Readers’ wildlife photos

Bruce Lyon of the University of California at Santa Cruz favors us with some amazing whale-watching photos. His notes are indented.

A few days ago I went whale watching with my favorite company, Sanctuary Cruises, based in Moss Landing, California. There are so many whales in Monterey Bay right now that it seems like whale soup—everywhere we looked there were humpback whales (Megaptera novaeangliae). They are spending the summer in the bay feeding on the rich food supply, which this year seems to be anchovy.

Below: A pink-footed shearwater (Puffinus creatopus) flies by a surfacing whale.

The whales were very active and we saw many animals breaching (leaping mostly out of the water); but they were always in the distance and never close. We did come across a couple of cooperative tail-slappers and this may be some sort of display that serves a similar function to breaching—making a giant splash plus a loud noise that travels a long distance under water.

Below: A tail slapper sticks its rear end high above the water and then whacks the water with its tail, producing a mighty splash. The evidence that these slapping type displays (breaching, trail slaps and pectoral fin slaps) are a form of communication comes from observations that social context predicts their occurrence. One study found that breaches were more likely to occur by lone males and other singletons, while slaps were found in groups of whales. What exactly is being communicated is unclear.

Below: As impressive these displays are, it was the lunge feeding that stole the show on this trip. In lunge feeding, the whales dive down under a dense food aggregation that is near the surface, then swim upwards toward the food and just as they surface they open their mouth wide to take in a huge volume of water full of krill or fish. Humpbacks, like other rorqual whales, have pleated or furrowed throats and bellies that can expand like a balloon, which allows the animal to engulf a massive amount of water in a single gulp (referred to as the ‘big gulp’ in a couple of scientific papers). Lunge feeding is often done in groups and the whales all pop up at the surface at the same time in a spectacular performance. In the lunge below, five whales surfaced at the same time right beside our boat.

Below: The tour company’s naturalist, Chase Dekker, sometimes films whales with a drone and his videos give a pretty unique bird’s eye perspective on some of these behaviors. Chase’s video below was shot a couple of weeks ago on a different trip, and it provides a lovely view of a couple lunge-feeding humpbacks. Note that the ‘bait ball’ of anchovies remains in a dense aggregation near the surface, which is why lunge feeding works. It is also interesting to see that these massive whales can almost turn on a dime, helpful for following (and perhaps herding) the fish.

If you want to hear the accompanying music, which isn’t bad, be sure to turn up the volume:

Below: I find it challenging to photographing lunge feeding because it is not always easy to predict exactly where the whales will surface and, when they do, they are only above the water for a few seconds. Fortunately other animals sometimes provide clues as to where a lunge feed is likely to occur. California sea lions (Zalophus californianus) often join in the fun and typically form sudden dense congregations close to where the whales will pop up. When we saw these sea lions going crazy we knew it was time to get the cameras ready.

Below: The whales often surface very close to the sea lions, which have to scatter. Here a sea lion seems to be trying to stay out of the way. Several lunge feeds occurred right at the boat (≤ 20 feet). Of course, that was when I did not have my wide-angle lens on the camera so I could only capture part of the action, as is the case with this photo. It is quite something to see these animals so close, especially when several suddenly pop up out of the water together.

Below: Birds like gulls and shearwaters can also be helpful sentries. Since they can see the bait balls from the air, they often hover above where the whales are about to surface and then feast on anchovies forced to the surface. This particular group seems to be only gulls. In one memorable lunge feed, the pressure wave from the surfacing whales blasted a cloud of anchovies into the air!

Below: This time I was successful at predicting where the animals would come up. This photo was taken with a normal lens (so no real magnification) and several times they were even closer than this. Note the interesting shape of the blowhole on the second whale from the right. At one point we had several whales feeding right at the boat for about an hour, often too close to photograph. This apparently happened on several previous trips as well and the boat crew suggested that the swarm of anchovies might be trying to take refuge under the boat, and the whales then follow them.

Below: The enormous amount of water engulfed in a lunge greatly extends the throat and belly. In part this is made possible by the expanding furrows, which can be seen in the photos (rorqual comes from a Norwegian word meaning furrow whale). The biomechanical aspects of lunge feeding are complex and intriguing and have been studied in some detail recently by Jeremy Goldbogen (Stanford) and various colleagues. They report in one paper that the volume of water taken in by fin whales (Balaenoptera physalus) in a single lunge feeding weighs more than the whale itself. This is not an easy task and apparently there are several morphological features that help make this remarkable feat possible. One of the more interesting of these is floppy loose tongue that can invert and form a concave sac that accommodates the water on the belly side.

Below: To extract the food from the big gulp, water has to be pushed out of the mouth without the food going with it. This is done by filtering the water through the baleen plates, which are made of keratin, as is our own hair and nails. In the first photo below, a wreath of baleen can be seen on the skinny upper jaw. To me the texture resembles a shoe brush. This sequence of three photos also shows the feeding style of a smaller animal that fed with a technique that seemed like a cross between a breach and lunge feeding; it often came quite high out of the water. These photos were taken a motor drive and span less than a second interval. Comparing the change in jaw positions in the three photos shows that the lower and upper jaw come together surprisingly quickly. A few lucky escaping anchovy can also be seen, particularly in the top photo.

Below: I think this is the same animal as the sequence of three above, but showing a different ‘breach-lunge’. This image clearly shows the water being pushed out of the whale in a gush. For orientation, we are looking at the top of the whale’s head and its belly is facing away from us.

Below: Another photo showing a couple of whales with distended bellies and the expanded furrows. The animal on the left is also ‘decorated’ with many dozen whale barnacles (Coronula diadema) on its throat. Each whale barnacle species seems to be specific to one whale species; this one is found only on humpbacks. The barnacles are passive hitchhikers that let the whale do the work of making the water flow over them (by the whale swimming) while they filter feed tiny particles from the water. They are thought mostly to not cause problems for the whales, but extreme infestations might increase drag and make swimming less efficient.

Below: A closer view of some barnacles on the very front of a whale’s snout. Like many barnacles, these appear to have planktotrophic (free swimming) larvae. However, other barnacles live on solid substrates that don’t move, like rocks or pilings. It is interesting to think about the difficulties that whale barnacle larvae face in finding their moving target of a host.