Measurements of foraging success in a highly pelagic marine predator, the northern elephant seal

Robinson, Patrick W.; Simmons, Samantha E.; Crocker, Daniel E.; Costa, Daniel P.

doi:10.1111/j.1365-2656.2010.01735.x

Cited by 90 publications

(116 citation statements)

References 75 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…Endurance capacity (stamina) for example requires investment in ventilation systems and oxygen transport systems, which define an individual's aerobic scope. This trait is known to influence success in demanding interactions [30][31][32][33]. In aggressive displays, for example, high-quality individuals that win fights tend to have greater stamina [32], and similar links between stamina and positive outcomes can also be seen in courtship behaviour [34] and in foraging [30,31].…”

Section: Introductionmentioning

confidence: 99%

Individual quality and personality: bolder males are less fecund in the hermit crabPagurus bernhardus

2015

View full text Add to dashboard Cite

One explanation for animal personality is that different behavioural types derive from different life-history strategies. Highly productive individuals, with high growth rates and high fecundity, are assumed to live life at a fast pace showing high levels of boldness and risk taking, compared with less productive individuals. Here, we investigate among-individual differences in mean boldness (the inverse of the latency to recover from a startling stimulus) and in the consistency of boldness, in male hermit crabs in relation to two aspects of life-history investment. We assessed aerobic scope by measuring the concentration of the respiratory pigment haemocyanin, and we assessed fecundity by measuring spermatophore size. First, we found that individuals investing in large spermatophores also had high concentrations of haemocyanin. Using doubly hierarchical-generalized linear models to analyse longitudinal data on startle responses, we show that hermit crabs vary both in their mean response durations and in the consistency of their behaviour. Individual consistency was unrelated to haemocyanin concentration or spermatophore size, but mean startle response duration increased with spermatophore size. Thus, counter to expectations, it was the most risk-averse individuals, rather than the boldest and most risk prone, that were the most productive. We suggest that similar patterns should be present in other species, if the most productive individuals avoid risky behaviour.

show abstract

Section: Introductionmentioning

confidence: 99%

Individual quality and personality: bolder males are less fecund in the hermit crabPagurus bernhardus

2015

View full text Add to dashboard Cite

show abstract

“…21 , to reduce the impact of abrupt transitions from 20.1 to þ0.1 m s 21 (see [44] for a detailed discussion). Finally, we fitted a cubic spline to the drift rate data using a built-in function (interpolate2) in IGOR Pro v. 6.04 (WaveMetrics Inc., Lake Oswego, OR, USA) to estimate the daily drift rate (as per [44]). Finally, the daily estimates of drift rates were used for comparisons with daily-averaged values of other parameters.…”

Section: (Iii) Estimating Seal Buoyancymentioning

confidence: 99%

“…After running the automated algorithm, we excluded 5.3 + 5.8% (mean + s.d.) of drift rates as outliers by visual inspection of dive shape [44]. 21 , to reduce the impact of abrupt transitions from 20.1 to þ0.1 m s 21 (see [44] for a detailed discussion).…”

Section: (Iii) Estimating Seal Buoyancymentioning

confidence: 99%

“…of drift rates as outliers by visual inspection of dive shape [44]. 21 , to reduce the impact of abrupt transitions from 20.1 to þ0.1 m s 21 (see [44] for a detailed discussion). Finally, we fitted a cubic spline to the drift rate data using a built-in function (interpolate2) in IGOR Pro v. 6.04 (WaveMetrics Inc., Lake Oswego, OR, USA) to estimate the daily drift rate (as per [44]).…”

Section: (Iii) Estimating Seal Buoyancymentioning

confidence: 99%

See 1 more Smart Citation

The foraging benefits of being fat in a highly migratory marine mammal

et al. 2014

Self Cite

View full text Add to dashboard Cite

Foraging theory predicts that breath-hold divers adjust the time spent foraging at depth relative to the energetic cost of swimming, which varies with buoyancy (body density). However, the buoyancy of diving animals varies as a function of their body condition, and the effects of these changes on swimming costs and foraging behaviour have been poorly examined. A novel animalborne accelerometer was developed that recorded the number of flipper strokes, which allowed us to monitor the number of strokes per metre swam (hereafter, referred to as strokes-per-metre) by female northern elephant seals over their months-long, oceanic foraging migrations. As negatively buoyant seals increased their fat stores and buoyancy, the strokes-per-metre increased slightly in the buoyancy-aided direction (descending), but decreased significantly in the buoyancy-hindered direction (ascending), with associated changes in swim speed and gliding duration. Overall, the round-trip strokes-per-metre decreased and reached a minimum value when seals achieved neutral buoyancy. Consistent with foraging theory, seals stayed longer at foraging depths when their round-trip strokes-per-metre was less. Therefore, neutrally buoyant divers gained an energetic advantage via reduced swimming costs, which resulted in an increase in time spent foraging at depth, suggesting a foraging benefit of being fat.

show abstract

“…As a pre dator feeds and increases its body condition, the relative proportion of adipose tissue increases, thereby increasing its buoyancy (Robinson et al 2010). There fore, a predator species that performs dives during which the animals drift passively in the water column is an ideal study model to inform analysis of body condition based on in situ buoyancy (Biuw et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Horizontal and vertical movements as predictors of foraging success in a marine predator

Dragon¹,

Bar-Hen²,

Monestiez³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

With technical advances in wildlife telemetry, the study of cryptic predators' responses to prey distribution has been revolutionised. In the case of marine predators, high resolution tagging devices have been developed recently to collect precise diving datasets covering extended periods of time. In this study, we investigated changes in the horizontal movements and diving patterns of a marine predator, the southern elephant seal, at fine temporal and spatial scales. Satellite tracking data collected for 9 seals were processed with switching state-space models. Seal body condition, as a proxy for foraging success, was estimated through changes in drift rate from Time Depth Recorder (TDR) data. We identified (1) statistically distinct behavioural modes from the tracking data (intensive vs. extensive foraging modes) and (2) distinct dive classes from the TDR diving data (drift, exploratory, shallow active and deep active dives). Active dives, associated with vertical foraging and chasing, were more numerous when the seals were in intensive foraging mode. Improved body condition and mass gain of seals were also associated with the intensive foraging mode and, within the vertical dimension, with sets of highly active dives. In conclusion, proportions of dive classes varied according to seals' horizontal behaviour. Intensive foraging detected from surface tracking data is a good predictor of diving activity and foraging success occurring in the vertical dimension.

show abstract

Measurements of foraging success in a highly pelagic marine predator, the northern elephant seal

Cited by 90 publications

References 75 publications

Individual quality and personality: bolder males are less fecund in the hermit crabPagurus bernhardus

Individual quality and personality: bolder males are less fecund in the hermit crabPagurus bernhardus

The foraging benefits of being fat in a highly migratory marine mammal

Horizontal and vertical movements as predictors of foraging success in a marine predator

Contact Info

Product

Resources

About