Month: July 2017

By Rachael Orben, Research Associate, Department of Fisheries and Wildlife, Oregon State University

In late May, I returned to St. George Island, Alaska to study the foraging ecology of red-legged kittiwakes using a mix of high-tech biologging tags, physiology measurements, and observations.  The study was designed to identify differences in behavior and physiology between birds that reproduce successfully and birds that don’t and then to see how this might carry over to the winter season (and vice versa).  Things didn’t go as planned.

This was my fourth spring on the island, and like prior seasons we arrived in late May, when birds should be building nests. However, unlike previous seasons, red-legged kittiwake’s didn’t look like they had done much nest building. I was accompanied by Abram Fleishman, a superstar MS student from San Jose State who is studying the winter spatial ecology of red-legged kittiwakes in relationship to mercury concentration in their feathers.

We immediately set about recapturing birds that had carried geolocation data loggers over the winter. We wanted to catch as many as possible before eggs were laid, so that their blood samples would represent the pre-lay period. The weather was wonderful, so it wasn’t until three weeks after we arrived that we had our first day-off. It was at about this time that I finally lost my optimism and realized the majority of red-legged kittiwakes were not going to lay eggs. By late June kittiwakes are usually incubating eggs. We only saw a handful of eggs and very few of these were being incubated. Most birds didn’t even build nests, or if they did, the nest was dismantled by other birds when the nest building pair didn’t stick around to guard their pile of mud and moss.

When I designed the study, I thought collecting enough data to answer my questions about successful versus failed breeders would be hard, since failed breeders would be challenging to work with and red-legged kittiwakes typically have high breeding success, meaning that sample sizes of failed breeders would be small. Instead our three seasons occurred with progressively worse breeding success and we will now have to shift the focus of our analysis to see if we can find differences between birds that laid eggs and birds that didn’t, if we have the sample sizes! With ~80% laying success in the 9 years preceding the beginning of our study in 2015, this is something I would never have expected! The egg laying failure of 2017 is unprecedented in the productivity monitoring time series collected by the Alaska Maritime Wildlife Refuge.

Seabirds are often touted as indicator species of marine health (Cairns 1988, Piatt et al 2007), and while there are always caveats and additional questions to be answered, seabirds are reliant on the ocean for food and observing their behavior and condition tells us something about how easy (or hard) it is for them to find food.

So, what do I think the red-legged kittiwakes told us this year? I think they were squawking loud and clear, that they were not able to find myctophid fishes within their foraging range to the south and west of the Pribilofs. Myctophids are small fatty mesopelagic bioluminescent fish that come to the surface at night where red-legged kittiwakes catch them.

Besides just observing the laying failure, we were able to GPS track a few birds, collect a few diet samples, catch birds for blood and feather samples, and resight banded individuals. It is these pieces of information that I will be analyzing in the coming months to try to understand why some individuals were able to lay eggs during our study years, while most were not.  These years should also help us understand what capacity red-legged kittiwakes have to cope (or not) with changes in prey availability. However, after three years, I still don’t know what a ‘good’ year looks like for red-legged kittiwakes. Fingers crossed next season is finally a decent year for this sentinel seabird of the pelagic Bering Sea.

You can read more about our red-legged kittiwake research in a series of blog posts written for the Seabird Youth Network, a partnership between the Pribilof School District, the Aleut Community of St. Paul Island, the City of St. Paul, Tanadgusix Corporation, the St. George Traditional Council, St. George Island Institute, the Alaska Maritime National Wildlife Refuge, and the wider scientific community. The network creates opportunities for youth to learn about seabirds with the aim of building local capacity for the collection of long-term seabird monitoring data on the Pribilof Islands.

By Leila Lemos, Ph.D. Student, Department of Fisheries and Wildlife, OSU

On June 6th the GEMM Lab officially started the second year of fieldwork of our “Noise Physiology” Project with gray whales along the Oregon coast. To date, we have spent 14 days at sea (12 around the Newport area and 2 in Port Orford, our control area), with a total of 32:31 hrs of effort. In 29 whale sightings of approximately 40 whales we have been able to collect 6 fecal samples for hormonal analysis, to fly the drone 17 times over the whales, to deploy a GoPro 6 times for qualitative prey analysis, and to deploy a light trap 2 times for quantitative prey analysis. While this sounds good, we have only just begun, with our field season extending into October. The graph below displays the sightings and data collection by area.

We have added a couple new components to our project this year. First, we are now using a “the light trap”, as mentioned above, to capture zooplankton prey of gray whales. The light trap (Figure 2), designed by our collaborator of Kim Bernard (OSU, College of Earth, Ocean, and Atmospheric Sciences). The light trap is composed of a water jug with a cut-out cone entrance where prey might enter the jug after being attracted by the chem lights we put in the jug. The jug is weighted down to maintain position, but swivels off the drop line by its own floats; and it’s all connected to a surface float.

The light trap is left overnight and recovered in the next day. Trapped prey are sieved (Figure 4), stored in properly labeled jars or Ziploc bags, and kept frozen until analysis (Figure 5 and 6) including species identification, community analysis, and caloric content.

The second component we have added this year is the fixed-location hydrophone (Figure 7) to record acoustic noise data over the entire summer season. Last year we used a temporarily deployed “drifting hydrophone” that only recorded noise data punctually. Because of the fixed hydrophone, this year we will be able to compare our hormone data with a wider range of acoustic data, and improve our analyses.

We also made our first trip down to Port Orford, our control area, to intensively collect data over only two days (July 5^th and 6^th). Since Port Orford is a smaller city with reduced vessel traffic, we want to evaluate if whales observed in this area show a reduced stress response when compared to the whales that inhabit the area around Newport and Depoe Bay, where vessel traffic is higher. However, we were not able to collect any fecal sample during this trip to Port Orford, so more trips south to come!

The other components we used last year such as photo identification (Figure 10), fecal samples (Figures 11 and 12), drones, and GoPros are still being put to use this year. If you want to know more about our Noise Physiology project, check here.

We are progressively spotting more gray whales along the Oregon coast and we will continue our field efforts and data collection until October. So, for now enjoy some photos taken during the last couple of months. Until next time!