The colony-breeding northern bald ibis (Geronticus eremita) is seasonally monogamous, meaning that couples mate with each other for one season, but return to dating the following season. This changes the stability of the pair bond during the year, with strong bonds at the beginning and weaker outside the breeding season. However, some couples breed together over several years. Parents need to spend a lot of energy during incubation, in terms of egg production, incubation, and rearing of the young, which can increase stress levels. As a result, there is also an increased parasite infestation in the gastrointestinal tract. [read more]

Puehringer-Sturmayr, V., Wascher, C.A.F., Loretto, M.-C., Palme, R., Stoewe, M., Kotrschal, K., Frigerio, D. Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions. PLOS ONE, 2018 Doi: 10.1371/journal.pone.0191441