Summary: Migrating birds 'share the pain' of the arduous task of leading a v-formation, so that they can then take turns saving energy by following in another bird's wake, a new study shows.
The research, by an international team led by Oxford University scientists, is the first convincing evidence for 'turn taking' reciprocal cooperative behavior in birds. It is also only the second good example of reciprocal cooperation in animals, following a study that revealed how vampire bats shared blood to keep other unrelated individuals alive.
The team studied 14 juvenile Northern Bald Ibis (Geronticus eremita) migrating from Salzburg in Austria to Orbetello in Italy. The 'human-imprinted' birds followed a powered parachute carrying their handlers. Tiny 23g data loggers worn by each bird enabled the researchers to examine how individuals within a flying v-formation interacted.
Although the human-imprinted birds followed a powered parachute the experiment was designed to replicate the behavior of wild ibis where juveniles from the same location tend to migrate together. The behavior of the ibis from the study, including group size and travelling speed, closely matches that of wild flocks.
The researchers found that individual birds changed position frequently within the flock, flying in formations of 2 to 12 birds. Overall, individuals spent an average of 32% of their time benefiting by flying in the updraft produced by another bird's flapping wings and a proportional amount of time leading a formation.
Migrations are inherently risky for birds: previous research suggests that up to 35% of juvenile birds can die of exhaustion on their first migration. Flying in formation can help to save vital energy: it is estimated geese can make energy savings of 10-14% by gaining lift from flying in the updraft of other birds.
The team investigated why supposedly 'selfish' individuals would 'altruistically' use up more of their energy leading a formation and how flocks guard against 'free-loaders' benefitting from travelling in the wake of other birds without ever leading themselves.
'Our study shows that the 'building blocks' of reciprocal cooperative behavior can be very simple: ibis often travel in pairs, with one bird leading and a 'wingman' benefiting by following in the leader's updraft,' said lead author Dr Bernhard Voelkl of Oxford University's Department of Zoology. 'We found that in these pairs individuals take turns, precisely matching the amount of time they spend in the energy-sapping lead position and the energy-saving following position.'
Even by travelling in a pair the energy costs for both individuals are reduced, whilst larger formations bring even greater energy savings (although large formations are more unstable).
'We found that larger formations of ibis were still made up of these 'turn-taking' pairs,' said Dr Voelkl. 'The checking that went on within these pairs was sufficient on its own to prevent any freeloaders hitching a free ride within a v-formation without leading. In fact, surprisingly, we found no evidence of 'cheating' of any kind within these flocks with the level of cooperation, with individuals benefiting from following 32% of the time, significantly higher than expected.
'We think that it is the extreme risks associated with long migration journeys that have driven the evolution of such cooperative behavior where something like saving 10% of your energy can make the difference between life and death.'
Further studies are planned to see how the cooperative behavior of the juvenile ibis develops over time and whether they learn to fine-tune their energy-saving tactics. The team also say more research is needed to quantify the energy-saving benefits for individuals by fitting the birds with sensors to, for instance, monitor heart rate and respiration.
One of our great San Joaquin Audubon Society members has left us. Steve was a huge contributor to our club for decades, leading bird and wildflower field trips, serving as our President, Director at Large, Education Chair, Hoot Owl Newsletter Editor, Historian, and Christmas Bird Count Compiler. Never one to be idle, Steve also served as Conservation Chair for our local Sierra Club, Delta-Sierra Group, the California Native Plant Society, the Nature Conservancy, the Sequoia Natural History Association, the League of Women Voters, Calaveras Big Trees Association and the American Association for the Advancement of Science.
Steve loved to observe nature and talk to people about it, to share his knowledge and thoughts about the birds, the plants, and the environment. Steve was not afraid to share his views on unchecked development, destruction of the environment, or unsustainable habitat. He was an active contributor to the "Letters to the Editor" column in the Stockton Record where he shared his views on the environment and other topics. But he didn't just talk, Steve made things happen. He believed in helping shape the world to be a better place. He played a major role in crafting the San Joaquin Habitat Conservation Plan with Waldo Holt and the Council of Governments to guarantee habitat would exist in the future for threatened and endangered plants and animals. He was instrumental in establishing Oak Grove Regional Park with Verna Johnston and others, ensuring there was a natural area in the park available for wildlife.
Although Steve retired after 35 years of teaching, first at Franklin High School then San Joaquin Delta College, he never stopped teaching or learning. He was always mentoring others to carry on the work he started. David Yee spoke of how Steve enthusiastically recruited him to become an active Audubon Board member in the 1970's and how Steve was still discussing the mysterious distribution of Acorn woodpeckers with him just this past October. And Kathy Hieb, recipient of the Sandhill Crane Festival's 2014 Conservation Award, talked about how Steve Stocking inspired her to be active in conservation during her acceptance speech this November.
Steve was a teacher to many, an inspiration to most, and a friend to all.
.Kasey Foley, Programs Chair, San Joaquin Audubon Society
borrowed from Audubon At Home
Plants for Birds and Wildlife
|Spicebush, photo courtesy USDA-NRCS Plants Database
Birds and wildlife have adapted to utilize native plants that provide food, cover, nesting sites or a combination of resources. Native plants provide food at different times of the year to birds in the form of seeds, fruit or as invertebrate host sites. The growth habits of native plants present recognizable, safe nesting sites and cover that protect birds from inclement weather and predation. The importance of these plants to birds, insects and other wildlife cannot be overstated.
Using native plants in your backyard landscape will offer the most resources to birds and wildlife and serve as rewarding attractants. On these pages you will find some examples of plants that are particularly valuable to specific birds and other beneficial organisms. A more comprehensive database with regional references is in the works at Audubon At Home and will be available online in the near future.
Plantings for birds in our area:
Nuttall's Woodpecker, Oak Titmouse, Yellow-rumped Warbler- California Live Oak
Wrentit, California Towhee, Spotted Towhee - California Wax Myrle
For more information about native plants please visit:
California Native Plant Society
Master Gardener's Program in San Joaquin County
Plants for Beneficial Insects
Predators. Parasitoids. Pollinators.
Welcome them into your Healthy Yard.
These are the insects, bugs and other organisms on the front line of pest control in your yard, guarding against destructive bugs and helping plants reproduce. Nature supplies these beneficial bugs of course, but you can encourage them to remain in your yard by providing them with some essential elements.
Nearly every plant in a natural environment will sustain at least some damage by pests…it is part of the natural balance. But pests don’t overpopulate a natural ecosystem due to the presence of natural enemies. In a healthy yard with its native plants and pesticide-free environment, pests will appear—and so will natural enemies.
THE INSECTS – Wild Friends, Natural Enemies
|Ladybug feeding on cottonwood leaf beetle eggs, photo by James Solomon, USDA Forest Service
Move Over, Lady - It has long been known that ladybugs (or lady beetles), especially in their larval stage, are "good bugs" with voracious appetites for aphids. Without dismissing the value of ladybugs as garden friends, there are other natural pest enemies that are much less conspicuous but even more valuable. The lowly "gnat" that flies by your ear may in fact be the tiny eulophid wasp – a full-grown one is just one-eighth inch – on her way to lay up to one hundred eggs in the pupae of tree-destroying beetles.
Predatory and parasitoid flies and wasps are key players in the biological control of insect pests. Many, in fact, are reared in laboratories and dispersed into crops, forests and neighborhoods to control exotic insect pests (i.e. elm leaf beetle). Click on the link below to learn more about the tiny denizens of your yard and other beneficial organisms.
THE PLANTS – Nectar for Natural Pest Enemies
|Syrphid (hover) Fly, photo by Carl Dennis, Auburn University
Nectar is an important dietary supplement for beneficial wasps and flies. Asters and their cousins (such as daisies and goldenrod) offer excellent resources and there are native varieties in every part of the country. Flowers that are composites - where many small symmetrical flowers occur in a central disk - are perfect for small wasps and flies such as the common predaceous hover fly (pictured left). Many of the beneficial insects are small and require a short flower structure in order to access the nectar.
These same flowering plants will attract a wide range of important pollinators such as native bees, butterflies and honeybees. When they produce seed, these plants will provide a valuable food source for birds and other wildlife in the fall and winter.
Plant a variety of plant types such as groundcover, trees, and shrubs, mimicking natural growth patterns to form complex habitat that will be home to a greater variety of beneficial insects.
THE INSECTS – Information and pictures of the lesser-known but effective natural enemies that occupy your backyard.
PLANTS TO ATTRACT BENEFICIAL INSECTS – Your guide to some stellar examples of the useful plants that will attract a variety of beneficial insects. Look for examples of similar native flowers occurring in your region.
For more information about beneficial insects please visit:
Beneficial Insects in Your Garden
BIRDS AND CLIMATE CHANGE
The National Audubon Society has released an extensive new study on the potential impact of global warming on North American birds. After a nearly eight year study Audubon scientists have concluded that climate change is the No. 1 threat to North American birds! Audubon’s science models predict that 314 species of birds in the U.S. are under direct threat of extinction by 2050 if we don’t take action to prevent their decline by protecting strongholds, passing stronger climate policy, and reducing global greenhouse gas emissions.
The September-October issue of Audubon magazine has extensive coverage on this issue and gives suggestions on what individuals and groups can do to help reduce the negative impacts on birds in their local area. (Refer to Audubon.org/climate for more information).
Dave Wagner, Conservation
If you’re interested in finding out what rare and unusual birds are being seen in California (or anywhere in the US, for that matter), you should check out Sialia, aka The Birding Lists Digest. Sialia (http://digest.sialia.com) was created to help birders find out "what's going on lately" in various regions of the U.S. with a minimum of hassle. The Digest automatically compiles all posts to dozens of birding email lists and organizes them by region, by day, and by list. Birders can view the current day's messages, or browse messages from the last 30 days. This system allows birders to find information about rare bird sightings and other goings-on around the country in a timely and efficient manner. Check it out!
Rare and Unusual Occurrences
at Stockton, Cal.
(from The Condor, Mar., 1901)
This year seems an unusual one in the way of bird migration in San Joaquin County, having added to the list thus far several new visitants and also causing an influx of a single species heretofore unknown in this locality, though common in the eastern foothills. I refer to the Blue-Fronted Jay (Cyanocitta stelleri frontalis.) (Steller’s Jay)
This species has become so numerous in San Joaquin County, and especially within the city of Stockton, that it has for the time being, taken the place of the noisy California Jay (Aphelocoma californica.) (Western Scrub Jay) My record of its first appearance is dated November 11, 1900, at which time I saw two of this species in the vicinity of Stockton. Two days later I saw several of the birds within the limits of the city and from that time on they became quite numerous, showing very little fear in their new haunts and being seemingly at home in the white oaks (Valley Oaks) with which the city abounds. Mr. Belding (Lyman Belding) informs me that he has found them in the heart of the Sacramento Valley, but has no record of their occurrence in this locality previous to this year.
The abundance of the birds is shown by the result of a “blue-jay” shoot which five sportsmen from Stockton took part in on December 2, 1900. They confined themselves to a small area northeast of the city and as a result of their shoot brought home 220 birds, 100 of which were California Jays (Western Scrub Jays) while the remaining 120 were of the Blue-fronted (Steller’s) species. The birds are still here in large numbers and show no signs of decreasing.
W. B. Sampson
Stockton, Cal., Feb. 14, 1901
Verna Johnston, 95, a founding member of the Calaveras Big Trees Association and resident of Camp Connell, died in Carmel Valley March 1st. Verna was a science educator, photographer and writer as well as a self-described lover of nature.
Born and educated in Illinois, she came to California, where she taught biology and environmental science at San Joaquin Delta College in Stockton for 37 years. A well-known naturalist, Mrs. Johnston lived to educate and reveal the beauty and wonder in nature.
She published more than 100 articles in professional journals and popular magazines ranging from Audubon to The New York Times. Her first book, “Sierra Nevada,” was published in 1970 as part of the series “A Naturalist’s America,” edited by Roger Tory Peterson. Life Magazine featured her in an article in November 1998.
In 1982, she retired to Camp Connell to “hibernate, hike and write.” It was there that she wrote two more books, “California Forests & Woodlands: A Natural History” in 1994 and “Sierra Nevada: The Naturalist’s Companion” in 1999, both published by The University of California Press. Her photos illustrate these books and the most recent is still available at the new Calaveras Big Trees State Park bookstore.
Ms. Johnston was an active member of the Sierra Club, National Audubon Society, the Wilderness Society and other groups. She was one of the first presidents of the (then) Stockton Audubon Society and was a respected environmental leader in Stockton for many years. She worked to protect native plants and animals in the Sierra and in California’s Central Valley, and was also active in helping to set aside Point Reyes National Seashore. She served on the San Joaquin County Parks and Recreation Commission during the time when Oak Grove Regional Park was developed and was a leader in having part of that park preserved as a natural area. She was also a founding member of the Calaveras Big Trees Association, where her photos will be on view at the new visitors’ center.
Verna donated books and photos to the Calaveras Big Trees Association and supported the Park in other ways as well. Her love of books and the out-of-doors also led her to establish the Verna Johnson Nature Collection at the Arnold branch of the Calaveras County Public Library.
Following her wishes, Verna's ashes will be mixed with the earth of the Sierra Nevada, the place she called "home.”
Steve Stocking, Education Chair
San Joaquin Delta College, Retired
Board Member, Calaveras Big Trees Association