Tag: Seabird Oceanography Lab

Beyond the Rock: Using Satellite Trackers to Study the Lives of Common Murres

By Stephanie Loredo, Seabird Oceanography Lab, OSU

Photo credit: Seabird Oceanography Lab

Common murres (Uria aalgee) are the most abundant seabird on the Oregon Coast. At least half of the population in the California Current Ecosystem breeds on the Oregon Coast (half a million seabirds). This makes them ecologically important consumers of forage fish, especially during the breeding season when they use state-waters.

While they spend most of their time at sea, murres must come to shore to breed. During this time, they are highly visible by humans as they breed in large masses on rocky islands. While they are not the most agile on land, due to their short and stubby legs, they are actually amazing divers. Their short flipper-like wings help them swim, and they typically reach depths of 30-60m to catch their prey.

Aside from their underwater aviation skills, they make great parents as well. Both parents will incubate and care for their chick – murres only lay one egg a year – until they fledge; once they leave the rock, male murres take full responsibility for their chicks while the moms go on vacation (they worked hard to lay the egg so they need some time to recuperate). After the breeding season, murres leave the rock in large quantities – this is often the last time humans will see them this year in large aggregations from shore.

Despite their omnipresence and importance as a marine predator in Oregon, there is still a lot we don’t know about murres. Where do murres go when they are not breeding? Do they migrate? Where do they feed during the breeding and non-breeding period? What habitat characteristics are associated with feeding areas? By answering these questions, we increase knowledge of murre ecology in Oregon. Moreover, a more comprehensive understanding of the year-round movements of murres aids marine spatial planners take more informed actions on the current decisions regarding offshore renewable energy development. This is what I hope to achieve through my Masters research project at OSU.

Most of what is known about the offshore distribution of murres in Oregon comes from vessel observations. However, vessel data only provide snapshots in time, and not a continuous picture of area-use. Within the Seabird Oceanography Lab (SOL), we are using individual satellite tracking devices to follow the movements of murres associated with the Yaquina Head colony, which is a prominent breeding colony in Oregon located near Newport.

A common murre displaying a satellite tag prior to release.

SOL was able to track 15 common murres associated with the Yaquina Head colony in 2015 and 2016.  These tags were deployed periodically throughout the breeding period and have been successful in tracking birds for up to three months. Thus far, we have tracking data ranging from May to December (only one bird tracked during December).

Tracking data from 2015 and 2016 of murres off the Yaquina Head colony provide an interesting comparison.  In both years, murres experienced warmer ocean conditions, high Bald eagle disturbance rates, and consequently high Western gull egg predation at the colony. Some data also indicate low prey availability.  The combination of all these factors is most likely the reason for the observed reproductive failure at the colony in both years. Tracking data showed that 13 of the 15 birds tagged dispersed from the colony earlier than expected. The maps below summarize the dispersal of birds by year and by time of deployment.

 

Each map (Left: 2015, Right: 2016) illustrates all birds that dispersed from the colony and did not engage in central-place foraging (feeding trips to and from the colony). Sample size: n2015=7, n2016_spring=1, n2016_summer=3.

Most birds made a northward movement and traveled as far north as British Columbia, Canada.  Along their movement north, they used inlets and bays, but one of the most prominent areas used was the Columbia River plume. Birds used the Columbia River mouth area during the summer and fall, with the most time spent there during the summer. Dispersal from the colony was not what we expected; we expected individuals to breed on colony and engage in central-place foraging  (feeding to and from the breeding site) nearshore until mid-August when they usually leave the rock. However, we are still interested in the habitat characteristics of feeding areas and the conditions that led to movement from one feeding area to the next.

Prior to examining habitat associations of murre feeding areas, we must first determine their behavior state at each point location derived from the satellite tags.  After data cleaning and filtering out erroneous locations, we applied a behavioral analysis (Residence in Space and Time method) to determine behaviors associated with each point location. This analysis has allowed us to distinguish between intensive foraging, transiting, and extensive foraging. Extensive foraging locations can be interpreted as a set of locations that are mostly spread out in space, where murres searched for prey. On the other hand, intensive foraging locations can be interpreted as a set of locations that are very close together in space where murres likely found prey, and thus spent more time.

We are finalizing the extraction of environmental data for each point location from satellite data. Once all data are extracted, we can begin analysis for determining what environmental conditions were sought during dispersal and what types of habitats are preferred. Some of the ocean conditions that will be examined are sea surface temperate, wind, upwelling index, and primary net productivity. Some other habitat descriptors we are interested in assessing are substrate, distance to river mouth, salinity, depth, distance to the 200-m isobath, and distance to shore. For now, exploration of data indicates differences in habitat associations by behavior and between seasons.

Sample size means everything in a study like this so I am happy to say that more data is yet to come: SOL plans to deploy 15 more tags during spring and summer of 2017. I am excited to see what the additional tagged murres will do, and whether they will follow a pattern similar to those tracked in 2015 and 2016. However this time around, we will deploy tags as late in the summer/early fall as we can, in hope of acquiring some novel winter data to fill this knowledge gap. If we are successful, we may finally have a better idea of what life is like for common murres during more of the year beyond the rock.

 

Midway Atoll: Two weeks at the largest albatross colony in the world

By Rachael Orben, Postdoctoral Scholar, Seabird Oceanography Lab & Geospatial Ecology of Marine Megafauna Lab, Oregon State University

In January I was extremely lucky to accompany my former PhD advisor, Scott Shaffer to Midway Atoll National Wildlife Refuge in the Papahānaumokuākea Marine National Monument as part of my job as a postdoc working in Rob Suryan’s Seabird Oceanography Lab. We were there with the dual purpose of GPS tracking Laysan and Black-footed albatrosses as part of Scott’s long-term research and to collect fine-scale data on flight behavior to develop collision risk models for wind energy development (in other areas of the species ranges such as Oregon). Here are my impressions of this amazing island.

So many albatrosses! Our approximately four hour flight from Honolulu to Midway landed at night and as we stood around on the dark tarmac greeting the human island residents I could just make out the ghostly glistening outlines of albatrosses by moonlight. But I had to wait until the following morning to really take stock of where I had suddenly landed: Midway Atoll, the largest albatross colony in the world. This was my first trip to the Northwestern Hawaiian Islands, but I have been to other albatross colonies before and Midway is most definitely different.

First of all, it was hot(ish)!

Secondly, I was amazed to see albatrosses nesting everywhere. Unlike the southern hemisphere colonies I have visited, the albatrosses aren’t restricted to their section of the island or even nesting as close to each other as possible. Instead there are nests literally everywhere there might be enough loose substrate! Birds nest in the middle of the roads, in the bike racks (bikes are an easy quick means of transportation), along the paths, next to the extremely loud generator, near piles of old equipment, and around buildings. Hawaiian albatross nests are not much to look at compared to the mud pedestal nests of the southern hemisphere mollymawks (see the photos below) and are often made of just enough sand and vegetation to keep the egg in place. There are no aerial predators of these birds, beyond the occasional vagrant peregrine, and certainly nothing that might rival the tenacity of the skuas in the southern hemisphere. Perhaps it is this naiveté that has lead to their willingness to nest anywhere.

It may also be this naiveté that has facilitated the following unfortunate turn of events. Just before I arrived, the USFWS and a crew of volunteers had just finished up the annual albatross count. During their counting sweeps they noticed injured adults incubating eggs. After setting out trail cams, suspicions were confirmed. The introduced mice on Midway have discovered that albatrosses are a source of food. House mice are known to prey on albatross chicks on Gough and Marion Islands in the South Atlantic (more information here – warning graphic photos), but to my knowledge this is the first time that they have started eating adult birds. You can read the USFWS announcement here. The plane that I flew out on brought in people, traps, and resources to deal with the situation, but stay tuned as I fear this saga is just beginning.

Finally, and on a further less than positive note, I went to Midway fully aware of the problem that plastics pose to these birds and our marine ecosystem, but there is something to be said for seeing it first hand. The chicks were very small when I was there so I didn’t see any direct impacts on them, but see below for photos of carcasses of last year’s fledglings with plastic filled stomachs. Instead, it was the shear amount of random plastic bits strewn around the island and buried layers deep into the sand that struck me. I learned that sometimes the plastic bits are glow-in-the-dark! Sometimes fishing lures have batteries in them – I am not sure what they are used to catch – do you know? And toothbrushes are very common. All of the plastic that I saw among the birds arrived in the stomach of an adult albatross. All-in-all the experience gave me renewed inspiration for continuing to reduce the amount of plastic that I use (click here for more information on albatrosses and plastic, and here and here for info on marine plastic pollution in general). I collected interesting pieces to bring home with me (see the photos below), but it is a non-random sampling of what caught my eye. I left many many plastic shards where they were.

I have written mostly about the birds, but Midway is full of human history. As I biked along the runway, or past the old officer quarters, I often found myself wondering what all these albatrosses have seen over the years and what they might witness in the future. Two weeks was really just a blink-of-an-eye for an albatross that can live over 40 years (or longer like Wisdom the albatross). I was terribly sad to leave such a beautiful place, but I came home with amazing memories, photos, and gigabytes of data that are already giving me a glimpse into the world of albatrosses at sea.

Seabirds eat weird things

Chicken wings, toy dinosaurs, Easter eggs, driver’s licenses, ham, broccoli, and toy cars, to name a few things. I’ve even seen a gull try to eat a live, 2 ton elephant seal (and have got the pictures to prove it!).

Recently researchers from the GEMM lab, and the Seabird Oceanography lab (SOL) at Hatfield Marine Science Center, have been collaborating with Dr. Scott Shaffer’s Avian Physiology and Ecology laboratory at San Jose State University to investigate the causes and implications of these strange eating habits.

When they aren’t scavenging off of your plate of French fries, Western gulls (Larus occidentalis) are either foraging for fish and invertebrates out at sea, or visiting the local dump to pick up dinner for the little ones. Unfortunately, during the breeding season dinner at the dump comes with the risk of bringing harmful contaminants and pathogenic microbes back to the colony. In addition to littering colonies with refuse, gulls can serve as potential vectors of disease that may affect other nearby wildlife. Seabird ecologists at OSU and SJSU are using GPS tags in order to better understand how different colonies of Western gulls along the West coast are affected by access to landfills. Over the past month, a handful of gulls at colonies in California and Oregon have been outfitted with these light weight tracking devices. The data gained from these tags will allow researchers to study the foraging ecology and habitat use patterns of these individuals. When the tags are recovered, biological samples such as blood and feathers will be collected to determine how these habitat-use patterns (and potentially, trips to the local landfill) are affecting these birds in terms of microflora and contaminant loads.

Last week I (Erin Pickett) assisted the GEMM and SOL labs in capturing a few of these birds in order to outfit them with tags. The local field site is just south of Yachats on a guano-covered rock that a small colony of Western gulls call home. Like all great fieldwork and adventures, our day began at 4:00 am (and it was raining!). About an hour later we arrived at our field site, where we assessed the ocean conditions and determined that the treacherous crossing from the mainland to the colony was passable (it was low tide). There is some great GoPro footage of a crossing the week before that consisted mostly of a current rushing over rocks and the occasional flash of a wetsuit or a yellow dry bag while two hands reached out for something stable to hold onto. When I heard about this I became even more excited about the opportunity to join in on the fun.

We spent our morning focused on two tasks. The first was to recapture the two birds who we had put tags on the previous week. Since the tags have to be small and light-weight, they can only collect data for as long as their battery lasts. However, this is long enough to log a few foraging trips and get a good idea of where the gulls are concentrating their foraging effort. Our second goal was to put tags on eight more birds. We used a combination of capture techniques, including a very long pole with a small noose on the end of it, to recapture one of our birds from last week, along with seven new birds who we deployed new tags on. By the end of the second morning the weather was nice enough to enjoy changing into a wetsuit and jumping into the water for the crossing back to shore. Now we just need to get the rest of our tags back. Wish us luck!

P.S. It’s not often that you purposely put photos of gulls in photo galleries, so I’ve taken this opportunity to find my best shots. These are a couple more of the field sites where our collaborators are working- on Southeast Farallon Island, and Ano Nuevo Island, California

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