We are happy to back home on Cape Cod and over the past week have started to get back out in the field to see how the slow warming trends of spring here are signaling the changes and new wild visitors. Here are a few images we captured.
Of Hawaii’s birds, the honeycreepers (Drepanidinae) are most famous, having put on what is arguably the world’s most dazzling display of adaptive radiation–an explosion of species from a single unspecialized ancestor to at least 54 species that filled available niches in the islands’ habitats. In fact, speciation in the Hawaiian honeycreepers dwarfs the famed radiation of Darwin’s 14 Galapagos finches. Robert Fleischer, Cheryl Tarr, and Carl McIntosh at the National Zoo’s Molecular Genetics Laboratory estimate that the honeycreepers’ ancestor arrived three to four million years ago; others put the arrival farther back, at closer to seven million years ago. This ancestor–one colonizing species of finch, possibly a Eurasian rosefinch (Carpodacus sp.) or, less likely, the North American house finch (Carpodacus mexicanus)–started what proved to be an evolutionary snowball. “There must have been a lot of open niches, and the birds hit the islands and speciated very rapidly,” says Fleischer, who studies the genetics of fossil and living Hawaiian birds. Rapidly, in terms of geologic time, is thought to be within the first 200,000 to 300,000 years after the first finch touch-down.
Nectar-feeding honeycreepers evolved dramatically curved bills designed for probing and extracting the nectar from the flowers of Hawaii’s endemic lobelias and other plants. Insectivorous honeycreepers developed thin, warbler-like bills for picking insects from the foliage. Seed-eaters developed stouter, stronger bills for cracking tough husks. Some species probed or cracked bark with strong hooked bills seeking wood-boring insects, thereby filling a niche woodpeckers do elsewhere.
Honeycreepers shared the islands with an array of other unique bird species. In 1991, Storrs L. Olson and Helen F. James of the Smithsonian’s National Museum of Natural History described for the first time 32 extinct species they identified from bones found in lava tubes, sinkholes, dunes, and excavated Polynesian refuse piles (middens) on the main Hawaiian Islands over the past 19 years. Three others had been previously described. When their analyses are through, at least 20 more species will likely be added. These recent findings conjure up a vision of an almost mythical world where birds, not mammals, dominated. Large flightless waterfowl called moa nalos were the islands’ large herbivores. A harrier, a hawk, an eagle, and four owls topped the food chain as predators. No mammals patrolled the ground (Hawaii’s only native land mammal is a bat), and, with the need to fly gone, many of the castaway bird species, such as endemic ducks, ibis, and rails, lost their powers of flight.
The rare `akia pola`au occurs in only a few areas of upper elevation on the Big Island. Its bill is the most unusual in the honeycreeper family. The lower bill is short, straight, and stout. With mouth agape, it is used to chisel holes, woodpecker style. The upper bill is long, curved, and slender. It is used to probe, pierce, and pull insects and caterpillars from the hole. The male is brilliant yellow with a black mask; the female is dull green with a less distinctive mask and slightly shorter bill.
The `akepa is an insect-eating bird with a short, straight bill. The male is blaze orange; the female is gray-green with tinges of yellow or orange on the breast. It is the only Hawaiian honeycreeper that always nests in natural tree cavities.
The largest endangered forest bird in Hawaii is the ‘Io (Hawaiian Hawk). It is frequently seen soaring high above the tree canopy in search of birds, large insects, mice, and rats. Rarely seen in the 1960s and 1970s, hawks are now frequently observed from the coast to the tree line on mountain slopes.
On a recent visit from my friend Wayne, I made a conscious decision to embark on an early morning birding excursion without bringing my camera. Wayne is an avid birder who doesn’t get to wander on the outer beaches of Monomoy National Wildlife Refuge very often so I was keen on making sure he had a good experience. Common practice for birders here is to have good binoculars but especially for small shorebirds to pack a spotting scope on a tripod. We each decided to bring a scope. Though a beautiful early morning we did not have favorable tidal conditions ( a falling tide) forcing us to anchor in fairly deep water before wading out to examine a large mixed flock of shorebirds foraging along the waters edge. The light was mellow and the birds showed well in golden light as they jostled around while feeding aggressively for their next hop in the long flight south.
As we eased our way in shallow water toward the flock we began to scan for the birds that were different hoping to find a rare vagrant. This is a “bird watcher” thing. In this case we were looking at a flock of maybe three hundred Black Bellied Plovers in non breeding plumage with a few dunlins, sanderlings and ruddy turnstones mixed in. The Black bellies’ were a bit drab compared to the dramatic black markings of the breeders we might see heading north in the spring. One particular bird caught our attention and we trained the scopes on it hoping to see the subtle differences that indicate the rare American Golden Plover. This bird species occasionally passes through Cape Cod beaches heading south. At this moment I was just beginning to regret NOT bringing my camera….when the entire flock of birds exploded into the air in flight. The target of our observation was now lost amongst the blizzard of panicked birds. Experienced birders know that this sort of excitement can be caused by the sudden presence of a predator threat so we immediately scanned to see. Within seconds a perfectly silent deadly attacker came streaking in about 6 feet off the beach at 60 miles an hour. “Peregrine!” I yelled. ..very excited but now really regretting I did not have my camera. Wayne corrected me and said ,”Merlin, looks like a female” (NOTE: the female merlin is slightly larger than the male but both falcons are considerably smaller than a peregrine.
What was to happen next are one of those experiences you cannot soon forget. As the streaking falcon came into the panicked flock she quickly picked out one of the tiny dunlins as her target narrowly missing with extended talons on the first strike. Stunned into jaw dropping wonder we watched as the merlin darted and the dunlin flailed as the rest of the flock separated to a safe distance oscillating in erratic flight. In one panicked motion the little dunlin headed directly for us – the two gawking bird watchers standing in knee high water and looking like some kind of cover. Whoosh – the falcon bolted over our heads and swung tightly in pursuit of the poor shorebird who was in the flight of its life and had pivoted back to the beach. With predator precision the merlin climbed up to about 50 feet overhead and then dove into a blistering stoop with talons extended and this time struck the dunlin with such force about three feet above the water that both birds powered into the sea with a massive splash. Unlike ospreys, falcons of this type are not comfortable in water and this maneuver could have been dangerous for lift off – soaking wet is difficult. In this case the dunlin was left stunned and floating in the water while the merlin struggled to attain lift with totally drenched feathers hoping to gain altitude and set up for another strike to retrieve its now helpless stunned prey. At this very moment however, an attentive Greater Black backed Gull who had been carefully observing the melee, now launched from a nearby beach position, crashing into the water and plunged its wide open beak over the still bewildered dunlin, engulfing the hapless shorebird in one gulp! YIKES!
Meanwhile the Merlin, still soaked and having missed the gull’s surgical strike was in a frantic search overhead looking for her prey, flying back and forth , alternately hovering to try to see the meal she had worked so hard to procure. Alas it was not to be. After about 2 or 3 minutes of searching she made her way back to the beach and perched on a piece of driftwood to dry off. Wayne and I looked at each other and mused that with my camera I may have captured one of nature’s great spectacles but we also agreed the odds were better that while trying to follow the battle in a view finder I would more likely have missed the action altogether.
The pictures included here were taken at a different time just to give you a little sense of the actors in this natural drama.
The fall shorebird southerly migration is winding down but there is still much to see if you look carefully on the barrier beaches off Chatham. We have had family & friends visiting for the past week and have had a chance to explore some of our favorite places.
The end of winter in the Lowveld region of South Africa means the end of the long dry season. Temperatures are warming , small green buds can be seen trying to germinate in local shrubs and trees. The rains are right around the corner. Many animals have recently borne young and are nurturing youngsters in the bush. The very first European bird migrants are starting to return to their summer home in the South. We had some fantastic views of the regions most beautiful residents. Second in a series.
These are from the backyard birding efforts of the last few days. We have a young family of Ruby Throated Hummingbirds including a tender young bird. They are seen routinely bombing around our garden and this time of year they are frequenting the blooms of Rose-of-sharon. Very hard to get to stay in one place for a photograph but managed a couple of decent images on a stormy day this week.
We are finally managing to secure some quality time offshore. Our friends the Gulf of Maine humpback whales are feeding voraciously in the waters off Chatham. It is also now wonderful to see mother and calf combinations with young whales that were likely born this year or last on the Silver Bank off the Dominican Republic.
Spring gives way to summer on the outer beaches of Cape Cod quite abruptly. The water warms the air warms and the strong sea breezes pipe up in the last few days of June. Summer is on. Among other adventures the white shark returns to waters off of Chatham. Our first clues come from observing the seal carcasses that appear on our beaches.
We were very fortunate to get the call from our friends Scott Jensen and Courtney Lipson to travel with them on the 68 foot ketch Island Odyssey to explore the wild southern islands of Haida Gwaii off of the British Columbia coast and near the Alaska border. The attraction is a remote set of unspoiled wilderness made up of the finest temperate rainforest anywhere on planet earth. In addition this is the ancestral homeland to the Haida Nation who have lived there for more than 8000 years and whose people are regarded as the most prolific artists of the indigenous North American cultures that lived here before European contact. In recent years there long traditions of carving poles to tell stories and to commemorate events has undergone a resurgence and many new pieces are appearing all over the islands and elsewhere in the Pacific Northwest. An additional reason for exploring this coast was to visit the ancient and now quiet ancestral villages that flourished in the mid 19th century but are now uninhabited except my “watchmen” who have Haida heritage and live on site in small cabins during the summer season to allow visitors like us to come ashore and appreciate the beautiful, fragile and valuable ruins. This is a pristine park which is now protected for all time.