Research
An Integrative Approach to Sex Role Evolution
“Now if we might assume that the males in the present class have lost some of that ardour which is usual for their sex, so that they no longer search eagerly for the females; or, if we might assume that females have become much more numerous than the males then it is not improbable that females would have been led to court the males, instead of being courted by them.” - Charles Darwin
Classical theory of sex roles has explored reproductive strategies in modular way, studying each different component of sex roles (mating, pair bonding and caring) separately.
In our pursuit of understanding sex differences and sex roles, we've adopted an integrative model that doesn't rely on predefined assumptions. Instead, we let the behavior of animals in their natural environment reveal the intricate pair bonding patterns, parental care, and mating systems. Our unique approach disentangles the complex web of causes, consequences, and feedback loops between the different components of sex roles. We view mating and parental care patterns as interrelated elements, both intricately linked to the animals' states and interactions.
We employ diverse scientific methods from ecology, genetics, demography, modeling, and molecular biology to understand this dynamic. Our approach involves three key methods: field studies, comparative analysis, and dynamic game theory modeling to tackle sex role mysteries.
Dynamic sex roles in shorebird parental care. Diagram highlights differences in the duration of male and female parental care across the typical stages of offspring development from incubation, brood care to extended care after fledging for four example species of shorebirds: (a) Eurasian Dotterel, (b) Kentish Plover, (c) Eurasian Oystercatcher and (d) Pectoral Sandpiper. Taken from Székely et al. 2023.We mainly focus on understanding sex role evolution in shorebirds, including plovers, sandpipers, and related species. Shorebirds are an ideal group for our research due to their remarkable diversity in breeding systems, parenting behaviors, and sexual size dimorphism. They exhibit a wide range of parenting strategies, including biparental care, uniparental care, and cooperative breeding. This diversity is associated with variations in breeding systems and has evolved independently multiple times. Even closely related species within this group show a range of mating systems, making shorebirds an excellent model for studying sex role evolution
Key Conceptual Publications
Székely, T., Carmona‐Isunza, M. C., Engel, N., Halimubieke, N., Jones, W., Kubelka, V., Rice, R., Tanner, C. E., Tóth, Z., Valdebenito, J., Wanders, K., & McDonald, G. C. (2023). The causes and implications of sex role diversity in shorebird breeding systems. Ibis. DOI: 10.1111/ibi.13277 📄
Amano, T., Székely, T., Sandel, B., Nagy, S., Mundkur, T., Langendoen, T., Blanco, D., Soykan, C. U. & Sutherland, W. J. (2018). Successful conservation of global waterbird populations depends on effective governance. Nature, 553(7687), 199-202. DOI: 10.1038/nature25139 📄
Eberhart-Phillips, L. J., Küpper*, C., Miller, T. E. X., Cruz-López, M., Maher, K. H., dos Remedios, N., Stoffel, M. A., Hoffman*, J. I., Krüger*, O. & Székely*, T. 2017. Adult sex ratio bias in snowy plovers is driven by sex-specific early survival: implications for mating systems and population growth. Proceedings of The National Academy of Sciences US, 114: E5474-E5481. *Joint senior authors. DOI: 10.1073/pnas.1620043114 📄
D'Urban Jackson, J., Dos Remedios, N., Maher, K. H., Zefania, S., Haig, S., Oyler-McCance, S., Blomqvist, O., Burke, T., Bruford, M. W., Székely, T.* & Küpper, C.* (2017). Polygamy slows down population divergence in shorebirds. Evolution, 71(5), 1313-1326. *Equal contribution. DOI: 10.1111/evo.13212 📄
Székely, T., Webb, J. N., & Cuthill, I. C. (2000). Mating patterns, sexual selection and parental care: an integrative approach. In Vertebrate mating systems (pp. 159-185). DOI: 10.1142/9789812793584_0008 📄
View publications listed of the following topics below. The publications listed are five key recent publications produced in Tamás Szekely's Lab of each topic. PDFs for all publications are available. Current and former lab member are highlighted in bold.
Mate selection in animals is the process of choosing reproductive partners, which varies across species, involving elaborate courtship rituals, subtle cues, and diverse strategies that impact genetic diversity and fitness. Gaps in our knowledge persist, including the underlying mechanisms of mate choice and the influence of environmental factors on this crucial aspect of animal behavior.
Through our research, we have discovered that breeding systems, natural and social environmental conditions, and sexual dimorphism all play crucial roles in shaping these patterns. We have shown how polygamous and monogamous populations can exhibit differences in courtship behavior and sex biases over the breeding season, shedding light on the dynamic nature of mate selection. Moreover, we documented the presence of sex-biased ornamentation, vocalizations, and territorial behaviors in different. Our focus is now on integrating spatial, temporal and within-population variation in breeding systems and environmental conditions that may influence mate selection.
Key Recent Publications
Song, Z., Liker, A., Liu, Y., & Székely, T. (2022). Evolution of social organization: phylogenetic analyses of ecology and sexual selection in weavers. The American Naturalist, 200(2), 250-263. DOI: 10.1086/720270 📄
Fresneau, N., Lee, Y. F., Lee, W. C., Kosztolányi, A., Székely, T., & Liker, A. (2021). Sex Role Reversal and High Frequency of Social Polyandry in the Pheasant-Tailed Jacana (Hydrophasianus chirurgus). Frontiers in Ecology and Evolution, 9, 742588. DOI: 10.3389/fevo.2021.742588 📄
McDonald, G. C., Engel, N., Ratão, S. S., Székely, T., & Kosztolányi, A. (2020). The impact of social structure on breeding strategies in an island bird. Scientific Reports, 10(1), 13872. DOI: 10.1038/s41598-020-70595-w 📄
Carmona-Isunza, M. C., Küpper, C., Serrano-Meneses, M. A., & Székely, T. (2015). Courtship behavior differs between monogamous and polygamous plovers. Behavioral ecology and sociobiology, 69, 2035-2042. DOI: 10.1007/s00265-015-2014-x 📄
Serrano-Meneses, M. A., Córdoba-Aguilar, A., Méndez, V., Layen, S. J., & Székely, T. (2007). Sexual size dimorphism in the American rubyspot: male body size predicts male competition and mating success. Animal Behaviour, 73(6), 987-997. DOI: 10.1016/j.anbehav.2006.08.012 📄
Parental care in animals refers to the behaviors and strategies employed by parents to ensure the survival and well-being of their offspring. This care can take on various forms and strategies, depending on the species. Common examples of parental care include providing food, shelter, protection, and imparting essential skills to the offspring. For example, mammals often exhibit extensive parental care, with mothers nursing and nurturing their young. Birds may construct nests and feed their chicks, while certain fish species guard their eggs against predators. In contrast, parental care in amphibians and reptiles can exhibit significant variation, ranging from species with minimal parental investment, limited to providing a safe environment for eggs, to those where parents actively defend and nurture their young.
The investigation of individual and environmental factors predicting the diversity of parental care in the animal kingdom has been a long-standing research focus. However, our lab has made two novel contributions that significantly advanced the field. First, we demonstrated that the social environment, particularly the adult sex ratio, plays a critical role in predicting parental cooperation across various taxa. Second, we uncovered that parental care strategies are adaptive and function to enhance individual reproductive success.
Key Recent Publications
Mokos, J., Scheuring, I., Liker, A., Freckleton, R. P., & Székely, T. (2021). Degree of anisogamy is unrelated to the intensity of sexual selection. Scientific reports, 11(1), 19424. DOI: 10.1038/s41598-021-98616-2 📄
Engel, N., Végvári, Z., Rice, R., Kubelka, V., & Székely, T. (2020). Incubating parents serve as visual cues to predators in Kentish plover (Charadrius alexandrinus). PLoS One, 15(7), e0236489. DOI: 10.1371/journal.pone.0236489 📄
Vági, B., Végvári, Z., Liker, A., Freckleton, R. P., & Székely, T. (2019). Parental care and the evolution of terrestriality in frogs. Proceedings of the Royal Society B, 286(1900), 20182737. DOI: 10.1098/rspb.2018.2737 📄
Vincze, O., Kosztolányi, A., Barta, Z., Küpper, C., Alrashidi, M., Amat, J. A., Argüelles Ticó, A., Burns, F., Cavitt, J., Conway, W. C., Cruz-López, m., Desucre-Medrano, A. E., dos Remedios, N., Figuerola, J., Galindo-Espinosa, D., García-Peña, G. E., Gómez Del Angel, S., Gratto-Trevor, C., Jönsson, P., Lloyd, P., Montalvo, T., Parra, J. E., Pruner, R., Que, P., Liu, Y., Saalfeld, S. T., Schulz, R., Serra, L., St Clair, J. J. H., Stenzel, L. E., Weston, M. A., Yasué, M., Zefania, S. & Székely, T. (2017). Parental cooperation in a changing climate: fluctuating environments predict shifts in care division. Global Ecology and Biogeography, 26(3), 347-358. DOI: 10.1111/geb.12540 📄
Ball, A. D., van Dijk, R. E., Lloyd, P., Pogány, Á., Dawson, D. A., Dorus, S., Bowie, R. C. K., Burke, T. & Székely, T. (2016). Levels of extra‐pair paternity are associated with parental care in penduline tits (Remizidae). Ibis, 159(2), 449-455. DOI: 10.1111/ibi.12446 📄
Pair-bonding in animals is a selective affiliation between two individual mating partners, which occurs before mating and often continues into parental care, and this phenomenon exhibits intriguing variations across different species. It involves intricate bonding rituals, subtle behaviors, and a variety of strategies that can significantly impact the stability and success of these bonds. Nevertheless, there are still gaps in our understanding of the mechanisms that underlie pair-bonding and the ways in which environmental factors influence this crucial aspect of animal behavior.
Our research has revealed that factors such as prolactin, plumage ornamentation and developmental modes all play essential roles in shaping the patterns of pair-bonding. We've uncovered how populations with different genetic similarities, and the differences in reproductive costs in each sex influence the strength of these pair bonds over the course of the breeding season. Additionally, we've documented the importance of adult sex ratio as a critical signal in the pair-bonding process, helping individuals identify suitable partners and strengthen their bonds. Our current focus is to determine the causal influence of pair-bonding on mating decision, through experimental manipulations and phylogenetic comparative analyses across taxa.
Key Recent Publications
McDonald, G. C., Cuthill, I. C., Székely, T., & Kosztolányi, A. (2023). Remating opportunities and low costs underlie maternal desertion. Evolution, 77(1), 97-109. DOI: 10.1093/evolut/qpac020 📄
Halimubieke, N., Kupán, K., Valdebenito, J. O., Kubelka, V., Carmona-Isunza, M. C., Burgas, D., Catlin, D., St Clair, J. J. H., Cohen, J., Figuerola, J., Yasué, M., Johnson, M., Mencarelli, M., Cruz-López, M., Stantial, M., Weston, M. A., Lloyd, P., Que, P., Montalvo, T., Bansal, U., McDonald, G. C., Liu, Y., Kosztolányi, A. & Székely, T. (2020). Successful breeding predicts divorce in plovers. Scientific Reports, 10(1), 15576. DOI: 10.1038/s41598-020-72521-6 📄
Wang, Y., Székely, T., Zhang, Z., & Que, P. (2020). Prolactin concentrations predict parental investment and nest survival in a free-living shorebird. Hormones and Behavior, 119, 104633. DOI: 10.1016/j.yhbeh.2019.104633 📄
Halimubieke, N., Valdebenito, J. O., Harding, P., Cruz‐López, M., Serrano‐Meneses, M. A., James, R., Kupán, K. & Székely, T. (2019). Mate fidelity in a polygamous shorebird, the snowy plover (Charadrius nivosus). Ecology and Evolution, 9(18), 10734-10745. DOI: 10.1002/ece3.5591 📄
Maher, K. H., Eberhart‐Phillips, L. J., Kosztolányi, A., Remedios, N. D., Carmona‐Isunza, M. C., Cruz‐López, M., Zefania, S., St Clair, J. J. H., Alrashidi, M., Weston, M. A., Serrano-Meneses, M. A., Krüger, O., Hoffman, J. I., Székely, T., Burke, T. & Küpper, C. (2017). High fidelity: extra‐pair fertilisations in eight Charadrius plover species are not associated with parental relatedness or social mating system. Journal of Avian Biology, 48(7), 910-920. DOI: 10.1111/jav.01263 📄
We not only delve into the interaction of key components of sex roles but also consider its evolutionary implications. Our research encompasses the exploration of phylogeographic, molecular, and genetic consequences related to mating systems and sex-specific movement patterns.
Our findings have unveiled critical insights into the divergence of subspecies within Kentish and snowy plovers, as well as shedding light on the phylogeography of Eurasian penduline tits. Furthermore, our research underscores the significance of genetic markers in comprehending heterozygosity-fitness correlations within these species. Additionally, our work has contributed to our understanding of avian sex determination and gene flow, revealing substantial levels of gene flow on a continental scale. Moreover, we have demonstrated how social interactions and polygamy can impact population divergence and genetic diversification, emphasizing the importance of conserved transcriptomic profiles in behaviors like monogamy. Furthermore, our studies explore phylogeny, transposable elements, and sex chromosome evolution within the basal lineage of birds. Collectively, our research advances our knowledge of the processes that underlie avian evolution, speciation, and diversification.
Key Recent Publications
Wanders, K., Chen, G., Feng, S., Zhang, G., Székely, T., Bruford, M., Végvári, Z., Eichhorn, G. & Urrutia, A. (2023). Polygamy and purifying selection in birds. Evolution, 77(1), 276-288. DOI: 10.1093/evolut/qpac010 📄
Wei, C., Schweizer, M., Tomkovich, P. S., Arkhipov, V. Y., Romanov, M., Martinez, J., Lin, X., Halimubieke, N., Que, P., Mu, T., Huang, Q., Zhang, Z., Székely, T. & Liu, Y. (2022). Genome-wide data reveal paraphyly in the sand plover complex (Charadrius mongolus/leschenaultii). Ornithology, 139(2), ukab085. DOI: 10.1093/ornithology/ukab085 📄
Dos Remedios, N., Küpper, C., Székely, T., Zefania, S., Burns, F., Bolton, M., & Lee, P. L. (2020). Genetic structure among Charadrius plovers on the African mainland and islands of Madagascar and St Helena. Ibis, 162(1), 104-118. DOI: 10.1111/ibi.12694 📄
Cunningham, C., Parra, J. E., Coals, L., Beltrán, M., Zefania, S., & Székely, T. (2018). Social interactions predict genetic diversification: an experimental manipulation in shorebirds. Behavioral Ecology, 29(3), 609-618. DOI: 10.1093/beheco/ary012 📄
Eberhart‐Phillips, L. J., Hoffman, J. I., Brede, E. G., Zefania, S., Kamrad, M. J., Székely, T., & Bruford, M. W. (2015). Contrasting genetic diversity and population structure among three sympatric Madagascan shorebirds: parallels with rarity, endemism, and dispersal. Ecology and Evolution, 5(5), 997-1010. DOI: 10.1002/ece3.1393 📄
Our lab has conducted a diverse range of research in the field of natural history, with a focus on various avian species. Notably, we've explored topics such as aggression among female lapwings and the survival of Kentish plovers in Turkey. In Madagascar, our work has contributed to understanding the breeding distribution and ecology of endangered species like the Madagascar plover. These studies have employed innovative methods, such as habitat suitability models to estimate population sizes.
Additionally, our lab has investigated intriguing phenomena in bird behavior, including unusual incubation sex-roles in the rufous-chested dotterel. Our lab's contributions to the field of natural history are extensive and include publications that provide valuable insights into the ecology and conservation of various bird species, as well as topics like animal migration and amphibian reproductive strategies.
Key Recent Publications
Ding, P., Song, Z., Liu, Y., Székely, T., Shi, L., & Turghan, M. A. (2023). Variations in the Reproductive Strategies of Different Charadrius alexandrinus Populations in Xinjiang, China. Animals, 13(14), 2260. DOI: 10.3390/ani13142260 📄
Vági, B & T. Székely. (2023). Diversity of reproductive strategies in Amphibia. In: Moreno-Rueda, G. & M. Comas (eds). Evolutionary Ecology of Amphibians. CRC Press, Boc Raton. DOI: 10.1201/9781003093312 📄
Zefania, S. & T. Székely. (2022). Charadriidae: Charadrius, plovers. In: Goodman, S. M. (ed.). The new natural history of Madagascar. Princeton, Princeton University Press. DOI: 10.1515/9780691229409 📄
Rice, R., Valdebenito, J. O., Ottensmann, M., Engel, N., Adrião, A., & Székely, T. (2020). Breeding ecology of the Cream-coloured Courser in Cape Verde. Ostrich, 91(1), 65-73. DOI: 10.2989/00306525.2019.1704900 📄
Almalki, M., Shobrak, M., AlRashidi, M., dos Remedios, N., & Székely, T. (2015). Sex differences and breeding ecology of a burrow-breeding shorebird, the Crab Plover Dromas ardeola. Wader Study Group Bulletin, 121, 169-176. 📄
Finally, our lab has made significant contributions to the general scientific community through a series of methodological advances in the field of behavioral ecology and evolutionary biology. These advances include pioneering the use of transponder systems for monitoring incubation routines of snowy plovers, enhancing the utility of conserved microsatellite markers in shorebirds, developing a framework for population monitoring in the East Asian-Australasian flyway, and introducing an infrared motion detector system for real-time monitoring of animal preference tests. We have also conducted essential research on molecular sex-typing in shorebirds, optimized next-generation sequencing transcriptome annotation for species lacking sequenced genomes, and provided protocols for collecting behavioral data of shorebird populations.
Key Recent Publications
Ancona, S., Dénes, F. V., Krüger, O., Székely, T., & Beissinger, S. R. (2017). Estimating adult sex ratios in nature. Philosophical Transactions of the Royal Society B: Biological Sciences, 372(1729), 20160313. DOI: 10.1098/rstb.2016.0313 📄
Székely T. & Kubelka V. (2019). Protocol for collecting behavioural data for ÉLVONAL shorebird project, version 2. Unpublished report, University of Debrecen, Hungary. 📄
AlRashidi, M., Long, P. R., O'Connell, M., Shobrak, M., & Székely, T. (2011). Use of remote sensing to identify suitable breeding habitat for the Kentish Plover and estimate population size along the western coast of Saudi Arabia. Wader Study Group Bulletin, 118(1), 32-39. waderstudygroup.org/article/1757/ 📄
Székely, T., Kis, J., & Kosztolányi, A. (2004). Using a mobile hide in wader research. Wader Study Group Bulletin, 103, 40-41. 📄
Kosztolányi, A., & Székely, T. (2002). Using a transponder system to monitor incubation routines of Snowy Plovers. Journal of Field Ornithology, 199-205. jstor.org/stable/4131146 📄