David SlipTaronga Conservation Society Australia
David Slip
About
80
Publications
14,630
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,482
Citations
Citations since 2017
Publications
Publications (80)
Coastal pelagic ecosystems are highly variable in space and time, with environmental conditions and the distribution of biomass being driven by complex processes operating at multiple scales. The emergent properties of these processes and their interactive effects result in complex and dynamic environmental mosaics referred to as “seascapes”. Mecha...
We describe the Australian Shark-Incident Database, formerly known as the Australian Shark-Attack File, which contains comprehensive reports of 1,196 shark bites that have occurred in Australia over 231 years (1791–2022). Data were collated by the Taronga Conservation Society Australia using purpose designed questionnaires provided to shark-bite vi...
RATIONALE The use of sulfur isotopes to study trophic ecology in marine ecosystems has increased in the last decade. Unlike other commonly used isotopes (e.g., carbon), sulfur can better discriminate benthic and pelagic productivity. However, how lipid extraction affects sulfur isotopic values has not been assessed, despite its frequent use to remo...
Shark bites on humans are rare but are sufficiently frequent to generate substantial public concern, which typically leads to measures to reduce their frequency. Unfortunately, we understand little about why sharks bite humans. One theory for bites occurring at the surface, e.g. on surfers, is that of mistaken identity, whereby sharks mistake human...
Land transformation for anthropogenic use is the leading cause of species decline globally. However, few species are able to succeed in anthropogenically disturbed environments. African clawless otters (Aonyx capensis) occur in a wide variety of habitats, and thus are good model species to investigate animal adaptation to anthropogenic environments...
Individual specialization, which describes whether populations are comprised of dietary generalists or specialists, has profound ecological and evolutionary implications. However, few studies have quantified individual specialization within and between sympatric species that are functionally similar but have different foraging modes. We assessed th...
Modern pinnipeds (true and eared seals) employ two radically different swimming styles, with true seals (phocids) propelling themselves primarily with their hindlimbs, whereas eared seals (otariids) rely on their wing-like foreflippers.Current explanations of this functional dichotomy invoke either pinniped diphyly or independent colonizations of t...
Terrestrial and aquatic birds have been proposed as sentinels for the spread of antimicrobial resistant bacteria, but few species have been investigated as sentinels, specifically in the context of AMR in the marine ecosystem. This study contrasts the occurrence of class 1 integrons and associated antimicrobial resistance genes in wild and captive...
Context: Data obtained from camera traps are increasingly used to inform various population-level models. Although acknowledged, imperfect detection probabilities within camera-trap detection zones are rarely taken into account when modelling animal densities.
Aims: We aimed to identify parameters influencing camera-trap detection probabilities, a...
Physiology places constraints on an animal’s ability to forage and those unable to adapt to changing conditions may face increased challenges to reproduce and survive. As the global marine environment continues to change, small, air-breathing, endothermic marine predators such as otariids (fur seals and sea lions) and particularly females, who are...
The Cape Solander Whale Migration Study is a citizen science project that annually counts northward migrating humpback whales (Megaptera novaeangliae) off Cape Solander, Sydney, Australia. Dedicated observers have compiled a 20‐year data set (1997–2017) of shore‐based observations from Cape Solander's high vantage point. Using this long‐term data s...
Sexual segregation in foraging is often attributed to constraints arising from sexual size dimorphism, such as differing physiological abilities and energy requirements, or to reproductive commitments including nutritional requirements and behavioural limitations such as parental care. In species with sexual size dimorphism and a polygynous mating...
Background
Accurate time-energy budgets summarise an animal’s energy expenditure in a given environment, and are potentially a sensitive indicator of how an animal responds to changing resources. Deriving accurate time-energy budgets requires an estimate of time spent in different activities and of the energetic cost of that activity. Bio-loggers (...
Effective ecosystem-based management requires estimates of abundance and population trends of species of interest. Trend analyses are often limited due to sparse or short-term abundance estimates for populations that can be logistically difficult to monitor over time. Therefore it is critical to assess regularly the quality of the metrics in long-t...
Foraging site fidelity allows animals to increase their efficiency by returning to profitable feeding areas. However, the mechanisms underpinning why animals 'stay' or 'switch' sites have rarely been investigated. Here, we explore how habitat quality and prior prey capture experience influence short-term site fidelity by the little penguin (Eudyptu...
Background. Accurate time-energy budgets summarise an animal’s energy expenditure in a given environment and are potentially a sensitive indicator of how an animal responds to changing resources. Deriving accurate time-energy budgets requires a precise measure of time spent in different activities, and an estimate of the energetic cost of that acti...
Background. Accurate time-energy budgets summarise an animal’s energy expenditure in a given environment and are potentially a sensitive indicator of how an animal responds to changing resources. Deriving accurate time-energy budgets requires a precise measure of time spent in different activities, and an estimate of the energetic cost of that acti...
Direct measures of energy expenditure are difficult to obtain in marine mammals, and accelerometry may be a useful proxy. Recently its utility has been questioned as some analyses derived their measure of activity level by calculating the sum of accelerometry-based values and then comparing this summation to summed (total) energy expenditure (the s...
Energy expenditure of free-living fur seals and sea lions is difficult to measure directly, but may be indirectly derived from flipper stroke rate. We filmed 10 captive otariids swimming with accelerometers either attached to a harness (Daily Diary: sampling frequency 32Hz, N=4) or taped to the fur (G6a+: 25Hz, N=6). We used down sampling to derive...
Physiology may limit the ability for marine mammals to adapt to changing environments. Depth and duration of foraging dives are a function of total available oxygen stores, which theoretically increase as animals grow, and metabolic costs. To evaluate how physiology may influence the travelling costs for seals to foraging patches in the wild, we me...
Background
Semi-automating the analyses of accelerometry data makes it possible to synthesize large data sets. However, when constructing activity budgets from accelerometry data, there are many methods to extract, analyse and report data and results. For instance, machine learning is a robust approach to classifying data. We used a new method, sup...
Prey distribution acts at multiple spatial scales to influence foraging success by predators. The overall distribution of prey may shape foraging ranges, the distance between patches may influence the ability of predators to detect and move between profitable areas, and individual patch characteristics may affect prey capture efficiency. In this st...
Constructing activity budgets for marine animals when they are at sea and cannot be directly observed is challenging, but recent advances in bio-logging technology offer solutions to this problem. Accelerometers can potentially identify a wide range of behaviours for animals based on unique patterns of acceleration. However, when analysing data der...
Description and acceleration profile for 26 unique behaviours recorded.
Black line–x axis acceleration; grey line–y axis acceleration; orange line–z axis acceleration.
(PDF)
Pinnipeds generally target relatively small prey that can be swallowed whole, yet often include larger prey in their diet. To eat large prey, they must first process it into pieces small enough to swallow. In this study we explored the range of prey-processing behaviors used by Australian sea lions (Neophoca cinerea) when presented with large prey...
Biological markers (biomarkers) are invaluable and widely adopted in ecology, archaeology, and anthropology. Serially sampling biomarkers along continuously growing inert tissue, such as vibrissae, hair, nail, horn, or baleen, is an ideal method by which to capture the changes in an individual's diet, environment, climate, health, and stress levels...
The world's oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming "hotspots", we use a novel...
ABSTRACT: Migratory Group V (Stock E1) humpback whales Megaptera novaeangliaeare at riskof entanglement with fishing gear as they migrate north and south along the east coast of Aus-tralia. This study investigated the effectiveness of 2 distinct tones for use as an alarm to acousti-cally alert whales to fishing gear presence and therefore reduce th...
Abstract: How to manage the recovery of large vertebrates into areas with established human
populations is an increasingly vexing issue for conservation practice. This
has been particularly difficult for wide-ranging marine fauna due to limitations
in quantifying habitat use, life-history requirements and population growth. We
quantify spatial and...
How to manage the recovery of previously exploited large vertebrates with increasing range-incursions into areas with established human populations is an increasingly vexing issue for conservation practice. This has been particularly difficult for wide-ranging marine fauna due to limitations in quantifying habitat use, life-history requirements and...
Determining where, when and how much animals eat is fundamental to understanding their ecology. We developed a technique to identify a prey capture signature for little penguins from accelerometry, in order to quantify food intake remotely. We categorised behaviour of captive penguins from HD video and matched this to time-series data from back-mou...
ABSTRACT: Cetacean entanglements in fishing gear cost governments, fishermen and stakehold- ers millions of dollars a year, and often result in serious injury or death of the entangled animals. Entanglements have been implicated in preventing the recovery of some large whale populations. Acoustic deterrents on fishing nets are widely used to reduce...
Humpback whales (Megaptera novaeangliae) migrating along the east coast of Australia are exposed to a growing number of anthropogenic activities. We investigated the effects of three types of activities within the whale migratory corridor off Sydney; (1) vessels, (2) underwater construction and (3) fisheries mitigation. Observational and spatial da...
The extensive territorial waters of Australia and New Zealands (NZ) (over 8 million km2 for Australia and a further 4 million km2 for NZ) are home to approximately 49 species of whales and dolphins, 11 species of seals and the dugong. Within Australia, at least eight species are listed as threatened, though there is insufficient information on a fu...
The recovering population of Group V (stock E1) humpback whales (Megaptera novaeangliae) is exposed to a growing number of anthropogenic activities as they migrate along the east coast of Australia. This study investigated the effects of three types of activities within the whale migratory corridor off Sydney, Australia; (1) vessels, (2) underwater...
While males and females may co-exist in the same habitat, sexual segregation in foraging behaviour is common among vertebrates. It is usually attributed to physiological differences, trophic niche divergence, size dimorphism, or reproductive role specialisation, and is ubiquitous in adult otariids. We investigated whether sexual segregation in fora...
Migratory Group V (stock E1) humpback whales (Megaptera novaeangliae) annually risk entanglement with fishing gear along the east coast of Australia. Around Australia, types of fishing gear that cause whale entanglements include longlines, gillnets, lobster pots, crab pots and shark nets. Whale entanglement mitigation measures can have two approach...
The largest southern hemisphere humpback whale Megaptera novaeangliae stock
(E1) uses the east coast of Australia as a migratory corridor to travel between their high-latitude
feeding grounds in the Southern Ocean and low-latitude breeding grounds in northeast Queensland
and the south-west Pacific Ocean. The population is recovering at close to the...
Stomach contents were lavaged from 76 southern elephant seals (Mirounga leonina) at Heard Island between July 1992 and March 1993. Eighty-six percent of stomachs contained cephalopods of 17 species. Numerically the most important was Psychroteuthis glacialis (21.1%), and from estimated biomass the most important was Kondakovia longimana (40.4%). Th...
Geolocating-time-depth-temperature-recorders (GLTDTR) provided a continuous record of diving behaviour in relation to water temperature for ten female southern elephant seals from Macquarie Island during their post-breeding trips to sea. Four water bodies were determined from depth/temperature profiles recorded by the GLTDTRs. These water bodies co...
Geolocating-time-depth-temperature-recorders (GLTDTR) provided a continuous record of diving behaviour in relation to water temperature for ten female southern elephant seals from Macquarie Island during their post-breeding trips to sea, Four water bodies were determined from depth/temperature profiles recorded by the GLTDTRs. These water bodies co...
Southern elephant seals (Miroungo leonina) were immobilised with a mixture of tiletamine and zolazepam administered intravenously at a mean (sd) dose rate of 0.46 (0.08) mg/kg. This dose provided a satisfactory degree of anaesthesia with no side effects, and the induction, duration and recovery times were short. The mean (sd) induction time was 26...
The ability to forage successfully during their first trip to sea is fundamental to the ultimate survival of newly weaned southern elephant seals (Mirounga leonina). However, there is considerable variation in the body mass and fat content of seal pups at weaning, which results in some individuals having larger energy and oxygen stores than others,...
The ability to forage successfully during their first trip to sea is fundamental to the ultimate survival of newly weaned southern elephant seals (Mirounga leonina). However, there is considerable variation in the body mass and fat content of seal pups at weaning, which results in some individuals having larger energy and oxygen stores than others,...
. The number of predators from Heard Island foraging in shelf waters, their prey requirements, and the proportion of their
diet that was commercial and non-commercial fish were estimated. The calculated annual consumption of commercial fish species
varied between 36,360 and 84,166 tonnes. The non-commercial Krefftichthys anderssoni was the preferre...
CLOSE ENCOUNTERS OF FOUR KINDS: MOVEMENT PATTERNS OF RECENTLY WEANED ELEPHANT SEAL PUPS FROM MACQUARIE ISLAND.
(1) Fedak , M.A., (1) McConnell, B.J., (2)Slip, D.J., (3)Hindell M.A., (4) Reijnders, P.J. (5) Burton, H.R.
(1) Sea Mammal Research Unit, University of St Andrews, Scotland KY16 8LB UK
(2,5) Australian Antarctic Division, Channel Hwy, Ki...
We compared intravenous and intramuscular administrations of ketamine and diazepam to immobilize juvenile (8 to 24-month-old) southern elephant seals (Mirounga leonina), to determine the most appropriate method for immobilizing seals to a level required for stomach flushing or attaching electronic activity recorders. With intravenous injections, ti...
The use of doxapram to stimulate breathing was examined in southern elephant seals chemically restrained with ketamine and xylazine. Animals which were breathing spontaneously received doxapram (approximately 0.5, 1, 2, or 4 mg/kg) or saline into the extradural intravertebral vein. Doxapram caused a dose-dependent increase in the depth and rate of...
Stomach contents were lavaged from 76 M. leonina. Eighty-six percent of stomachs contained cephalopods of 17 species. Sixty-six percent of stomachs contained fish remains. The diet of adults differed from that of juveniles, particularly pups in their first year. Smaller seals ate smaller squid. The species and size of cephalopods eaten by these sea...
Thirteen female southern elephant seals moulting at Macquarie Island lost an average of 4.460.80 kg/day (10.011.20g/kg/day). There was no significant difference between this rate of body mass loss and that reported for moulting female southern elephant seals from South Georgia. Moulting female southern elephant seals however exhibited larger mass s...
Blood samples collected from Leopard Seals, Hydrurga leptonyx, from Heard Island and Macquarie Island were surveyed electrophoretically for allozyme variation in blood proteins. Thirty four proteins encoded by a minimum of 39 genetic loci were surveyed; six of these were found to be polymorphic, but only one could be considered polymorphic at the 9...
The diving behaviour of 14 adult southern elephant seals was investigated using time depth recorders. Each of the seals performed some dives that were longer than its theoretical aerobic dive limit. Forty-four percent of all dives made by postmoult females exceeded the calculated limit compared with 7% of those made by postbreeding females and less...
The mass of subcutaneous fat was determined for 14 male southern elephant seals, Mirounga leonina, by a modified version of a previously described ultrasound model (Gales and Burton 1987). The new model took into account fat slumping and was more accurate than the first model. The accuracy of the new technique was assessed by flensing. Total body w...
The energetic requirements of male southern elephant seals, Mirounga leonina, were estimated from mass loss, and changes in blubber mass determined by ultrasound in 11 seals over the moulting fast. Mean rate of mass loss was 9.60+/-2.25 kg day-1 or 6.46+/-0.77 g kg-1 day-1, with about 63% of this lost as fat. Blubber was depleted by about 48% over...
Sections of coastline of Heard and Macquarie Islands were surveyed for marine debris in the summer of 1987–88 and 1989, respectively. These surveys were carried out at the same sites as previous surveys in 1986–87 at Heard Island, and in 1988 at Macquarie Island. The minimum rate of artefact accumulation was 13 objects per km of shoreline per year...
Fourteen time-depth-temperature recorders were recovered from adult southern elephant seals (Mirounga leonina) returning to Macquarie Island to breed or moult. The resulting temperature/depth profiles indicated that all four males spent most of their time in waters lying over the Antarctic Continental Shelf, whereas only one of ten females spent an...
Over 50 000 individual dive records collected by time-depth recorders were analysed with respect to sex of the seal, time of year and the approximate geographic location of the dive. Six distinct dive types were described on the basis of parameters such as the amount of time spent at the maximum depth of the dive, the rate of ascent and descent, an...
The total breeding population of Adelie penguins at the Windmill Islands region in 1989/90 was 93 092±9300 pairs at 14 breeding localities. The population has apparently increased by 209% since a survey in the early 1960s, a trend shared with many other breeding localities where long-term data are available. Relict colony areas (former breeding sit...
Analysis of specimens representing 13 species of Australasian pythons showed that females generally exceed males in average adult body size and mature at a higher proportion of mean adult snout-vent length (SVL). Reproductive biology is conservative, with all taxa apparently oviparous and with maternal attendance at the nest. Female reproductive cy...
One hundred eighty-one female and thirteen postweanling pup southern elephant seals (Mirounga leonina) were sedated using a combination of ketamine hydrochloride and xylazine hydrochloride. Physiological state had a profound effect on response of the animals to sedation. Physiologically stressed postlactation and postpartum cows had significantly l...
1.1. Miniature temperature-sensitive radiotransmitters were implanted surgically into eighteen adult diamond pythons and thermoregulation of these snakes studied in a large thermal gradient in the laboratory.2.2. Unfed diamond pythons selected temperatures in the range 26–33°C. Selected body temperature changed after feeding, with mean temperatures...
Temperature-sensitive radiotransmitters were implanted in 18 free-ranging diamond pythons (Morelia spilota), and the snakes monitored for 4-34 mo. Body temperatures rose during a period of morning basking to between 28 and 30 C then fell gradually until the following morning. Unlike many other heliothermic reptiles, diamond pythons generally showed...
Miniature radio transmitters were surgically implanted in 15 adult diamond pythons from two areas
near Sydney, N.S.W., in south-eastern Australia, and the snakes monitored for intervals of 4-32
months. We document patterns of habitat use and movements, and interpret these in terms of the
feeding habits and reproductive biology of the pythons. These...
Both sexes mature at about 150 cm snout-vent length (SVL) prior to copulation. Reproductive activities occurred in spring (late September to early November). Two to 6 males aggregated around a single female; >1 male was seen to copulate with the same female, in the presence of other males. Mating aggregations lasted from 4-6 wk. Females oviposited...
Projects
Projects (2)
Warming waters due to strengthening western boundary currents have unknown consequences for coastal marine food webs. This project aims to integrate data on oceanographic conditions and fish distribution with the foraging patterns and breeding success of seabirds. The project is significant for understanding the effects of climate change on marine food webs, from plankton production to predation by iconic marine fauna. Innovative prey capture signatures from accelerometers, together with advanced movement models from satellite locations will be used to show how fish schools are located and preyed upon by predators. The outcome will be new insight into how changing resource availability in the oceans affects ecosystem resilience.