Since Russia's full-scale aggression against Ukraine, there have been thousands of instances of civilian casualties, damage to the natural environment and cultural property, destruction of buildings and infrastructure, blockading of ports, siege, capturing installations containing dangerous forces, and other consequences that accompany hostilities. In addition to the fatalities related to humans (civilians and combatants alike) and their property or environment, the war in Ukraine has also accounted for non-human tolls – namely, the destruction of animals or damage to their habitats.

The primary objective of this article is to study three patterns of animal suffering documented during Russia's invasion of Ukraine: (i) targeting zoos and killing zoo animals; (ii) extermination of the Black Sea dolphin population; and (iii) eating pigeons or other pets in besieged localities, and to analyse these patterns in the light of applicable rules of international humanitarian law (IHL).

The idea of this research is to underline that war can have a significant effect on various categories of animals, and Russia's invasion of Ukraine is just another example of this. The article also discusses how, and the extent to which international law can provide protection for animals in armed conflict, and whether there are any gaps in the applicable IHL rules related to the protection of animals.

Despite the number of dolphins that have been kept in dolphinaria, and the many behavioural studies that have been conducted on captive dolphins, few have focused on their welfare. Some behaviours have been described in detail, but insufficient attention has been paid to the diurnal variations in their occurrence.

Behavioural observations were conducted upon two groups (two and six individuals each) of captive bottlenose dolphins (Tursiops truncates) over a period of six weeks. Behavioural descriptions were produced and the amount of time the animals spent engaged in different behaviours was sampled. General trends of both groups and differences in patterns of variation throughout the day were also analysed. The use of area by the dolphins and their degrees of association were recorded. Considerable individual variation and differences between the two groups were observed.

In comparing the behaviour of different dolphins and in considering their welfare it is necessary to take into account their marked degree of individuality. The observations have shown that behavioural data such as variability of behaviour patterns, spontaneous variations in the daily activities and frequency of playing and exploration may constitute good welfare indicators. It is argued that social diversity, appropriate physical characteristics of the pools, existence of play objects in the pools, easy access to visual contact with people, and frequent interactions with the trainers throughout the day at unscheduled times may be important ways of improving environmental stimulation.

Biopsy sampling is an effective technique for collecting cetacean skin and blubber samples for various biological studies. However, determining the impact of this research practice is important, as it may vary between sites, species and equipment used. We examined the short-term behavioural reactions of four small (160-278 cm in length) delphinid species (Stenella longirostris, S. attenuata, Tursiops aduncus and Peponocephala electra) to remote biopsy sampling in the vicinity of the island of Mayotte (12°50’S, 45°10’E, SW Indian Ocean). Two scales of behavioural reactions were considered: i) the behavioural reaction of the individual, and ii) the reaction of the focal group to which the targeted individual belonged. Three main categories of behavioural responses were defined on the basis of character and duration: low, moderate and strong. This study underlines that biopsy sampling induces moderate reactions in individuals. No inter-specific variations of responses, at the scale of the individual or focal group, were observed. In other words, smaller delphinids were not more reactive than larger ones. No effect of group size was observed on the strength of behavioural reactions. However, it was clear that biopsy success during sampling sessions was higher in species with large group size. Finally, in the spinner dolphin (S. longirostris), we investigated whether initial behavioural state affected the level of reaction. Resting and socialising groups showed a stronger response than milling and travelling groups. This study confirms the limited impact of remote biopsy sampling in small delphinids, especially in the spinner dolphin. However, as a precautionary approach, wherever possible, biopsy sampling of milling and travelling dolphins may be preferable.

Activities displayed by animals are usually cyclic, and fluctuations in behavioural repertoires can be observed on a daily or seasonal timescale. The present study describes daily and seasonal variations in the aerial events – such as leaps, spins and slaps with body parts – by spinner dolphins in Baía dos Golfinhos, Fernando de Noronha Marine National Park, in Brazil. To measure aerial events by dolphins, we compiled and analysed data collected from January 2006 to December 2010. A total of 113,027 aerial events were recorded during 1431 days of land-based daytime observations. Our results show that the frequency of aerial events was positively correlated with the number of dolphins in the bay. The relative frequency of aerial events was higher in the rainy season, when compared with the dry season. Aerial activities also varied throughout the day, with dolphins being more active in the morning, specifically from 8:00 a.m. to 8:59 a.m., regardless of the season.

The beaching and stranding of whales and dolphins around the world has been mystifying scientists for centuries. Although many theories have been proposed, few are substantiated by unequivocal statistical evidence. Advances in the field of animal magnetoreception have established that many organisms, including cetaceans, have an internal ‘compass,’ which they use for orientation when traveling long distances. Astrobiology involves not only the origin and distribution of life in the universe, but also the scientific study of how extraterrestrial conditions affect evolution of life on planet Earth. The focus of this study is how cetacean life is influenced by disturbances in its environment that originate from an astrological phenomenon – in the present study that involves solar flares and cetacean beachings. Solar storms are caused by major coronal eruptions on the Sun. Upon reaching Earth, they cause disturbances in Earth's normally stable magnetosphere. Unable to follow an accurate magnetic bearing under such circumstances, cetaceans lose their compass reading while travelling and, depending on their juxtaposition and nearness to land, eventually beach themselves. (1) This hypothesis was supported by six separate, independent surveys of beachings: (A) in the Mediterranean Sea, (B) the northern Gulf of Mexico, (C) the east and (D) west coasts of the USA and two surveys (E and F) from around the world. When the six surveys were pooled (1614 strandings), a highly significant correlation (R2 = 0.981) of when strandings occurred with when major geomagnetic disturbances in Earth's magnetosphere occurred was consistent with this hypothesis. (2) Whale and dolphin strandings in the northern Gulf of Mexico and the east coast of the USA were correlated (R2 = 0.919, R2 = 0.924) with the number of days before and after a geomagnetic storm. (3) Yearly strandings were correlated with annual geomagnetic storm days. (4) Annual beachings of cetaceans from 1998 to 2012 were linearly correlated (R2 = 0.751) with frequency of annual sunspot numbers. Thus, consistently strong statistical correlation evidence indicates that an astronomical phenomenon – solar flares – can cause cetaceans to change their behaviour and become disoriented, which eventually causes them to swim onto a shore and beach themselves.

Including a multi-year collection of samples (2004–2011) the present research fills 20 years of an information gap regarding the PCB burden in south-west Atlantic franciscana dolphins (Pontoporia blainvillei) while aiming to test the null hypothesis that PCBs congeners are increasingly bioaccumulating in south-west Atlantic specimens in relation to northern hemisphere records. In addition, the present survey analyses indicators of potential biological impairment associated to PCBs tissue burden. The results could associate each sampling area group of dolphins to one or two Aroclor® patterns and point to dominant regional diffuse sources entering PCBs mixtures to the marine environment with a possible regional/long-range atmospheric contribution. In addition, total PCB levels were from four to seven times lower than the closer precedents for the area (18–26 years ago) indicating a progress in the environmental release and biota exposure of PCBs and posing an objective indicator of success of the present international elimination programme. Further, when compared with regional and global bioaccumulation patterns, PCBs congeners in Argentinean specimens appeared to occur in a decreasing tendency. Finally, calculated TEQs TCDD levels raised a concern in regards to environmental safety, showing guideline values to be widely exceeded and the occasional occurrence of positive correlations between PCBs bioaccumulation vs. sexual immaturity.

An initial inventory of the dolphins and whales occurring in Guinea's coastal waters is documented primarily from specimens and photographic evidence obtained from strandings and by-catches. Seven species are fully validated, four odontocetes, Tursiops truncatus, Sousa teuszii, Stenella frontalis, Kogia breviceps and three balaenopterid whales: Balaenoptera brydei, Balaenoptera acutorostrata and Megaptera novaeangliae. Another three reported species (Globicephala macrorhynchus, Steno bredanensis and Delphinus delphis) are insufficiently supported but thought to be valid. Small cetaceans landed as by-catch and a stranded whale were used for human consumption, but no evidence of substantial takes, directed or by-catch, was found. However, concern is raised about even minimal takes of the vulnerable Atlantic humpback dolphin. The seasonal presence of three confirmed humpback whales, two strandings (July and September) and a sighting (October), is synchronous with the species' southern hemisphere wintering/breeding season in low latitudes. We hypothesize that these whales may comprise the north-westernmost range of the population that breeds/overwinters in coastal waters of the Bight of Benin, northern Gulf of Guinea.

Explorations of Stone Age diversity take another step forward with this study of a group of neighbouring sites in Arctic Norway. While all are situated around a fjord, and only a few kilometres apart, the faunal assemblage shows that some are seal specialists, while others hunt reindeer and others again ambush dolphins. Each was creating its own local environment, hunting territory and landscape, not defended but respected, with intimate connections between people and places.

A comparison between the diet of the franciscana and the boto-cinza is presented through the proximate-composition and caloric value of their main prey. The fish Stellifer cf. rastrifer, Pellona harroweri, Anchoa filifera, Isopisthus parvippinnis and Trichiurus lepturus and the squids Loligo sanpaulensis and L. plei were analysed for water, protein, lipid and mineral contents and gross energy (GE). The fish are more important in the diet of the boto-cinza and squids are consumed mostly by the franciscana. Loligo sanpaulensis had the higher water content and protein was the largest fraction of the organic matter in all prey species. Squids presented greater GE values than fish. The data on prey composition and energy from this study are the first for these South American dolphins.

During a monitoring programme of stranded marine mammals conducted along the north-east coast of the Rio de Janeiro State, Brazil, we collected marine tucuxi dolphins (Sotalia guianensis) stranded along the beach. We examined the carcasses to identify characteristic evidences of fishery by-catch. From July 2001 to August 2007 43 S. guianensis were found in the study area, with an annual mean of 6.1 stranding events. Dolphins stranded with evidence of fishery interaction (‘by-catch’) occurred in almost every year (annual mean = 2). The majority of the by-catch events occurred during winter and spring. Most of the stranded dolphins were sexually mature. From 43 S. guianensis stranded from 2001 to 2007, 32.5% (N = 14) of these presented evidence of by-catch. Twenty-nine other dolphins did not show clear evidence of by-catch or it could not be evaluated. Most of the by-caught dolphins occurred in the northern zones of the study area where gill-net use is intense.

Rapid growth in demand for tourist interactions with cetaceans in the wild constitutes a challenge to management. Short-term animal behaviour changes can have long-term biological consequences for individual animals and populations. This paper reviews the whale-watching management context, describing the interplay of the macro (global), meso (national/regional) and micro-level (local/site specific) policy, planning and management settings. Here, an integrated and adaptive management model based largely upon the delineation and monitoring of limits of acceptable change (LAC) parameters is proposed to address current shortcomings in the long-term sustainable management of whale-watching activities. Although no integrated management framework currently exists, a comprehensive management approach must be developed and applied in the interests of the long-term sustainable management of tourist interactions with cetaceans in the wild. The proposed management model highlights the importance of integrating multiple stakeholder perspectives in a way that is both research-informed and adaptive. Beyond tourist interactions with cetaceans, this management framework could be applied to a wide range of wildlife management contexts.

Previous studies identified the Amazon river dolphin (Inia geoffrensis) as the species frequently traded in public markets of Pará and Amazonas State (Brazil). In order to investigate the geographic origin and the taxonomic identification of these specimens we analysed 21 samples provided by residents of the city of Belém and vicinities (Pará State, Brazil), presumably purchased in the ‘Ver-o-Peso’ Market (Belém) or the Manaus Municipal Market. DNA was extracted from dehydrated genitalia or from genitalia conserved in alcohol and the cytochrome b gene was PCR-amplified. Phylogenetic analyses showed identical topologies in both MP and NJ trees, with Sotalia splitting into two groups, one clade comprising the estuarine dolphin (S. guianensis) and all eight haplotypes from market-samples and another one, comprising the tucuxi (S. fluviatilis) haplotypes from the GenBank. Our findings indicated that the marine species is under a stronger commercial pressure than the Amazonian river dolphin (I. geoffrensis) and the tucuxi (S. fluviatilis) in the region. Therefore population dynamic studies as well as population monitoring should be carried out in order to evaluate the effects of this commercial hunting on the species and its local populations. The marine dolphins have been incidentally captured in gill-nets in the region, suggesting that these activities must also be monitored at the same time that social programmes must be implemented in order to inform and clarify local community and people involved in fishery activity to avoid that more animals might be captured and killed.

Climate change is now known to be affecting the oceans. It is widely anticipated that impacts on marine mammals will be mediated primarily via changes in prey distribution and abundance and that the more mobile (or otherwise adaptable) species may be able to respond to this to some extent. However, the extent of this adaptability is largely unknown. Meanwhile, within the last few years direct observations have been made of several marine mammal populations that illustrate reactions to climate change. These observations indicate that certain species and populations may be especially vulnerable, including those with a limited habitat range, such as the vaquita Phocoena sinus, or those for which sea ice provides an important part of their habitat, such as narwhals Monodon monoceros, bowhead Balaena mysticetus and beluga Delphinapterus leucas whales and polar bears Ursus maritimus. Similarly, there are concerns about those species that migrate to feeding grounds in polar regions because of rapidly changing conditions there, and this includes many baleen whale populations. This review highlights the need to take projected impacts into account in future conservation and management plans, including species assessments. How this should be done in an adequately precautionary manner offers a significant challenge to those involved in such processes, although it is possible to identify at this time at least some species and populations that may be regarded as especially vulnerable. Marine ecosystems modellers and marine mammal experts will need to work together to make such assessments and conservation plans as robust as possible.

Enhanced oxygen reserves in the blood facilitate diving in marine mammals. For pinnipeds (seals and sea lions), a developmental period of 4 to 24 months is required for blood oxygen stores to reach adult capacities. We investigated whether a similar developmental period for the blood occurs in cetaceans (dolphins and whales), a group of mammals that are exposed to diving immediately after birth. Blood samples were collected from wild and zoological park bottlenose dolphins Tursiops truncatus aged 0–12 years. Red blood cell number (RBC), haemoglobin content (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean cell haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) were determined for each sample. We found that during postnatal development, RBC, Hb and Hct decreased from 0 to 1.5 months and then increased from 1.5 to 6 months, reaching adult levels by 3 years. MCV and MCH both increased from birth. MCHC decreased from 0 to 3.2 months and then increased. Adult levels for MCV were attained as early as 2 months of age while adult levels for MCH and MCHC were attained by 6 months of age. These results indicate that, for bottlenose dolphins, the development of the blood and its capacity to store oxygen is not complete with weaning, which generally occurs at 1.5 years old. The lower oxygen storage capacity of immature dolphins is likely to limit dive capabilities. Calculated aerobic dive limits (cADLs) for 0- to 2-year-old dolphin calves are 1.9–3.6 min, compared to 4.8–5.4 min for 3- to 12-year-old dolphins. Increases in cADLs from 0 to 3 years are attributed to increases in both body mass and mass specific oxygen stores while body mass alone explains the increases in cADLs from 3 to 9 years. The limited diving capacity of young dolphins may influence the foraging behaviours of newly weaned juveniles and females accompanied by calves.

Studies of animal culture have not normally included a consideration of cetaceans. However, with several long-term field studies now maturing, this situation should change. Animal culture is generally studied by either investigating transmission mechanisms experimentally, or observing patterns of behavioural variation in wild populations that cannot be explained by either genetic or environmental factors. Taking this second, ethnographic, approach, there is good evidence for cultural transmission in several cetacean species. However, only the bottlenose dolphin (Tursiops) has been shown experimentally to possess sophisticated social learning abilities, including vocal and motor imitation; other species have not been studied. There is observational evidence for imitation and teaching in killer whales. For cetaceans and other large, wide-ranging animals, excessive reliance on experimental data for evidence of culture is not productive; we favour the ethnographic approach. The complex and stable vocal and behavioural cultures of sympatric groups of killer whales (Orcinus orca) appear to have no parallel outside humans, and represent an independent evolution of cultural faculties. The wide movements of cetaceans, the greater variability of the marine environment over large temporal scales relative to that on land, and the stable matrilineal social groups of some species are potentially important factors in the evolution of cetacean culture. There have been suggestions of gene-culture coevolution in cetaceans, and culture may be implicated in some unusual behavioural and life-history traits of whales and dolphins. We hope to stimulate discussion and research on culture in these animals.

The importance of interactions between sharks and cetaceans has been a subject of much conjecture, but few studies have addressed these interactions. Sharks (order Selachii) have been hypothesized to be important predators on dolphins and porpoises (suborder Odontoceti). Unfortunately, there are often few data to back up claims that certain shark species are major threats to cetaceans. To help identify potential shark predators in specific locations, available data on interactions with odontocetes for all shark species that may include cetaceans in their diet are reviewed. Shark species are categorized into groups based on predatory interactions with dolphins and porpoises (regular predators, occasional predators, potential predators, ectoparasites and insufficient data). Several shark species that have been overlooked in the cetacean literature are identified as potentially important predators while others that have been suspected to be important predators are probably at most occasional predators. How shark predation can influence dolphin populations, habitat use, group size and behaviour is discussed. How risk of shark predation can vary with habitat attributes in both nearshore and pelagic waters is also discussed. Predator–prey interactions have been the focus of most studies of shark–dolphin interaction, but competitive interactions may also occur. The first analysis of shark–dolphin dietary overlap is presented, which shows it to be significant between common dolphins and several species of sharks, including species that prey upon these dolphins.