scholarly journals Diving behaviour of green turtles: dive depth, dive duration and activity levels

2000 ◽  
Vol 208 ◽  
pp. 297-298 ◽  
Author(s):  
GC Hays ◽  
S Hochscheid ◽  
AC Broderick ◽  
BJ Godley ◽  
JD Metcalfe
Keyword(s):  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Activity Levels ◽  
Green Turtles

scholarly journals Heart rates and abdominal temperatures of free-ranging South Georgian shags, Phalacrocorax georgianus

1997 ◽  
Vol 200 (4) ◽  
pp. 661-675 ◽  
Author(s):  
R M Bevan ◽  
I L Boyd ◽  
P J Butler ◽  
K Reid ◽  
A J Woakes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
The South ◽  
Data Logger ◽  
Heart Rates ◽  
The Mean ◽  
Free Ranging ◽  
Mean Heart Rate

The South Georgian shag (Phalacrocorax georgianus) shows a remarkable diving ability comparable to that of penguins, yet nothing is known of the physiology of these birds. In this study, heart rates and abdominal temperatures were recorded continuously in four free-ranging South Georgian shags using an implanted data-logger. A time­depth recorder was also attached to the back of the implanted birds to record their diving behaviour. The diving behaviour of the birds was essentially similar to that reported in other studies, with maximum dive durations for individual birds ranging between 140 and 287 s, and maximum depths between 35 and 101 m. The birds, while at the nest, had a heart rate of 104.0±13.1 beats min-1 (mean ± s.e.m.) and an abdominal temperature of 39.1±0.2 °C. During flights of 221±29 s, heart rate and abdominal temperature rose to 309.5±18.0 beats min-1 and 40.1±0.3 °C, respectively. The mean heart rate during diving, at 103.7±13.7 beats min-1, was not significantly different from the resting values, but the minimum heart rate during a dive was significantly lower at 64.8±5.8 beats min-1. The minimum heart rate during a dive was negatively correlated with both dive duration and dive depth. Abdominal temperature fell progressively during a diving bout, with a mean temperature at the end of a bout of 35.1±1.7 °C. The minimum heart rate during diving is at a sub-resting level, which suggests that the South Georgian shag responds to submersion with the 'classic' dive response of bradycardia and the associated peripheral vasoconstriction and utilisation of anaerobic metabolism. However, the reduction in abdominal temperature may reflect a reduction in the overall metabolic rate of the animal such that the bird can remain aerobic while submerged.

Diving behaviour of lactating southern sea lions (Otaria flavescens) in Patagonia

1995 ◽  
Vol 73 (11) ◽  
pp. 1975-1982 ◽  
Author(s):  
Rodolfo Werner ◽  
Claudio Campagna
Keyword(s):  
Median Duration ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Diel Variation ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Aerobic Dive Limit

The diving behaviour of six lactating female southern sea lions (Otaria flavescens) was recorded during 52.4 animal-days at sea. Information was obtained from 18 057 dives. Females spent 52.7 ± 6.2% of the time at sea diving. Median and maximum dive depths ranged from 19 to 62 and from 97 to 175 m, respectively. Dives were short, with median and maximum durations ranging from 2.1 to 3.2 and from 4.4 to 7.7 min, respectively. Dives deeper than 10 m represented 56 – 89% of total dives and involved 93 – 97% of total diving time. Mean dive depth and duration of dives greater than 10 m were 61 m and 3 min, respectively. Most of these dives (69%) had a flat-bottomed U-shaped profile, bottom time constituting about half of the dive duration. Shallow dives, with a modal depth of 2 m, were short (median duration 0.1 –0.8 min), with virtually no time spent at the bottom of the dive. During trips to sea, which ranged from less than 1 day to more than 4 days, females dove continuously. Mean dive frequency was between 11 and 19 per hour. Surface intervals were short (median 0.9–1.2 min) and there was no apparent diel variation in dive depth or frequency. The estimated aerobic dive limit of the females was exceeded on only a few dives (0.7 – 6.2%). Transit to potential foraging areas took 0.2–8.3 h.

Forage-diving behaviour of adult Japanese female loggerhead turtles (Caretta caretta) inferred from Argos location data

2004 ◽  
Vol 84 (4) ◽  
pp. 855-856 ◽  
Author(s):  
Hideo Hatase ◽  
Wataru Sakamoto
Keyword(s):  
Body Size ◽  
Caretta Caretta ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Sea Surface ◽  
Loggerhead Sea Turtles ◽  
Satellite Pass ◽  
Location Data ◽  
Japanese Female

Adult female loggerhead sea turtles (Caretta caretta) nesting in Japan use different feeding habitats as a function of body size. The Argos location data of two females inhabiting either oceanic or neritic habitats were analysed to infer their foraging and diving behaviour. There were no significant differences in the number of transmissions received per satellite pass, the number of locations per day, and the frequency of location-accuracy classes between oceanic and neritic females, implying that there was little difference in the time these two turtles stayed at the sea surface. Two possible forage-diving behaviours are suggested for these turtles: (1) both dive duration and depth were not different between the two feeding habitats; or (2) although dive duration was not different between feeding habitats, dive depth was different.

In the shallow end: diving behaviour of recolonising female New Zealand sea lions (Phocarctos hookeri) around the Otago Peninsula

2011 ◽  
Vol 89 (12) ◽  
pp. 1195-1205 ◽  
Author(s):  
Amélie A. Augé ◽  
B. Louise Chilvers ◽  
Lloyd S. Davis ◽  
Antoni B. Moore
Keyword(s):  
New Zealand ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Marine Habitat ◽  
Sea Lions ◽  
The Core ◽  
The Mean ◽  
Historical Range ◽  
Phocarctos Hookeri

Female New Zealand sea lions ( Phocarctos hookeri (Gray, 1844)) at the Auckland Islands (remnant populations) are the deepest and longest diving otariids. These remnant populations are found at the margin of the historical range of the species. We hypothesized that diving behaviours of animals in the core of their historical range is less extreme owing to a better marine habitat. All female New Zealand sea lions (n = 13, aged 2–14 years) born on the Otago Peninsula (initial recolonising population) were equipped with time–depth recorders during April and May 2008, 2009, and 2010. The mean dive depth was 20.2 ± 24.5 m and mean dive duration was 1.8 ± 1.1 min, some of the lowest values reported for otariids. Otago female New Zealand sea lions did not exhibit two distinct diving specialisations as reported at the Auckland Islands. Otago adult females exceeded calculated aerobic dive limits in 7.1% of dives compared with 68.7% at the Auckland Islands. The contrasting differences in diving behaviour between Otago and the Auckland Islands suggest that Otago represents a better marine habitat for New Zealand sea lions, with food easily accessible to animals of all ages.

Ranging and diving behaviour of two ‘offshore’ bottlenose dolphins, Tursiops sp., off eastern Australia

2004 ◽  
Vol 84 (2) ◽  
pp. 465-468 ◽  
Author(s):  
Peter. J. Corkeron ◽  
Anthony R. Martin
Keyword(s):  
Bottlenose Dolphins ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Core Area ◽  
Clear Relationship ◽  
Principal Curves ◽  
Eastern Australia

This paper describes a study of the ranging and diving behaviour of two ‘offshore’ bottlenose dolphins, Tursiops sp., in the waters off south-east Queensland, determined using satellite-linked time-depth recorders attached to two animals. Animal 1's tag transmitted for 30 days, Animal 2's for 143 days. Immediately after tagging, Animal 1 swam south, reaching a point 146 km south of the point of tagging, then swam generally northwards until the tag ceased working. Animal 2's observed range covered 778 km2, with a core area of 86 km2. The greatest north–south distance between all locations for Animal 2 was 43 km. The manner in which maximum dive depth was related to dive duration was analysed using constrained principal curves. These analyses indicated that for both animals, short dives were to less than 5 m, and there was no clear relationship between dives of greater duration and depth. These dolphins appear to behave differently from ‘offshore’ bottlenose dolphins studied elsewhere.

Seasonal diving patterns and body temperatures of juvenile green turtles at Heron Island, Australia

2003 ◽  
Vol 81 (6) ◽  
pp. 1014-1024 ◽  
Author(s):  
Amanda L Southwood ◽  
Richard D Reina ◽  
Vivienne S Jones ◽  
David R Jones
Keyword(s):  
Chelonia Mydas ◽  
Dive Depth ◽  
Dive Duration ◽  
Ambient Water ◽  
Reef Habitat ◽  
Physiological Factors ◽  
Green Turtles ◽  
Significant Difference ◽  
Ambient Water Temperature ◽  
Coral Reef Habitat

This study compared diving patterns of juvenile green turtles, Chelonia mydas, in a coral reef habitat during summer and winter. Dataloggers were deployed on green turtles at Heron Island, Australia, during December 2000 and August 2001 so that dive variables and ambient water temperature (TW) could be monitored. Cloacal temperatures (TB) were recorded from green turtles upon capture to assess their ability to maintain a thermal gradient between TB and TW. Data show that green turtles altered diving behaviour seasonally. Green turtles spent significantly more time in shallow water (<1 m) during winter than during summer. Dive depth for dives that exceeded 1 m was 2.9 ± 0.4 m (mean ± SEM) during summer and 4.4 ± 0.6 m during winter. Dive duration in summer (13.1 ± 1.2 min) was approximately half the dive duration in winter (24.3 ± 1.6 min), and surface interval in summer (0.6 ± 0.1 min) was one-third that of the surface interval in winter (1.8 ± 0.1 min). The observed changes in behaviour may be due to seasonal changes in environmental and physiological factors. There was no statistically significant difference between TB and TW during summer or winter.

The ontogeny of diving behaviour in New Zealand fur seal pups (Arctocephalus forsteri)

2005 ◽  
Vol 83 (9) ◽  
pp. 1149-1161 ◽  
Author(s):  
A M.M Baylis ◽  
B Page ◽  
K Peters ◽  
R McIntosh ◽  
J Mckenzie ◽  
...  
Keyword(s):  
New Zealand ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
South American ◽  
Fur Seal ◽  
Time Periods ◽  
Prey Remains ◽  
New Zealand Fur Seal ◽  
Prey Items

This study investigated the development of diving in 21 New Zealand fur seal pups, Arctocephalus forsteri (Lesson, 1828), prior to weaning at Cape Gantheaume, Kangaroo Island. Diving behaviour was examined using time–depth recorders, which were deployed during two time periods, 5 months prior to weaning (n = 6) and 2 months prior to weaning (n = 15). Scats were also examined to assess whether fur seal pups foraged prior to weaning. The maximum dive depth attained was 44 m, while the maximum dive duration was 3.3 min. Immediately prior to weaning, fur seal pups spent a greater proportion of their time diving at night, and concomitantly several measures of diving performance also increased. In general, pups dived successively deeper (6–44 m between June and September), and the average number of dives per day, dive frequency, and vertical distance travelled increased. Prey remains were present in approximately 30% of scats and indicated that some pups were foraging as early as June (5–6 months of age, approximately 4–5 months prior to weaning). Of the scats that contained prey remains, fish (South American pilchard, Sardinops sagax (Jenyns, 1842); Australian anchovy, Engraulis australis (White, 1790); and redbait, Emmelichthys nitidus Richardson, 1845) accounted for 43% of the prey items found, crustaceans accounted for 36%, and cephalopods (Gould's squid, Nototodarus gouldi (McCoy, 1888)) accounted for 20%.

Seasonal changes in buoyancy and diving behaviour of adult grey seals

2000 ◽  
Vol 203 (15) ◽  
pp. 2323-2330 ◽  
Author(s):  
C.A. Beck ◽  
W.D. Bowen ◽  
S.J. Iverson
Keyword(s):  
Body Mass ◽  
Seasonal Changes ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Temporal Separation ◽  
Body Fat Content ◽  
Phocid Seals ◽  
Negative Buoyancy ◽  
Negatively Buoyant

Phocid seals go through dramatic seasonal changes in body mass and composition as a result of the spatial and temporal separation of foraging, reproduction and moulting. These changes in body fat content and body mass result in seasonal changes in buoyancy, which in turn may influence diving behaviour. We examined the longitudinal changes in buoyancy and diving behaviour of 14 adult grey seals (Halichoerus grypus) during two periods that represent maximal contrast in body mass and composition. During both the post-moulting (PM) and pre-breeding (PB) periods, grey seals were negatively buoyant. However, buoyancy increased by 47.9 % between the PM and PB periods. Descent rate was significantly faster during the PM period (1.0+/−0.07 m s(−1)) than during the PB period (0.7+/−0.06 m s(−1)), suggesting that seals were aided by negative buoyancy during the downward portion of dives. Ascent rate was also significantly faster during the PM period (0.8+/−0.06 m s(−1)) than during the PB period (0.6+/−0.05 m s(−1)), contradicting the prediction that more buoyant animals should ascend faster. The effects of drag could not account for this discrepancy. Dive depth and surface interval between dives did not differ significantly between the two periods. Similarly, the distribution of dive shapes used by individuals did not differ between the two periods. However, dive duration was significantly longer during the PB period than during the PM period (5.5+/−0.25 min compared with 4.4+/−0.24 min, respectively) as was time spent at the bottom of the dive (3.1+/−0.22 min compared with 2.5+/−0.15 min, respectively).

Diving behaviour of harbour porpoises, Phocoena phocoena

1995 ◽  
Vol 52 (5) ◽  
pp. 1064-1073 ◽  
Author(s):  
Andrew J. Westgate ◽  
Andrew J. Head ◽  
Per Berggren ◽  
Heather N. Koopman ◽  
David E. Gaskin
Keyword(s):  
Data Collection ◽  
Dive Depth ◽  
Maximum Depth ◽  
Diving Behaviour ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
Diel Pattern ◽  
Maximum Capacity ◽  
Gill Nets ◽  
Free Ranging

The diving behaviour of seven free-ranging harbour porpoises (Phocoena phocoena) was examined using time–depth recorders. In total, 8167 individual dives were recorded over 254 h. The longest period of data collection from an individual was 106.1 h. Mean dive depths and durations ranged from 14 ± 16 to 41 ± 32 m, and from 44 ± 37 to 103 ± 67 s, respectively. The maximum recorded dive depth and duration was 226 m and 321 s. This performance may not represent the maximum capacity of harbour porpoises but rather the maximum depth of the study area. Individual dives had similar rates of descent and ascent, which ranged from 1.1 ± 0.6 to 2.3 ± 1.4 m/s, and from 0.9 ± 0.6 to 2.1 ± 1.4 m/s, respectively. Two porpoises with monitoring periods >2 days demonstrated a diel pattern in their diving, making fewer, but deeper dives at night. Comparison of the diving behaviour of harbour porpoises with data on the depth of 140 porpoises entanglements in groundfish gill nets in the Bay of Fundy showed these seven porpoises made between 22 and 70% of dives to depths (range 20–130 m) where the majority of entanglements were reported.

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