Course:CONS200/2023WT1/Homosexual Behaviour in Seabirds and its Implications for Conservation

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Introduction

Seabirds on a rock

Homosexual behavior and parenting has been commonly documented in many species of seabirds.[1][2][3][4][5] Behavior varies from same-sex mounting and displays of ‘affection’ to acting as surrogate parents for eggs. Same-sex pairs often still copulate with other individuals to get eggs that they then raise with their partner. The nature of a pairing (e.g. homosexual vs heterosexual) may or may not have an effect on the egg’s success depending on the species. From a conservation standpoint, homosexuality is potentially advantageous for entire populations with skewed sex ratios because homosexual pairs means there is still energy being put towards fostering fertilized eggs.[6] In addition, there are instances in which a clutch of eggs raised by a homosexual pair are from both parenting birds, so both individuals still have a chance to produce offspring. Homosexual behavior may also play a role in the social hierarchies of seabird populations.[7]. Ultimately, it is difficult to make a generalization about the effect homosexual behaviour has on egg viability and overall population survival. The lack of data on same-sex behavior among seabirds could be an indication that more attention should be put on indicative species such as these in order to better understand how coastal ecosystems and their inhabitants are changing in response to anthropogenic causes.[8]

Overview of Seabirds

Generally, the term ‘seabird’ applies to any bird species that has evolved to spend a significant portion of its life in a marine environment. Scientifically, a true seabird is a bird that has tubular structures on its bill that cover its nostrils.[9] These tubular structures are accompanied by glands that allow for the intake of seawater and the excretion of salt. ‘True seabirds’ are commonly correlated with order Procellariiformes and families Procellariidae and Hydrobatidae, nicknamed “tubenoses”.[10] Penguins, skuas, gulls, terns, the Alcids family, boobies, tropicbirds, frigatebirds, and skimmers are considered seabirds although not all of them are dependant on marine environments. Albatrosses, storm-petrels, petrels and shearwaters, gannets, many cormorants; some pelicans, loons, jaegers, plus a few ducks and sandpipers can also be looped in as seabirds because they favour marine environments.[11] Some herons and shorebirds, as well as some flamingos are also included because they include populations that occupy salt water habitats. Overall, the term ‘seabird’ loosely refers to members of the orders Procellariiformes, Suliformes, and Galliformes, as well as families Sphenicidiae, Laridae, Stercorariidae, Alcidae, Gaviidae, Phaethontidae, and Pelecaniformes.[12]

Shark scare (535163908).jpg

Seabirds tend to be relatively long-lived and invest their resources in a few offspring instead of many. They nest in colonies in close proximity to salt water and most use the ocean as a food source. Their reliance on oceans makes them an effective indicator of ocean and coastal health.[13] Note that as of November 1, 2023, the American Ornithological Society has decided to rename bird species (within their jurisdiction) that were previously referred to using names that were offensive and exclusionary. A newly formed committee will be responsible for the renaming process.[14]

Homosexual Behaviour in Seabirds: Prevalence and Patterns

Homosexual behaviour in seabirds is mostly exhibited in same-sex pair formation and chick rearing; most seabird species do not see same-sex copulation. This phenomenon is not restricted to any specific family or order, manifesting in various seabird species, including gulls, terns, true seabirds, albatrosses, and penguins[1][2][7][15][16]. Exploring the prevalence, patterns, and ecological implications of this behaviour sheds light on the intricate social fabric and adaptive strategies within the avian world. Almost all observed instances of homosexual behaviour in seabirds are of female-female pairs, who have been observed in multiple species to lay supernormal clutches of typically infertile eggs, i.e. 4-6 eggs in comparison to the standard 2-3 eggs, more often.[1][17][18][19] In some species clutches of female-female pairs have significantly lower hatching and fletching success than those of heterosexual pairs.[1][19] The number of female-female pairs increases when there is a surplus of females. Penguins represent the only known example of male-male pairing in seabirds.[16]

Prevalence Rates and Variations in Different Geographic Locations

Given that most species of seabirds exhibit massive ranges that can span multiple continents, geographically specific trends in homosexual behaviours within seabird populations have not been extensively documented. But because male-male relationships are only found in penguin species, this is a behaviour that is only found in the Southern hemisphere since that is where all the species live where the behaviour was observed. While the geographic location has not been conclusively identified as a direct cause of this behaviour in scientific studies, it is noteworthy that penguins in captivity also display this behaviour in various locations across the world.[20][21][22] This global occurrence suggests that environmental and social factors, rather than geographical location, play pivotal roles in influencing or causing this behaviour. Although specific regional trends may not be easily discernible, the consistency of male-male pairing in penguin populations across diverse locations underscores the significance of broader environmental and social factors in shaping the expression of homosexual behaviour in seabirds.

Seasonal and Environmental Influences on Homosexual Behaviour

Nearly all studies on homosexual behaviour in seabirds have indicated a higher frequency of female-female pair formation in populations with a surplus of females. This finding, coupled with the observation of supernormal clutches of infertile eggs, suggests potential implications for the reproductive viability and long-term sustainability of these pairings within specific ecological contexts.[1][17][18][19] Despite the scarcity of comprehensive research on seasonal and environmental factors influencing homosexual behaviour in seabirds, it is noteworthy that this behaviour is observed across various environments worldwide, including in captivity. The global occurrence of homosexual behaviour in seabirds, irrespective of distinct environmental or seasonal influences, challenges the notion of the existence of these influences on this specific behaviour. While the scarcity of research in this area doesn’t allow for definitive conclusion, it does highlight the need for further investigation to better comprehend all factors shaping the prevalence of homosexual behaviour in seabird populations, both in natural habitats and controlled environments.

At the turn of the twentieth century most sexologists agreed that sex-segregated environments produced only temporary homosexual bonds, for example, among prisoners or men aboard ships. Ellis (referring to another sexologist) also included zoo animals among such. The zoo was easily regarded as a place that harbored homosexual behavior simply as an outlet for the biological sex drive. [23]

Theories and Explanations for Homosexual Behaviour in Seabirds

There are numerous theories related to the reasoning for homosexual behaviour in seabirds, related to social and fitness benefits. A frequent explanation for this behaviour is skewed sex ratios among populations, causing a species to create pairings in order to fulfil social needs. In other words, “the natural tendency towards social monogamy in this species is what causes it to persist”. Female pairs may be formed as a last resort to better fitness and experience of females that are unable to find a male. According to a study on a Laysan Albatross colony, female-female pairings don’t have as much reproductive success as female-male pairs, but they have more success than when a female is unable to find a mate.[7]

Bar graph depicting reproductive success of female–female and male–female Laysan albatross pairs on Oahu

The second reasoning for same sex pairs in seabirds is to better fitness and survival. Once again this is due to skewed sex ratios, when a female cannot find a male partner, she will find a female to partner with. Research shows that female-female pairs are less successful than male-female pairs, but are more successful than if the female were to not mate at all. In Albatross, who generally mate long-term, some female-female pairs stayed together even after the sex ratio evened out. The explanation for this could be that a longer amount for time is needed to adapt to cooperation.[7]

In another study of Adélie Penguins Pygoscelis Adeliae, male-male pairs were observed when there was a lack of females in the group. One explanation for this could be high sexual motive but a lack of females, causing the males to attempt to mate with each other. In this species, there is currently no adaptive value found for the male-male mounting, therefore it is most likely a physiological changes in in the absence of female birds. Another argument was that males may derive some benefit from the male-male pairings in that they gain more copulation experience. Male-male pairs may be a mechanism in juvenile males (as is the case in many of the bowerbirds) to facilitate learning of courtship displays from adult males. There is speculation that male-male sexual interactions occur to facilitate social alliances and inclusion, allowing resource exchange required for reproduction.[16] Such homosexual behavior may serve social and/or sexual functions that aren’t related to reproduction; indirect fitness benefits or adaptively neutral but co-occurring with reproductive opportunity.

There are no published theories as to why some species exhibit only one kind of homosexuality, i.e. male-male or female-female, and why other species have demonstrated both types of relationships. Differences in the frequency of same-sex sexual behaviour across different species are also currently inexplicable.[6]

Reproductive Implications of Homosexual Behaviour

Considering the behaviour of Laysan albatross, In female-female pairs, females had lower reproductive success than females in male-female pairs; they raised fewer offspring on average each year, and individual females in female-female pairs produced fewer total offspring. These differences in reproductive output between the pair types would be increased over the lifetime of the birds because females in female-female pairs also appeared to have lower survival rates, which would further reduce their overall fitness compared to females in male-female pairs.[24]

The reduced survival of females in successful female-female pairs likely occurred because the female took the first three-week incubation shift, which typically would be done by the male, and experienced greater nutritional stress because she just laid an egg but could not return to sea to feed.[25]

Waves lajolla.jpg

While the survival of females in failed female-female pairs was high, it didn't lead to improved fitness because these birds did not reproduce. To acquire a male mate, a female in a failed female-female pair needed to breed successfully in a female-female pair or skip a year of breeding and become available for potential mates again. This suggests that competition for male mates may lead to fewer females skipping breeding to hold onto mates even when they are in poor condition, as birds usually skip breeding to improve their body condition.

Conservation and Management Implications of Homosexual Behaviour

From a conservation stance, homosexuality is potentially advantageous for entire populations with skewed sex ratios because homosexual pairs means there is energy being put towards fostering fertilized eggs.[26] In addition, there are instances in which eggs raised by a homosexual pair are from both parenting birds, so both individuals still have a chance to produce offspring.[27] Ultimately, it is difficult to make a generalization about the effect homosexual behaviour has on egg viability and overall population survival. The lack of data on seabirds could be an indicator that more attention should be put on indicative species such as these in order to better understand how coastal ecosystems and their inhabitants are changing in response to anthropogenic causes.[28] More research on coastal species and their role as indicators of ocean and coast line health could shed light on how homosexuality ties into avian conservation. Protection of coastal ecosystems should be supported on a federal, communal, and individual level, especially if there is not enough data to fully understand how these ecosystems are changing in response to habitat degradation/climate change.[8]

Social Implications of Homosexual Behaviour

LGBTQIA+ community

The term “nature” has historically been co-opted to marginalise the LGBTQIA+ community by perpetuating the idea that queer identities are ‘deviant’ from a societal ‘norm’. Heterosexuality has been assumed to be the natural, default sexual orientation of both animals and people, resulting in the common, specifically western and european, concept of heteronormativity. On the other hand, homosexual orientations have been considered unnatural, and therefore wrong and bad. Societal stigmas surrounding homosexuality have consequentially been constructed to insinuate that LGBTQ+ individuals are ‘violating’ an allegedly ‘natural’ state of human being. For sexual reformers, such as Magnus Hirschfeld or Havelock Ellis, including queer animals in their ever-expanding taxonomies presented an opportunity to evidence the naturalness and universality of homosexuality across species and time.[23] Shedding light on the prevalence and activity of same-sex seabird couples holds larger meaning in the previously less accessible field of scientific academia.

Observations of homosexual behavior in birds highlight the natural diversity of sexual behaviours in the animal kingdom. This diversity can be used to challenge anthropocentric views of sexuality and promote acceptance of queer individuals. By recognizing that same-sex pairings and behaviours occur widely in the world, including among seabirds, it becomes evident that diverse sexual orientations are intrinsic to the broader spectrum of life. This understanding fosters inclusivity and serves as a reminder that the richness of sexual diversity is not limited to human societies. Incorporating such observations into discussions surrounding the LGBTQIA+ community encourages a broader and more inclusive perspective on the complexities of sexuality in both human and non-human populations.

In Media

Homosexuality in seabirds has recently gained popularity online, through the documentation of homosexual seabird relationships by several zoos. In 2019 during Pride Month, Denver Zoo revealed that a flamingo couple (Chilean flamingo Lance Bass and American flamingo Freddie Mercury) had been together for several years, and were practising incubation with a dummy egg to practise being surrogate parents.[29] In 2018, same-sex penguin couple Sphen and Magic from an aquarium in Sydney successfully hatched an adopted chick, a similar story to penguins Roy and Silo in Central Park Zoo.[30] At Whipsnade Zoo in Bedfordshire, flamingos Hudson and Blaze gained minor media attention for the same accomplishment.[31] Some of these pairs have inspired other forms of media, such as “Queer Ducks (and Other Animals)”, a children’s book by Eliot Screfer.[32]

While the majority of public attention has been positive, there has also been a good amount of negative attention towards homosexuality in seabirds in captivity. For example, the book “And Tango Makes Three” based on the true story of Roy and Silo is about two male penguins who are given an egg by their zookeeper which they help hatch.[33] This book faced considerable controversy and was frequently challenged in the United States, becoming the sixth-most challenged book between 2010 and 2019.[34] Despite this, the positive attention garnered by documented instances of homosexuality in seabirds offers potential benefits for local conservation efforts.

Criticisms and Controversies

Seabird homosexuality is not a recent finding. Since 1911, if not earlier, penguins have been observed engaging in homosexual behavior. George Murray Levick’s initial documentation of this behaviour among Adélie penguins at Cape Adare characterised it as “depraved”. His report was withheld from public release because it was considered too shocking. Additionally, the only copies that were privately available to research were imbued with Greek letters in the otherwise English text to prevent the content from becoming more widely known. The report was only discovered and published in Polar Record in June 2012, a full century later. Such heteronormative attitudes were prevalent among the older scientific community. In 1906, naturalist Edmund Selous also observed homosexual behavior in an all-male group of ruffs, including one couple, a type of shorebird. He dismissed their behaviour as “mistaking one another for the female”.[35]

Short tailed Albatross1.jpg

It should also be observed that most scientific research on seabird homosexuality is heavily centred around what causes it and what function it serves. Biologically, this is a valid purpose, but it implies that homosexuality is an abnormality; something that is strange and not standard. While low observed instances of homosexuality may be characteristic of some seabird species, there are other species of animals that commonly demonstrate homosexuality. The widespread nature of homosexuality across the animal kingdom suggests that such behavior evolved earlier in time, rather than independently within the lineage of each species that has demonstrated homosexual behavior. Perhaps heterosexuality only appeared after differentiation between different sexes and the recognition of physical differences evolved. Some scientists speculate that traits and behaviours, no matter how old, won’t disappear unless they become detrimental from a selection standpoint. It is entirely possible that homosexuality in birds, much like in other animals, was the baseline, not the alternative.[36]

Conclusion

Homosexuality in seabirds is a well-observed occurrence that is not novel in the animal kingdom. Hatchling success among same-sex pairs varies across species, as well the type of pair (female-female or male-male) and the frequency of same-sex pairings. Homosexual behavior is also thought to play a role in social interactions among birds, and potentially in courting experience. Little is known about the factors that contribute to demonstrations of homosexual behavior, or how prevalent it has been throughout evolutionary history. The most common indication of same-sex pairings is a skewed sex ratio in a population. More research should be done with seabirds to gauge the potential value in their homosexuality from a population standpoint.

Seabirds are highly dependent on the coastal/saltwater environments in which they form colonies. The health of their populations is an evident indicator of habitat health, making them important in conservation. Seabirds may have a larger role to play in the monitoring of coastal and saltwater habitats and future land management. The publicity received by certain homosexual individuals from various zoos could also aid conservation efforts by garnering public interest.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Conover, M. R. (1983). Female-Female Pairings in Caspian Terns. The Condor, 85(3), 346. https://doi.org/10.2307/1367073
  2. ↑ 2.0 2.1 Conover, M. R., & Hunt, G. L. (1984). Female-Female Pairing and Sex Ratios in Gulls: An Historical Perspective. The Wilson Bulletin, 96(4), 619–625. https://www.jstor.org/stable/4161995
  3. ↑ Conover, M. R., Miller, D. E., & Hunt, G. L. (1979). Female-Female Pairs and Other Unusual Reproductive Associations in Ring-Billed and California Gulls. The Auk, 96(1), 6–9. https://doi.org/10.1093/auk/96.1.6
  4. ↑ Fitch, M. (1980). Monogamy, Polygamy, and Female-Female Pairs in Herring Gulls. Proceedings of the Colonial Waterbird Group, 3, 44–48. https://www.jstor.org/stable/4626696
  5. ↑ Shugart, G. W., Fitch, M. A., & Fox, G. A. (1988). Female Pairing: A Reproductive Strategy for Herring Gulls? The Condor, 90(4), 933–935. https://doi.org/10.2307/1368851
  6. ↑ 6.0 6.1 MacFarlane, G. R., Blomberg, S. P., Kaplan, G., & Rogers, L. J. (2006). Same-sex sexual behavior in birds: expression is related to social mating system and state of development at hatching. Behavioral Ecology, 18(1), 21–33. https://doi.org/10.1093/beheco/arl065
  7. ↑ 7.0 7.1 7.2 7.3 Young, Lindsey; Brenda, Zaun; VanderWerf, Eric (August 23, 2008). "Successful same-sex pairing in Laysan albatross". Biology Letters. 4: 323–325 – via PubMed Central.
  8. ↑ 8.0 8.1 NOAA Fisheries. (2022, March 14). What Makes a Bird a Seabird? | NOAA Fisheries. NOAA. https://www.fisheries.noaa.gov/science-blog/what-makes-bird-seabird
  9. ↑ NOAA Fisheries. (2022, March 14). What Makes a Bird a Seabird? | NOAA Fisheries. NOAA. https://www.fisheries.noaa.gov/science-blog/what-makes-bird-seabird
  10. ↑ Fulmar, Shearwaters & Storm Petrels | Center for Coastal Studies. (n.d.). Coastalstudies.org. Retrieved December 15, 2023, from https://coastalstudies.org/connect-learn/stellwagen-bank-national-marine-sanctuary/sea-birds/fulmar-shearwaters-storm-petrels/
  11. ↑ Lowe, J. (2022, December 2). Seabirds: Nature’s Winged Mariners. American Bird Conservancy. https://abcbirds.org/blog/seabirds/
  12. ↑ The Cornell Lab of Ornithology. (n.d.). Explore Taxonomy - Birds of the World. Birdsoftheworld.org. https://birdsoftheworld.org/bow/species
  13. ↑ Seabirds. (n.d.). www.noaa.gov. https://www.noaa.gov/seabirds
  14. ↑ The American Ornithological Society Will Change the English Names of Bird Species Named After People. (n.d.). American Ornithological Society. https://americanornithology.org/about/english-bird-names-project/
  15. ↑ Amundsen, T., & Lifjeld, J. T. (2000). Molecular Evidence for Extrapair Paternity and Female-Female Pairs in Antarctic Petrels. The Auk, 117(4), 1042–1047. https://doi.org/10.2307/4089648
  16. ↑ 16.0 16.1 16.2 Davis, Lloyd; Hunter, Fiona; Harcourt, Robert; Heath, Sue (April 1997). "Reciprocal Homosexual Mounting in Adélie PenguinsPygoscelis adeliae". Austral Ornithology. 98: 136–137 – via Taylor & Francis Online.
  17. ↑ 17.0 17.1 Betleja, J., Skórka, P., & Zielinska, M. (2007). Super-normal Clutches and Female-female Pairs in Gulls and Terns Breeding in Poland. Waterbirds, 30(4), 624–629. https://doi.org/10.1675/1524-4695(2007)030%5B0624:scafpi%5D2.0.co;2
  18. ↑ 18.0 18.1 Hunt, G. L., & Hunt, M. W. (1977). Female-Female Pairing in Western Gulls (Larus occidentalis) in Southern California. Science, 196(4297), 1466–1467. https://doi.org/10.1126/science.196.4297.1466
  19. ↑ 19.0 19.1 19.2 Kovacs, K. M., & Ryder, J. P. (1983). Reproductive Performance of Female-Female Pairs and Polygynous Trios of Ring-Billed Gulls. The Auk, 100(3), 658–669. https://www.jstor.org/stable/4086468
  20. ↑ Cardoze, Cristina. "Gay Penguins". Timeless Spirit Magazine. Retrieved December 15, 2023.
  21. ↑ "Denmark's Gay Penguins Become Fathers". HuffPost. February 2, 2016. Retrieved December 15, 2023.
  22. ↑ "Cold Shoulder for Swedish Seductresses". Deutsche Welle. February 10, 2005. Retrieved December 15, 2023.
  23. ↑ 23.0 23.1 Szczygielska, M. (2022). Animal Sex in Public. Environmental Humanities, 14(3), 641–660. https://doi.org/10.1215/22011919-9962948
  24. ↑ Young, L. C., & VanderWerf, E. A. (2013). "Adaptive value of same-sex pairing in Laysan albatross." Proceedings of the Royal Society B: Biological Sciences, 281(1775), 20132473–20132473. https://doi.org/10.1098/rspb.2013.2473
  25. ↑ Fisher, H. I. (1975). The Relationship between Deferred Breeding and Mortality in the Laysan Albatross. The Auk, 92(3), 433–441. https://doi.org/10.2307/4084599
  26. ↑ MacFarlane, G. R., Blomberg, S. P., Kaplan, G., Rogers, L. J. (2007). Same-sex sexual behavior in birds: expression is related to social mating system and state of development at hatching, Behavioral Ecology, 18-1, 21–33, https://doi.org/10.1093/beheco/arl065
  27. ↑ Young, L. C., Zaun, B. J., & VanderWerf, E. A. (2008). Successful same-sex pairing in Laysan albatross. Biology Letters, 4(4), 323–325. https://doi.org/10.1098/rsbl.2008.0191
  28. ↑ Mahala, G. (2015, February). Seabirds and Songbirds: Habitat Preferences, Conservation and Migratory Behavior – Nova Science Publishers. https://novapublishers.com/shop/seabirds-and-songbirds-habitat-preferences-conservation-and-migratory-behavior/
  29. ↑ Holcombe, Madeline (June 12, 2019). "Denver Zoo shares the story of same-sex flamingo couple Lance Bass and Freddie Mercury". CNN. Retrieved December 15, 2023.
  30. ↑ Kolirin, Lianne (October 26, 2018). "Same-sex penguins become parents". CNN. Retrieved December 15, 2023.
  31. ↑ Penketh-King, Charlotte (August 10, 2022). "'Gay' flamingo fathers raise abandoned chick as their own". Independent. Retrieved December 15, 2023.
  32. ↑ Schrefer, Eliot (2022). Queer Ducks (and Other Animals): The Natural World of Animal Sexuality. New York City: HarperCollins. ISBN 9780063069510.
  33. ↑ Richardson, Justin & Parnell, Peter (2005). And Tango Makes Three. New York City: Simon & Schuster Children's Publishing. ISBN 0-689-87845-1.
  34. ↑ American Library Association. (2020, September 9). Top 100 most banned and challenged books: 2010-2019. American Library Association. https://www.ala.org/advocacy/bbooks/frequentlychallengedbooks/decade2019
  35. ↑ Yeoman, Barry (July 4, 2023). "Same-Sex Behavior Among Animals Isn't New. Science Is Finally Catching Up". The National Wildlife Federation. Retrieved December 15, 2023.
  36. ↑ Monk, J. D., Giglio, E., Kamath, A., Lambert, M. R., & McDonough, C. E. (2019). An alternative hypothesis for the evolution of same-sex sexual behaviour in animals. Nature Ecology & Evolution, 3(12), 1622–1631. https://doi.org/10.1038/s41559-019-1019-7
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