North to the land of liquid sunshine and red-legged kittiwakes – Linking individual foraging behaviour and physiology to survival and reproductive output

My name is Rachael Orben and I am a postdoctoral scholar affiliated with both the Seabird Oceanography Lab and the GEMM Lab here at Hatfield Marine Science Center. I am writing this from Anchorage, Alaska where Abram (a Master’s student at San Jose State University) and I are just finishing gear gathering and shopping before flying on to St George Island to spend the end of May and June observing, tracking, and sampling red-legged kittiwakes.

This video is taken looking down to the beach from the top of High Bluffs, St George Island.  Turn up the volume!

Just a little bit of background

Red-legged kittiwakes are endemic to the Bering Sea and most of their population nests on the cliffs on St George Island. St George is one of the Pribilof Islands located in the southeastern Bering Sea and is home to over a million nesting seabirds including auklets, cormorants, kittiwakes, murres, and puffins.  The Pribilofs are also known for the large rookeries of Northern Fur Seals (http://www.afsc.noaa.gov/nmml/education/pinnipeds/northfs.php).  St. George has a small Aleut community (http://www.apiai.org/tribes/st-george/) so we will be living in town and commuting by ATV and foot to the bird cliffs.

 

Click on the link below – Can you spot the red-legged kittiwake?

SeabirdsofPribilofs

Photo credits: Caitlin Kroeger

 

We would like to know how individual foraging behaviour and physiology influence reproductive success and then how these might carry over to wintering behaviour.

 

Tracking: We will be using GPS dataloggers (10g) and geolocation/wet-dry dataloggers (1g) to track movements and foraging behaviour of red-legged kittiwakes during incubation and overwinter.

GPS
GPS Logger from Rachel’s Kittiwake study

 

 

Physiology: When we catch birds we will take physiological samples to measure individual stress levels, mercury loads, and body condition that we can link to foraging behaviour.

 

Observations: We will observe the birds that we track so that we know when eggs are laid, chicks hatch and fledge so that foraging and physiology can be connected to these measures of breeding success.  And next year we will return and resight these birds to measure survival.

 

This study is funded by the North Pacific Research Board (http://www.nprb.org/) with additional support from OceanClassrooms (http://oceanclassrooms.com/) for pre-breeding tracking.  I also have been writing short blogs about project with the Seabird Youth Network aimed for middle schoolers that you can check out here:  (http://seabirdyouth.org/category/kittiwake-behavior/)

 

Internet access will be intermittent on St George, but I hope to periodically post updates via Twitter @RachaelOrben (#OCGrants), Instagram @raorben, and the Seabird Youth Network Blog.

CliffsofStGeorge
Cliffs of St. George

 

Seabird Research on the Western Antarctic Peninsula

I’d venture to say that I’m not the first field biologist to stare into the distance past my computer for a long while before deciding that trying to describe the smell of a seabird colony in a blog was futile.

My name is Erin Pickett and I am a graduate student at OSU’s Marine Mammal Institute. I am affiliated with the Biotelemetry and Behavioral Ecology Laboratory, a sister-lab of GEMM, and am here to share my recent experience conducting field research in Antarctica.

I’ve recently returned from a field season at Palmer station on Anvers Island, along the Western Antarctic Peninsula. Throughout the month of January I was collecting data for my masters’ project, while partaking in an on-going study conducted by the Palmer Long Term Ecological Research (LTER) program. I was fortunate enough to join the seabird research team at Palmer, a group that has been monitoring the area’s breeding seabirds for over two decades. January is the team’s busiest Antarctic summer month as the seabirds are in the midst of their annual breeding season. Our primary focus was studying the foraging ecology and demography of Adelie penguins; however, we also monitored Chinstrap and Gentoo penguins, southern giant-petrels, brown and south polar skuas, and blue-eyed shags. Before I delve into a description of this research, I’ll tell you a bit more about what it’s like to work in Antarctica.

It became quickly apparent to me that working with a team of experienced field biologists who have spent a collective thirty or so seasons in Antarctica meant that I would be the only one distracted by the scenery. This situation was exacerbated by the fact that I had never witnessed snow falling before I had arrived in Antarctica. I tried to play it cool, but inevitably rolled down every snow-covered hill I came across, and I couldn’t help but stop and stare into the sky every time it snowed.

There might have been some misunderstanding when in an email to a friend I referred to the weather as balmy. By Antarctic standards this was true, the average daily temperature hovered around 35°F. By my Hawaii-born standards, it was only balmy once I donned three or four layers, slipped toe warmers in my boots, and sipped on hot coffee while I hiked up a hill. Still, I considered myself lucky to have escaped my first Oregon winter by travelling south.

At Palmer I quickly learned that birders don’t come in for lunch. I adjusted my rations accordingly, although I have to admit that my “emergency food” in my “emergency boat bag” got eaten despite the fact that no real (non-hunger related) emergencies occurred. Every day after packing lunch and suiting up, we would load a small zodiac with our gear and set off to work on the numerous islands surrounding the station where seabirds were nesting.

One of the main objectives of the Palmer LTER program is to research the effects of climate variability and change on the marine ecosystem surrounding Palmer station. As an apex predator, the Adelie penguin plays a focal role in this project by providing insight into ecosystem-wide changes in the marine environment and the surrounding coastal habitat. Over the last four decades, Adelie penguins on the Western Antarctic Peninsula have experienced a decline of over 85% of their population. During this same time period Gentoo and Chinstrap penguins, who were previously unknown in this area, established founder colonies and they have been increasing in number ever since.

These recent population trends have been alarming and have driven Palmer LTER research objectives aimed at understand the mechanisms behind these changes. The proximal cause behind these demographic shifts is a warming-induced loss of sea ice along the peninsula. Over the last 50 years, the average mid-winter temperature in this region has risen by 6°C (five times higher than rise of the average global temperature). By decreasing the extent, duration and concentration of winter sea-ice, this warming has altered marine primary productivity and transformed coastal habitat along the peninsula.

These transformations have caused the climate along the WAP to more closely resemble the warmer and moister sub-Antarctic, rather than the traditionally cold and arid Antarctic it once was. This has resulted in a southward expansion of the ranges of sub-polar, ice-avoiding species (e.g. the Gentoo penguin) and a contraction of the ranges of ice-obligate species (e.g. the Adelie penguin). The strong influence of sea ice on the ranges of these two species makes it difficult to determine whether sea ice driven marine variability has also influenced these trends. The life history of Antarctic krill, a primary prey item of both Adelie and Gentoo penguins, is intricately tied to the seasonality of sea ice. In regions north of Palmer, decreasing sea ice has resulted in declining krill stocks. In the future, trends at Palmer are predicted to mirror those seen in the northern WAP.

For my master’s research, I am working with the seabird biologists at Palmer station to gain a better understanding of how prey variability affects the foraging strategies of Gentoo and Adelie penguins in this area. Specifically, I will be investigating how the foraging behaviors of Adelie and Gentoo penguins change in relation to inter-annual krill recruitment variability. I will be utilizing a long time series of data collected at Palmer by outfitting Adelie and Gentoo penguins with satellite transmitters and time depth recorders. This data will allow me to describe the foraging behavior and effort expended by these penguins on the daily foraging trips they make to feed their chicks. Determining how each of these species responds to prey variability will help us better understand the current community structure of penguins at Palmer. This is important because it will leave us better informed to predict the effects of future ecosystem shifts on the reproductive success and geographic distributions of these two species.

I’m looking forward to sharing more of this research as time goes on. Until then, enjoy the photos!