Microplastic ingestion by seabirds: ongoing research at the Slater Museum

Plastic from a Northern Fulmar stomach 

Research on ingestion of microplastics by seabirds continues at the Slater Museum.  With the help of Shep Thorpe, VMD, we have examined additional Northern Fulmar stomachs from 2012 from the WA and OR coast.  These were recovered by Wildlife Center of the North Coast (WCNC), Sharnelle Fee director.  There was an additional bird from Ocean Shores, WA provided by Sheila McCartan, Nisqually NWR.  The Ocean Shores bird was remarkable in having 6.0 gm of plastic in the proventriculus and 1.04 gm in the ventriculus (pictured).  Some pieces were the size of guitar picks.  There was one nurdle (labeled) which is a premanufactured plastic pellet.  Typically fulmars have less than 1 gm.  The Ocean Shores bird probably had enough plastic to incapacitate it leading to its demise. 

Research continues to rely on collection of specimens by Sharnelle Fee, Wildlife Center of the North Coast and Shep Thorpe, DVM, for dissection and separation of stomach contents.  Shep expanded discovery to the intestines where he has discovered small particles of plastic, parasites and clues to causes of mortality.   

Professor Peter Hodum in Biology is directing the research with students Alicia Terepocki, Alan Brush and Olivia Feinstein.  All are presenting posters based on their research over the past year at the Pacific Seabird Conference in Portland this month.

Abstracts from the Pacific Seabird Group 40^th Annual Meeting 20-24 February 2013 Portland

USE OF A DIVING PROCELLARIIFORM, THE SOOTY SHEARWATER, TO EXPAND A MARINE PLASTIC BIODINDICATOR NETWORK

Alexander Brush, Gary Shugart and Peter Hodum, Biology Dept & Slater Museum., University of Puget Sound, 1500 N. Warner, Tacoma, WA 98416 USA, ABrush@pugetsound.edu

There is growing recognition that plastic pollution in our oceans has reached a critical level and must be addressed. Seabirds, especially procellariiforms, have proven to be a useful bioindicator of marine plastic debris through the monitoring of their ingestion habits. To date, most efforts in documenting procellariiform ingestion of plastic have focused on primarily surface-foraging species. There is reason to suspect, however, that pursuit diving species may not reflect the same plastic ingestion patterns. In this study, we examined the stomach contents of Sooty Shearwaters (Puffinus griseus), a species that uses both surface seizing and pursuit diving to forage. We collected samples from 26 birds from the northern Oregon/southern Washington region to quantify the frequency of occurrence, abundance, color and size of plastics in the diet. Plastic was found in 69% (18 out of 26) of specimens, which is lower than incidences of plastics in Fulmar stomachs. The abundance, color and size of plastics found in the Shearwaters will also be presented. Due to the differing feeding habits in Shearwaters versus Fulmars, it was expected that plastic categorizations would produce different results in the two species for amounts and types of plastics found. If our hope is to create a comprehensive network of seabird bioindicators of plastic debris then our knowledge base must be expanded to species that reflect a wide variety of foraging guilds, as they are likely to provide unique insights into the marine plastic issue.

NOTHERN FULMARS (FULMARIS GLACIALIS) AS BIOINDICATORS OF ENDOCRINE DISRUPTING PLASTICIZERS IN THE MARINE SURFACE ENVIRONMENT

Olivia Feinstein*¹, Erica Donnelly², Hannah Nevins² and Peter Hodum^1,2, ¹Biology Dept., University of Puget Sound, Tacoma, WA, 98416 USA, ofeinstein@pugetsounde.edu 2Oikonos Ecosystem Knowledge, Benicia, CA

Many phthalates used to synthesize plastics have been identified as endocrine disrupting chemicals (EDCs), with studies showing dramatic deleterious effects on a variety of species as a result of exposure to growing numbers of EDCs in the environment. The Northern Fulmar (Fulmarus glacialis) is an opportunistic seabird which inadvertently consumes plastics as it forages. Previous studies of Fulmars suggest that plastics are leaching EDCs into the bird’s systems. We determined the percentage of plastics ingested by fulmars that contain EDCs. A collaboration with the Long Marine Research Lab allowed for geographic comparisons of EDC concentration intensities along the West Coast. The percentage of plastics in the diet of fulmars that contained plasticizers was below 3% in all tested regions. Plastic proportions in Alaska differed significantly from those in California and Washington. Our analyses confirmed that fulmars are effective bio-indicators of plastics in surface marine environments and that the surface waters in tested regions are not highly contaminated by plastics containing EDCs. EDC-containing plastics typically displayed negative buoyancy and sank in seawater and may be accumulating in benthic regions. The impacts of plastic ingestion may be a more significant source of contaminant uptake by seabird species than previously assumed. Additionally, there are physical consequences to species; plastics take up volume in the stomach reducing digestive capacity which blocks nutrient absorption.

PLASTICS IN THE PACIFIC: REGIONAL COMPARISONS OF MARINE PLASTIC INGESTION BY NORTHERN FULMARS

Alicia Terepocki*¹, Erica Donnelly², Hannah Nevins², Gary Shugart1 and Peter Hodum^1,2, ¹Biology Dept & Slater Museum., University of Puget Sound, Tacoma, WA, 98416 USA, aterepocki@pugetsounde.edu 2Oikonos Ecosystem Knowledge, Benicia, CA

Plastic pollution is increasingly recognized as an escalating threat to marine ecosystems. In the face of this developing issue, monitoring ocean-wide levels of pollution has become crucial. Successful monitoring programs utilizing Northern Fulmars (Fulmarus glacialis) as bioindicators of marine plastic pollution have been instituted in northern Europe and central California. As generalist and surface feeders, fulmars are an ideal indicator due to their susceptibility to ingesting plastic debris. In this study, we examined fulmars from northern Oregon and southern Washington (n=89) to determine the frequency of occurrence, abundance, size and color of plastic ingested and make inferences about the state of marine plastic pollution in the Pacific Northwest and feeding habits of fulmars. We compared these findings with those of birds from Alaska (n=46) and California (n=44) to obtain information on regional differences in plastic pollution in the northeastern Pacific. Results suggest marine plastic densities vary regionally, in all regions plastic ingestion was prevalent.

PSG’s 40^th Annual Meeting:

February 20-24, 2013 at the Portland Hilton

*

What the heck is a groundhog?

A Groundhog (Marmota monax)

Happy Groundhog Day, everyone! During this time of groundhog celebration, do you ever stop and wonder, "What in the world is a groundhog?"

We have all watched Punxsutawny Phil or Wiarton Willie emerge from his burrow to forecast the weather countless times, but where in the world did this tradition come from? And what is a groundhog in the first place?

Well, I am glad you asked, dear reader, for although these rotund rodents are national celebrities, most Groundhog Day revelers don't realize what a groundhog really is.

Groundhogs go by many names, other than "Phil" and "Willie" of course. Some call them whistle-pigs, land beavers, and, more commonly, woodchucks. But groundhogs do not have any immediate relations in the swine family (Suidae) and definitely aren't beavers. Rather, groundhogs are squirrels. Yes indeed, groundhogs (Marmota monax to be precise), and all other marmots for that matter, are the largest members of the squirrel family, Sciuridae.

An Olympic Marmot (Marmota olympus)

Here in the Northwest, we do not have groundhogs, but we have plenty of marmots, ground squirrels and gophers if you are searching for a woodchuck-related encounter.

What's the difference between these mammals, you ask?

Well, that depends on your definition of each critter.

Marmots are large Scuirids in the genus Marmota. In some regions, prairie dogs are also known as marmots, however these squirrels are in the genus Cynomys. Fun fact: the Olympic Marmot (Marmota olympus) is the only mammal uniquely endemic to Washington State.

A Mazama Pocket Gopher (Thomomys mazama)

Ground squirrels are a bit more difficult to define. In fact, recent phylogenetic revisions have split what was once a monogeneric clade (Spermophilus) into eight genera... In other words, nobody really agrees. And colloquial definitions vary as well. Typically, when one is referring to "ground squirrels," one could be referring to antelope squirrels (Ammospermophilus), typical ground squirrels (Urocitellus, Callospermophilus, and Ostospermophilus, all formerly in Spermophilus), prairie dogs (Cynomys), or even chipmunks (Tamias).

Gophers are equally difficult to define. Colloquially, gophers can include Scuirids, such as typical ground squirrels (as mentioned above) and prairie dogs, or it can include or members of the pocket gopher family, Geomyidae. The most common pocket gophers here in the Pacific Northwest are members of the genus Thomomys such as the Northern Pocket Gopher (T. talpoides) and the endemic Mazama Pocket Gopher (T. mazama).

A White-tailed Antelope Squirrel (Ammospermophilus leucurus)

Perhaps most confusing of all, is the fact that Groundhog Day has its origins with a different creature entirely - a badger. The tradition may have its roots in - yes, you guessed it - ancient Pagan celebrations of weather lore, where a badger or sacred bear would perform antics similar to those seen with today's Phil and Willie. Although the exact history of pre-American Groundhog Day is spotty, we know for sure that the event was first celebrated in the US in the 18th century by German-Americans in Pennsylvania. Today, celebrations occur throughout Canada and the United States, with the exception of Alaska where Marmot Day takes its place. Throughout North America however, it appears that groundhogs (and marmots for that matter) are equally bad at predicting meteorological events.

To learn more about Groundhog Day and its history check out this Wikipedia page. To learn more about "gophers" click here. Still curious about groundhogs and marmots? Click here!
And for those of you still intrigued by a rodent's weather-predicting capabilities, according to Punxsutawny Phil, we are set to have an early spring!
Happy Groundhog Day!

-Robert Niese
Education and Outreach Specialist

A California Ground Squirrel (Otospermophilus beecheyi)

A Least Chipmunk (Tamias minimus)

A Black-tailed Prairie Dog (Cynomys ludovicianus)

PACIFIC NORTHWEST DEER

Deer are the most common large wild mammals that most of us see. The only areas that lack deer entirely are within the city limits of our biggest cities. Any of us who live out in the countryside are likely to have them in our garden, not necessarily a preferred situation.

Two species inhabit the Pacific Northwest, Mule (Odocoileus hemionus) and White-tailed (O. virginianus). Mule occur everywhere, White-tailed mostly in forested habitats east of the Cascades in Washington and northeast Oregon, with a small population along the Lower Columbia River. The latter population is usually listed as a separate subspecies and is of conservation concern.

There are two very distinctive subspecies of Mule in the Northwest, the true Mule Deer (O. h. hemionus) and the Columbian black-tailed Deer (O. h. columbianus). Black-tails are smaller and darker than "muleys" and live in the wetter and more heavily forested areas west of the Cascades crest. They are typically seen at forest edge, although where not harassed they feed well out in open meadows. Mule Deer are common in open woodland and grassland east of the Cascades, drier habitats where their pale coat is more appropriate.

The three types can be distinguished by several characteristics. White-tailed have a long tail, brown above and white below, that is elevated like a flag when one is disturbed and goes bounding away. Mule and Black-tailed keep their smaller tails down. In both, the tail is white below, but in Black-tailed, as the name implies, it is black above, while Mule have the tail base entirely white. Intermediates between these two types are fairly common near the Cascade crests, where they meet and interbreed freely.

Males are larger than females and have antlers in fall and early winter. The antlers serve them to impress other males and keep them away from any female they are protecting as a potential mate. The antlers of Mule and Black-tailed branch dichotomously, with even-length branches, while those of White-tailed have a main branch ("tine") with smaller tines branching off from it.

Deer are generalized herbivores, nibbling leaves from a great variety of shrubs, trees and herbaceous plants, including grasses. A listing of their diets would include all of the common plants in their range except those that are protected by chemicals or serious thorns. Because they are generalists, not many plants in your yard are immune to their incisors.

Most mating takes places in late fall and births in early summer. One young is usually produced, but twins are also common, especially in older female Mule and Black-tailed.

White-tailed Deer have increased and expanded their range, while Mule Deer have declined In Washington state in recent years. As in eastern North America, human land use —both opening up forests and planting trees—seems to favor White-tailed, while our activities in general are less favorable for Mule Deer. Black-tailed Deer are holding their own, probably because their habits are more like those of White-tailed. They are protected in many areas just because they live in close proximity to human neighborhoods.

Dennis Paulson

PINE SISKIN—INVASIVE NATIVE

The winter of 2012-2013 has seen record number of Pine Siskins (Spinus pinus) in the Pacific Northwest. Numbers in the thousands have been reported on some Christmas Bird Counts. What's going on? It turns out that siskins are cyclic, on the average peaking in a given area in alternate years, and the peaks on occasion are very high. Thus they have a two-year cycle. The cause of this cycle is usually thought to be food availability, which varies in both space and time.

Siskins are among our smallest birds. They are members of the finch family Fringillidae, a family of interest because of its adaptive radiation into the seed-eating niche. The biggest species eat large seeds, the smallest very small seeds, and so forth. Pine Siskins eat a great variety of seeds of weedy herbaceous plants in the summer, but in winter in the Pacific Northwest they are strongly associated with red alders (Alnus rubra).

Alders bear their seeds in small conelike structures, and the slender bill of the siskin is well adapted to extract these seeds. Flocks of siskins visit alder trees and spend quite a bit of time working through the abundant cones. These flocks can be of surprising large size, up to and over 100 birds, but are usually smaller.

Pine Siskins also eat a variety of other seeds, from dandelions to hemlocks, and are frequent visitors to bird feeders, especially preferring thistle seeds. Unfortunately, this can be their undoing, as they seem very subject to infection from salmonella, which is spread in their feces. Birds may defecate while at feeders, and thus the salmonella bacteria are spread from bird to bird. Most winters, people who feed birds report sick and dead siskins at their feeders, sometimes dying right on a feeder.

Pine Siskins are very aggressive little birds. Perhaps they have to be because they go around in flocks, and a bird has to defend its feeding site against others. But they are also aggressive toward any other species, and at feeders, it is an impressive sight to see a siskin chase away a larger finch or sparrow. Siskins often have yellow in the wing and tail, and larger yellow patches may enhance a bird's success in driving away others.

Dennis Paulson

SHRIKES, SONGBIRDS OF PREY

We are all familiar with hawks and owls, raptorial birds with strong feet and long, curved talons for capturing and carrying prey and a strong, sharp-edged, hooked bill for tearing that prey into bite-sized morsels.

But there is another group of common birds that are just as predatory, although with somewhat different anatomy. These are the shrikes. Shrikes are members of the perching bird order Passeriformes, and although that order is full of insect eaters (shrikes do this), it's not so full of birds that eat small vertebrates such as lizards, songbirds and rodents (shrikes do this too).

Loggerhead Shrikes (Lanius ludovicianus) are widespread breeders in interior sagebrush habitats in the Pacific Northwest. With us only in the summer, they feed primarily on large insects such as grasshoppers and beetles, but they also eat small vertebrates whenever they can capture them, including voles and birds right up to their own size.

Northern Shrikes (Lanius excubitor) breed in the boreal forest and drop down to the PNW in the winter. They are more widespread than Loggerheads, occurring throughout the region in open country. Although they take many insects on their breeding grounds, Northerns are bird and mammal eaters in the winter. Voles are among their most common prey, but they will chase and capture small birds of any sort.

Shrikes have typical perching-bird feet, not raptorial, and they don't capture or kill their prey with their feet, but they do use their feet to carry prey, especially heavy items and even up to their own weight; otherwise prey is carried in their bill.

Although not just like a hawk's, the bill is strong and hooked at the end. It has a pair of toothlike structures near the tip of the upper mandible (tomial teeth) that are important in prey-killing. The shrike bites a vertebrate just behind the head, and the "teeth" apparently sever or injure the spinal cord sufficiently to kill or paralyze the prey, which then cannot struggle and possibly injure the predator.

Not having feet to hold a prey animal down while tearing pieces of flesh off, shrikes have evolved a substitute. They carry their prey to something on which they can position it. In nature, this would involve impaling on thorns or hanging from crotches where two branches diverge. They can then begin to dismember the prey.

Having evolved this behavior and often taking prey much too large to be eaten in one session, shrikes further evolved the behavior of leaving the prey hanging and returning later to eat some more. Wherever shrikes occur, such prey are liable to be found. Nowadays, we can watch for shrike prey caches on barbed-wire fences!

Dennis Paulson

WAXWINGS, THE SMOOTHEST BIRDS

Anyone who looks closely at a waxwing usually exclaims "how smooth it is!" What is there about waxwing feathers that gives this impression? They really do seem smooth, perhaps in part because the body is uniformly colored and the individual feathers thus difficult to make out. Maybe that's all we need to know. Their jaunty crests, black face masks, and yellow tail tips make waxwings unmistakable birds.

Cedar Waxwings (Bombycilla cedrorum) are very common in the Pacific Northwest. Small numbers of them spend the winter, especially in the interior, but many more arrive in spring to breed throughout our deciduous and mixed woodlands. Because they are confirmed fruit-eaters, they breed later than many other migrants, so the young when just off the nest can find plenty of fruit. Many native trees and shrubs flower in early summer and have mature fruit in late summer, if you didn't know.

Waxwings are really tied to fruit and can survive on a fruit-only diet longer than other temperate zone songbirds. Males offer berries to females for courtship feeding, and the young are fed fruit more than is the case in most of our birds. Of course this diet is augmented with insects, which are better sources of some nutrients. Waxwings spend much time around water looking for emerging aquatic insects such as dragonflies, which they often catch in the air.

You can see waxwings hawking for insects above the treetops in late summer, but they are still seeking fruit at that time, and any plant fruiting in September may harbor small flocks of waxwings. In October, most of them take off for lower latitudes.

The "waxy" tips on wing feathers in waxwings are merely modifications of the feathers. Imagine the individual feather barbs becoming thicker and thicker, fusing, and becoming bright red. As a waxwing matures, it develops more of these tips, and their size and number are a sign of maturity. Birds with more red tips tend to breed together and breed more successfully, so more "wax" may be a sign of a bird with higher fitness.

Bohemian Waxwings (Bombycilla garrulus), bigger and more colorful, visit the Northwest only in winter from their breeding grounds in the boreal forest. They are more common on the east side of the Cascades, where flocks may be encountered in fruiting trees, many of them non-natives and often in cities and towns.

There is only one additional waxwing, the Japanese species (Bombycilla japonica). It looks much like the other two but has red tail tips; I wish I had a photo to share, but I've never seen one.

Dennis Paulson

PSYCHEDELIC ROBIN OF THE NORTHWEST

Some people, seeing their first Varied Thrush (Ixoreus naevius), wonder if they are having vision problems. This psychedelically colored thrush looks more or less like an American Robin (Turdus migratorius) and feeds on the ground or in fruit trees like a robin, but the similarity is only superficial.

Male Varied Thrushes are vividly colored in gray, black and russet, much more brightly patterned than robins. Females are more subdued, with less conspicuous facial markings and breast band, but they still show the vivid wing markings typical of the species. Note also their black instead of yellow bill.

While robins run about our yards looking for earthworms that have surfaced, Varied Thrushes are foraging for a much greater variety of invertebrates. A robin is a visual forager, cocking its head to scan for worms, but a Varied Thrush gets down and dirty, pulling leaf litter up and hopping backward to examine the ground exposed. The complex web of life beneath the litter furnishes up dietary items one after another to the thrush.

In addition, Varied Thrushes take fruits and seeds of all kinds, even acorns, from the ground. They often visit bird feeders to take seeds or suet, something robins never do. Both species are attracted to fruiting trees and shrubs, where they may gobble berry after berry, jumping up or briefly hovering to pull them from branches to small for a comfortable perch.

Varied Thrushes breed in wet conifer forests in the mountains of the Pacific Northwest, and they are present in the lowlands only in winter, when they come down from the mountains. In some winters, probably the colder and snowier ones, they are more common than at other times, numerous enough to be called an invasion. At intervals they wander much more widely than their usual range in the far West, turning up as far east as the Atlantic coast.

The call note of a Varied Thrush is a sharp 'tup,' much like that of a Hermit Thrush, but the song is magical. It is a series of drawn-out notes at different pitches, sometimes with overtones. Note after note comes out of the bird with an ethereal quality that seems well suited for our dark evergreen forests. Fortunately for us, they sing commonly in the spring before they depart for the mountains, so you may hear this song in your suburban yard.

Watch for the psychedelic robin; it's that time of year!

Dennis Paulson