A large-scale automated radio telemetry network for monitoring movements of terrestrial wildlife in Australia

Technologies for remotely observing animal movements have advanced rapidly in the past decade. In recent years, Australia has invested in an Integrated Marine Ocean Tracking (IMOS) system, a land ecosystem observatory (TERN), and an Australian Acoustic Observatory (A2O), but has not established movement tracking systems for individual terrestrial animals across land and along coastlines. Here, we make the case that the Motus Wildlife Tracking System, an open-source, rapidly expanding cooperative automated radio-tracking global network (Motus, https://motus.org) provides an unprecedented opportunity to build an affordable and proven infrastructure that will boost wildlife biology research and connect Australian researchers domestically and with international wildlife research. We briefly describe the system conceptually and technologically, then present the unique strengths of Motus, how Motus can complement and expand existing and emerging animal tracking systems, and how the Motus framework provides a much-needed central repository and impetus for archiving and sharing animal telemetry data. We propose ways to overcome the unique challenges posed by Australia’s ecological attributes and the size of its scientific community. Open source, inherently cooperative and flexible, Motus provides a unique opportunity to leverage individual research effort into a larger collaborative achievement, thereby expanding the scale and scope of individual projects, while maximising the outcomes of scant research and conservation funding

Hunting between the air and the water : the Australasian gannet (Morus serrator) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Auckland, New Zealand

Appendix 1 and 2 removed due to copyright restrictions: Machovsky Capuska, G.E., Huynen, L., Lambert, D., Raubenheimer, D. (2011), UVS is rare in seabirds, Vision Research, 51, 1333-1337 Shuckard, R., Melville, D.S., Cook, W., Machovsky Capuska, G.E. (2012), Diet of the Australasian gannet (Morus serrator) at Farewell Spit, New Zealand, Notornis, 59, 66-70Australasian gannets (Morus serrator) are the second rarest member of the seabird group Sulidae. Among the three species of gannets worldwide, they are the only species that regularly breeds in southeastern Australia and New Zealand. Like all gannets, M. serrator face considerable challenges in foraging, relying on sparsely and patchily distributed pelagic prey, which move in a 3D environment. Whereas most predators are specialise hunters in one media, gannets have to hunt within a complex air-water interface. The aim of the present thesis is to examine the hunting strategies of Australasian gannets, with particular emphasis on how these birds use both aerial and aquatic adaptations to locate and capture prey. The acquisition of information concerning food sources was analysed using GPS data loggers, field observations and high resolution video footage. I tested the hypothesis that gannets obtain information of food resources from their partners using bill fencing as referential signals analogous to the waggle dance in honeybees (Apis mellifera) (Chapter 2). Results did not support this hypothesis but suggested that Australasian gannets use a combination of strategies, probably including memory that facilitates their return to locations where prey was previously captured (Chapter 3) and local enhancement to locate active feeding sites (Chapter 2). The impact of intraspecific competition for local resources was studied between large (Cape Kidnappers, 7,300 breeding pairs) and small (Farewell Spit, 3,900 breeding pairs) colonies in New Zealand using GPS data loggers (Chapter 3). Results indicated that gannets from the larger colony invested more in foraging (greater foraging times and foraging distances). This is consistent with previous studies of other gannet species, suggesting that M. serrator experience intraspecific competition for food when living in large colonies. Pelagic prey are able to evade predation by descending to depths beyond the reach of diving birds. Among the adaptations evolved by gannets for dealing with this challenge is plunge-diving, where the bird uses gravity in the aerial phase of the hunt to gain speed and momentum for descending into the water column. I conducted a fine scaled analysis using videography of the aerial and aquatic phases of this highly specialised hunting strategy. Analysis of the aerial phase (Chapter 4) showed that the initiation of plunge dives are synchronised among members of foraging groups, suggesting a form of group-level behaviour in which gannets might benefit from the sensory experiences (prey detection) of conspecifics. The analysis also showed that gannets adapt the aerial phase of their dives in presence vs. absence of heterospecific predators. In the aquatic phase (Chapter 5), gannets perform short and shallow V-shaped dives and long and deep U-shaped dives in pursuit of pelagic fish and squid. My findings revealed that gannets adjusted their dive shape in relation to the depth of their prey rather than prey type, as previously hypothesised. Although the maximum number of prey captured per dive by the gannets was higher than previously reported, reaching up to five fish in a single U-shaped dive, the results presented herein suggest that the two dive profiles were equally profitable. To examine the role of underwater vision in prey capture, I used underwater video footage, photokeratometry and infrared video photorefraction (Chapter 6). Analysis of video footage confirmed that there are two distinct phases in the underwater component of plunge dives in Australasian gannets, an initial phase in which the bird is propelled through the water column by the momentum of the plunge (M phase) and a phase in which it is actively propelled by wing flapping (WF phase). The highest prey capture rate was observed during the WF phase, a result that suggests the use of vision in underwater prey pursuit. I therefore used photokeratometry and video photorefraction to test whether gannets are able to adapt optically in the transition from aerial to aquatic media. My measurements showed that underwater visual accommodation in the gannets was attained within 2 - 3 frames (80 - 120 ms) of submergence, a remarkably short timescale in relation to the optics of most vertebrate eyes. The preceding chapters demonstrate some highly effective behavioural and sensory capacities used by gannets in foraging. In Chapter 7 I demonstrate evidence of fatal injuries due to collision between conspecifics in plunge-diving Australasian and Cape gannets (M. capensis). The analysis also revealed a case of attempted underwater kleptoparasitism, in which a diving bird targeted a previously captured fish in the beak of another gannet. This novel observation suggests a further challenge for hunting gannets, namely to retain prey following the capture

Using non-systematic surveys to investigate effects of regional climate variability on Australasian gannets in the Hauraki Gulf, New Zealand

Few studies have investigated regional and natural climate variability on seabird populations using ocean reanalysis datasets (e.g. Simple Ocean Data Assimilation (SODA)) that integrate atmospheric information to supplement ocean observations and provide improved estimates of ocean conditions. Herein we use a non-systematic dataset on Australasian gannets (Morus serrator) from 2001 to 2009 to identify potential connections between Gannet Sightings Per Unit Effort (GSPUE) and climate and oceanographic variability in a region of known importance for breeding seabirds, the Hauraki Gulf (HG), New Zealand. While no statistically significant relationships between GSPUE and global climate indices were determined, there was a significant correlation between GSPUE and regional SST anomaly for HG. Also, there appears to be a strong link between global climate indices and regional climate in the HG. Further, based on cross-correlation function coefficients and lagged multiple regression models, we identified potential leading and lagging climate variables, and climate variables but with limited predictive capacity in forecasting future GSPUE. Despite significant inter-annual variability and marginally cooler SSTs since 2001, gannet sightings appear to be increasing. We hypothesize that at present underlying physical changes in the marine ecosystem may be insufficient to affect supply of preferred gannet main prey (pilchard Sardinops spp.), which tolerate a wide thermal range. Our study showcases the potential scientific value of lengthy non-systematic data streams and when designed properly (i.e., contain abundance, flock size, and spatial data), can yield useful information in climate impact studies on seabirds and other marine fauna. Such information can be invaluable for enhancing conservation measures for protected species in fiscally constrained research environments.Fil: Srinivasan, Mridula. National Marine Fisheries Service; Estados UnidosFil: Dassis, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Benn, Emily. University of Sydney; AustraliaFil: Stockin, Karen A.. Massey University; Nueva ZelandaFil: Martinez, Emmanuelle. Massey University; Nueva Zelanda. Pacific Whale Foundation; Estados UnidosFil: Machovsky Capuska, Gabriel E.. Massey University; Nueva Zelanda. University of Sydney; Australi

A nutritional perspective on plastic ingestion in wildlife

International audienceAlthough the perils of plastics to living organisms including humans have been neglected for decades, they have recently been recognized as a major environmental problem worldwide. Little progress has been made on understanding the factors that drive species' and populations' susceptibilities to the ingestion of plastic. Here, we propose using nutritional ecology as a multidisciplinary framework for bridging the gaps that link nutrition, behavior, plastics, physiology and ecology. We show that nutritional niches are tightly linked to plastic ingestion, illustrating the application of our framework in the context of nutritional niche theory, habitat-specific foraging from species to populations, and transfer patterns in food webs

Eat yourself sexy: how selective macronutrient intake influences the expression of a visual signal in common mynas

Producing colored signals often requires consuming dietary carotenoid pigments. Evidence that food deprivation can reduce coloration, however, raises the question of whether other dietary nutrients contribute to signal coloration, and furthermore, whether individuals can voluntarily select food combinations to achieve optimal coloration. We created a two-way factorial design to manipulate macronutrient and carotenoid access in common mynas (Acridotheres tristis) and measured eye patch coloration as a function of the food combinations individuals selected. Mynas had access to either water or carotenoid-supplemented water and could either eat a standard captive diet or choose freely between three nutritionally defined pellets (protein, lipid or carbohydrate). Mynas supplemented with both carotenoids and macronutrient pellets had higher color scores than control birds. Male coloration tended to respond more to nutritional manipulation than females, with color scores improving in macronutrient- and carotenoid-supplemented individuals compared with controls. All mynas consuming carotenoids had higher levels of plasma carotenoids, but only males showed a significant increase by the end of the experiment. Dietary carotenoids and macronutrient intake consumed in combination tended to increase plasma carotenoid concentrations the most. These results demonstrate for the first time that consuming specific combinations of macronutrients along with carotenoids contributes to optimizing a colorful signal, and point to sex-specific nutritional strategies. Our findings improve our knowledge of how diet choices affect signal expression and, by extension, how nutritionally impoverished diets, such as those consumed by birds in cities, might affect sexual selection processes and, ultimately, population dynamics

The contribution of private and public information in foraging by Australasian gannets

International audiencePredators that forage on foods with temporally and spatially patchy distributions may rely on private or public sources of information to enhance their chances of foraging success. Using GPS tracking, field observations, and videography, we examined potential sites and mechanisms of information acquisition in departures for foraging trips by colonially breeding Australasian gannets (Morus serrator). Analyses of the bill-fencing ceremony between mated pairs of breeding gannets did not detect correlations between parameters of this reciprocal behavior and foraging trips, as would have been predicted if gannets used this behavior as a source of private information. Instead, 60 % of the departing birds flew directly to join water rafts of other conspecific en route to the feeding grounds. The departure of solitary birds from the water rafts was synchronized (within 60 s) with the arrival of incoming for-agers and also among departing birds. Furthermore, solitary departing birds from the rafts left in the same directional quadrant (908 slices) as the prior arriving (67 %) and also prior departing forager (79 %). When associated plunge dives of conspecific were visible from the colony, providing a public source of information, gannets more often departed from the water rafts in groups. Our study thus provides evidence for the use of water rafts, but not the nest site, as locations of information transfer, and also confirms the use of local enhancement as a strategy for foraging flights by Australasian gannets

Stable isotope signatures and nutritional composition data for juvenile white sharks (Carcharodon carcharias) and their prey

Individual foraging niche specialisation is recognised as an important determinant of ecological structure and function, particularly for species with high per-capita trophic influence like marine apex predators. Stable isotopes provide a powerful approach to understand the mechanisms and consequences of niche specialisation, especially in cryptic predators, yet have poor resolution for incorporating nutrition, which is a critical aspect of foraging interactions. Multidimensional nutritional ecology compartmentalises foods and diets as mixtures of nutrients (e.g. proteins, lipids, carbohydrates) to draw mechanistic links between individual nutrition, physiology, behaviour and fitness, the drivers of foraging decisions and their trophic implications. Yet difficulties in establishing time-integrated nutrient intakes has hampered progress in predator nutritional ecology. We employed a novel approach integrating stable isotopes and a multidimensional nutritional niche framework to investigate individual diet specialisation across multiple niche realisations in juvenile white sharks (Carcharodon carcharias). We sampled tooth files to generate individual isotopic profiles (δ13C, δ15N, δ34S) and characterise individual isotopic niches (δ-space). We then contextualised isotopic specialisation patterns by estimating individual prey use (p-space) using Bayesian mixing models, and further combined this with nutritional geometry framework models to quantify the nutritional dimension (N-space) of individual specialisation. Isotopic analyses indicated that juvenile white sharks mostly foraged as individual specialists within a broader, generalist, population niche. Mixing models showed individual differences in the consumption of dolphin, shark and batoid prey (rays), which comprised much of the overall diet. Despite δ-space and p-space variance, modelled nutrient intakes were similar for most sharks, which may suggest complementary feeding on nutritionally disparate prey among individual sharks towards a particular nutritional goal. Our approach helps to address the challenges of estimating time-integrated nutrient intakes in cryptic species, expanding our knowledge of individual diet specialisation into a nutritional dimension and revealing how specialisations may differ across niche realisations (prey use and nutritional niches). We argue that this can facilitate stronger links between individual diet specialisation, its intrinsic (e.g. nutritional goals, fitness) and extrinsic (e.g. trophic dynamics) outcomes

Sexual segregation in tropical seabirds: drivers of sex-specific foraging in the Brown Booby Sula leucogaster

Sexual segregation in the behaviour, morphology or physiology of breeding seabirds can be related to divergent parental roles, foraging niche partitioning or sex-specific nutritional requirements. Here we combine GPS tracking, dietary and nutritional analysis to investigate sex-specific foraging of Brown Boobies breeding on Raine Island, Great Barrier Reef, Australia. We observed sex-specific segregation in: a) foraging location: females undertook longer trips, foraging at more distant locations than males; b) foraging time: male activity and foraging occurred throughout the day, while female activity and foraging increased from midday to an afternoon peak; and c) prey type, females mostly consumed flying fish, whereas males consumed equal proportions of flying fish and squid. Brown Booby diets contained five tropical prey species that significantly differed in their nutritional composition (Protein, Lipid and Water, wet mass). Despite this variation we found no differences in the overall nutritional content of prey caught by each sex. The observed sex-specific differences in prey type, location and time of capture are likely driven by a combination of a division of labour, risk partitioning and competition. However, Brown Boobies breeding on Raine Island, and other populations, might flexibly partition foraging niche by sex in response to varying competitive and environmental pressures. In light of such potential foraging dynamism, our inconclusive exploration of nutritional segregation between sexes warrants further investigation in the species

Linking cadmium and mercury accumulation to nutritional intake in common dolphins (Delphinus delphis) from Patagonia, Argentina

Bioaccumulation of Hg and Cd from food is a complex ecological process that has been oversimplified in the past. Common dolphins (Delphinus delphis) provide a powerful model to biomonitor metal concentrations in marine environments worldwide. We combined proportions-based nutritional geometry with metal analysis, stomach content analysis and the proximate composition of prey, to yield novel insights into the accumulation of Hg and Cd. Our analysis showed an age-related accumulation trend for Cd and Hg in kidney and liver, with highest concentrations found at 18 years of age. When view through the lens of nutritional ecology, Argentine anchovy (58.1 Mass %) and South American long-finned squid (22.7 Mass %), provided most of the dietary intake of protein (P) and lipids (L) (P:L ratio = 2.6:1.0) and also represented the main source for Cd and Hg levels accumulated in their bodies. This study presents unprecedented evidence on metal accumulation in relation to age and nutritional intake in a marine predator.Fil: Machovsky-capuska, Gabriel. University of Sydney; Estados UnidosFil: von Haeften, Gabriela. No especifíca;Fil: Romero, Maria Alejandra. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; ArgentinaFil: Rodríguez, Diego Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Gerpe, Marcela Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Marinas. Laboratorio de Ecotoxicología; Argentin