisation-time of flight mass spectrometry to show that Klebsiella septicaemia could have historically been, and continues to be, the most important cause of pup mortality, but has been previously underrepresented due to the often cryptic presentation and sometimes peracute course of disease. Hypermucoviscous K. pneumoniae should be considered a serious threat to pup survival in the species, causing on average 60.2% of pup deaths annually at Enderby Island between 2013 and 2018, with likely more continuing mortality following pup dispersal and the cessation of the summer monitoring season. Less common causes of death included starvation (14.8%), trauma/asphyxiation (9.9%) and other infections (7%). This study forms the basis for further evaluation of risk factors for pup mortality in the species, with a view to developing active mitigation.

Klebsiella pneumoniae is a Gram-negative bacterium that can be found in the environment, as well as on mucosal surfaces of humans and animals. Here, we report the genome sequence of five K. pneumoniae isolates from substrate samples and bird feces collected in the Subantarctic Islands of New Zealand.

CASE HISTORY: A 1-year-old female New Zealand sea lion (Phocarctos hookeri) was intermittently observed in the Otago region of New Zealand over an 11-month period, always dragging her hind flippers. In December 2012 the sea lion was found dead, after a period of several days being observed to be harassed by male sea lions.PATHOLOGICAL FINDINGS: At gross postmortem examination the sea lion was in moderate body condition with signs of recent bite wounds and bruising. The lungs were dark and poorly inflated. Histological findings included meningoencephalomyelitis, radiculomyelitis of the cauda equina, myocarditis and myositis. Toxoplasmosis gondii organisms were detected histologically and following immunohistochemistry in the brain, spinal cord, spinal nerves and pelvic muscles.MOLECULAR BIOLOGY: Nested PCR analysis and sequencing confirmed the presence of T. gondii DNA in uterine and lung tissue. A variant type II T. gondii genotype was identified using multilocus PCR-restriction fragment length polymorphism analysis.DIAGNOSIS: Systemic toxoplasmosis.CLINICAL RELEVANCE: Infection with T. gondii involving the spinal cord and nerves was the likely cause of the paresis observed in this sea lion before death. Ultimately, death was attributed to crushing and asphyxiation by a male sea lion, presumably predisposed by impaired mobility. Diagnosis of toxoplasmosis in a New Zealand sea lion highlights the possibility that this disease could play a role in morbidity and mortality in this endangered species, particularly in the recently established mainland populations that are close to feline sources of T. gondii oocysts.

Brucella spp infections of marine mammals are often asymptomatic but have been associated with reproductive losses and deaths. Zoonotic infections originating from marine isolates have also been described. Hector's dolphins (Cephalorhynchus hectori) are an endangered species with a declining population, and the role of infectious disease in population dynamics is not fully understood. In this study, 27 Hector's dolphins found dead around the New Zealand coastline between November 2006 and October 2010 were evaluated for lesions previously associated with cetacean brucellosis. Tissues were examined using histological, immunohistochemical, and molecular (polymerase chain reaction [PCR]) techniques. Seven of 27 dolphins (26%) had at least 1 tissue that was positive on PCR for Brucella spp. Lesions consistent with brucellosis were present in 10 of 27 (37%) dolphins, but in 8 of these dolphins Brucella infection could not be demonstrated in lesional tissues. Two dolphins (7%) were diagnosed with active brucellosis: 1 female with placentitis and metritis, and 1 stillborn male fetus. Brucella identified in these 2 dolphins had genetic similarity (99%) to Brucella pinnipedialis. The omp2a gene amplicon from the uterus of the female had 100% homology with ST27 genotype isolates from a human in New Zealand and a bottlenose dolphin of Pacific origin. The remaining 5 PCR-positive dolphins were assessed as having asymptomatic or latent infection. While most Brucella infections identified in this study appeared to be subclinical, the finding of 2 dolphins with reproductive disease due to Brucella infection suggests that this disease has the potential to affect reproductive success in this species.

AIMS: To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was>30%), and latex agglutination test (LAT; with titres 1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.

Stillbirth is a small and often cryptic fraction of neonatal mortality in mammals including pinnipeds. As part of an investigation into the poor reproductive success of the endangered New Zealand sea lion ( Phocarctos hookeri), archived tissues from 37 stillborn pups born on Enderby Island between 1998 and 2012 were examined using histopathological techniques. Apart from bronchopneumonia with neutrophilic infiltration in 4 cases, few inflammatory conditions were identified in stillborn pups. However, 27/32 (84%) stillborn pups had aspirated squames present in the respiratory tract, without meconium. It is unclear if this finding represents fetal distress during parturition or whether it is a normal finding for this species. Three pups lacked histological evidence of hepatic glycogen storage, which may indicate placental defects or maternal undernutrition. No evidence of infectious disease was found on histopathological analysis, consistent with the low seroprevalence in New Zealand of infections known to cause reproductive failure in other pinniped species. This study forms an important baseline for further examination of stillborn New Zealand sea lion pups, as pup mortality is investigated as a contributor to the species’ decline.

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission.

Context Hookworms (Uncinaria spp.) are a common parasite of neonatal fur seals and sea lions around the world and may contribute to decreased pup growth and survival. Removal of these parasitic burdens by administration of the anthelmintic ivermectin has been trialled in New Zealand (NZ) sea lion (Phocarctos hookeri) pups at Sandy Bay, Enderby Island, with initial benefits in growth and survival reported. Long-term effects, however, are not known. Aims To determine the impact of ivermectin treatment administered in the first month of life, on long-term survival and fecundity in a sample of NZ sea lion pups. Methods For a sample of treated and control pups born between 2002 and 2004, resighting data to 2012 was assessed with the Cox proportional hazards analysis to evaluate survival to maturity and fecundity. Key results Sample size was a limiting factor as juvenile survival was very low, but a trend of improved survival was observed in the ivermectin-treated group. Year of birth was significant due to the effects of a bacterial epizootic in the first year of the trial. Reproductive rate was not significantly different between groups. Conclusions The effect of disease and parasitism on the survival of NZ sea lions is apparent, contributing to early pup mortality, with potentially wider-ranging implications for juvenile survival and beyond. Implications Further research is warranted to investigate anthelmintic treatment of NZ sea lion pups as a safe and effective management tool to improve survival and recruitment in declining populations.

Backpack harnesses are commonly used to attach radio and satellite transmitters to a wide range of bird species for research and conservation management. They are an integral part of the conservation management of the New Zealand Takahē (Porphyrio hochstetteri), an endangered flightless rail. Radio transmitters mounted on backpack harnesses enable the birds to be tracked in their remaining native range of remote, mountainous Fiordland, New Zealand. We evaluated 26 Takahē retrospectively at necropsy by gross examination, radiography, and computed tomography to assess damage from the backpack harness. Ten birds that had never worn a harness had no evidence of wing injury. Of the 16 birds that had worn a harness, 10 (63%) had superficial soft tissue injury to skin or patagium or more severe injury, such as remodeling of the distal humerus at the harness cord-wing interface, or pathologic fractures. Such injuries are hypothesized to be associated with discomfort, increased risk of infection or fracture, and therefore reduced fitness. These findings have implications for all avian species deployed with backpack harnesses.

The health of captive Tasmanian devils (Sarcophilus harrisii) is currently of increased interest because wild populations are being decimated by the spread of devil facial tumour disease. This report describes the pathology of an aged captive Tasmanian devil that had a pulmonary mycobacterial infection caused by Mycobacterium intracellulare in addition to multiple neoplastic processes.