Thursday, November 21, 2013

Island Entomology

Mike Valainis and Bret Robinson, SJSU Entomology students
My name is Bret Robinson and I am a graduate student at San Jose State University.  I have been taking multiple boat trips out to the bone, guano, and insect covered South East Farallon Island for almost a year now.  I, along with Mike Valainis - another San Jose State grad student, am investigating the insects of the island. Mike is concentrating on the endemic cricket species Farallones caverniculus

My thesis is more general and will provide a baseline for further entomological studies and identifications of Farallon insects. I collect, and then determine, what species are found throughout the year.  Seasonality is observed through frequent trips that last roughly two weeks.  I collect insects found on the island and those traveling to the island from the mainland.  I’m also examining the abundance and diversity of insects on the Farallones before potential proposed eradications of invasive plants and mice.

Farallon collections from spring 2013
So far, we have found a diverse array of multiple orders of insects on the island.  Three main orders seem to dominate the insect biodiversity. These are Diptera (Flies), Coleoptera (Beetles), and Lepidoptera (Moths/Butterflies).  
You wouldn't think that there were many different flies since throughout the year you are bombarded by the infamous "Corm" Fly, Fucelliinae thinobia, but so far it is the most diverse order. Many of these flies are mere millimeters in size.

Beetles are also a dominant species on the island. Two beetles in particular are the Darkling beetle, Eleodes planatus or the black beetle of the genus Coniontis. Any time you lift up a rock your chances of finding one of these are high.   
Farallon "Corm" Fly
Fucelliinae thinobia


Everyone loves Butterflies and this island’s got them.  Observations have determined that most butterflies are migrants and they are taking to the wind and making it all the way out to the island.  Two butterflies species have successfully set up a permanent residence here on the Farallones by taking a liking to the Mallow plants, Lavatera arborea and Malva neglecta.  These two butterflies are; painted lady, Vanessa cardui and the west coast lady, Vanessa annabella.  These butterflies will dance around you as you take a leisurely walk through the marine terrace on a warm sunny day.

West Coast Lady, Vanessa annabella

Butterflies are cool, however it is the other Lepidoptera group, moths, which excite me the most.  There are micro moths that take residence in the caves and just love feeding on that nutrient rich guano.  Among these you will find day and night a variety of larger moths that seem to appear during certain seasons.  With an ever-changing island of macro species, birds and pinnipeds,  there is right under our noses a diverse changing group of moth species throughout the year.    

Yellow Hindwing Moth, 
Noctua pronuba

All in all there is more out here on the island than we could ever dream.  Many specimens have been collected and now with the help of an academic community of experts such as Universities and organizations like Cal Academy we can identify these amazing creatures 


I can’t wait to get back on the Island in January for another insect expedition and to see those massive male elephant seal behemoths duke it out for love. 


Monday, October 21, 2013

Farallonathon Wrap-up

Day 2 (Oct 5th) - The day after our big wave, we awoke to fairly gusty east winds. Although east winds do not typically bring large numbers of birds, they can bring interesting birds that don't normally cross large bodies of water. So we were hoping for raptors, especially for a hawk or an eagle. A big chunk of our day, though, was devoted to getting our groceries from The Rainbow, a boat in the Farallon Patrol. The Farallon Patrol consists of several skippers that volunteer their time and boats to ferry people and supplies to and from the island. In addition to bringing us food, this boat brought out a new intern, Xeronimo Castaneda, and departed with Kristie Nelson. After The Rainbow departed, Dan Maxwell and Jim Tietz took our boat over to a massive flock of seabirds feeding off the east side of the island. Here we found our one-and-only Rhinoceros Auklet amongst the thousands of Common Murres. Back on the island, we found several other arrivals, including a Rufous Hummingbird, which was our first for the fall. Normally, we see these in late August and September, but we saw very few birds during those months, so we were happy to finally see one. We also found two Brewer's Sparrows, a Grasshopper Sparrow, a late Bullock's Oriole, and our first European Starlings of the fall (a flock of 30). East winds are also great for migrant insects, and we added several such as Painted Lady, Monarch butterflies, and four species of dragonflies: Blue-eyed Darner, Green Darner, Variegated Meadowhawk, and Black Saddlebags. Our final addition was from a pair of Harbor Porpoises that strayed far away from their typical near-shore local. The 17 additional points from this day, plus one for a Willow Flycatcher positively identified from a photo taken the previous day, brought our total up to 128.






Day 3 (Oct 6th) - Our third day started out just like the day before, with strong east winds, warm temperatures, and greater than 60 miles of visibility. Although these winds did not bring us a big bird wave, a few new arrivals visited us to keep the day interesting. Surprisingly, this weather brought out four Barn Owls, which were found roosting in the three trees around our houses. Historically, Barn Owls used to be quite rare, but their numbers have increased by 310%. in the past 15 years. During this increase, we have documented numerous Cassin's Auklets and other breeding seabirds that have been killed by the Barn Owls. Other western migrants included Tree Swallow, Pacific Wren, Vesper Sparrow, and Lark Sparrow. These winds also brought us our best day of the fall for East Coast warbler diversity, with just one Western Palm Warbler, one Blackpoll Warbler, and one Black-and-white Warbler. September typically brings us the East Coast warblers, but the wind and fog must have kept them away. A second Blue-footed Booby joined the one first seen on Day 1, which added another five points for being a CBRC bird. Our first shark point of the Farallonathon happened when Cameron Rutt spotted a shark surface off of Shubrick Point. At the end of the day our total had crept up to 145.



 

Day 4 (Oct 7th) - The winds switched to northwest today, starting out light, but then strengthening. Combined with 30 miles of visibility, these conditions bring few migrant birds. Once it became obvious that there were not many arrivals, Boo Curry and Jim Tietz visited West End Island to conduct a Northern Fur Seal count at their Indian Head colony and to look for tags. Before the 1850's, the Farallones had a Fur Seal rookery of a few hundred thousand individuals. Unfortunately, once Europeans discovered this, they set about to kill as many fur seals as they could and shipped the pelts to China for profit. After several years of exploitation, any remaining fur seals abandoned their colony on the Farallones and were not seen again on the islands until the 1970's when the occasional individual would haul out to rest. In 1996, a pup was discovered at Indian Head Beach on West End Island. Following this discovery, annual ground survey visits were made to the colony to document its growth. In 2006, we noted that the colony had dramatically increased in size, and we noted that there were several fur seals with tags on their fore flippers. Since tags can provide the known age and sex of each seal as well as its origin, we increased the frequency of trips to the colony to improve our understanding of this colony's demographics. So far, we have read over 100 tags at this colony. The vast majority of the seals with tags were tagged at the San Miguel Island colony, which is in the Channel Islands off southern California. However, we also found a tag that was from the Commander Islands off northeastern Russia. On this last trip, all the tags appeared to be from San Miguel Island, except for one that may be from another location. Now that the government shutdown is over, we may get an answer. At the end of our survey, we had counted 486 individuals on land, and we estimated that there were at least 100 in the water right off the colony. The colony still has a long ways to go to reach a hundred thousand. But so long as we continue to protect their rookery from human exploitation and disturbance and their feeding grounds in the California Current from over-fishing, they should continue to rebound.

Only four points were added this day from the following sightings: a pair of Blue Whales seen far to the south from the lighthouse during a cetacean survey, one Pomarine Jaeger seen during the afternoon seawatch, and one Rock Pigeon and one Least Flycatcher seen during an area search. These four points brought our total up 149.





Day 5 (Oct 8th) - Strong northwest winds and clear skies meant that many birds departed and few arrived. Only one bird arrived that gave us a new point, an Aleutian Cackling Goose. It showed up behind our house extremely thirsty. We gave it a little water which it gratefully accepted. This was our only point for the day, so our paltry sum increased to 150.


Day 6 (Oct 9th) - Even stronger northwest winds gave most of the birds that were still on the island a nice tailwind for departure. No points were added this day, so our total remained at 150. 

Day 7 (Oct 10th) - The dawn weather appeared more promising, with light winds out of  the west, and the visibility down to just 5 miles. Sadly there were not many birds about. But then during the AM area search, Cameron spotted a Great Crested Flycatcher. Although there were 11 previous records for the island, this was the first since 1989! In addition, this species is on the CBRC review list, so it counted for five Farallonathon points! Other species this day that were new for the week were Killdeer, Parasitic Jaeger, South Polar Skua, Lapland Longspur, Wilson's Snipe, and Short-eared Owl.


In addition to birds, we found two new species of insects, a Familiar Bluet, which is a kind of migratory damselfly, and a Farallon Cricket, the only endemic species on the Farallon Islands.


Our final point was found at 9:30 on this last night of Farallonathon. The Farallon crew set out to find the only salamander on the island. Ironically, the name of this species, which occurs on an island with just 4 introduced trees, is the Arboreal Salamander. It is uncertain how this salamander got to the island, but it's possible that it came across the ocean on a log as has been documented in the San Francisco Bay (fide, Peter Pyle), or perhaps it was assisted by humans on a boat, or the species may have persisted here ever since the islands split away from the mainland millions of years ago.



With the 11 bird points (6 regular + 1 CBRC), 2 insect points, and 1 salamander point, our final total stood at 164 points. Compared to the previous 21 years of Farallonathons, this year ranked 13th. Despite our auspicious first day, poor subsequent weather and zero shark attacks meant we were doomed to have a low score. We hope you enjoyed hearing about our Farallonathon and support our cause for conservation. If so, please consider giving to the Farallon program at the following website: 


Thursday, October 10, 2013

Farallonathon update for Day 1 - The Big Wave

The Farallonathon kicked off this year with a bang on Friday, October 4th. Although we were going to start our week-long bio-blitz fundraiser this day anyway, we did not anticipate that ten knot winds out of the west combined with 60 miles of visibility would produce one of the largest bird waves of the decade. At dawn we began noticing sparrows flying about the yard, and it quickly became obvious that we had several new arrivals, but the full magnitude of the migration would not become apparent for another hour. Shortly after dawn, Cameron Rutt climbed Lighthouse Hill  to see what arrivals would be up there. In the meantime, two of us, Boo Curry and Jim Tietz, were getting gear ready to visit West End Island to count pinnipeds and read tags on fur seals.

Just as we were about to leave, news came over the radio from Kristie Nelson that a sapsucker was on Lighthouse Hill. Three of the four species of sapsuckers had already been seen on the island: these were the Red-breasted, Yellow-bellied, and Red-naped Sapsuckers, each with several records on the island, but still quite rare. As we tried to figure out over the radio which species it was, Cameron, who had been having radio problems, finally got through that it was a male Williamson's Sapsucker, a first island record for this species. Whereas the other three species of sapsuckers have breeding ranges that extend well to the north and annually undertake long-distance southward migrations during the fall, Williamson's is a montane species that mostly migrates downslope for the winter, and interestingly, there are no coastal records north of the San Francisco Bay Area. Needless to say, we quickly postponed our trip to West End Island so we could enjoy this new island bird and help document the abundance and diversity of these newly arrived migrants. Unfortunately, the sapsucker flew to the west soon after we shot a few documentary photos and was not relocated afterwards.



For the next hour, we searched for the sapsucker along the cliffs on the western side of the island, and looked through the flocks of sparrows, thrushes, and kinglets to increase our species list. It quickly became apparent that this bird wave was almost entirely composed of western species, especially Golden-crowned, White-crowned, Fox, and Savannah Sparrows, Hermit Thrushes, Audubon's Warblers, and Ruby-crowned Kinglets. Normally, large bird waves on the Farallones are associated with a few to several stray eastern vagrants, but despite much searching, the only "eastern" birds we could find were singles of White-throated Sparrow and Yellow-shafted Flicker. Although both of these species winter more commonly in the East and are thus considered "eastern", their breeding ranges extend quite far west in Canada and a decent number winter in California as well.


The person conducting the island-wide area search this morning had a much busier day than the few days previously when we were only seeing a few individuals of a few species. On this day, Luke Musher recorded dozens of individuals of 34 species. To help us determine numbers of arrivals and to track individuals over time, we also banded as many birds as we could safely capture in our mistnets. By the end of the day, we had banded 146 birds of 21 species. As with the area search, Golden-crowned, White-crowned, Fox, and Savannah Sparrows, Hermit Thrushes, and Ruby-crowned Kinglets were the most abundant. Hammond's Flycatchers are an uncommon species on the Farallones, so we were quite surprised to capture three of these birds. Probably the most interesting thing we discovered through banding on this day was the preponderance of adult birds to juveniles. Along coastlines, juveniles typically outnumber adults by a large margin, so whatever caused this massive misdirection by adults must have been pretty unusual.

This bird wave also produced a few subspecies that have rarely been seen before on the island. The most interesting were within the Fox Sparrow complex. There are at least 17 subspecies that have been recognized in this species, and they have been lumped into four groups based on geographical proximity and morphological and genetic similarity. Although Thick-billed is the only group with a widespread breeding distribution within California, this is the only one that we failed to see. Sooty Fox Sparrow is the most common winter visitor to California. It breeds from southwestern British Columbia north through southern Alaska, and we determined there were at least 80 of these on the island. We also found three Slate-colored Fox Sparrows, which breed in the Rocky Mountains and Great Basin. Although they winter in California from the Central Valley south to Southern California, they are scarce along the Northern California coast, and there are few records for the Farallones. The individual photographed here appears to be of the Alberta subspecies, altivagans. This subspecies is morphologically intermediate between Slate-colored and Red, but genetically it falls solidly within the Slate-colored group.


Red Fox Sparrows breed in northern Canada and northern Alaska, and they winter in the eastern United States. This is a casual vagrant to California, so we were excited to find one in a mistnet and another that Dan later captured with his camera! This individual appears to be of the zaboria subspecies, which occupies the western half of the Red Fox Sparrow range during the breeding season. Note how much more red there is in the crown, face, and back of the Red below compared to the Slate-colored above.



Another interesting bird seen this day was a Song Sparrow that wandered about the intertidal. The subspecies of this bird is thought most likely to be fisherella, which breeds in drier habitats from northeastern California to British Columbia, but could possibly be the montana subspecies of the Great Basin- either way it would be a first for the island.


We also had a continuing Burrowing Owl, Peale's Peregrine Falcon, Sandhill Crane, and Blue-footed Booby. The latter was either the continuing third bird (see our previous blog post about Blue-footed Boobies) or our fourth for the fall season.


In addition to birds, we also added a point for a rather rare butterfly to the Farallones called a Common Buckeye.


At the end of a lengthy evening journal, we determined that we had observed a total of 826 landbird individuals of 51 species - including waterbirds, we saw 75 species. After adding up all the points we got for birds, pinnipeds, whales, butterflies, dragonflies, and bonus points for first island records and California Bird Record Committee review species, we found that we were doing quite well for our first day with 110 Farallonathon points. If you would like to contribute to our research on the Farallon Islands, please visit our donation page at the following link:

 http://birdathon.kintera.org/faf/search/searchTeamPart.asp?ievent=1082358&lis=1&kntae1082358=AB4D517D0B7042EA899EAEF4D2A1F918&team=5733934

Saturday, October 05, 2013

Farallonathon is ON!!!


It’s Bird-A-Thon season at Point Blue Conservation Science – our biggest fundraiser. On the Farallones, we count all of the animals we find including birds, fish, marine mammals, insects, and any other wildlife. We even assign points for rare and interesting wildlife events such as shark attacks and birds never before seen on the Farallones. This highly anticipated annual event is fondly referred to as the Farallonathon!

Initiated in 1992 by Peter Pyle, the Farallonathon was created to recognize the truly unique elements of the Farallones, while at the same time participating in Point Blue’s Annual Bird-A-Thon. The Farallonathon consists of a one week bio-blitz when we identify as many species of wildlife as possible.


Money raised from this event goes directly to supporting Farallon research allowing us to purchase biological equipment, food and supplies for island personnel, and pay Point Blue staff to analyze and publish the data we collect. The information gathered from our research help us and others protect the wildlife that use these special islands and the marine environment that surrounds it. You can support our research by either pledging an amount of money per point or a flat amount.

What’s a typical ‘score’ for a Farallonathon? During the last 18 years, scores have ranged from a low of 133 points to a high of 240 (a good year for shark attacks!). The very first Farallonathon began auspiciously with a mega-rare Asian vagrant, the Northern Wheatear, but ended with only a modest 152 points due to very few shark attacks.

This unique fundraising event is truly fun, but it is also part of our daily research. As Farallon biologists, we are constantly studying the wildlife of these near-pristine islands and documenting their activities. Every observation is a piece of the data that we record on the island--our outdoor laboratory on the Pacific. The Farallonathon gives us a way to celebrate our work on the island and share these experiences with you.

To pledge your financial support for our research, you can pledge a flat amount or you can make your pledge based on the Farallonathon point system. If you pledge your support, you will receive a detailed summary of our experience at the end of the Farallonathon week. Your participation allows us to continue studying this unique and vital ecosystem on the California Coast.

Donation should be sent to:

Russ Bradley
Point Blue Conservation Science
3820 Cypress Drive #11
Petaluma, CA 94954

In the memo on the check write, “Farallonathon”

I hope you will join us!

Thank you,

Jim Tietz
Point Blue Farallon Biologist

Saturday, September 28, 2013

Blue-footed Booby Invasion Finds The Farallones

On August 25th, some tourists visiting the east side of the Sierras took a photograph of a strange bird on the shoreline of Mono Lake. Later that day, they showed it to Max Henkels, an intern who was leading a bird walk for the Mono Lake Committee. He immediately recognized the bird in the photograph as a Blue-footed Booby. He was likely very excited, as this species had never been recorded at Mono Lake. Unfortunately, the bird was never re-found by Max or any other birders or biologists. The tourists then left town without leaving any contact info and the photo was lost. However, this story was only the first of a series of Blue-footed Booby sightings in California this year. An unprecedented number of Blue-foots have shown up all over the state since this first individual was spotted at Mono Lake.

Over the next several weeks, dozens of Blue-footed Boobies were reported from coastal and inland Southern California. By September 11th, they had reached Northern California. A single bird was spotted by birders Mark Butler and Roger Harshaw at the Point Reyes Lighthouse; and in the following days there were sightings from San Mateo, San Francisco, Marin, and Sonoma Counties. Astoundingly, a single bird was found all the way up in British Colombia! On the Farallones, it was only a matter of time before one showed up here.



A map showing the locations of all Blue-footed Boobies reported to eBird so far in 2013.

Finally, on September 18th, a call came over the handheld radios on Southeast Farallon Island that a Blue-footed Booby was perched on the western edge of Saddle Rock. Moments later, everyone on the island was peering intently through binoculars, cameras, and spotting scopes at the Farallon's first ever Blue-footed Booby. The juvenile bird preened nonchalantly before taking a short flight and landing back on the rock, never suspecting how special the humans on shore considered it to be. It was quite a relief for us to finally see one after reading so many reports from the mainland.


The first Farallon record, pictured here, had a thin white stripe down the center of its tail, making it distinguishable from the rest of the Boobies to follow.


The second Farallon Blue-footed Booby showed up in the same place on the west end of Saddle Rock, an islet off the south end of our main island. The central tail feathers on this bird are dark, showing a different pattern from the first bird.

Cameron snapped off a few shots of this third Island Record Blue-footed Booby as it flew in during his sea watch. The longer central tail feathers (rectrices) distinguished this bird from the previous two individuals.

Can you spot the Booby amongst the Brandt's Cormorants? We are currently trying to determine if this booby is the same individual pictured above, in flight.

One more of Cameron's shots of the 3rd (or possibly 4th) Farallon Blue-footed Booby.

The California Bird Records Committee's publication Rare Birds of California tells us that Blue-footed Boobies breed in the tropical Eastern Pacific Ocean. Off their breeding colonies, they can be found anywhere from Baja California to Chile. However, they are known to periodically irrupt north into California and Arizona between July and October, during their post-breeding dispersal. During these irruptions, there have been relatively few records from coastal California. The bulk of the sightings (7 of every 8) have typically occurred many miles inland, at the Salton Sea, not far from the Mexican border and their breeding grounds in the Gulf of California. For example, in 1972 a flock of about 40 Blue-footed Boobies was seen at the north end of the Salton Sea at the Whitewater River delta. Prior to 2013, it had been over 30 years since the last irruption, which was minuscule in comparison. This time around, Boobies have been detected in at least 15 California counties, as well as Arizona and New Mexico, not to mention in much larger numbers. 


 On 24 September, Oscar Johnson made a conservative high count of 26 Blue-footed Boobies at the south end of the Salton Sea. How many of them can you see in his photo above? The next day, birder Dave Goodward saw 47 at the Whitewater River delta! This was the highest count ever recorded in California for Blue-footed Boobies.

The Farallon bird marked the fifth Sulid species to occur on this island, since biologists began keeping track of such things in 1967. Sulids, or members of the family Sulidae, are large seabirds with long wings, wedge-shaped tails, and stout, conical bills. Sulidae is comprised of ten species of Boobies and Gannets in three genera, but only five have been seen in North America. Remarkably, all five of these species have now occurred on the Farallones. Northern Gannet, Red-footed, Brown, Masked, and now Blue-footed Booby have all been seen from this tiny rocky island.


Last year, the birding world was shocked when Farallon biologists located a Northern Gannet on the island. Not only was the Gannet a first Island Record, it was the first to ever be spotted in the Pacific Ocean. The Gannet has been sighted roosting at the island nearly everyday since, and it is still seen daily, roosting on Sugar Loaf. Check out the Gannet story by clicking here.


This is one of my many photographs of the Farallon Northern Gannet from Fall 2012. Hundreds of people have visited the island on tour boats to get a glimpse (or some photos) of this amazingly rare bird.


The name Booby comes from the Spanish word bobo ("stupid", "fool", or "clown") because the Blue-footed Booby is, like other seabirds, clumsy on land. They are also regarded as foolish for their apparent fearlessness of humans. Sailors thought them unintelligent due to their habit of landing on boats at sea, where they were easy prey and inevitably ended up in the hungry seamen's cook pots.


Here, a Brown Booby takes a free ride to the Farallones aboard a fishing boat during Fall 2012.

So if you are interested in seeing some Sulids for yourself, and you live in California, now is the time to get to some rocky coastline and scan for Blue-footed Boobies. After all, it may be 30 years before they come back.

Friday, September 06, 2013

Covered in Flies

In a season that is usually highlighted by migrant birds and rare vagrant species, this incipient fall field season has been anything but, and to our chagrin, our attention has been focused on something entirely different. Since the arrival of the fall bird crew, Southeast Farallon Island (SEFI) has been inundated and plagued by a surfeit of flies. If any bird were interested, SEFI would be the ultimate buffet, but unfortunately there just aren’t enough migrant songbirds (thanks to the current weather pattern) to put a dent in the daunting number of flies. As they have spread over the island in one of the worst excesses seen in recent years, our incessant swatting, slapping, and twitching is driving us all mad. Being field ornithologists, 75% of our work requires us to be outside. To deal with the horrendous nuisance, we take preemptive measures to cover every inch of our bodies, even on calm, hot days, by tucking pant legs into socks, cinching sleeves tightly around gloves, and wrapping bandanas around our faces. Alas, the flies still manage to crawl under our protective layers to tickle us until we smash or release them. Imagine the perseverance it takes to stand motionless in a swath of flies for an hour conducting a bird survey. Quite frankly, the flies are wearing on us.

For healthy birds, the flies provide a much needed snack.  For a sick or weakened bird, the flies turn the tables and swarm the moribund individual. Take for instance this recently fledged Western Gull that has clearly lost the battle to live. 


A few of us have found a comical, to some vile, way to handle the flies. Ryan Potter, the carryover seabird biologist, has decided that letting the flies run amuck is the best way to overcome the problem. He theorizes that by exposing more skin, there is an overstimulation that is easier to deal with than just one or two flies crawling under heavier wraps. Thankfully, there are days when the flies don’t seem as bad and being outside becomes bearable. This mostly occurs when a steady force of wind keeps the flies clinging to the rocks, or when a cold fog keeps them at bay. Unfortunately, these are not the conditions that bring songbirds to the island. The few birds that are on the island, though, are making the most of this fly cornucopia, such as this Townsend’s Warbler making a tasty afternoon snack out of this hapless bugger, or this juvenile Western Gull picking away at a fly-covered sea lion corpse.  




Prior to writing this blog, it was assumed that the pest we were dealing with was the widely dispersed kelp fly, Coelopa frigida. This species of fly is common along beaches where it utilizes deposited kelp or seaweed for its reproductive cycle. However, thanks to a bit of recent sleuthing, we now know we are dealing with a completely different species. And it makes sense. SEFI is a rocky outcrop with little area or space for kelp to deposit, and kelp flies don’t tend to display the relentless desire to land on humans in massive numbers anywhere else. In fact, the fly that has proliferated on SEFI is better known as a Cormorant Fly. The species we appear to have here, Fucillia thinobia, primarily lays its eggs on dead cormorants and is only found near cormorant colonies. Dr. Robert Kimsey, an entomologist from UC Davis, recently studied this fly on Alcatraz Island in the San Francisco Bay, where it annoys tourists, and discovered the link between this species and cormorants. As it turns out, Alcatraz is also experiencing a profusion of flies and recently posted the following advisory: 

Visitor Advisory – Why are there so many flies on Alcatraz Island and on Alcatraz Cruises vessels?


During this time of year (September & October), one of the 17 identified species of flies on Alcatraz Island is found in large numbers around the dock area and on Alcatraz Cruises boats. These flies are commonly referred to as Cormorant flies, and they do not bite or pose a health risk to island visitors. The presence of these flies is an indicator of a healthy population of cormorants on the island. In the last two years, the cormorant population on the island was decimated by several natural events. This year, the population is rebounding, so the fly population has temporarily increased. These flies are a very important part of the island ecosystem and are not caused by any adverse conditions on Alcatraz Island or on Alcatraz Cruises vessels. We apologize for the annoyance these flies may cause and hope you will enjoy your visit to Alcatraz Island.

Because the type-specimen (the first of a species to be collected and described to science) of Fucillia thinobia was collected on SEFI, we currently believe that Corm Flies are also pestering us. In terms of its general biology, the adult flies deposit their eggs on dead cormorant bodies, and the larvae feed and mature in the guano-stained soil. One thing that makes this species of fly unique from other types of carrion flies is that it specializes on a specific type of carrion. By restricting itself to a particular group of birds in a seabird colony, the Corm Fly has evolved to take advantage of a predictable time and place of high mortality (many seabird young die before fledging) where it may reproduce. Here on SEFI we have three breeding species of cormorants with the most populous being the Brandt’s Cormorant. With 2013 being an early breeding season for seabirds in general and a rather productive year for the Brandt’s Cormorants, this year produced a bumper crop of corm flies. And with the seabirds having recently fledged, it appears that the flies may be exploring the rest of the island for a secondary host in which to lay their eggs. 

Now that we know the species we are dealing with, we may begin to search for answers to our many burning questions. For example, why are adult corm flies attracted to humans? It has been proposed that perhaps they land on humans as they would on any other substrate, but it is obvious to us that they swarm on us in much higher concentrations than on the surrounding substrates. So, are they attracted to us because we smell like carrion? Perhaps they wish to lay their eggs on us and this is just a case of mistaken identity. Originally we wondered if they could be feeding on us, but we do not observe them “licking” us with their proboscis (fly mouth-parts). Either way, we have found, as you may have wondered, showering does not deter them from swarming on us.

It is also apparent that some years have more flies than others, and it would be interesting to know exactly what factors affect their population. Is it just numbers of cormorants breeding, or do Corm Flies reproduce in greater numbers following a couple years of poor cormorant productivity? The last really big year for Corm Flies was in 2004, and an intern related his experience this way:

"A plague of flies during [my internship] provided few places for rest when outside, and howling NW winds became my friend. While on shark-watch, I would stand in the brunt of a gale, and watch flies launch out towards me from the protected south wall of the lighthouse, only to be immediately caught in the high winds and vanish. Standing there with a fly swatter I could kill 20 at a time, only to have 20 more instantly begin to feed on the smashed bodies of their cousins, which I would then swat again. But there was no end to this game... Scoping from behind the carpenter shop was perhaps worse still. Clothing had to cover EVERY bit of skin to avoid insanity. Only a small hole in your hood to view the eyepiece was possible. Afterward, your clothing was peppered in tiny fly turds, innocent enough until you contemplated the sheer number of them"

With a list of numerous unanswered questions, we look forward to delving deeper into researching these little buggers. Until then, though, we are simply trying to avoid being carted off the island in straitjackets. And we are extremely hopeful that our next blog will be about the swarm of birds that descended upon the island and devoured every last Corm Fly.

                         Here's a look at what we really mean by Covered in Flies.

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Wednesday, July 17, 2013

Bird Photography: Beyond Just the Subject

Words by RJ Roush



Over the last three and a half months I’ve spent on the Southeast Farallon Islands I have had countless opportunities to take amazing photographs and have done my best to take advantage of all of them. With all life and death on the island I feel like I could spend an entire season on SEFI just photographing all that happens. I really do feel privileged to have had such an experience. I am by no means a professional photographer; I consider myself an eager-to-improve novice. Anyway, I’ve gathered enough experience in my 7 years to know that I have a lot more to learn when it comes to photography, but what I do know I would like to share.

Now, before I go into the meat of this article, I want to start with a note about the gear I use. It’s true that the photograph is more the photographer than the camera they’re using, but the lenses and camera body are still crucially important. My best advice is to use what you know well. The less time you spend fiddling with settings and the more time you spend shooting. I use a few different lenses that range anywhere from 10 to 300mm, but I will just go ahead and say that my 70-300mm telephoto lens was one of the best investments I could have made toward my outdoor photography. It allows me to bring my subjects (most often birds) close so that their beauty can be admired without them being disturbed by my presence.

This is a photo where the subject is really all that’s going on in the picture. A shot of three Western Gull chicks, two hatched a day or two ago and the third just taking in its first breaths of fresh air. Taken May 31, 2013 in K-plot.
Let’s talk about the subjects. Like I said earlier, I am a bit biased towards photographing birds, so that is what I will focus on. Often times, it is the subject that will make or break the photo, and one of the easiest ways to ruin a photo is to have you’re subject out-of-focus. It can be a crushing experience to find out that out of the 100+ frames you just shot, only 2 were in focus. That’s why when shooting birds, I only use manual focus on my lenses. I often find that my eyes are more accurate and faster to react than the autofocus on my lenses; I know the subject that I want to shoot much better than the camera’s AF does. Using MF has helped me get some amazing pictures that could have otherwise been missed if I had waited for the lenses AF to pick up my desired subject.

This Wilson’s Warbler was hopping about in the Monterey Pine, April 26th, 2013. Had I used AF instead of MF, I may have missed the crisp contrast in the WIWA’s cap and head.
The photo above is also an example of using the foreground and background to lead the eyes to the nice bright Wilson’s Warbler near the center of the frame. This photo uses the out of focus region to bring the eyes straight to the subject.

It seems like one topic that is often overlooked in wildlife photography is the framing of the subject. Sometimes you’re just too focused in on the subject to even think about how it is placed in the frame of your image. The earlier photo of the gull chicks is an example of where the subject is all I wanted my audience looking at, so I made it dead center and had it take up the entire frame. Another strategy is where you put your subject slightly offset from the center and you use what’s in the foreground or background of the image to bring the viewer’s eyes toward the subject. When putting the subject out of the center, it shifts the “weight” of the photo to one side or the other, so it is important pay attention and balance it out. You can balance a photo with the use of light and dark colors or different color tones on different parts of the photograph. In the Wilson’s Warbler photo, I kept the subject slightly to the left of center to keep the photo a little more dynamic, as if the warbler was photographed right before it was going to jump to the right side of the photo. The lighter green on the right helps to balance out the dark tree branches on the left.

"The Anonymous Flycatcher" is what I like to call this one. This photo has the weight slightly shifted to the right of center due to the silhouetted subject being there and the black branches. Taken May 2, 2013 in the Cypress Tree next to the PRBO house.
In the photo above, the eyes are drawn toward the subject immediately due to the extreme contrast between the background and foreground. The “heavy” black is kept out of center and balanced out with the lighter background taking up the majority of the photo. The vignette of the tree branches around the edge of the photo also help to balance the light and dark in the photo and keep the eye towards the center of the frame.

Another important thing to consider while shooting is the background that your subject will be set in. The background can turn a good photo into a great one by adding greater depth to the scene you’re capturing. Below is a crisp photo of an Olive-sided Flycatcher, posing on a dying shrub. This ended being one of my favorite photos of the season because of the background. The bright blooming Farallon Weed (Lasthenia maritime) makes for a vibrant background that nearly overloads the senses. I think the contrast between the drab plumage of the flycatcher and the brightness of the blossoms is what makes me enjoy it most.

One of my favorites of the season, a visiting Olive-sided Flycatcher on April 26th, 2013
Another note on background: sometimes you don’t really need one. A plain black or white background can give a photo a very intense look and will really make your subject stand out.
A pair of stern eyes and a solid black background make for one very serious Burrowing Owl. Seen Aprill 11th, 2013 in a crevice under the Corm Blind.
And before I sign off, I wanted to mention the use of black and white and other effects. B&W is what I learned first so it is very fond to me, and yet most of the time I shoot wildlife in color. A lot of the time, the color is one of the most alluring parts of the subject you’re photographing, but every once and awhile it can be distracting. Take the photo of Brandt’s Cormorants below. I was originally shooting in color until I noticed an annoying splash of color in the background that was taking the focus away from the dark gray corm chicks and their parent. So, I switched to black and white on my camera for the rest of the shots and was much happier with how they all turned out. Black and white also allows you to bring attention to detail in structure, which can be quite a treat if you’re shooting macro shots of birds.

Black and white, and other tones like sepia, can help bring attention to your subject. In the cormorant photo, the black heads of the birds stand out quite nicely against the lighter background, whereas if the photo were in color they would be competing against a strangely colored object in the background.
So, that’s what I have to share. I hope it helps out some of you. If you’re at all interested, feel free to view some of my other photography at my blog (RJ Roush Photography) or my flickr. Feel free to ask any questions and lend any criticism; remember: I’m still very much learning myself!