Cetacean mother-calf behavior observed from a small aircraft off Southern California

Smultea, Mari A.; Fertl, Dagmar; Bacon, Cathy E.; Moore, Meggie R.; James, Vanessa R.; Würsig, Bernd

doi:10.12966/abc.01.02.2017

Cited by 19 publications

(13 citation statements)

References 25 publications

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“…However, a conservative approach is recommended, as environmental factors, flight parameters, and aircraft specifications can lower the effective resolution [10]. In addition to photogrammetry and censuses, we support the idea that they can provide high-quality video of marine mammal behavior in a non-invasive way [17,32], and from a perspective that allows for the tracking of the position of the animals even when they are submerged [6].…”

Section: Discussionmentioning

confidence: 53%

“…In contrast, the standard boat-based estimates are often biased, as the animals are not readily identifiable and they rarely breathe synchronously [21]. Additionally, important behaviors that normally take place underwater and are therefore invisible from a boat-based platform, such as socializing, foraging, and nursing [32], are observable from above ( Figure 5). Finally, tests are also being performed for flights at different heights to assess the potential behavioral responses of targeted animals to the aircraft presence [53].…”

Section: Whale Plume Sampling and Behavioral Studiesmentioning

confidence: 99%

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The Use of Unmanned Aerial Systems in Marine Mammal Research

et al. 2017

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Unmanned aerial systems (UAS), commonly referred to as drones, are finding applications in several ecological research areas since remotely piloted aircraft (RPA) technology has ceased to be a military prerogative. Fixed-wing RPA have been tested for line transect aerial surveys of geographically dispersed marine mammal species. Despite many advantages, their systematic use is far from a reality. Low altitude, long endurance systems are still highly priced. Regulatory bodies also impose limitations while struggling to cope with UAS rapid technological evolution. In contrast, small vertical take-off and landing (VTOL) UAS have become increasingly affordable but lack the flight endurance required for long-range aerial surveys. Although this issue and civil aviation regulations prevent the use of VTOL UAS for marine mammal abundance estimation on a large scale, recent studies have highlighted other potential applications. The present note represents a general overview on the use of UAS as a survey tool for marine mammal studies. The literature pertaining to UAS marine mammal research applications is considered with special concern for advantages and limitations of the survey design. The use of lightweight VTOL UAS to collect marine mammal behavioral data is also discussed.

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Section: Discussionmentioning

confidence: 53%

Section: Whale Plume Sampling and Behavioral Studiesmentioning

confidence: 99%

The Use of Unmanned Aerial Systems in Marine Mammal Research

et al. 2017

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“…It is apparent that females can nurse their calves between foraging events as they balance their needs and the needs of their calf. Many studies rely on surface behavior (e.g., the calf alternating sides while surfacing on either side of their mother and diving in towards their mother's pectoral flipper or peduncle) (Clapham & Mayo, 1987;Smultea et al, 2017;Videsen et al, 2017) to identify probable nursing behavior; however, during our study the majority of the time the calf spent close to the mother's ventral side was not spent nursing. Therefore, caution should be used when using surface behaviors to quantify nursing behavior on feeding grounds since it likely overestimates the amount of time a mother-calf pair is nursing.…”

Section: Discussionmentioning

confidence: 97%

From a calf’s perspective: humpback whale nursing behavior on two US feeding grounds

Tackaberry

Cade

Goldbogen

et al. 2020

PeerJ

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Nursing influences growth rate and overall health of mammals; however, the behavior is difficult to study in wild cetaceans because it occurs below the surface and can thus be misidentified from surface observations. Nursing has been observed in humpback whales on the breeding and calving grounds, but the behavior remains unstudied on the feeding grounds. We instrumented three dependent calves (four total deployments) with combined video and 3D-accelerometer data loggers (CATS) on two United States feeding grounds to document nursing events. Two associated mothers were also tagged to determine if behavior diagnostic of nursing was evident in the mother’s movement. Animal-borne video was manually analyzed and the average duration of successful nursing events was 23 s (±7 sd, n = 11). Nursing occurred at depths between 4.1–64.4 m (along the seafloor) and in close temporal proximity to foraging events by the mothers, but could not be predicted solely by relative positions of mother and calf. When combining all calf deployments, successful nursing was documented eleven times; totaling only 0.3% of 21.0 hours of video. During nursing events, calves had higher overall dynamic body acceleration (ODBA) and increased fluke-stroke rate (FSR) compared to non-nursing segments (Mixed effect models, ODBA: F1,107 = 13.57756, p = 0.0004, FSR: F1,107 = 32.31018, p < 0.0001). In contrast, mothers had lower ODBA and reduced FSR during nursing events compared to non-nursing segments. These data provide the first characterization of accelerometer data of humpback whale nursing confirmed by animal-borne video tags and the first analysis of nursing events on feeding grounds. This is an important step in understanding the energetic consequences of lactation while foraging.

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“…Thus, similar to what was found by Videsen et al (2017) for humpback whales, acoustic signals of southern right whale mother-calf pairs in this study are more likely to be recorded during dives with a higher activity level which are unlikely to be associated with nursing. Instead, nursing dives in southern right whales are likely to be related to low activity levels of the mother, where she will remain stationary, often submerged, while the calf dives down beneath her to suckle (Smultea et al, 2017;Thomas and Taber, 1984;Zoidis and Lomac-Macnair, 2017). This indicates that acoustic signals are cohesion calls for maintaining contact when moving.…”

Section: Vocal Behaviour and Masking Noisementioning

confidence: 99%

Acoustic crypsis in southern right whale mother–calf pairs: infrequent, low-output calls to avoid predation?

Nielsen

Bejder

Videsen

et al. 2019

Journal of Experimental Biology

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Southern right whales (Eubalaena australis) invest substantial amounts of energy in their calves, while facing the risk of having them predated upon by eavesdropping killer whales (Orcinus orca). We tested the hypothesis that southern right whale mother-calf pairs employ acoustic crypsis to reduce acoustic detectability by such predators. Specifically, we deployed multi-sensor DTAGs on nine lactating whales for a total of 62.9 h in a Western Australian breeding ground, and used a SoundTrap to estimate the concomitant acoustic background noise. Vocalisations were recorded at low rates of <10 calls h −1 (1 call per dive) and at low received levels between 123±8 and 134±10 dB re. 1 µPa RMS depending on call type. We conclude that such acoustic crypsis in southern right whales and other baleen whales decreases the risk of alerting potential predators and hence jeopardizing a substantial energetic investment by the mother.

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Cetacean mother-calf behavior observed from a small aircraft off Southern California

Cited by 19 publications

References 25 publications

The Use of Unmanned Aerial Systems in Marine Mammal Research

The Use of Unmanned Aerial Systems in Marine Mammal Research

From a calf’s perspective: humpback whale nursing behavior on two US feeding grounds

Acoustic crypsis in southern right whale mother–calf pairs: infrequent, low-output calls to avoid predation?

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