The impact of the “Anthropause” on the communication and acoustic habitat of Southeast Alaskan humpback whales

2021 ◽  
Vol 149 (4) ◽  
pp. A136-A136
Author(s):  
Michelle E. Fournet ◽  
Leanna P. Matthews ◽  
Christine Gabriele
Keyword(s):  
Humpback Whales ◽  
Acoustic Habitat ◽  
The Impact

scholarly journals High pregnancy rates in humpback whales ( Megaptera novaeangliae ) around the Western Antarctic Peninsula, evidence of a rapidly growing population

2018 ◽  
Vol 5 (5) ◽  
pp. 180017 ◽  
Author(s):  
Logan J. Pallin ◽  
C. Scott Baker ◽  
Debbie Steel ◽  
Nicholas M. Kellar ◽  
Jooke Robbins ◽  
...  
Keyword(s):  
Population Growth ◽  
Antarctic Peninsula ◽  
Pregnancy Rates ◽  
Growth Potential ◽  
Humpback Whales ◽  
Western Antarctic Peninsula ◽  
Tissue Samples ◽  
Commercial Whaling ◽  
Reproductive Rates ◽  
The Impact

Antarctic humpback whales are recovering from near extirpation from commercial whaling. To understand the dynamics of this recovery and establish a baseline to monitor impacts of a rapidly changing environment, we investigated sex ratios and pregnancy rates of females within the Western Antarctic Peninsula (WAP) feeding population. DNA profiling of 577 tissue samples (2010–2016) identified 239 males and 268 females. Blubber progesterone levels indicated 63.5% of the females biopsied were pregnant. This proportion varied significantly across years, from 36% in 2010 to 86% in 2014. A comparison of samples collected in summer versus fall showed significant increases in the proportion of females present (50% to 59%) and pregnant (59% to 72%), consistent with demographic variation in migratory timing. We also found evidence of annual reproduction among females; 54.5% of females accompanied by a calf were pregnant. These high pregnancy rates are consistent with a population recovering from past exploitation, but appear inconsistent with recent estimates of WAP humpback population growth. Thus, our results will help to better understand population growth potential and set a current baseline from which to determine the impact of climate change and variability on fecundity and reproductive rates.

scholarly journals Fluctuating reproductive rates in Hawaii's humpback whales, Megaptera novaeangliae , reflect recent climate anomalies in the North Pacific

2019 ◽  
Vol 6 (3) ◽  
pp. 181463 ◽  
Author(s):  
R. Cartwright ◽  
A. Venema ◽  
V. Hernandez ◽  
C. Wyels ◽  
J. Cesere ◽  
...  
Keyword(s):  
Climate Change ◽  
North Pacific ◽  
Megaptera Novaeangliae ◽  
Anthropogenic Climate Change ◽  
Humpback Whales ◽  
Encounter Rates ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Population Segment

Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, Megaptera novaeangliae , between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother–calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.

scholarly journals The Impact of Vessels on Humpback Whale Behavior: The Benefit of Added Whale Watching Guidelines

2021 ◽  
Vol 8 ◽  
Author(s):  
Jens J. Currie ◽  
Jessica A. McCordic ◽  
Grace L. Olson ◽  
Abigail F. Machernis ◽  
Stephanie H. Stack
Keyword(s):  
Respiration Rate ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Whale Watching ◽  
Modeling Framework ◽  
Marine Tourism ◽  
Generalized Additive Modeling ◽  
The World ◽  
Additive Modeling ◽  
The Impact

The concurrent increase in marine tourism and vessel traffic around the world highlights the need for developing responsible whale watching guidelines. To determine the impact of vessel presence on humpback whale behaviors in Maui Nui, a land-based study was conducted from 2015 to 2018 in Maui, Hawai'i. Theodolite tracks were used to summarize humpback whale swim speed, respiration rate, dive time, and path directness to determine the potential impacts of various types of vessel presence on whale behavior. Vessel presence, proximity, and approach type in conjunction with biological parameters were used in a generalized additive modeling framework to explain changes in whale behaviors. The results presented here show increases in swim speed, respiration rate, and path directness in conjunction with decreasing dive times, which has been shown to be an energetically demanding avoidance strategy. These observations, in conjunction with increasing awareness on the implication of non-lethal effects of human disturbance and changing oceanic environments on humpback whales, highlights the need for a pre-cautionary approach to management. Stricter guidelines on whale watching will limit the level of disturbance to individual humpback whales in Hawai'i and ensure they maintain the fitness required to compensate for varying ecological and anthropogenic conditions.

scholarly journals Vocal learning and the dimensionality of the mating environment

2019 ◽  
Author(s):  
Jan Verpooten
Keyword(s):  
Vocal Learning ◽  
Vocal Music ◽  
Humpback Whales ◽  
Research Attention ◽  
Learning Capacity ◽  
Selection Processes ◽  
Spatial Environment ◽  
New Perspective ◽  
Spatial Dimensionality ◽  
The Impact

Vocal learning, the capacity to add new vocalizations to one’s repertoire, has gained much research attention because it is a key prerequisite for spoken language and vocal music. As a result, major progress has been made regarding its developmental, genetic and morphological underpinnings. However, why it evolved and, more specifically, why it is so peculiarly distributed across species, remain long standing questions. For instance, animals as distinct as hummingbirds and humpback whales share well-developed vocal learning capacity in common with humans, while this ability appears quite limited in nonhuman primates. In order to tackle these questions, this article brings together existing hypotheses, such as about the evolutionary functions of vocal learning and the impact of the spatial environment on sexual selection processes. Consistent with these hypotheses, I suggest, based on a systematic review of the latest evidence, that the cross-species distribution of vocal learning is associated with the spatial dimensionality of ancestral environments, and that this association is mediated by mate choice. This new perspective on the evolution of vocal learning is expected to open up novel avenues for further research on this pivotal cognitive ability. One implication is that human vocal learning may have evolved in (semi-)arboreal hominins at the base of the human clade, such as Ardipithecus ramidus, and thus much earlier than commonly assumed.

scholarly journals Impact of unequal distances among acoustic sensors on cross-correlation based fisheries stock assessment technique

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaik Asif Hossain ◽  
Monir Hossen
Keyword(s):  
Cross Correlation ◽  
Stock Assessment ◽  
Humpback Whales ◽  
Practical Implementation ◽  
Acoustic Sensors ◽  
Multipath Interference ◽  
Assessment Technique ◽  
Sensors Array ◽  
Dascyllus Aruanus ◽  
The Impact

Abstract Cross-correlation based fisheries stock assessment technique utilized array of multiple acoustic sensors which were equidistant pair. However, at practical implementation of this technique, equal distances among acoustic sensors is sometimes challenging due to different practical phenomenon. Therefore, in this study, we work on this issue and investigated the impact of unequal distances among the acoustic sensors. We found that cross-correlation based technique proved its effectiveness even for the unequal spacing among acoustic sensors. We considered chirp generating species of fish and mammals, i.e., damselfish (Dascyllus aruanus), humpback whales (Megaptera novaeangliae), dugongs (Dugong dugong), etc., species, and three acoustic sensors array for simulation purposes. Some limitations including negligence of multipath interference, assuming the delays to be integer were compromised during simulations.

scholarly journals Vessel noise levels drive behavioural responses of humpback whales with implications for whale-watching

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kate R Sprogis ◽  
Simone Videsen ◽  
Peter T Madsen
Keyword(s):  
Low Frequency ◽  
Humpback Whales ◽  
Noise Levels ◽  
Whale Watching ◽  
Noise Emission ◽  
Sensory Stimuli ◽  
Fitness Consequences ◽  
Controlled Exposure ◽  
Vessel Noise ◽  
The Impact

Disturbance from whale-watching can cause significant behavioural changes with fitness consequences for targeted whale populations. However, the sensory stimuli triggering these responses are unknown, preventing effective mitigation. Here, we test the hypothesis that vessel noise level is a driver of disturbance, using humpback whales (Megaptera novaeangliae) as a model species. We conducted controlled exposure experiments (n = 42) on resting mother-calf pairs on a resting ground off Australia, by simulating whale-watch scenarios with a research vessel (range 100 m, speed 1.5 knts) playing back vessel noise at control/low (124/148 dB), medium (160 dB) or high (172 dB) low frequency-weighted source levels (re 1 μPa RMS@1 m). Compared to control/low treatments, during high noise playbacks the mother’s proportion of time resting decreased by 30%, respiration rate doubled and swim speed increased by 37%. We therefore conclude that vessel noise is an adequate driver of behavioural disturbance in whales and that regulations to mitigate the impact of whale-watching should include noise emission standards.

scholarly journals First description of migratory behavior of humpback whales from an Antarctic feeding ground to a tropical calving ground

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Michelle Modest ◽  
Ladd Irvine ◽  
Virginia Andrews-Goff ◽  
William Gough ◽  
David Johnston ◽  
...  
Keyword(s):  
Linear Regression ◽  
State Space ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Migratory Behavior ◽  
Migration Speed ◽  
Feeding Ground ◽  
Excellent Starting Point ◽  
Departure Date ◽  
The Impact

Abstract Background Despite exhibiting one of the longest migrations in the world, half of the humpback whale migratory cycle has remained unexamined. Until now, no study has provided a continuous description of humpback whale migratory behavior from a feeding ground to a calving ground. We present new information on satellite-derived offshore migratory movements of 16 Breeding Stock G humpback whales from Antarctic feeding grounds to South American calving grounds. Satellite locations were used to demonstrate migratory corridors, while the impact of departure date on migration speed was assessed using a linear regression. A Bayesian hierarchical state–space animal movement model (HSSM) was utilized to investigate the presence of Area Restricted Search (ARS) en route. Results 35,642 Argos locations from 16 tagged whales from 2012 to 2017 were collected. The 16 whales were tracked for a mean of 38.5 days of migration (range 10–151 days). The length of individually derived tracks ranged from 645 to 6381 km. Humpbacks were widely dispersed geographically during the initial and middle stages of their migration, but convened in two convergence regions near the southernmost point of Chile as well as Peru’s Illescas Peninsula. The state–space model showed almost no instances of ARS along the migratory route. The linear regression assessing whether departure date affected migration speed showed suggestive but inconclusive support for a positive trend between the two variables. Results suggestive of stratification by sex and reproductive status were found for departure date and route choice. Conclusions This multi-year study sets a baseline against which the effects of climate change on humpback whales can be studied across years and conditions and provides an excellent starting point for the investigation into humpback whale migration.

scholarly journals Entanglement of humpback whales in artisanal fishing gear in Ecuador

2020 ◽  
pp. 283-290
Author(s):  
Fernando Félix ◽  
Mercedez Muñoz ◽  
Jéssica Falconí ◽  
Natalia Botero ◽  
Ben Haase
Keyword(s):  
Humpback Whales ◽  
Northwest Coast ◽  
Fishing Gear ◽  
Austral Winter ◽  
Artisanal Fishing ◽  
Short Term ◽  
Southeastern Pacific ◽  
The Impact ◽  
And Training

Southeastern Pacific humpback whales (Breeding Stock G) congregate along the northwest coast of South America during the austral winter (July–October). Information collected from stranded animals for more than a decade in Ecuador and Colombia indicates that entanglement in fishing gearis a major threat for this population during the breeding season. Twelve new cases are reported here of live individual whales entangled in artisanalgillnets on the central coast of Ecuador from 2004 to 2007. The varying severity of the entanglement and the behaviour of the animals involvedindicated that they had differing chances of survival. The findings confirm that the problem persists, although the impact on the population isunknown. The necessity of taking conservation measures to reduce the current level of entanglement is reiterated. Creation and training of rescueteams seems an appropriate alternative in the short-term, but in the long-term it will be necessary to design and implement actions with a widerregional scope, since the problem extends also to at least other two neighbouring countries.

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