Hector's dolphins (Cephalorhynchus hectori) produce both narrowband high-frequency and broadband acoustic signals

Odontocetes produce clicks for echolocation and communication. Most odontocetes are thought to produce either broadband (BB) or narrowband high-frequency (NBHF) clicks. Here, we show that the click repertoire of Hector's dolphin (Cephalorhynchus hectori) comprises highly stereotypical NBHF clicks and far more variable broadband clicks, with some that are intermediate between these two categories. Both NBHF and broadband clicks were made in trains, buzzes, and burst-pulses. Most clicks within click trains were typical NBHF clicks, which had a median centroid frequency of 130.3 kHz (median -10 dB bandwidth = 29.8 kHz). Some, however, while having only marginally lower centroid frequency (median = 123.8 kHz), had significant energy below 100 kHz and approximately double the bandwidth (median -10 dB bandwidth = 69.8 kHz); we refer to these as broadband. Broadband clicks in buzzes and burst-pulses had lower median centroid frequencies (120.7 and 121.8 kHz, respectively) compared to NBHF buzzes and burst-pulses (129.5 and 130.3 kHz, respectively). Source levels of NBHF clicks, estimated by using a drone to measure ranges from a single hydrophone and by computing time-of-arrival differences at a vertical hydrophone array, ranged from 116 to 171 dB re 1 μPa at 1 m, whereas source levels of broadband clicks, obtained from array data only, ranged from 138 to 184 dB re 1 μPa at 1 m. Our findings challenge the grouping of toothed whales as either NBHF or broadband species.

Impact of pile-driving on Hector's dolphin in Lyttelton Harbour, New Zealand

Several dolphin species occur close inshore and in harbours, where underwater noise generated by pile-driving used in wharf construction may constitute an important impact. Such impacts are likely to be greatest on species such as the endangered Hector's dolphin (Cephalorhynchus hectori), which has small home ranges and uses this habitat type routinely. Using automated echolocation detectors in Lyttelton Harbour (New Zealand), we studied the distribution of Hector's dolphins using a gradient sampling design over 92 days within which pile-driving occurred on 46 days. During piling operations, dolphin positive minutes per day decreased at the detector closest to the piling but increased at the mid-harbour detector. Finer-grained analyses showed that close to the piling operation, detections decreased with increasing sound exposure level, that longer piling events were associated with longer reductions in detections, and that effects were long-lasting - detection rates took up to 83 h to return to pre-piling levels.

Underwater noise levels of pile-driving in a New Zealand harbour, and the potential impacts on endangered Hector's dolphins

Impact pile-driving generates loud underwater anthropogenic sounds, and is routinely conducted in harbours around the world. Surprisingly few studies of these sounds and their propagation are published in the primary literature. To partially redress this we studied pile-driving sounds in Lyttelton Harbour, New Zealand, during wharf reconstruction after earthquake damage. That Lyttelton harbour is routinely used by Hector's dolphins (Cephalorhynchus hectori), an endangered species found only in New Zealand, provided further context for this study. Steel piles of 0.61 or 0.71 m diameter were driven using three different pile-drivers. Maximum calculated source SEL was 192 dB re 1 μPa²s @ 1 m (SPL_0-p of 213 dB re 1 μPa @ 1 m). Propagation of piling noise was strongly influenced by harbour bathymetry and a rock breakwater near the piling operation. We calculated range estimates at which Hector's dolphins may suffer temporary hearing threshold shift and behavioural change.

Quantitative analysis of the acoustic repertoire of southern right whales in New Zealand

Quantitatively describing the acoustic repertoire of a species is important for establishing effective passive acoustic monitoring programs and developing automated call detectors. This process is particularly important when the study site is remote and visual surveys are not cost effective. Little is known about the vocal behavior of southern right whales (Eubalaena australis) in New Zealand. The aim of this study was to describe and quantify their entire vocal repertoire on calving grounds in the sub-Antarctic Auckland Islands. Over three austral winters (2010-2012), 4349 calls were recorded, measured, and classified into 10 call types. The most frequently observed types were pulsive, upcall, and tonal low vocalizations. A long tonal low call (≤15.5 s duration) and a very high call (peak frequency ∼750 Hz) were described for the first time. Random Forest multivariate analysis of 28 measured variables was used to classify calls with a high degree of accuracy (82%). The most important variables for classification were maximum ceiling frequency, number of inflection points, duration, and the difference between the start and end frequency. This classification system proved to be a repeatable, fast, and objective method for categorising right whale calls and shows promise for other vocal taxa.

Upstream migratory behaviour of wild and ranched Atlantic salmon Salmo salar at a natural obstacle in a coastal spate river

The upstream migratory behaviour of wild and ranched Atlantic salmon Salmo salar in a small Irish coastal spate river was investigated using acoustic telemetry. Prespawning migratory behaviour was investigated including movement patterns at a large natural waterfall in the lower reaches of the river. A strong diurnal pattern was observed for upstream migrants at the waterfall indicative of the need for daylight to ascend this complex natural obstacle to migration. Successful passage of the waterfall was also associated with distinct environmental conditions and no difference in migratory ability was detected between wild and ranched origin S. salar. Wild S. salar tended to exhibit a non-erratic, stepwise upstream migration pattern after ascending the waterfall while ranched S. salar had an increased probability of displaying more erratic migratory behaviour. Wild S. salar penetrated further into the river catchment than ranched S. salar, although male ranched S. salar exhibited the greatest cumulative distance moved prior to the spawning period. The management implications of escaped or released ranched S. salar and movement at natural obstacles are discussed.

Acoustically derived growth rates of sperm whales (Physeter macrocephalus) in Kaikoura, New Zealand

A non-invasive acoustic method for measuring the growth of sperm whales was developed based on estimating the length of individuals by measuring the inter-pulse interval (IPI) of their clicks. Most prior knowledge of growth in male sperm whales has come from from fitting growth curves to length data gained from whaling. Recordings made at Kaikoura, New Zealand, were used to estimate the length and growth of 32 photographically identified, resident whales that have been recorded repeatedly between 1991 and 2009. All whales recorded more than six months apart (n = 30) showed an increase in IPI. Using established relationships between IPI and total length, it was found that the average growth rate in the Kaikoura population is lower, especially for smaller whales (13-14.5 m), than that derived from historical whaling data from other populations. This difference may be due to ecological differences among populations but might also reflect upward bias in measurements gained in whaling. The ability to track growth of individuals through time is only possible via non-lethal means and offers a fundamentally different kind of data because differences among individuals can be measured.

Laser photogrammetry to determine dorsal fin size in a population of bottlenose dolphins from Doubtful Sound, New Zealand

Laser photogrammetry (also known as laser-metrics) can provide valuable morphological data but the measurement error associated with the technique has not been quantified. Here laser-metrics were used to measure the dorsal fins of an entire resident population of bottlenose dolphins (Tursiops truncatus) from Doubtful Sound, New Zealand. Dorsal fin base length, height and surface area were measured from dorsal fin photographs. Sources of measurement error were estimated by repeatedly measuring multiple photographs of dorsal fins of known individuals. Measurement error accounted for less than 6% of the total variation in dorsal fin base length and height, indicating that the technique was repeatable. Adults were the only age-class to express sexual dimorphism, with males significantly larger than females in all measurements. The relationship between dorsal fin height and base length was significantly different between male and female adults: dorsal fins of males were proportionately taller. Laser photogrammetry is an inexpensive and non-invasive measurement technique that can provide valuable size data when used in conjunction with routine dorsal fin photo-identification studies.

New abundance estimates suggest Doubtful Sound bottlenose dolphins are declining

The bottlenose dolphins (Tursiops sp.) of Doubtful Sound, Fiordland, New Zealand, live at the southern limit of the species' worldwide range. They are subject to impacts from tourism and habitat modification. Photographic resightings of individually distinctive dolphins were gathered from 19 225 dorsal fin photographs taken during systematic surveys of the fiord. Field effort spanned nine seasons from summer 2004/2005 to summer 2006/2007, including 142 days on the water. Both capture-recapture and census approaches were taken in analysis. A total of 71 individuals were observed over the study period (54 adults, sub-adults and calves more than one year old and 17 newborn calves). Births were seasonal, occurring in the Austral summer and autumn, with calf survival (9 survivors of 17 births) lower than observed for this population in the past. Individual dolphins were resighted frequently within and across seasons, confirming the group is resident within the fiord year-round. Fifty-six bottlenose dolphins (CV=1.0%) were resident in Doubtful Sound in summer 2006/2007. Comparison with prior abundance estimates (for adults and sub-adults) indicates an apparent population decline of 34?39% over the past 12 years. This apparent decline suggests that precautionary management of human impacts is vital for the dolphins' long-term survival.

Click rates and silences of sperm whales at Kaikoura, New Zealand

Analysis of the usual click rates of sperm whales (Physeter macrocephalus) at Kaikoura, New Zealand, confirms the potential for assessing abundance via "click counting." Usual click rates over three dive cycles each of three photographically identified whales showed that 5 min averages of usual click rate did not differ significantly within dives, among dives of the same whale or among whales. Over the nine dives (n= 13 728 clicks) mean usual click rate was 1.272 clicks s(-1) (95% CI= 0.151). On average, individual sperm whales at Kaikoura spent 60% of their time usual clicking in winter and in summer. There was no evidence that whale identity or stage of the dive recorded affects significantly the percentage of time spent usual clicking. Differences in vocal behavior among sperm whale populations worldwide indicate that estimates of abundance that are based on click rates need to based on data from the population of interest, rather than from another population or some global average.

Measuring sperm whales from their clicks: stability of interpulse intervals and validation that they indicate whale length

Multiple pulses can often be distinguished in the clicks of sperm whales (Physeter macrocephalus). Norris and Harvey [in Animal Orientation and Navigation, NASA SP-262 (1972), pp. 397-417] proposed that this results from reflections within the head, and thus that interpulse interval (IPI) is an indicator of head length, and by extrapolation, total length. For this idea to hold, IPIs must be stable within individuals, but differ systematically among individuals of different size. IPI stability was examined in photographically identified individuals recorded repeatedly over different dives, days, and years. IPI variation among dives in a single day and days in a single year was statistically significant, although small in magnitude (it would change total length estimates by <3%). As expected, IPIs varied significantly among individuals. Most individuals showed significant increases in IPIs over several years, suggesting growth. Mean total lengths calculated from published IPI regressions were 13.1 to 16.1 m, longer than photogrammetric estimates of the same whales (12.3 to 15.3 m). These discrepancies probably arise from the paucity of large (12-16 m) whales in data used in published regressions. A new regression is offered for this size range.

Abundance and seasonal residence of sperm whales at Kaikoura, New Zealand

Photographic identification was used to document patterns of occurrence of individual sperm whales in the deep nearshore waters off Kaikoura, New Zealand. Between 1988 and 1993, 86 individuals were identified from nicks and marks in the trailing edge of their flukes. All individuals photographed were uniquely identifiable and no substantial changes in mark occurred over the study period. Resightings show that some whales spend several weeks or months in the area. Half have been seen in more than one field season. One individual has been seen every year from winter 1989 to winter 1992, and like several others appears to return to the area regularly. Others (35%) have been photographed on 1 day only and may be transients. Almost all (88%) of our sightings were of single whales. We used "open" capture–recapture models to estimate the size of the population that visits Kaikoura. These models suggest an average population of between 60 and 108 individuals present in any one season.

Long-stay versus short-stay hospital treatment of children suffering from severe protein-energy malnutrition

OBJECTIVE

To contrast early discharge versus attempted full nutritional rehabilitation in hospital of children suffering from severe protein-energy malnutrition (PEM).

DESIGN

Field experiment, two-way analysis of variance with one between group (short- versus long-stay) and one repeated measures factor (admission, then 12, 18, 24, 30 and 36 months post-admission). Covariates introduced.

SETTING

Primary health care, Kingston, Jamaica.

SUBJECTS

n = 81; mean age 11 months; 79 contribute longitudinal data; 44 every measurement.

INTERVENTIONS

When concurrent illnesses had been treated and normal feeding re-established (weight gain 5 g/kg.day-1), subjects were randomly allocated to short-stay (SS) or long-stay (LS) group. LS retained in hospital for full nutritional rehabilitation mean 40 days). SS discharged immediately (mean 18 days) for standard Health Service care at home for 6 months plus high-energy supplement (3.31 MJ with 20.6 g protein daily) for first 3 months. After discharge LS received 6 months home care, but without supplementation.

RESULTS

Significant advantages for LS group on NCHS weight & length for age at discharge, and at 12, 18, 24 and for length also 30 months (P < 0.05 to P < 0.001). Weight advantage peaked at 12 and 18 months, length later at 18 and 24 months.

CONCLUSIONS

Contrary to earlier reports, full nutritional rehabilitation can be achieved in hospital for children suffering from PEM. Although in the long-term both groups move towards expected levels in their home community, a significant advantage maintained for approximately 2 years is developmentally advantageous during the critical time after weaning.

Associations among photographically identified Hector's dolphins

Associations among Hector's dolphins photographically identified in the waters off Banks Peninsula, New Zealand, were studied using cluster analyses of simple and half-weight association indices. In addition, we carried out a temporal analysis of association patterns, plotting changes in the standardized reassociation rate over time. Some individually identified Hector's dolphins were photographed in the study area in successive seasons and years, and appeared to be resident in the area. Social organization was characterized by relatively fluid association patterns, with little stability over periods longer than a few days. Both male and female Hector's dolphins interacted with a large number of other individuals, males more so than females. Association patterns and other evidence support the hypothesis that Hector's dolphins have a promiscuous mating system.

The abundance and distribution of bottlenosed dolphins (Tursiops truncatus) in Doubtful Sound, New Zealand

Photographic identification and standardized zigzag surveys were used to study the distribution and abundance of bottlenose dolphins in Doubtful Sound, New Zealand. Forty individuals were identified from nicks and markings on their dorsal fins. Chapman's and Bailey's modifications to the Lincoln–Petersen estimate and the computer program CAPTURE were used to estimate the number of marked individuals in the population, which ranged from 30 to 40 animals for three survey periods (two summers and a winter). The proportion of identifiable individuals in the population was assessed empirically as 65.5%. These data resulted in a total population estimate of approximately 58 individuals. The majority of the dolphins in the catalogue were found in each survey period, indicating their residency in the fiord. Movements of dolphins around the sound were not predictable, but there were areas in which dolphins were more likely to be found and other areas in which dolphins were never seen. However, there were no obvious seasonal or daily movement patterns.

Thrombolysis with systemically administered t-PA in a new venous thrombosis model

Early thrombosis of either the arterial or venous supply of a free flap or island pedicle flap results in total flap necrosis. Until very recently, the only option for flap salvage was surgical intervention and, often, revision of the vascular pedicle. Current advances in the pharmacologic treatment of coronary artery and deep leg vein thrombosis have kindled interest in the field of reconstructive surgery for pharmacologic treatment of thromboses that compromise flaps. In the past, there has been research on the local and systemic administration of thrombolytic agents for lysis of experimentally induced thrombi in various animal models. A new venous inversion graft thrombosis model is presented here, which possesses many advantages over previously employed research models. This study demonstrates thrombolysis with systemically administered tissue plasminogen activator (t-PA) in this model.

The effect of glutathione and vitamins A, C, and E on acute skin flap survival

Vitamins A, C, and E act as antioxidants and as free radical scavengers in biological systems. Glutathione is involved in several reactions in vitamin metabolism and also plays an important role in cell membrane protection against lipid peroxidation by free radicals. We sought to use these natural defense mechanisms against oxygen free radicals formed during reperfusion of ischemic skin flaps. An acute axial random skin flap model was utilized in the rat. Vitamins or glutathione were administered by oral gastric tube or intravenously in the perioperative period, and survival of the flap was measured at 1 week. Glutathione, beta-carotene, ascorbic acid and alpha-D-tocopherol showed mean flap survival of 84% to 89%, each of which was significantly improved over saline controls (67% p less than .0005). The mechanisms and biochemistry of these vitamins, and their interactions with other vitamins and with glutathione, are discussed, along with clinical implications of free radical scavenging and skin flap survival.