Winter Whales Linger On

While the winter season here at Southeast Farallon Island usually focuses on the soap-opera-esque, high stakes drama of elephant seal pupping and mating season, there are many other marine mammals that utilize the high productivity and unique location of the Farallon islands in their ocean travels.   These islands are a regular stopover for other seals and sea lions, as well as their larger ocean companions – whales and dolphins.  Many whale species are known for their great yearly migrations – humpbacks from Alaska to Hawaii, grays from the Arctic to Baja - moving from cold but nutrient-rich northern waters to temperate  (but less full of food) or tropical waters in the winter.  These whales make the trips for the same reason elephant seals return to the Farallones year after year – it’s a great place to raise a kid.  Warmer waters are better for newborn whales, and they nurse from mom long enough to build up a nice blubber layer before heading back up to the cold waters of the north. 

Most of these whale migrations start in late fall or early winter, as grays, blues, humpbacks, and more pass by our houses on Southeast Farallon, one at a time or in large groups with whale blows visible in every direction.  A few months later, the blows start showing up in the south, as the whales return to summer feeding grounds, this time often with a new calf in tow.  In the past few years, researchers here on SEFI have noticed a few of those whale blows in months when they shouldn’t be here.  Some “resident” gray whales – those that don’t migrate all the way south – settle in around the Farallones, probably taking advantage of the wonderful food supply provided by our proximity to the continental shelf.   This subset of “residents” may be younger whales that are not yet sexually mature, and do not need to complete the full migration to the calving and breeding grounds down south, so they decide the Farallones look like a good spot to stay for the winter.

 

Not a bad view...

We keep track of these resident whales, as well as the migrating ones and any dolphins who happen to pass our way, with our daily “Cetacean Watch.”  Twice a day, and sometimes more often if the weather and visibility cooperate, we climb the trail to the lighthouse, where visibility on a clear day is 40+ miles in all directions, and set up with our scope, binoculars, and an iPad.  The iPad is a new addition to our daily whale watches, not just because it’s easier to use its built-in GPS and compass when spotting whales, but because of a new app called “Spotter Pro,” by Conserve.IO.  This app (currently only for Apple’s iPad & iPhone) allows users to collect field data of animals, plants, and other environmental information, and provides a unique opportunity to participate in “citizen science.”  Recently, the app has been used to track and upload sightings of whales and dolphins off the California coast.  We use Spotter Pro to upload real-time information on the locations of these animals around the Farallones.  By providing information on where they are, the app helps to reduce the chances of whales being struck by large vessels when they’re in California shipping lanes. 

A gray whale passes close by SEFI

Ship strikes are one of the biggest threats to whales and dolphins, and often go unnoticed – dead animals often either sink out at sea or wash ashore too decomposed to determine the real cause of death.  Reducing the co-occurrence of whales and large boats (making sure they’re not in the same place at the same time) is the best way to prevent ship strikes, and using the Spotter Pro app to map the locations of whales and dolphins could be a simple, user-friendly and openly available way to prevent co-occurrence.  Recent changes in the size and locations of California’s shipping lanes were implemented with whale protection in mind, and with both researchers (like us on SEFI) and citizens out on boats or onshore uploading information on where they see whales, we can assess the effectiveness of these changes while preventing strikes from occurring. 

 

A screencap of Whale Alert (from iTunes app store)

From a recent SEFI cetacean survey

These shipping lanes pass close by SEFI, and while drinking a morning cup of coffee on the porch, it’s not unusual to see huge container ships cruising by on the horizon, along with 5 or 6 blows closer to shore, while looking in just one direction.  One of the main goals of Spotter Pro and its East coast sister app, Whale Alert, is to allow ship captains access to real-time location information, so they can either avoid areas with lots of whales or slow down while passing through them.  Our unique location in the midst of these shipping lanes and our ability to look for whales on a daily basis provides important information on their location – especially for the resident whales that decide to stick around.  The Farallones might be a great whale buffet, but they’re also in the middle of some heavy ship traffic, and providing daily information on whales in the area will help reduce their chances of being run over.  

It has been a banner year for whale watching off the California coast, and this season it seems they are sticking around longer than usual, a strange occurrence that only emphasizes the need to protect them from collisions.  Here at SEFI, we are seeing blue whales almost every day, unusual for this time of year, and we’ve had a few humpbacks also making a later trip down south, in additional to a few pods of Risso’s dolphins.  Last week, we caught a glimpse of a distinctly v-shaped blow among some southbound gray whales, which usually have bushy or heart-shaped blows.  Right whales, one of the most endangered species of marine mammals, have very prominent v-shaped blows, though some gray whales have also been seen with a larger divot in their blow, making it appear v-shaped.  Sightings of North Pacific right whales are extremely rare, and it is even more rare to see one this far south.   Two sightings occurred earlier this year off the coast of British Columbia, the first for that area in 62 years.  Unfortunately, we couldn’t confirm the identity of the whale with the v-shaped blow, but we alerted NOAA and other organizations further down the coast, hoping that the southbound whale would be seen and confirmed somewhere on its travels.

The v-shaped blow of a right whale (left) is notably more separated than the bushy, heart-shaped blow of a gray whale (right)

Our great gray whale migration is just starting to pick up, and I look forward to seeing more and more of their huge spouts passing us by every day (along with any other random whale and dolphins that may appear), while trying our best to conserve and protect them along with all the other wonderful creatures at SEFI – residents and visitors alike.

Lighthouses and Migrants

For the first few decades that PRBO worked on the Farallones, a powerful rotating light on the lighthouse acted as a beacon to lost ships, birds, and bats.  An analysis of 38 years of hoary bat arrivals on the island revealed that nights during the dark phases of the moon had a greater likelihood of bats being detected in the trees the following day than bright phases of the moon (Cryan & Brown, 2007, Biological Conservation).  The authors theorized that the darker nights increased the probability that these migrating bats would see and be attracted to the lighthouse.  And in fact, there are several accounts by previous biologists of bats circling the lighthouse during dark nights. At the time of the published paper, island biologists were finding bats on average >7 days per fall.  However, since the powerful rotating beam on the lighthouse was switched to a weaker, pulsating light, the number of hoary bat arrivals to the island has plummeted to approximately one per fall.  What effect, if any, this lighthouse switch has had on bird arrivals to the island is unknown, but it does seem that fewer birds are finding the island at night, with most birds arriving during the day.

The 16th through the 18th brought low winds and high overcast skies, which meant that good numbers of migrant birds descended upon the island. On the 16th we banded our first Yellow-rumped Warbler of the fall as well as our second Baltimore Oriole of the season; interestingly we have yet to record a Bullock's Oriole for the fall, which is normally our most common oriole. In addition, we had 11 species of warbler including a Black-and-white Warbler, 2 Chestnut-sided Warblers, a new Magnolia Warbler, and 3 Blackpoll Warblers. We also spotted a Vaux's Swift zipping past the lighthouse.

On the Farallones, we color-band six songbird species, including this Townsend's Warbler.  Each individual bird gets a unique color combination, which allows us to identify individual birds in the field without recapturing them, so that we can keep track of how many birds of our most common species are on the island each day.

The 17th brought us more migrants including a mixed flock of six teal, 3 Blue-winged Teal and 3 Cinnamon Teal. The Cinnamon were the first in over a decade, while the Blue-wings represented the 11th, 12th, and 13th records for the island and an island high count. Immatures and females of these two species are very similar in appearance, but lucky for us, they circled close to the island a few times, and we were able to get some good photos to aid in identifying them. The primary features to distinguish them are bill size (longer and spatulate in Cinnamon) and facial plumage (distinct white wrapping around the underside of the bill in Blue-winged). Can you figure out which are which?   The day continued with the first Vesper Sparrow of the Fall, a male Indigo Bunting, a male Dickcissel, and a Bobolink. We also added to the warbler count with 2 MacGillivray's Warblers, a Wilson's Warbler, and a Tennessee Warbler.

The 18th continued to be calm and cloudy and added several new migrants to the many birds still refueling from the previous two days. Notable arrivals for the day included a Willow Flycatcher, a Hammond's Flycatcher, the first Hermit Thrushes of the fall, a Painted Bunting, and 3 more species of Warbler including Blackburnian Warbler and Bay-Breasted Warbler - all and all a pretty nice little wave. We ended up seeing 17 species of Warbler over the 3-day wave. Although the last few days have been windy, with thick fog the past two days, we're hopeful that conditions will improve in the near future so we can catch another wave. 

In addition to studying the flying migrants, we conduct daily surveys from the lighthouse to document the occurrence of white sharks around the island as they fuel up each fall for their annual migration to the middle of the Pacific, where breeding is thought to occur.  The Farallones is the only places in California where white shark attacks can be routinely viewed. A recent analysis of shark genetics and transmitter data has revealed that the population in the northeastern Pacific (the ones we see in California) is genetically and geographically isolated from the other populations around the world (Jorgensen et al., 2009, Proc. Roy. Soc).  Furthermore, using underwater videography to identify individuals has led researchers to believe that this population is extremely low, possibly less than 400 adults (Chapple et al., 2011, Mar. Bio.).  For this reason, there is a push amongst conservation groups to get this population listed as federally threatened or endangered.  Over the past several years, the numbers of attacks at the Farallones has been steadily declining, so the seven attacks we have witnessed thus far during September have been a welcomed turn of events.

While looking for sharks, we also document the number of cetaceans within sight. For the first two weeks of September, we were seeing three resident Gray Whales that spend their time foraging around the island, but lately a fourth may have joined the group. After spending hours watching them cruise around during shark watch, we have become pretty familiar with each individual and have given them names so we can discuss which ones we are seeing. The two in this photo are affectionately known as Big Moby (in the back) and Lil' Moby (in the front). The third resident, Big Spot, is one that we have been seeing for at least the past three years. The fourth individual is also small and has quite a bit of red on its forehead. Its name is less settled, but has been referred to as Red Face or Lil' Red.

 

Tune in next week for more excitement.