Earlier this week, we hosted Blake Mathys, Ph.D., an environmental scientist who has been banding birds throughout the Hawaiian Islands, for a day at our home on Kauai. Blake is an assistant professor at Ohio Dominican University, and this data on non-native bird species is part of an academic tenure project. Banding birds is a data collection tactic long used to study habituation, migratory patterns and behavior. Blake’s data will be used by grad students and others in conjunction with many hypotheses concerning non-native species in island-based ecologies. For bird nerds like us, hosting a super bird nerd like Blake was an opportunity we couldn’t pass up!
Because Hawaii is over 2000 miles from the nearest large land mass, established bird species have evolved from the original individuals who were introduced via migration (both human and avian) and by accident. When human populations arrived in great numbers, the non-native species they introduced changed the ecosystems. Adaptations within individual species occurred due to different conditions here – presence or absence of competitors, predators, diseases; differences in habitat and food supply, and so on. Certain birds became extinct after the arrival of the Polynesians, and, according to the Audobon Society, more than 20 types of birds have become extinct, with even more endangered, after the arrival of Europeans just over two hundred years ago. The ecosystem here on Kauai happens to be a little more distinct from those on the other islands due to its more isolated geographical positioning in the archipelago.
Since we’ve lived here on Kauai, we’ve been highly entertained by the various birds on our rented property, which is situated within a tropical rainforest environment within the Wainiha Valley. Most, if not all, of the birds we’ve become acquainted with around our home are non-native passerine (perching) birds: White-rumped Shama (my personal favorite, introduced on Kauai in 1931 from Malaysia), Red-crested and Northern Cardinals (introduced in the 1930’s), Common Mynas (introduced from India in the 1860’s for insect control), Spotted and Zebra Doves (introduced from Asia in the 1800’s), Japanese White-eye (introduced as early as 1929 from Japan), and Java Sparrow (originally introduced in 1867 from Indonesia on Oahu; Kauai’s colony is increasing here on the North Shore from a re-introduction on other islands in the 1960’s).
Blake arrived early in the morning to set up several long nets after observing potential flight paths around the property. The nets are airy, loose black mesh, virtually invisible to birds and humans alike. We were familiar with this process, having observed it used to identify migrating raptors at Hawk Ridge in Duluth (see our post, A Bird in the Hand, from one of our visits), so Pete was glad to assist.
Blake used our lanai as a workstation, unpacking different envelopes, metal bands, measuring instruments, a sensitive scale for weighing, collection bags, and handwritten data records. During his six weeks in Hawaii, Blake has caught and banded over 450 birds. His data will be used in conjunction with a variety of hypotheses related to adaptation and evolution.
We were happy that, after a series of very rainy days, this day looked to be a little more dry. Wet birds are difficult to extricate from the open netting. It took quite a while for the first birds, a pair of Japanese White-eyes to be netted. Blake easily extricated both of them and bagged them individually in white cloth bags. I asked him why white? In Duluth, black bags were used; the absence of light calmed the birds, making them easier to work with. Blake explained that white bags kept the birds cooler in the hot Hawaiian temperatures. As he prepared for data collection, the little White-eyes were quiet in their hanging bags above the lanai workstation.
The White-eye is a little wren-sized bird, about 4-½ inches long. Its yellow-green color allows it to easily blend into a forest environment. We’d been very amused by its ability to hang upside down to get nectar from the florets on the end of banana cluster outside our dining room window. We continued to notice their acrobatics by keeping a lookout for quick movements in the dense greenery surrounding our house. The White-eye’s eye ring gives it an alert, intelligent appearance, too.
Blake deftly handled the birds in a typical grasp known as a ringer’s hold, keeping their heads gently immobilized between two fingers as he made his measurements. There is an additional, more showy grasp birders use by holding the bird’s legs. This allows you to see almost all of the bird up close. Both White-eyes remained quite calm during the banding and data collection process. Blake thought it might be a fatalistic attitude on their part; “they’re expecting now that they’ve been caught, to be eaten.” Kind of dark humor for a bird nerd, no?
Here is a video of Blake explaining the measurements he takes on all birds with the White-eye. (YouTube link here).
Blake also collects a DNA sample from each bird by taking a couple of covert feathers. The bird’s DNA can be obtained from the feather’s shaft where it is in contact with the skin. This is a much less traumatic way to obtain DNA than a blood sample would be, not to mention the difficulties encountered with handling and stabilizing the sample once it has been taken. Here is a video of that process (YouTube link here). As you can see, the White-eye literally did not make a peep!
After a long interval during which we were getting somewhat discouraged, the male White-rumped Shama, whose daily singing is so entertaining, was in the net and he was not happy about it. This video shows Blake calmly and deftly extracting our vociferously complaining Shama from the net. (YouTube link here) I love how he fixes the evil eye on Blake and snaps back at me at the end!
The Shama’s complaining continued throughout the banding and data collection process. Here, Blake explains step by step as he bands the Shama’s leg and collects the data. We had observed this Shama had lost his long tail feathers and were happy to see them growing back. Throughout this video, I was hoping the Shama’s annoyance with us would be short-lived. (YouTube link here) His singing has become such a dependably wonderful part of our days that we would have hated to influence a move away should he have preferred after this to establish a more hospitable kingdom.
The same net that yielded our Daddy Shama tripped up his mate, a beautiful female. She handled things with a lot more equanimity by comparison with her husband. 🙂
All good things must come to an end. Prior to wrap-up and pack-up, we said good-bye to Mrs. Shama by admiring and cooing over her. She wasn’t particularly impressed. 🙂 (YouTube link here)
During Blake’s six weeks in Hawaii, he has been to all five of the main islands, and has collected data on approximately 460 birds. He is continuing the final aspects of this particular trip here on Kauai on the south side of the island. We were very happy he accepted our offer to come to our place, and we really appreciated the opportunity to hover over him and interrupt his work with all our questions, videotaping and photo-taking. It was another fascinating morning in our little neck of paradise. And, I’m delighted to report we observed our banded Mr. and Mrs. Shama behaving and singing the next day just as if nothing out of the ordinary had ever occurred.