Observation by Nikki Whittern:
August 8th, 2019, a crew aboard the search vessel, the Tiglax, arrived at Bogoslof. The crew were the first people to be there since its 2017 eruption. Since 2017, the island has changed immensely. It had endured a number of changes in the past few years, and not just in size. Prior to the eruption in 2017 it was noted that the there were gulls that inhabited the island, but there were not nests or chicks on the island. After our visit to to the island this past week, we noted that the general bird population was abundant and there were in fact gull chicks and nesting gulls. We also did notice that there was a number of puffin burrows in the volcanic sand. Attached below is a picture of the gull chicks, all seemingly very healthy and doing well. In addition to the chicks, we saw juvenile gulls as well as adults of course, a variety of ages amongst the population. Although the birds that we saw seemed to be healthy, there was also a handful of dead birds scattered throughout the island. I wonder what might have caused the island to become habitable for the gull chicks, and what is killing these birds?
I’ve been curious as to what might have caused the gulls to be able to nest their chicks on Bogoslof after the eruption. One reason that I thought to why this might have happened is change in environment. As we know, the island has changed drastically geographically, growing in size and height. Maybe with the change in the land the gulls thought the land to be more favorable than before. I noticed that most of the gulls nested on an elevated ridge leading up the peak, away from the seals. Maybe with the change of the land they felt more protected and more comfortable to nest? This is just an idea as to why this might have occurred.
As for the dead birds, lately there has been an increase in the number of dead birds in the surrounding area. In Unalaska, there has been a decline in bird population as well. Just in one location, there were 18 dead birds washed up on the beach. Maybe this is tied to a larger issue and larger than just Bogoslof.
Nora Rojek, Wildlife Biologist with the Alaska Maritime National Wildlife Refuge, writes:
Thank you for sending your message to the Alaska Maritime NWR regarding Nikki Whittern's observation and questions. Nikki was able to join our refuge staff on our research vessel, the R/V Tiglax in August for a research trip in the eastern Aleutians that included a stop at Bogoslof Island. I was not on that particular trip, but I am a biologist at the refuge that has been actively involved in research at Bogoslof. My particular focus is monitoring the seabird colonies on the island.
A couple clarifications to the observation submitted. The 8 August 2019 trip was not the first refuge visit since the last eruption event that ended in August 2017. In August 2018, we had a diverse team of scientists visit the island for first time to initiate post-eruption studies. This team visited the island again in July 2019 to continue post-eruption studies. In August 2019, there were two more refuge trips to the island, one in which Nikki participated and a second trip with marine mammal biologists from NOAA (National Oceanic and Atmospheric Association), National Marine Fisheries Service (that trip focused on surveying northern fur seals and Steller's sea lions).
Since the last eruption event, most seabird species that previously nested on the island have returned and made attempts to breed again. This includes glaucous-winged gulls and tufted puffins, which were nesting prior to the eruption. Many seabird species have fidelity to their colony location; thus, the birds returned to a much changed island and continued to attempt to breed there, with the habitat changed to various degrees depending on the species' needs. The glaucous-winged gulls did attempt to breed the last two seasons (and produced chicks) but the habitat is not currently ideal; for example material for building nests was extremely limited and no vegetation was available to provide cover. As for Nikki's observation of dead birds, in an active seabird colony there will always be deaths that occur during the coarse of the season. Given that Bogoslof now lacks soil and vegetation, those carcasses are quite obvious. But in addition, in particular for the glaucous-winged gulls, which were able to produce chicks, the chicks are currently lacking protective cover. Normally, young gull chicks would be able to hide from predators within vegetation. The only source for hiding for the gull chicks at this time is under boulders or within burrows that tufted puffins have been working hard at digging through the volcanic material. In addition, on the July visit this year, I observed two bald eagles on the island, and the eagles were foraging on the island (gull chicks out in the open would be an easy target).
Bogoslof Island