Category: Education

By Brie Drummond, Wildlife Biologist at Alaska Maritime National Wildlife Refuge

A special bird that few people see, red-legged kittiwakes nest on only a few remote islands in the Bering Sea.  With few breeding colonies and a highly specialized diet of myctophid fish, red-legged kittiwakes are especially vulnerable to changes in their breeding and marine foraging habitats, including those brought about by climate change and introduced predators.  All red-legged kittiwakes in Alaska (85% of the global population) breed on Alaska Maritime National Wildlife Refuge.  For the last four decades, Refuge staff have collected extensive data on this species during the summer breeding season, including numbers of birds returning to colonies each year, numbers of chicks hatching and fledging, and what chicks are fed.  However, we know very little about what happens to red-legged kittiwakes the rest of the year.  Research on other seabird species shows that winter conditions can play a large role in both survival and success at the colony the following summer, so we wanted to learn more about what kittiwakes experienced when away from the colony. 


Red-legged kittiwakes (photo by Brie Drummond, AMNWR)

We used geolocation loggers (or geolocators) to record locations and behaviors of red-legged kittiwakes during the winters of 2016-2017 and 2017-2018.  Geolocators are small data recording devices (~1 gram or the size and weight of a large raisin) that attach to a plastic leg band and record light levels and immersion in saltwater.  From those data, we generate twice-daily latitude and longitude positions for each bird and estimate how birds spent their time (flying, sitting on the water, or actively foraging). 

To explore whether red-legged kittiwakes from different colonies had similar wintering locations and behavior, we deployed geolocators on birds from the two largest breeding colonies in Alaska, St. George Island in the Pribilof Islands and Buldir Island in the western Aleutian Islands, separated by1000 kilometers.  We captured and tagged kittiwakes during the summer breeding season when birds were attending nests at the colonies.  Geolocators do not transmit data remotely, so biologists must recapture the birds in subsequent breeding seasons in order to retrieve devices and download data.  For the St. George component of the study, we collaborated with Dr. Rachael Orben, an Oregon State University researcher.

We found where red-legged kittiwakes from the two colonies spent the winters depended on the time of year.  Birds from both locations left their breeding colony in late August or early September.  During the fall and early winter (October-December), St. George kittiwakes were in the Bering Sea whereas Buldir kittiwakes were thousands of miles west off the Russian coast in the Sea of Okhotsk.  However, during late winter (January-March), the two colonies overlapped in their distribution, especially in an area east of the Kuril Islands.  By April, birds were back at their respective breeding colonies.  These patterns were almost identical during the two winters of our study.

From the behavior data, we learned that birds from both colonies had similar activity budgets during the non-breeding season, spending most of the night sitting on water and flying during the day.  Most active foraging occurred the hour before and after dawn; this may reflect foraging for myctophids, which are generally available at the ocean’s surface only at night.

We learned important information about where and how red-legged kittiwakes from Alaska’s two largest colonies spend their time when away from the breeding grounds.  The region east of the Kuril Islands appears to be crucial for the global red-legged kittiwake population; interestingly, this area is a winter vacation hotspot for many other Alaskan seabirds.  We hope to publish these data in a scientific journal soon to share this information with other seabird researchers.

Need a stunning backdrop for your next zoom meeting?  How about a quick virtual yoga break with wildlife?  Are the kids getting you down?  Need new distractions for them where they will also learn something?  Dreaming of escaping to a wild place teeming with wildlife?  Alaska’s Refuges have you covered!  Check out these offerings.

• Eagle, puffin, walrus or salmon to loom over your shoulder during your next zoom meeting.  Download the zoom backgrounds here.
• Arctic Refuge Wildlife Yoga with Refuge Ranger Allyssa Morris. On Facebook here.  Also Kanuti Refuge Wildlife Yoga. and coming soon – Yukon Flats Wildlife Yoga
• Spring ice fishing story time for kids with Selawik National Wildlife Refuge Ranger Brittany Sweeney.
• A hot-off-the presses virtual tour of the Izembek National Wildlife Refuge.  Stunning scenery and impressive wildlife footage of bears, fish and birds highlight this 17-minute film made by Cornell Lab of Ornithology.  Download here.

I am hoping we can embed these urls  maybe the highlighted words would be best to link

Caption:  Would two photos side by side work or not enough width?  Maybe best to stick with one for those who view on phones. If one I am thinking the eagle what do you think?

Alaska Regional Friends Coordinator Helen Strackeljahn models one (some) of the wildlife zoom backgrounds available from Alaska Refuges online.  Helen is our principle contact in the Fish & Wildlife Service and is a great supporter of Friends.

By Delia Vargas-Kretsinger, wildlife biologist at Yukon Flats National Wildlife Refuge

Elodea, the genus for waterweed, can be a nasty plant outside its native range. Known as the first submersed aquatic invasive plant to establish in Alaska, it propagates vegetatively from stem fragments. These fragments hitchhike on boats, trailers and float plane rudders to waterbodies all over Alaska where they can establish and spread quickly. Elodea degrades aquatic habitats by reducing oxygen, increasing sedimentation, altering stream flow and displacing native flora. Dense infestations impede boat navigation into hunting and fishing areas, even hindering floatplane operations.

Rosemary McGuire (FWSCD crew) sampling Bettles floatpond.

Elodea was probably introduced to the Fairbanks area via an aquarium dump. Chena Slough was chock full of Elodea when it was first identified there in 2009 by a couple of Forest Service scientists. Fortuitously, they had a copy of the Introduction to Common Native & Potential Invasive Freshwater Plants in Alaska.

The discovery led invasive species managers to think about where else Elodea had spread. The Fairbanks Soil and Water Conservation District (FSWCD) took the early lead, conducting Elodea surveys in Chena Slough and popular lakes in the Fairbanks North Star Borough, even as fragments continued to flow down the Chena River. A fellow Fairbanksan said in 2015 that Elodea could be seen adrift in the current from the shore of the Chena Pump House Restaurant.

In 2015 I worked with the National Park Service, Fairbanks Soil and Water Conservation District (FSWCD), University of Alaska Fairbanks and other USFWS biologists to survey for Elodea downstream of Fairbanks. It has been found in Totchaket Slough and Manley Hot Springs Slough on the Tanana River, apparently in route to the Yukon River. The Koyukuk, Nowitna, Innoko, Kanuti and Yukon Flats National Wildlife Refuges are all at risk, either downstream of known Elodea infestations or within the dispersal range of floatplanes.   

Data sheet

When we considered the scope of the area and the abundance of waterbodies associated with the Yukon River and its major tributaries (Tanana and Koyukuk Rivers), it became clear pretty quickly that we’d have to weed out waterbodies that did not fit the habitat criteria for Elodea. In flowing systems, Elodea seems to prefer low velocity and clear water. Known infestations on the Tanana were found in sloughs with only one entrance (no upper mouth) so this is something we key into when reviewing aerial and satellite imagery. And, of course, we look for waterbodies with a clear connection to the main river. Then, navigating with an iPad, we search for Elodea from the boat or shore, using throw rakes to sample the water column. GPS coordinates are collected for each throw rake location. Collectively we put in a lot of boat time on these rivers.

Delia Vargas surveying Totchaket Slough

The good news is that even as we survey for Elodea, the FSWCD has begun treating infestations in the Fairbanks area with fluridone, an aquatic herbicide that at extremely low doses can eradicate Elodea but not native flora. To date, fluridone has been applied in Chena and Totchaket Sloughs, Chena Lake and Bathing Beauty Pond.  Birch Lake and Manley Hot Springs Slough will be treated this spring, but the coronavirus may derail that schedule.  Similarly, we had planned to survey the middle Yukon River this summer but the pandemic has put that on hold for now.

We are hopeful that Elodea can be contained and eradicated before it spreads further, but we need your help. Inspect your boat, plane and fishing gear before traveling to other waterbodies. If you see an aquatic plant that looks different, take a photo, note the location and REPORT IT: 1-877-INVASIV (468-2748).  Here’s a great app to help you identify Elodea and other weeds: Help us keep our waters free of invasives!

By John Morton, retired USFWS biologist

I called Pat Walsh, the Supervisory Biologist at Togiak National Wildlife Refuge, to ask him about an interesting article he published this past year in the journal Rangifer.  Titled “Influence of wolf predation on population momentum of the Nushagak Peninsula caribou herd, southwestern Alaska”, it essentially asks if wolf predation can be good for caribou.

Walsh laid out a fascinating ecological story.  During 1997−2007, the nonmigratory caribou herd on the Nushagak Peninsula, located within Togiak Refuge, declined from 1,400 to 500 individuals.  Walsh, working closely with his Alaska Department of Fish and Game State colleague, James Woolington, investigated the time budgets of three wolf packs that used the peninsula during the following five years (2007−2012) to figure out if wolves were responsible for the herd’s decline. During their study, wolf predation steadily increased on the caribou; however, contrary to expectations, the caribou population steadily increased as well!

These two field biologists tracked 20 GPS- and VHF-collared wolves during their study.  They found that only one of three packs regularly used the peninsula. This pack, known as the Ualik Lake pack, spent 35% of its time there.  Its use of the peninsula was disproportionately high in late summer and fall, disproportionately low in winter, and proportional during the caribou calving season in early summer.  The overall wolf use of the Nushagak Peninsula increased in direct response to increasing caribou abundance. Walsh and Woolington concluded that, in this instance, wolf predation was not driving caribou population dynamics.  Instead, the caribou population was the driver and wolves were simply responding to an increasingly abundant food.  The Nushagak herd had previously declined, then increased, due to internal demographic factors apparently unrelated to predation (see graph).

Not all wolf-caribou interactions are the same, and that the geography of the Nushagak Peninsula makes this situation somewhat unique.  The 800 mile² peninsula is narrow enough that this single wolf pack was able to establish its territory near the head of the peninsula, and thus defend the area from other wolves on the mainland.  So, as the Nushagak caribou population increased, the Ualik Lake wolf pack spent more time preying on them, and concurrently (and ironically) spent more time protecting them from predation by other wolves!  Life is not always as it seems. 

Since the conclusion of their study in 2012, the caribou population has continued to increase to the point that habitat damage is evident.  In short, high numbers of caribou may be eating themselves out of house and home.  Wildlife managers have attempted to address this by increasing human harvest through several regulatory changes, but lack of snow in recent winters has prevented snowmachine access, which is the primary transport used by hunters there.  Walsh told me, “We think it’s possible that the Nushagak Peninsula caribou will face winter food shortages in the near future, and may simply walk away”.  Should this happen, local villages could lose an important subsistence resource.

Although wolf predation has not served as a very effective population control for caribou, it is certainly working in the direction of management.  And to answer the question as to whether wolves can be beneficial for caribou, it appears that in this case, it could be that the protection resident wolves provide may be too much.  As Walsh sees it, a bit more predation might prevent degradation of caribou habitat, which could help sustain the caribou population itself.

Walsh and Woolington wrote that the principal reason they conducted their study was to assess whether wolf population control was necessary to prevent the population decline in this herd. Had predator control been instituted at the onset of this study (as requested by local management committees), it is reasonable to believe that the caribou population would have increased as it did.  However, these two seasoned biologists also point out “stakeholders might have incorrectly concluded that wolf control caused the caribou population response.” This case illustrates the importance of careful thought and having sufficient data for both ungulate and predator populations before invoking predator control.