| surveillance for arboviral zoonoses in new zealand birds. | given the significant burden that emerging infectious diseases place on global economies and public health, the monitoring and mitigation of, and early response to, potential infectious diseases are of the highest priority. the objective of this study was to survey for known and other potential arboviral zoonoses in multiple bird species at four locations in new zealand. | 2013 | 24478919 |
| piroplasms of new zealand seabirds. | blood and ectoparasitic ticks were collected from migratory seabirds in new zealand, including australasian gannets (n = 13) from two sites and red-billed gulls (n = 9) and white-fronted terns (n = 2) from a third location. blood smears were screened for parasite presence by microscopy, while dna from blood samples was subjected to pcr for the presence of tick-transmitted protozoan haemoparasites belonging to the order piroplasmida. parasites were identified by comparing small subunit ribosomal ... | 2014 | 25204728 |
| mate replacement entails a fitness cost for a socially monogamous seabird. | studies of the selective advantages of divorce in socially monogamous bird species have unravelled extensive variation among different lineages with diverse ecologies. we quantified the reproductive correlates of mate retention, mate loss and divorce in a highly philopatric, colonially breeding biparental seabird, the australasian gannet morus serrator. estimates of annual divorce rates varied between 40-43% for m. serrator and were high in comparison with both the closely related morus bassanus ... | 2010 | 19921137 |
| habitat-specific foraging strategies in australasian gannets. | knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. while seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. australasian gannets (morus serrator) typically forage in continental shelf regions on small schooling prey. the present study used gps and video da ... | 2016 | 27305927 |
| sexual size dimorphism and body condition in the australasian gannet. | sexual size dimorphism is widespread throughout seabird taxa and several drivers leading to its evolution have been hypothesised. while the australasian gannet (morus serrator) has previously been considered nominally monomorphic, recent studies have documented sexual segregation in diet and foraging areas, traits often associated with size dimorphism. the present study investigated the sex differences in body mass and structural size of this species at two colonies (pope's eye, pe; point danger ... | 2015 | 26637116 |
| eating locally: australasian gannets increase their foraging effort in a restricted range. | during the breeding season, seabirds adopt a central place foraging strategy and are restricted in their foraging range by the fasting ability of their partner/chick and the cost of commuting between the prey resources and the nest. because of the spatial and temporal variability of marine ecosystems, individuals must adapt their behaviour to increase foraging success within these constraints. the at-sea movements, foraging behaviour and effort of the australasian gannet (morus serrator) was det ... | 2015 | 26369928 |
| the contribution of private and public information in foraging by australasian gannets. | predators 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 corr ... | 2014 | 24337907 |
| an increase in minimum metabolic rate and not activity explains field metabolic rate changes in a breeding seabird. | the field metabolic rate (fmr) of a free-ranging animal can be considered as the sum of its maintenance costs (minimum metabolic rate, mmr) and additional costs associated with thermoregulation, digestion, production and activity. however, the relationships between fmr and bmr and how they relate to behaviour and extrinsic influences is not clear. in seabirds, fmr has been shown to increase during the breeding season. this is presumed to be the result of an increase in foraging activity, stimula ... | 2013 | 23348943 |
| analyses of sex and individual differences in vocalizations of australasian gannets using a dynamic time warping algorithm. | the study of the evolution of sexual differences in behavioral and morphological displays requires analyses of the extent of sexual dimorphism across various sensory modalities. in the seabird family sulidae, boobies show dramatic sexual dimorphism in their vocalizations, and gannet calls have also been suggested to be dimorphic to human observers. this study aimed to evaluate the presence of sexually dimorphic calls in the australasian gannet (morus serrator) through the first comprehensive des ... | 2012 | 22894237 |
| visual accommodation and active pursuit of prey underwater in a plunge-diving bird: the australasian gannet. | australasian gannets (morus serrator), like many other seabird species, locate pelagic prey from the air and perform rapid plunge dives for their capture. prey are captured underwater either in the momentum (m) phase of the dive while descending through the water column, or the wing flapping (wf) phase while moving, using the wings for propulsion. detection of prey from the air is clearly visually guided, but it remains unknown whether plunge diving birds also use vision in the underwater phase ... | 2012 | 22874749 |
| locational differences in metal concentrations in feathers of australasian gannet (morus serrator) in new zealand. | levels of lead, cadmium, mercury, selenium, manganese and chromium were examined in breast feathers of australasian gannets (morus serrator) from new zealand waters, where they breed on coastal rocky stacks, islands, and occasionally coastal headlands. there were significant differences in the concentrations of all metals except mercury, with gannets from ninety mile beach having significantly lower levels of all metals than those from the other beaches. ninety mile beach is on the northern tip ... | 1994 | 24214007 |
| geographical, temporal and individual factors influencing foraging behaviour and consistency in australasian gannets. | foraging is a behaviour that can be influenced by multiple factors and is highly plastic. recent studies have shown consistency in individual foraging behaviour has serious ecological and evolutionary implications within species and populations. such information is crucial to understand how species select habitats, and how such selection might allow them to adapt to the environmental changes they face. five foraging metrics (maximum distance from the colony, bearing from the colony to the most d ... | 2020 | 32537184 |
| consistent sociality but flexible social associations across temporal and spatial foraging contexts in a colonial breeder. | when the consequences of sociality differ depending on the state of individual animals and the experienced environment, individuals may benefit from altering their social behaviours in a context-dependent manner. thus, to fully address the hypotheses about the role of social associations it is imperative to consider the multidimensional nature of sociality by explicitly examining social associations across multiple scales and contexts. we simultaneously recorded > 8000 associations from 85% of b ... | 2020 | 32314533 |
| factors influencing prey capture success and profitability in australasian gannets (morus serrator). | knowledge of the factors influencing foraging efficiency in top predators can provide insights into the effects of environmental variability on their populations. seabirds are important marine predators foraging in a highly temporally and spatially variable environment. while numerous studies have focussed on search time and its effects on foraging energetics in seabirds, relatively little is known about the factors influencing capture success and prey profitability in these predators. in the pr ... | 2020 | 31941701 |
| evidence of sociality in the timing and location of foraging in a colonial seabird. | social foraging behaviours, which range from cooperative hunting to local enhancement, can result in increased prey capture and access to information, which may significantly reduce time and energy costs of acquiring prey. in colonial species, it has been proposed that the colony itself may act as a site of social information transfer and group formation. however, conclusive evidence from empirical studies is lacking. in particular, most studies in colonial species have generally focussed on beh ... | 2018 | 29997186 |
| the nutritional nexus: linking niche, habitat variability and prey composition in a generalist marine predator. | our understanding of the niche concept will remain limited while the quantity and range of different food types eaten remain a dominant proxy for niche breadth, as this does not account for the broad ecological context that governs diet. linking nutrition, physiology and behaviour is critical to predict the extent to which a species adjusts its nutritional niche breadth at the levels of prey ("prey composition niche," defined as the range of prey compositions eaten) and diet ("realized nutrition ... | 2018 | 29873067 |