Mother-calf Pairs Research Articles

New northernmost distribution records of the Eastern South Pacific southern right whale (Eubalaena australis), including the first cases from Ecuador and northern Peru.

The Eastern South Pacific Right Whale (SRW) (Eubalaena australis) population has gained interest due to its Critically Endangered conservation status. So far, this population has been confirmed only along the coasts of Chile (18°20'S to 56°30'S) and from southern to central Peru (17°38'S to 12°11'S). Recent records have extended the species' known range, highlighting its geographic distribution, now reaching 1500 km north. Here, we report six recent records, consisting of five sightings and one stranding, that expand the documented range to northern Ecuador (0.6°N). The northern extension of the population may be associated with the unusual three-year-long cold phase (La Niña) of the El Niño Southern Oscillation (ENSO) in the eastern South Pacific, population expansion, movement and re-distribution of the species, increased monitoring effort, or a combination of these factors. These observations raise hope for the Critically Endangered SRW population, as the occurrence of mother-calf pairs may indicate a potential for population recovery. Nevertheless, these findings intensify concerns for what is still the least abundant SRW population, underscoring the urgency for more targeted research and conservation measures.

Bryde’s whale (Balaenoptera edeni) occurrence and foraging behaviour along the east coast of Australia

ABSTRACT Despite their global occurrence in warm-temperate waters and their suspected non-migratory lifestyle, Bryde’s whales (Balaenoptera edeni spp.) are considered the least-known large baleen whale species. In Australian waters, information on their distribution, ecology and behaviour is scarce. This study documents Bryde’s whale occurrence and foraging behaviours along the Australian East Coast using opportunistic citizen science sightings via drone aerial photography, vessel and land-based observations. We observed foraging in both shallow (seafloor visible, beach and breaking waves present) and deep waters. We observed a range of foraging behaviours including lunge feeding (exhibited by individual whales and in pairs), sub-surface and surface skim feeding (shallow waters only) and described multispecies associations. We describe a potentially novel feeding behaviour in shallow waters, where Bryde’s whales are feeding directly within or behind the surf break (shallow water surf feeding). We quantify the presence of mother-calf pairs in Australian waters, highlighting the use of these waters for potential calving. This study provides insights into Bryde’s whale occurrence and foraging behaviour in both shallow and deep waters of eastern Australia.

Impact of weight variation on the microbiome of yak dams and calves.

Limited information exists regarding the microbiome composition of yak calves of varying weights. Therefore, this study aimed to investigate the microbiomes of mother-calf pairs with different weight profiles. Fecal and blood samples were collected from both lower-weight (CB) and higher-weight (HB) yak calves, along with their corresponding female yaks (CA, HA). The results revealed significantly higher levels of T-AOC (total antioxidant capacity) and GSH-Px (glutathione peroxidase) in HB animals (p < 0.001). Sequencing yielded 652,181 and 643,369 filtered reads in female and calf yaks, respectively. Alpha diversity analysis indicated that Chao1, Faith_pd, and Observed species were significantly higher in CA compared to HA (p < 0.01). Furthermore, nine genera were notably different between HA and CA yaks, including Avispirillum, Fimenecus, CAG-1031, Odoribacter 865974, and Jeotgalicoccus A 310962. Compared to CB yaks, CA animals exhibited significant differences in one phylum and six genera, including CAG-485 (p < 0.05), CAG-83 (p < 0.01), Copromorpha (p < 0.01), Phocaeicola A 858004 (p < 0.05), and UBA2253 (p < 0.05). In summary, higher-weight yak calves demonstrated increased oxidative resistance, and weight profiles were linked to the microbiomes of both female yaks and their calves. These findings offer valuable insights for optimizing yak breeding practices in high-altitude regions.

The effect of formation swimming on tailbeat and breathing frequencies in killer whales

In many aquatic taxa, formation traveling can reduce the energetic expenditure of locomotion by exploiting the vorticity trails shed by neighbors or through drafting. Cetaceans, especially odontocetes, often swim in groups; nevertheless, the possibility that whales gain energetic benefits from swimming in formation remains poorly studied, apart from mother-calf pairs. Between June and September in 2019 and 2021, we recorded aerial videos of Southern Resident killer whales (Orcinus orca) in the Salish Sea (USA) travelling in groups. We estimated whale tailbeat and breathing frequencies as proxies of the relative energetic costs of swimming, and tested the effect of swimming speed, relative positioning (e.g., leaders, whales in the middle of groups, or followers), sex and estimated size on these observed proxies. Our results reveal a complex relationship between physical characteristics, relative positioning, and energetic proxies. Intervals between respiration lasted longer in large-sized trailing individuals, but the overall breathing frequency was similar for all whales regardless of their position. The tailbeat frequency was mainly associated to whale sex, size, and swimming speed; in addition, tailbeat frequency showed a decreasing trend as the number of individuals in the formation increased. We found moderate evidence that position-based energetic effects may be present in the formation swimming of killer whales, and it is likely that additional factors such as social ties and hierarchies, play a key role in determining individual positioning in travelling groups.SignificanceSwimming in formation has been extensively studied in fish and other aquatic animals and has been documented to provide energetic advantages. Our understanding of the potential energetic benefits of wild cetacean formation swimming has been constrained by the difficulties of studying the movement of whale groups from traditional observation platforms. In recent years, non-invasive observations of cetaceans using unoccupied aerial systems have significantly improved the observation of these species in the wild, providing an exciting opportunity to better understand their behaviors and habits. Our results show a tendency for formation swimming to affect two energetic proxies (tailbeat frequency and the duration of underwater intervals between surfacing events). The results of this study set the stage for further research to identify the multiple determinants affecting killer whale formation swimming which go beyond purely energetic advantages, e.g. social relationships.

Investigating the effects of underwater noise from two vessels on the behaviour of short-finned pilot whales

Multiple whale-watching vessels may operate around cetaceans at any one time, and targeted animals may experience underwater noise effects. We hypothesised that the cumulative noise of two vessels with low source levels (SLs) will elicit lower behavioural disturbance in short-finned pilot whales (Globicephala macrorhynchus) compared to a single vessel with a higher SL. We measured the behaviour of whales during 26 controls (stationary vessel >300 m) and 44 treatments off Tenerife (Canary Islands, Spain). Treatments consisted of vessel approaches mimicking whale-watch scenarios (distance ∼60 m, speed 1.5 kn). Approaches with two simultaneous vessels, with maximum cumulative mid and low-frequency (0.2–110 kHz) weighted source levels (SLsMF-LF) 137–143 dB, did not affect mother-calf pairs’ resting, nursing, diving, respiration rate or inter-breath interval. However, a louder single vessel approach with twin petrol engines at SLsMF-LF 139–151 dB significantly decreased the proportion of time resting for the mother. The results suggest that if a single or two vessels are present, if the cumulative SL is < 143 dB, the behavioural disturbance on the whales will be negligible. By examining noise effects from multiple vessels on the behaviour of pilot whales, the importance of incorporating a noise threshold into whale-watching guidelines was emphasised.

Daytime spatial relationships in a family group of black rhinoceros Diceros bicornis at the Hiroshima City Asa Zoological Park, Japan.

Although black rhinoceros Diceros bicornis are mostly solitary in the wild, the Hiroshima City Asa Zoological Park (Asa Zoo) has kept a family group together during the daytime, with good reproductive performance over five decades. Management procedures at the zoo include temporary single housing of the mother before and after giving birth, which facilitates maintenance of a compatible family group. We recorded intra-group spatial relationships for 4 years and 4 months, during which time an adult female reared two consecutive calves. During daytime she remained in an enclosure with her new calf, one or two older offspring, and an adult male, the sire of all her offspring. Proximity (within two adult body-lengths) scores between the mother and her two calves were especially high during the first year after birth, and only slightly lower for her older offspring. The adult male had the lowest proximity scores. The spatial relationships were visualized by applying multidimensional scaling (MDS) to the proximity scores. Mother and calves were plotted close to each other, with older offspring slightly farther apart on the two-dimensional MDS representation; the adult male was more distant from the other group members. These findings indicate clear follower-type characteristics in the mother-calf pair and also older immature offspring, albeit to a lesser degree. Although black rhinoceros are generally solitary in the wild, our results duplicate observations of some wild black rhinoceros groups containing an adult female, her calf, and an older immature, with adult males being largely solitary.

Bycatch and pollution are the main threats for Burmeister's porpoises inhabiting a high-industrialized bay in the Humboldt Current System

Pollution and bycatch are two of the main threats for cetaceans worldwide. These threats are exacerbated for nearshore species particularly for those in regions with intense industrial and fishing activities. Burmeister's porpoise is endemic to South America, has a Near Threatened conservation status because of long-term mortality in fisheries. Burmeister's porpoise occur in Mejillones Bay, northern Chile, a hot spot for heavy metals pollution from the mining industry and an intense industrial and artisanal purse-seine fishing area. From 2018 to 2021, we conducted systematic marine surveys to assess the abundance, distribution and habitat use of Burmeister's porpoises. We responded to stranding reports from 2018 to 2022, and necropsied nine individuals. From five of these, we analyzed the metal concentrations (As, Cd, Cr, Cu, Pb, Hg, Se and Zn) in muscle and skin tissues. Results showed an abundance of 76.17 individuals (CV = 25.9%) and an average density of 0.45 individuals/km2 (CV = 26%). Burmeister's porpoises were observed year round, 22.2% were mother-calf pairs present in austral summer at an average of 90.6 m depth in the southwestern bound of the bay. Two-thirds of stranded specimens died due to bycatch and one died due to bottlenose dolphin (Tursiops truncatus) attack. We report a dead Burmeister's porpoise positive for avian flu virus A (H5N1). Metals analyzed were found in muscle and skin tissues of stranded Burmeister's porpoises in the following order (Zn > Cu > Cr > As > Hg > Pb > Cd). Although we could not assess pollution as a cause of mortality, Cr, As and Pb concentrations exceeded the concentrations found in other porpoises species worldwide. We conclude that bycatch and pollution as the main threats for Burmeister's porpoise survival in northern Chile. Future studies should investigate the use of acoustic deterrent alarms to mitigate the bycatch in the bay and consider the Burmeister's porpoise as a sentinel species of pollution in northern Chilean coast.

Allosuckling in southern right whale calves

Allosuckling, the suckling of milk from a non-biological mother, occurs in some species of mammals. Allosuckling has not been quantified in baleen whale calves; therefore, we examine allosuckling in southern right whales (SRWs; Eubalaena australis) off Australia. SRWs are listed as Endangered under the Australian Environment Protection and Biodiversity Conservation Act as their numbers remain below the estimated historical abundance. On a small aggregation area, where there were three mother–calf pairs present, we aimed to quantify the proportion of time that calves allosuckled relative to the time spent filial suckling. To achieve this, we conducted unmanned aerial vehicle focal follows on mother–calf pairs and video recorded all interactions among pairs (n = 22 interactions, 3 h total observation time). During interactions, allosuckling occurred in seven interactions, and filial nursing occurred in 11 interactions. One of the calves performed allosuckling, and it was the largest calf with the largest mother. The calf allosuckled from both of the non-biological mothers present. The average proportion of time allosuckling per interaction was 4% (95% CI = ± 0.01, range = 0–0.25), whilst filial nursing for the same calf was 8% (95% CI = ± 0.02, range = 0–0.37). It is important to understand the frequency of allosuckling, and to quantify the energetic benefits for allosuckling calves and the energetic cost incurred by targeted non-biological mothers. This is particularly pertinent for capital breeders who do not replenish lost energy reserves until they migrate to their feeding grounds.

Contact Exchanges in Bottlenose Dolphin Mother–Calf Pairs

The relationship between a dolphin mother and her calf has been well studied, but details regarding tactile exchanges within these dyads are limited. Contacts between five adult female bottlenose dolphins (Tursiops truncatus) and their calves, with data from three pairs analyzed statistically, were examined from video collected in October 2017, 2018, 2019, and in January 2018. Of 289 contact events, calves initiated 65.7% (n = 190), of which 82.6% (n = 157) were affiliative; 77.8% (n = 77) of mother-initiated contacts were categorized similarly. Thus, the overall trend for mother–calf contacts was affiliative. Mothers initiated contact with the dorsal fin less often (n = 3), while calves initiated with their dorsal fin more often (n = 40), especially one-year-old (C1) calves (n = 33). The body was used to initiate contact more by three-year-old (C3) calves (n = 47) and less by C1 calves (n = 22). Both results are likely an artifact of the infant position used by calves at different developmental stages. Only two-year-old (C2) calves initiated agonistic contact with their rostrum (n = 4); 75% of these contacts were initiated by one male calf. Mothers used the body to initiate contact with most calf ages, though contact by pectoral fin occurred more often than expected with their C2 calves (n = 11). Since 72.7% of these contacts came from one mother, a specific maternal style may be present. Only one mother used her rostrum with her C3 calf to initiate agonistic contacts; all others used the fluke. Several variables, including individual preference, calf sex, and maternal experience, may explain some of the contact patterns, but a larger sample size is needed to illustrate potential patterns among pairs. Still, these results support the notion that mother–calf dyads share more affiliative than agonistic contacts, expanding our knowledge on the tactile relationships of mother–calf pairs.

Agonistic interactions initiated by adult bottlenose dolphins on Antillean manatee calves in the Caribbean Sea.

The dynamics and drivers of inter-species interactions in the wild are poorly understood, particularly those involving social animal species. Inter-species interactions between cetaceans and sirenians have rarely been documented and investigated. Here, we report 10 cases of interaction initiated by adult bottlenose dolphins (Tursiops truncatus) towards Antillean manatee (Trichechus manatus manatus). Interactions were documented through behavioral observations in the wild (n = 7) and from the examination of orphaned calves (i.e., tooth rake marks on their body; n = 4) that entered a rehabilitation facility, one individual both observed interacting with dolphins and found stranded with bite marks. Bottlenose dolphins were observed interacting with orphan manatee calves and with mother-calf pairs, exhibiting agonistic behavior (n = 2), affiliative or neutral behaviors (n = 1), but the behavioral contexts of these interactions remain unclear in most cases (n = 7). Information on stranded individuals was collected from four calves (of 13 examined calves) recovered in poor condition with bottlenose dolphin tooth rakes and bite wounds on their bodies, one of which died. Injury from bite wounds varied in extent and severity, ranging from superficial scratches leaving rake marks to deep lacerations. Our findings suggest the regular occurrence of agonistic behaviors initiated by adult bottlenose dolphins and directed toward manatee calves. However, the drivers of these interactions remain unknown and need to be further investigated.

The observation records from whale and dolphin watching inshore of Hualien, eastern Taiwan.

The eastern waters of Taiwan have been lacking baseline and research data for several years. This study was initiated by Kuroshio Ocean Education Foundation (KOEF) in collaboration with the Turumoan whale-watching company since 1998, collecting long-term ecological data for cetaceans in the inshore of Hualien, eastern Taiwan. This dataset includes 10,675 records of cetacean sightings from June 1998 to December 2021. Collection of cetacean sighting records was paused for one year in 2001 due to budgetary reasons. All of the sighting records were collected by whale-watching boat guides that were trained by KOEF. Following a standardised protocol, guides used a handheld GPS device and cetacean sighting record sheets to document information about the cetacean species identification, location, time, number of individuals, the presence of mother-calf pairs and mixed-species groups and other states of each sighting during a whale-watching tour. The collection of citizen-science data during this period has significantly advanced Taiwan's cetacean baseline data in the study area. Additionally, we make data available to the public in the form of citizen-science, making a substantial contribution to the advancement of ocean scientific research. We have published the dataset on Global Biodiversity Information Facility, allowing users around the world to download the dataset. This is currently the largest dataset of cetacean sighting records in Taiwan (last updated on 2023-09-05). We have also recorded several species on the International Union for Conservation of Nature (IUCN) Red List categorised as "Data Deficient" during our survey inshore of Hualien, eastern Taiwan, including Ginkgo-toothed beaked whales (Mesoplodonginkgodens Nishiwaki & Kamiya, 1958), Omura's whales (Balaenopteraomurai Wada, Oishi & Yamada, 2003) and killer whales (Orcinusorca (Linnaeus, 1758)). There are also sperm whales (Physetermacrocephalus Linnaeus, 1758), categorised as "Vulnerable" in the IUCN Red List and false killer whales (Pseudorcacrassidens (Owen, 1846)), categorised as "Near Threatened". This study is also the first and only long-term study that has documented cetaceans in the study area.

Distribution of humpback whales along the coast of Ecuador and management implications

As part of a long-term population study of humpback whales breeding on the coast of Ecuador (2°S, 81°W), four sites on the central coast were surveyed: Puerto Cayo, Puerto López, La Plata Island and Salinas. The spatial, temporal and age class distributions of 322 groups positioned during the period of 1996-2003 were analysed regarding their distance from the shore and water depth with two statistical methods: one-way ANOVA and linear modelling. The average sighting distance from shore varied between 5.31km in Salinas and 10.16km in Puerto Cayo with mid values in Puerto López and La Plata Island. Average water depth was similar in Puerto López, La Plata Island and Salinas (36-39m) but lower in Puerto Cayo (19.43m). Differences were highly significant in both cases (p&lt;0.01). A progressive but not significant increase in the average distance from shore was found (6.2km in June to 7.17km in September). Sighting depth was constant between June and August (average 35-36m) but decreased significantly in September to 27m (p&lt;0.01). This difference was attributed to the presence of mother-calf pairs in shallower water by the end of the season. Age class analyses using ANOVA showed highly significant differences between groups of adults, and adults with subadults with respect to singleton subadults, and groups containing a mother-calf pair for both distance from shore and depth (p&lt;0.01); however, linear modelling analyses showed only depth was significant (p=0.026). This suggests that depth is a more important determinant of differences in distribution between these age classes than proximity to shore. The sightings distribution showed segregation of both mother-calf pairs (towards shallow waters) and of singleton subadults (towards the boundaries of the surveyed area). Since only eight sightings (2.5%) were in waters deeper than 60m, we propose that depth is a major feature determining humpback whale distribution in these waters. Implications of this coastal distribution are discussed, particularly with respect to bycatch in fishing gear and whalewatching. A review of recent southeast Pacific sightings showed that humpback whales are also abundant in coastal waters to the southwest of Ecuador (3°S) and confirmed that they are scarce offshore. However, whales are more widely distributed in the north of Peru (4°-6°S) where they make the transition between deeper oceanic and shallower coastal waters when arriving at and leaving the breeding area.

An approach to minimise bias in estimation of the lengthfrequency distribution of bowhead whales (Balaena mysticetus) from aerial photogrammetric data

Past attempts to estimate the length structure of the Bering-Chukchi-Beaufort (B-C-B) stock of bowhead whales have yielded quite different results from one study to the next because of size segregation on the summering areas or because of size segregation during the spring migration combined with inconsistent sampling during the migration period. A new approach is presented to document the length-frequency distribution of the B-C-B stock using length measurements from 3,107 whale images collected during the spring migrations of 1985, 1986, 1989-1992 and 1994. This method provides estimates of the proportion of calves (length &lt;6m), subadults (length 6-&lt;13m) and adults (length !13m). The data from all years are combined by weekly period and a bootstrap sampling procedure is used to construct the lengthfrequency by week. The distributions for each week are then combined to obtain the overall distribution, with each week’s contribution being in proportion to the fraction of the migration estimated from ice-based census studies to pass during that week. Corrections for differential detectability of mother/calf pairs and for calves born after they pass Point Barrow, Alaska, are allowed for in the analysis. This new approach eliminates some of the biases that affected past attempts to estimate the length-frequency distribution for the B-C-B population of bowhead whales. It is robust to inclusion or exclusion of data for any given year and the time interval chosen to define repeat images. The new approach estimates a slightly higher proportion of subadults and lower proportion of adults in the population than most previous studies. The proportion of calves is also lower, but that is suspected to result from our inability to accurately estimate the proportion of the migration late in the season when many of the mother-calf pairs pass Point Barrow. These late season migrants have not been accounted for during past photogrammetry studies or the ice-based census. Although the results do not differ substantially from those of most previous studies, sensitivity analyses indicate that several biases existed in the previous methods, but largely cancelled each other out.

Exposure of humpback whales to unregulated whalewatching activities in their main reproductive area in New Caledonia

Whale- and dolphin-watching activities are demonstrating a strong growth worldwide, raising concern of their potential impacts on cetacean populations and emphasising the need for management. Humpback whales recently have become the focus of an important tourism industry in the South Pacific, particularly in New Caledonia, where operators focus on a small population of humpback whales on their main breeding ground. Despite considerable growth since it began in 1995, the industry remains unregulated. Between 2005 and 2007, a study was conducted to assess the impact of whalewatching activities on the behaviour of humpback whales in New Caledonia. All data were collected from a land-based research station using a theodolite. Results show that 54% of all humpback whale groups sighted were exposed to whalewatching boats. Each group was watched simultaneously by an average of 2.5 boats. More than three boats were present within 300m of a group of whales 30% of the time. The length of time a group of whales was observed in the presence of boats each day was an average of one hour and 52 minutes but exceeded two hours 37% of the time. On average, each boat spent 52 minutes with the same group of whales. The closest point of approach was less than 100m for 86% of groups with a calf and 55% of non-calf groups. These results indicate that humpback whales are exposed to whalewatching boats in New Caledonia at a level exceeding the limits commonly recommended by management measures worldwide. Such exposure could be particularly problematic for mother-calf pairs, more vulnerable to threats. The strong site fidelity of individuals on this breeding ground raises concern of potential cumulative impacts. Management measures should be implemented to regulate whalewatching activities and ensure the conservation of this small, endangered population of humpback whales.

Breeding habitat of poorly studied humpback whales (Megaptera novaeangliae) in Boa Vista, Cape Verde

The waters surrounding Cape Verde comprise one of two known breeding grounds for humpback whales in the North Atlantic. The population remains very small and has apparently failed to recover since the cessation of whaling there. During the breeding seasons of 2011 and 2012, sighting surveys were carried out for humpback whales off Boa Vista, the easternmost island of the Cape Verde Island archipelago. The distribution and relative abundance of humpback whales and mother-calf pairs was investigated by plotting effort-corrected sightings using a 2km2 grid-square. The study area, a 206km2 region from the coastline up to 8km offshore, covered the western half of Boa Vista where whales have previously been regularly recorded. Following 1,954km of search effort, 117 sightings of humpback whales were made. An encounter rate of 0.11 whales per km was recorded for both years. It is hoped that these data may assist in implementing conservation measures to protect humpback whales and the habitat of Baia Sal Rei, which appears to be the single most important bay for winter breeding, calving and nursing humpback whales in the eastern North Atlantic.

Effects of whale-watching activities on southern right whales in Encounter Bay, South Australia

Southern right whales (Eubalaena australis) are listed as Endangered under the Australian EPBC Act 1999. They migrate to shallow, coastal waters during the winter to mate, calve and nurse their young. During this time, they are easily accessible to the boat-based whale-watching industry. The aim of the study was to determine if whale-watching at 300 m distance affects the behaviour of southern right whales. To achieve this, behavioural focal follows on mother-calf pairs were conducted using unmanned aerial vehicles (UAVs) in the presence and absence of a commercial whale-watching vessel. There was no significant effect of phase (control, before, during, after) on the whales’ respiration rate, swim speed, nursing rate and duration, maternal rate of active behaviours, tactile contact or calf pectoral fin contact. There was a significant reduction in resting between control and after phases, for both mothers (from 62% to 30%) and calves (from 16% to 1%). At 300 m distance and slow speed, vessel noise was measured to be slightly above ambient noise at the lower TOL0.25 kHz band, however, vessel noise was masked by ambient noise within the higher frequency TOL2–10 kHz bands. A factor which may have contributed to a decline in resting after whale-watch approaches, was an increase in vessel speed upon departure, which consequently increased vessel noise. Based on this, we recommend that vessels maintain a slow speed (e.g., ≤10 knots) within 1 km distance from the whales whilst conducting whale-watch activities.

Paternity patterns in a long-term resident bottlenose dolphin community

Genetic analyses, initiated in 1984, have played a major role in our understanding of the structure and social relationships of the long-term resident community of common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida (SBDC). One component of our ongoing study of the community’s social system involves using blood samples from periodic catch-and-release sampling for life history and health assessment studies, as well as skin from biopsy dart sampling studies and strandings, to investigate paternity and mating strategies in this community. These analyses, covering a span of four generations of calves, were originally based on chromosomes and protein electrophoresis, but with the advent of microsatellite DNA technology, the latter has become our analysis of choice. We have performed paternity analyses on 204 known mother-calf pairs. For 151 of the calves (74%), sires were identified within the SBDC, but for the remaining 26% of the calves all sampled males associated with the community were excluded and it is likely that a substantial contribution of paternity to the SBDC comes from outside the community. Of the SBDC males, only 52 males of the more than 200 potential sires were sires. The age of sires at time of conception of a calf ranged from 10 to 43 years, averaging 24 years old. These males have sired 1-7 calves during a documented period of reproductive tenure of as much as 24 years (average = 21.4 years). Four males have sired 6-7 calves each, these males siring calves in the community for more than 20 years. Another 19 males have each sired 3-5 calves and the remaining 30 males were identified as sires of 1-2 calves. Paired males sired 75% of the calves while 25% of the calves were sired by unpaired males. Females with multiple offspring generally had multiple sires for these offspring. These paternity analyses support the hypothesis that a major avenue of gene flow in the SBDC is through the males given their greater ranges, with occasional exchangeviavisits from males from other areas, as well as the occasional brief movements of females from outside the community range into the community.

Spatial and temporal dynamics of whalewatching in Península Valdés, Patagonia, Argentina

Península Valdés (Patagonia, Argentina) is considered one of the best places in the world to watch southern right whales (Eubalaena australis) due to the large number of animals as well as to their predictability and proximity to the coast. The present study describes the spatial and temporal dynamics of whalewatching, and the different groups of whales that were the focus of this activity in Península Valdés during six reproductive seasons (from 2005 to 2008 and from 2012 to 2013). The aim was to generate useful tools to improve whalewatching activity in this area. Data were recorded from 1,816 whalewatching trips operated from Puerto Pirámides. Every trip had several stopovers to watch whales, defined as ‘sightings’. At the beginning of the season, most sightings occurred near Puerto Pirámides port, while at the end of the season, sightings were farther from the port. During the first half of the whale season, trips tended to be coastal and shorter but the groups of whales sighted were more varied, including solitary animals, mating groups and mothers with their recently born calves. In the second half of the season, trips tended to be further from the coast and longer, but the whales sighted were mainly mother-calf pairs, the last group of whales to leave the area. This difference in the characteristics of the sightings as the whale season progressed could be the basis to generate different recreational experience opportunities. Whalewatching has a major impact on the regional economy and whalewatching regulations, if correctly applied, could improve the quality of a conservation plan, considering that both gulfs of Península Valdés (San José and Nuevo) are the main calving areas for this species in the South Atlantic Ocean.

First record of direct interaction between a potential predator – Orcinus orca (Odontoceti, Delphinidae) – and a mother-calf pair of Eubalaena australis (Mysticeti, Balaenidae) in Brazilian calving grounds

First record of direct interaction between a potential predator – Orcinus orca (Odontoceti, Delphinidae) – and a mother-calf pair of Eubalaena australis (Mysticeti, Balaenidae) in Brazilian calving grounds

Rare Sighting of a North Atlantic Minke Whale (Balaenoptera acutorostrata) Mother–Calf Pair in Massachusetts Bay

Rare Sighting of a North Atlantic Minke Whale (Balaenoptera acutorostrata) Mother–Calf Pair in Massachusetts Bay