I understand that the pelicans named after the Dalmatian coast of Croatia have not been seen there since the 1950s, and may be considered to be locally extinct. I was not aware of its immense population crash in the previous century when I admired this lone Dalmatian Pelican (Pelecanus crispus). When The Family called out to me, I came running with my camera ready, but I caught the featured photo seconds after a fish had disappeared into its gullet. There is really no understanding of why there was a major drop in the population of one of the largest freshwater birds in the world, but it now has only two breeding populations: a very small one in Mongolia and another larger one somewhat further west in Russia. The ones I saw in Bharatpur’s Keoladeo National Park were winter migrants.
I read the usual stories of hunting (mainly in Mongolia), habitat destruction by draining of swamps (mainly in Russia), and widespread disturbance of nests due to human activity having pushed it into the near-threatened category of the IUCN red list. But interestingly, there have been many investigations in their mysterious decline. It seems that intense parasite infestation is one reason. This was found in other pelican species too. Current thinking rates this as a more significant factor than chemical pollution. This kicked off studies of parasite epidemics and climate change, since the realization that the immune systems of host birds may be stressed in warmer climates.
If you thought that the end result is the disappearance of this species, you could be wrong. It seems that 6000 to 8000 years ago, when the temperatures were about 2 degrees Celsius warmer than today (a time called the Holocene temperature maximum), these pelicans could be found as far north as Denmark. This could happen again, as animals move to parts of the globe more suited to their lifestyles. As the earth warms, egrets have begun nesting and breeding in England in this decade. Strange to think that the tropical birders’ paradise we watched could be in northern Europe in a century.