Epidemiology and molecular phylogeny of Babesia sp. in Little Penguins Eudyptula minor in Australia

Blood parasites are potential threats to the health of penguins and to their conservation and management. Little penguins Eudyptula minor are native to Australia and New Zealand, and are susceptible to piroplasmids (Babesia), hemosporidians (Haemoproteus, Leucocytozoon, Plasmodium) and kinetoplastids (Trypanosoma). We studied a total of 263 wild little penguins at 20 sites along the Australian southeastern coast, in addition to 16 captive-bred little penguins. Babesia sp. was identified in seven wild little penguins, with positive individuals recorded in New South Wales, Victoria and Tasmania. True prevalence was estimated between 3.4% and 4.5%. Only round forms of the parasite were observed, and gene sequencing confirmed the identity of the parasite and demonstrated it is closely related to Babesia poelea from boobies (Sula spp.) and B. uriae from murres (Uria aalge). None of the Babesia-positive penguins presented signs of disease, confirming earlier suggestions that chronic infections by these parasites are not substantially problematic to otherwise healthy little penguins. We searched also for kinetoplastids, and despite targeted sampling of little penguins near the location where Trypanosoma eudyptulae was originally reported, this parasite was not detected

The benthic‐pelagic continuum: Age class and sex differences in the use of the vertical dimension by a rare pinniped

Abstract Sea lions as a group, display strong site fidelity, and varying degrees of vulnerability to environmental change, disease and fisheries interactions. One of the rarest pinnipeds, the New Zealand sea lion (NZSL, Phocarctos hookeri) has a very restricted breeding range. At Campbell Island/Motu Ihupuku, one of the two primary breeding sites, at‐sea foraging behaviour is unknown. We hypothesised that NZSL of various sex and age classes would utilise the water column differently due to differing physiological constraints and therefore have different accessibility to prey resources. We tested whether sea lion diving behaviour varied in relation to (i) age and sex class, (ii) time of day and (iii) water depth. We also hypothesised that the proportion of benthic/pelagic diving, and consequently risk of fisheries interaction, would vary in relation to age and sex. Satellite telemetry tags were deployed on 25 NZSL from a range of age/sex classes recording dive depth, duration and location. Adult females and juveniles used inshore, benthic habitats, while sub‐adult males also utilised benthic habitats, they predominantly used pelagic habitat at greater distances from the island. Adult females and juveniles exhibited shorter dives than the same age/sex classes at the Auckland Islands, suggesting a lower dive effort for these age/sex classes at Campbell Island/Motu Ihupuku. Adult females dived more frequently than other age/sex classes, likely operating closer to their physiological limits; however, further data for this age class is needed. Sub‐adult male use of pelagic prey may increase their exposure to mid‐water trawls; however, further research detailing the degree of spatial overlap with fisheries is required. This study highlights the utility of spatially explicit dive data to predict vertical habitat use, niche separation of various age and sex classes of marine predators and attribute potential fisheries interaction risk in relation to predator habitat use

Hematologic and biochemical characteristics of stranded green sea turtles

To improve understanding of pathophysiologic processes occurring in green sea turtles (Chelonia mydas) stranded along the east coast of Australia, we retrospectively examined the hematologic and biochemical blood parameters of 127 green turtles admitted to 2 rehabilitation facilities, Dolphin Marine Magic (DMM) and Taronga Zoo (TZ), between 2002 and 2016. The predominant size class presented was small immature animals (SIM), comprising 88% and 69% of admissions to DMM and TZ, respectively. Significant differences in blood profiles were noted between facility, size, and outcome. Elevated levels of aspartate aminotransferase (AST) and heterophils were poor prognostic indicators in animals from TZ, but not DMM. SIM animals at both institutions had lower protein levels than large older (LO) animals. SIM animals at DMM also had lower hematocrit and monocyte concentration; SIM animals at TZ had lower heterophil counts. Urea was measured for 27 SIM animals from TZ, but the urea-to-uric acid ratio was not prognostically useful. Strong correlations were seen between AST and glutamate dehydrogenase (GDH; r = 0.68) and uric acid and bile acids (r = 0.72) in the 45 SIM animals from DMM in which additional analytes were measured. χ2 contingency tests showed that the most recently published reference intervals were not prognostically useful. A paired t-test showed that protein levels rose and heterophil numbers fell in the 15 SIM animals from TZ during the rehabilitation process. Our results indicate that further work is required to identify reliable prognostic biomarkers for green turtles

Assessing the utility of two-and three-dimensional behavioural metrics in habitat usage models

For deep-diving, wide-ranging marine predators, foraging behaviour is often inferred from movement data. Various metrics are used to do this, and recently, metrics have been developed that consider both horizontal movement and vertical dive behaviour to better describe the use of the 3-dimensional environment these animals inhabit. However, the efficacy of these different metrics in predicting behavioural state is poorly understood. We used first passage time (2-dimensional) and first bottom time (3-dimensional) analyses on tracks derived from satelliterelayed data loggers to quantify and determine seal behavioural state while foraging at sea. Movement and dive data were collected from 38 southern elephant seals Mirounga leonina from Macquarie and Campbell Islands (in the Pacific sector of the Southern Ocean). Using a suite of environmental variables, linear mixed-effect models were derived for the 2 broad habitats visited by the seals: shelf and open ocean. The best-fitting models for each foraging metric in each habitat were then compared using a cross validation analysis to identify which foraging metric produced the best predictions of habitat use. In shelf habitats, the 3-dimensional foraging metric provided better predictions than the 2-dimensional metric, while the 2-dimensional foraging metric resulted in the best predictive capacity in the open ocean habitats. These findings highlight the importance of considering the appropriate foraging metrics when modelling foraging behaviour.12 page(s