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Multiple occurrences of king penguin (Aptenodytes patagonicus) sexual harassment by Antarctic fur seals (Arctocephalus gazella)
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Sexual coercion is the use of force to achieve mating, while reproductive interference encompasses many forms of interspecific interactions during mating. We describe three new occurrences of the sexual coercion of king penguins (Aptenodytes patagonicus) by Antarctic fur seals (Arctocephalus gazella) on sub-Antarctic Marion Island. These recurrent observations follow a common pattern where the seal chases, captures and mounts the penguin, followed by copulation attempts. These observations are similar to a previously published observation from the same island, and we suggest that this may be an emergent behaviour. Two hypotheses directed at possible drivers for these coercive actions are examined: it may be learned behaviour associated with some sort of reward or it may be an extreme case of reproductive interference that can be explained by the ‘mate deprivation hypothesis’, resulting from the continued growth of the A. gazella population on the island. Reporting of similar occurrences from a range of species may allow more robust inference towards the ultimate drivers of the behaviour.
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... The intense sexual drive of males has led juveniles of some species to copulate with stones and logs (e.g., northern fur seals; Ryazanov, 2021) or with other males (e.g., New Zealand sea lion and harbor seals, Phoca vitulina; Marlow, 1975;Thompson, 1988). Instances of young adult male Subantarctic fur seals (Arctocephalus tropicalis) sexually coercing adult king penguins have also been recorded (de Bruyn et al., 2008;Haddad et al., 2015). ...
... It may simply be a case of mistaken identity or an indicator of the species' small population size. With only 336 NARWs estimated to remain in 2020 and only ~20% of those being adult females (Pettis et al., 2022), there is some support for the "mate deprivation hypothesis," which states that males with limited access to females may exhibit more forced or deviant copulatory behavior (Thornhill & Thornhill, 1983, 1992Lalumière et al., 1996;Haddad et al., 2015). Ultimately, NARW reproductive rates have declined in the last decade due to increased anthropogenic stressors and a declining and shifting food source (Meyer-Gutbrod et al., 2015Pettis et al., 2017;van der Hoop et al., 2017;Moore et al., 2021;Stewart et al., 2021), and the connection between NCBs and successful or unsuccessful reproduction-if any-remains poorly understood. ...
https://www.aquaticmammalsjournal.org/index.php?option=com_content&view=article&id=2273:observations-of-adult-calf-nonreproductive-copulatory-behavior-in-north-atlantic-right-whales-eubalaena-glacialis&catid=210&Itemid=326
... Young fur seals play with penguins of various species, inflicting injuries on them, which may be fatal sometimes (Hofmeyer and Bester 1993). Haddad et al. (2015) also remind that Antarctic Fur Seals eat King Penguins; however, these penguins can be actually raped by Fur Seals (http://www. bbc.com/earth/story/20141117-why-seals-have-sex-with-penguins). ...
Two regions exist in the Bransfield Strait: the region of the Bransfield Strait along the South Shetland Islands with Transitional Zonal Water with Bellingshausen Sea influence and the region along the northeastern coast of the Antarctic Peninsula with colder and more saline Transitional Zonal Water with Weddell Sea influence. The narrow jet stream flows along the islands and transports relatively warm water from the Bellingshausen Sea. Most of the strait is occupied by cold waters from the Weddell Sea.
... Young fur seals play with penguins of various species, inflicting injuries on them, which may be fatal sometimes (Hofmeyer and Bester 1993). Haddad et al. (2015) also remind that Antarctic Fur Seals eat King Penguins; however, these penguins can be actually raped by Fur Seals (http://www. bbc.com/earth/story/20141117-why-seals-have-sex-with-penguins). ...
Cruise 79 of the R/V “Akademik Mstislav Keldysh” of the Russian Academy of Sciences in the Atlantic sector of the Southern Ocean took place from January to March 2020. The data were collected on 13.02–26.02.2020 when pieces of bird meat were discovered on the surface of the sea along the vessel’s route. Observations were performed on all days from dawn to dusk, from the broad direction-finder deck by one or two observers. We encountered remains of birds (carcasses, skins, pieces of meat). On some days, the sea surface was covered by these remains. It was mostly the remains of dead penguins, or sometimes whole bodies. In February, these were mostly juvenile Adélie Penguins, since they leave their colonies in this month, and high mortality of the young generation is known in birds and other animals. However, despite the fact that the absolute number of dead penguins is high, the proportion of them compared to the total population is quite low. Antarctic Fur Seals are suggested to be the main cause of the mortality of the young Adélie Penguins, and not Leopard Seals or Killer Whales. It looks like, the penguins are not just an occasional, but really an essential part of the Antarctic Fur Seal diet, especially in the period when starving males leave breeding grounds and commence migration.
... Penguin remains occurred in 8.2% of the Antarctic fur seal scats we examined, and none of the Subantarctic fur seal scats. Opportunistic predation of penguins has been reported in Antarctic as well as Subantarctic fur seals (Hofmeyr & Bester 1993, and references therein) and land-based predation on king penguins (Aptenodytes patagonicus) by Antarctic fur seals first reported on Marion Island in 1986 persists (Hofmeyr & Bester 1993;Haddad et al. 2015). Penguin remains were not abundant (0.6% of prey) or very frequent (8.2% of scats) in Antarctic fur seal scats, but the large mass represented by an individual penguin (2.7-12.0 ...
Antarctic (Arctocephalus gazella) and Subantarctic (A. tropicalis) fur seals are important predators in the Southern Ocean. Marion Island (southern Indian Ocean) hosts the largest sympatric breeding populations of these two species. Environmental and population changes here over two decades may have influenced their diet and trophic interactions. To quantify diet, we analysed prey remains in scat samples from Antarctic (661 scats) and Subantarctic (750 scats) fur seals collected at Marion Island (2006–2010). We assessed diet composition over time and calculated dietary overlap. The diet of both species was dominated by fish prey (98.2% and 99.4% of prey items), mainly myctophids. Antarctic fur seals consumed small numbers of penguins, cephalopods and crustaceans. In Subantarctic fur seal scats, crustaceans and cephalopods were rare and penguin remains were absent. The diets of the two species overlapped substantially (Pianka’s index = 0.98), however, small but significant differences in the relative proportions of prey were evident. Seasonal and annual diet changes suggest that their diet is similarly influenced by patterns of local prey availability and abundance. Despite substantial changes in the population size and trajectory of Antarctic and Subantarctic fur seals – which would be expected to influence trophic interactions between them – comparing our data to those from earlier studies (1989–2000) did not reveal significant long-term dietary changes in either species.
This naturalistic note presents a series of observation of interspecies sexual behaviour involving Japanese macaques (Macaca fuscata yakui) and Sika deer (Cervus Nippon yakushimae) on Yakushima Island, Japan. The initial observation in 2015 revealed a male macaque's attempt to engage in sexual activity with female deer, displaying mate-guarding behaviour. Subsequent observations in 2020, 2021 and 2023 showed the continuation of this behaviour and potentially the propagation to other macaques. We categorised this rare behaviour as a case of reproductive interference and explored hypotheses regarding its functionality. While some suggest nutritional benefits for the deer, others propose learning, incomplete species recognition, or mate deprivation hypotheses. This behaviour may also be selectively neutral, offering no direct fitness benefits, but rather represents a behavioural by-product of other interactions between these two species, which may themselves be adaptive. Furthermore, we hypothesise that the observed propagation may underlie social transmission and highlight the potential cognitive capacities of Japanese macaques involving social learning mechanisms and the willingness to adopt non-instinctual behaviours.
This study presents a remarkable observation of interspecies sexual behaviour involving Japanese macaques (Macaca fuscata yakui) and Sika deer (Cervus Nippon yakushimae) on Yakushima Island, Japan. The initial observation in 2015 revealed a male macaque’s attempt to engage in sexual activity with female deer, displaying mate-guarding behaviour. Subsequent observations in 2020 and 2021 showed the continuation of this behaviour and potential social transmission to other macaques. These findings raise questions about the motivations, evolutionary implications, and ecological consequences of such interspecies interactions. We categorised this rare behaviour as a case of reproductive interference and explored hypotheses regarding its functionality. While some suggest nutritional benefits for the deer, others propose learning, incomplete species recognition, or mate deprivation hypotheses. Furthermore, the observed social transmission highlights the cognitive capacities of Japanese macaques involving social learning mechanisms and the willingness to adopt non-instinctual behaviours. Cultural behaviours in Japanese macaques, including this interspecies behaviour, offer insight into their complex social and cultural lives, urging researchers to explore and analyse these behaviours in-depth.
Reproductive interference, reproductive interactions between heterospecific individuals including mating, is commonly reported across taxa but its drivers are still unclear. Studying interspecific matings in the context of their conspecific mating system— by relating an individual’s conspecific mating behavior to its heterospecific interactions— offers a powerful approach to address this uncertainty. Here we compare inter‐ and intraspecific mating dynamics in the squash bug Anasa tristis and its close relative Anasa andresii under semi‐natural conditions. Using replicated enclosures, we surveyed the mating behavior of individually marked A. tristis and A. andresii (5 males and 5 females of each species per trial) at hourly intervals using a robotic camera system over a 14‐day period. We uncovered high levels of reproductive interference (19% of individuals engaged in interspecific matings) but the majority of mating activity took place between conspecifics. A. tristis females which engaged in interspecific matings had comparable hatching success with those which did not. Therefore, in this system, relatively high levels of reproductive interference may emerge under semi‐natural conditions as a byproduct of limited intraspecific pre‐copulatory choice paired with limited fitness penalties for at least one of the species involved.
Cambridge Core - Evolutionary Biology - The Ape that Understood the Universe - by Steve Stewart-Williams
The Ape that Understood the Universe is the story of the strangest animal in the world: the human animal. It opens with a question: How would an alien scientist view our species? What would it make of our sex differences, our sexual behavior, our child-rearing patterns, our moral codes, our religions, languages, and science? The book tackles these questions by drawing on ideas from two major schools of thought: evolutionary psychology and cultural evolutionary theory. The guiding assumption is that humans are animals, and that like all animals, we evolved to pass on our genes. At some point, however, we also evolved the capacity for culture - and from that moment, culture began evolving in its own right. This transformed us from a mere ape into an ape capable of reshaping the planet, travelling to other worlds, and understanding the vast universe of which we're but a tiny, fleeting fragment.
Behavioral capabilities of seals and sea lions (the pinnipeds) are described and summarized in tabular form. Major features of sound detection, pitch perception, sound localization, visual spectral sensitivity, visual acuity, learning potential and constraints on learning and memory, and maximum diving depths are presented for these large-brained amphibious marine mammals. Among those species tested, phocids hear higher frequencies under water than do otariids and the opposite is true for airborne sounds. All pinnipeds are more sensitive to underwater sounds than they are to airborne sounds. There is little evidence to support the notion that most pinnipeds have evolved an echolocation capability. Scotopic sensitivity of several species is correlated with radiant energy in the marine environment. Visual acuity is equally sharp in air and under water, but deteriorates more rapidly in air than in water when the ambient light is decreased. Sea lions generally behave optimally when confronted with ambiguous cues signaling food reward. Although visual form discrimination and generalization is highly developed, thus far abstraction abilities have not been demonstrated easily in pinnipeds. Although many pinnipeds dive to 200–250 m, only the Weddell seal has been observed to dive to 600 m.
In this study we report the first documentation of mating between harp (Phoca groenlandica) and hooded seals (Cystophora cristata). The production of this hybrid was quite unusual, being the result of a cross between parents of different genera which are morphologically dissimilar and have quite different mating behavior and dramatically different body sizes. The molecular tech-niques (mtDNA and macrosatellite nuclear DNA banding patterns) used in this study will undoubtedly be applied widely to many different taxa in the near future, allowing us to re-examine many suspected cases of hybridization among marine mammals and, in a larger context, the meaning of the species concept.
Vocalizations recorded from captive harbor seals are described and illustrated. Pups of both sexes vocalized, but females over 1 year of age rarely vocalized. Sexually mature males were the most vocal animals. Two adult males produced sounds that mimicked one or more English words and phrases, which is noteworthy in view of the rarity of demonstrated vocal learning in mammals. Although similar in many ways to other seal sounds, these speechlike sounds contained a variety of human speech cues. We speculate that male harbor seals may mimic other males in the wild.
This note documents unusual predation of southern royal albatrosses Diomedea epomophora on land by an individual New Zealand sea lion Phocarctos hookeri. During a survey of albatross nests on Campbell Island in the New Zealand sub‐antarctic in January 2005, 128 corpses of adult albatrosses were found at or near nests within a 230 ha area. Flattened vegetation and flipper prints near the nests suggested sea lion predation, and subsequently a male sea lion was found near a line of freshly killed birds. The predation rate was estimated to be at least seven birds per day over a number of weeks; similar skeletal remains from the previous year were observed in a neighbouring area. The impact of one threatened species on another can be a dilemma for conservation managers. In this case, apparently only one male sea lion was involved and, because of the ongoing impact to the albatross population, permission was obtained to cull that individual on 17 January 2005. No further incidents were observed over the following three seasons (2006–08).
This chapter offers remarkable evidence of vocal flexibility in pinnipeds (seals, sea lions, and walruses), species whose learning capabilities are surprising indeed, and discusses published experiments and new observations on their vocal usage and production learning capabilities. It shows that some pinnipeds can learn to alter the contexts in which they emit natural vocalizations, as well as modify their call structure along several structural dimensions, to an extent not known to occur in most terrestrial mammals. The chapter suggests that pinnipeds do have some degree of voluntary control over their sound emissions and reveals that the walrus observations exhibit plasticity in sound production in a particularly vocal species with a strong potential for complex communicative interactions during development.
