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title: "Sexual dimorphism and foraging trips of the Laysan Albatross on Guadalupe Island"
---

# Sexual dimorphism and foraging trips of the Laysan Albatross on Guadalupe Island

Julio César Hernández Montoya ([Centro de Investigaciones Biológicas del Noroeste](https://www.cibnor.gob.mx/component/content/article/472), La Paz, Mexico) and colleagues have published open access in the journal [*Animals*](https://www.mdpi.com/journal/animals) on aspects of the biology of Laysan Albatrosses *Phoebastria immutabilis* breeding on Mexico’s [Guadalupe Island](https://www.acap.aq/en/news/news-archive/60-2013-news-archive/1412-acap-breeding-sites-no-34-isla-guadalupe-mexico-supports-an-increasing-population-of-laysan-albatrosses-despite-predation-by-feral-cats?highlight=WyJndWFkYWx1cGUiLCJubyIsIidubyJd).

 The paper’s abstract follows:

 “Sexual dimorphism in the Laysan albatross (*Phoebastria immutabilis*) on Guadalupe Island was evaluated during the breeding seasons of 2015–2018 by measuring and comparing 10 morphological attributes: cranial length, bill length, nostril length, cranial width, bill height, bill width, tarsus length, closed wing length, opened wing length, and wingspan length in reproductive adults (n = 135). Males were larger than females across all traits (Student’s t-test, p < 0.05, p < 0.05). We created a logistic model using stepwise regression to predict sex based on morphological variables. This model indicated four significant morphological predictor variables (z < 0.05) and was able to successfully predict the sex of P. immutabilis individuals in more than 90% of the cases. Based on these predictor variables, a web app was developed to determine the sex of the Laysan albatross in the field, providing a non-invasive method for rapid data collection that reduces costs and handling times while improving conservation efforts. We tracked Laysan albatross (n = 36) during breeding seasons and found no significant differences between females and males for either trip length (GLMM, F = 0.017, DF = 1, 1, p = 0.917 > 0.05) or maximum trip distance (GLMM, F = 0.374, DF = 1, 1, p = 0.651 > 0.05). Our results suggest that both sexes show a strong preference to travel to highly productive coastal waters northeast of the breeding colony that are influenced by the California Current. The present research will serve to establish a baseline to protect this species on Guadalupe Island and highlights the importance of understanding sexual dimorphism in at-risk seabird species.”

 ![](https://acap.aq/images/stories/acap/Islands/Guadalupe Ross Wanless s.jpg)

 ![](https://acap.aq/images/stories/acap/Birds/Albatrosses/L/Laysan/Guadalupe 16 Ross Wanless s.jpg)

  Guadalupe Island, with a Laysan Albatross family, photographs by Ross Wanless

 **Reference:**

 Hernández Montoy, J.C., Juárez-Rodríguez, M., Méndez-Sánchez, F., Aguirre-Muñoz, A., Rojas-Mayoral, E., Íñigo-Elias, E., Galina-Tessaro, P., Arnaud, G. & Ortega-Rubio, A. 2019. Sexual dimorphism and foraging trips of the Laysan Albatross (*Phoebastria immutabilis*) on Guadalupe Island.  [*Animals* *9*(6), 364 https://doi.org/10.3390/ani9060364](https://www.mdpi.com/2076-2615/9/6/364).

 *John Cooper, ACAP Information Officer, 18 July 2019*