Ornithology 1B Fall 2008 Calendar (Fall 2008)

If you miss a class, please check this page and study the listed topics in your field guide or in "The Birder's Handbook" by Ehrlich et al. ( Fireside, 1988). Many of the essays and species accounts from that book are available online. I also recommend visiting field trip sites on your own if you can't make the actual trips. Last semester's calendar is here.

• We finished the book, covering: woodpeckers, flycatchers, shrikes, vireos, corvids, larks, swallows, babblers, chickadees, verdins, bushtits, creepers, nuthatches, wrens, dippers, kinglets, gnatcatchers, thrushes. mockingbirds, starlings, pipits, waxwings, phainopeplas, warblers, tanagers, sparrows, cardinals, blackbirds, finches and old world sparrows.
• Male mimicry in juvenile woodpeckers was assigned as a topic for further research.
• The Western Flycatcher has recently been split into the Pacific-coast Flycatcher and the Cordilleran Flycatcher. These are examples of "cryptic species," i.e. biological species which do not differ morphologically.
• Shrike diversity in North America is less than in Eurasia. The Loggerhead Shrike is probably an evolutionary offshoot of the Northern Shrike after the latter species invaded North America prior to recent glaciations.
• The ability of a raven to seemingly count up to six was discussed in terms of the dangers in methodology of measuring intelligence.
• The Horned Lark illustrated the differences in diversity of larks in North America vs. Eurasia. Why are there many species of larks in Eurasia and only one in North America?
• We postulated that the Horned Lark was a relatively recent immigrant to North America which has not had time to diversify into multiple species.
• Geographic variation in the Chestnut-backed Chickadee has given rise to three isolated populations which are named as subspecies. The dividing lines are areas of unsuitable habitat, "Cristo's Line" between Petaluma and Bodega Bay and the Golden Gate are boundaries to gene flow between these subspecies.
• Causes of social plasticity in the Bushtit were discussed.
• Niche partitioning in the nuthatches of the San Francisco Bay area is based mostly on geography with White-breasted in the interior, Pygmy on the coast and Red-breasted in the mountains. But in the Sierra, these three coexist by partitioning the resources within the same tree. Pygmy on the outer branches and cones, White-breasted on the main trunks and Red-breasted on the larger limbs.
• Wrens are diverse in North and South America, but only one species is found in Eurasia. We hypothesized that the Winter Wren may be a fairly recent arrival to Eurasia from North America. We also suggested that polygeny, rather than predator avoidance, may be reasons for the evolution of multiple nest building in wrens.
• Geographic variation in the American Dipper was used to illustrate neoteny (retention of juvenile characters into adulthood) as an evolutionary mechanism.
• Gloger's rule of geographic variation can be seen in the race "caurinus" of the American Robin. A very dark form from the Pacific Northwest which winters in small numbers in California.
• Mockingbirds sing to attract females. Those with larger repertoires are more successful at breeding.
• The invasion of the European Starling in North America and its consequence to native species was discussed. The success of the American introduction while the native European population is declining may be caused by the small genetic sample size of the original introduced population.
• Flocking behavior in the Cedar Waxwing can be linked to its food requirements which are unreliable as it is an obligate frugivore.
• The relationship of the Brown-headed Cowbird and its hosts was discussed. Recent increases in cowbird numbers in California can be traced to clearing of the land for cattle. California's native species are less able to cope with parasitism than their Eastern counterparts because they have not had time to evolve protective mechanisms.
• Selander's findings on the geographic variation in the House Sparrow was discussed as illustrating the relatively rapid change in populations in the face of various climatic conditions.

  Please preregister if you plan to enroll in the Spring. Click here for details.

  Note: I will be presenting a free program on the birds and wildlife of Trinidad and Tobago for Marin Audubon in Tiburon at 8pm on Friday January 2, 2009. Click here for details.

• Families: parrots, cuckoos, owls, nightjars, swifts, hummingbirds, trogons, kingfishers & woodpeckers,
• Discussed the origins and identity of the various parrot populations in San Francisco. More information is available here.
• We outlined the evolution of egg mimicry in the Common Cuckoo.
• Discussed feather ruffling, fluffing, and other mechanisms of thermoregulation.
• Asymmetrical ears in owls enable the birds to accurately locate prey by hearing.
• Mechanisms for backwards flight in the hummingbird were explained.
• The correct mixture for a hummingbird feeder is 1 part sugar to 4 parts water.
• Trogons were used to highlight a discussion on the ethics of song playback in birding.
• We discussed the nature of the hybrid zone between two races of Northern Flicker and the possible evolutionary basis for the divergence of the two races. The vicariance model was compared with the Founder Principal. Geographic isolation caused by past ice-ages was suggested as a mechanism for the evolutionary independence of the two lineages. The different wing colors may be a consequence of genetic drift rather than natural selection.

• Families: stilts, sandpipers, gulls, jaegers, alcids and pigeons
• Discussed plumage maturation and molt in shorebirds.
• Discussed the role of the red spot on the mandible of gulls as part of a complex series of behavioral releasers.
• Outlined molt in the Western Gull pointing out the preformative molt.
• The "Morlan Method" gull identification key with full text is here. Adobe acrobat reader required. An abridged html version is here.
  amilies: , parrots and cuckoos.
• Discussed the historical dynamics of the population of Common Murres

• The Coyote Point field trip list is here and a link to the Rusty Blackbird page is here.
• A recent story on the Acorn Woodpecker controversy in Rossmoor is here, and a summary of their mating strategy is here.
• Families: falcons, limpkins, coots, cranes, plovers, jacanas & oystercatchers.
• The wing-spur of the jacana was discussed. I have researched this and found that ornithologists distinguish between "wing-claws" such as found on Archaeopteryx and "spurs." Spurs are used in combat and differ in structure from claws. Spurs are on the radial side of the carpus. Spur-winged Goose, Spur-winged Plover, Black-necked Screamer, and Sheathbill all have carpal spurs. Digital wing-claws persist into adulthood in the Secretary-bird, Black-necked Screamer, three species of finfoots and are found on the juveniles of the Hoatzin and a few other species.
• We discussed the possible evolution of distraction displays in shorebirds. 
• Discussed instinctive behavior in terms of "releaser" stimuli in the Oystercatcher where the egg provides a stimulus to incubate and contrasted that with gulls where the nest itself is the focus of incubation behavior.

Note: There is no class next Tuesday, November 25th. Classes will resume Tuesday, December 2nd.

• Families: vultures, hawks, falcons.
• The apparent increase in the Turkey Vultures in the East may be related to increases in forest habitat, rather than global warming or increases in road-kill..
• The use of thermals in raptors was discussed as was visual acuity in the Golden Eagle.
• We discussed the success of the Peregrine Recovery Program and causes of the species decline. We outlined the causes and consequences of eggshell thinning in the Peregrine Falcon noting that the banning of DDT has not resulted in significant increases in shell thickness.

• Families: herons, storks, flamingos, and ibises.
• Discussed molt and morphology using a sunning Great Blue Heron as an example.
• Storks are actually related to vultures; we discussed water levels and water quality in relation to breeding success or failure in the Wood Stork.
• Most North American sightings of flamingos are escapes. Filter feeding.
• White-faced Ibis decline as a breeding bird in the Central Valley impacted by water management practices.

• Families: pelicans, anhingas & cormorants.
• Click here for a diagram showing the annual cycle of breeding, molt, and migration of the Anhinga in North America. Thick lines indicate peak activity; thin lines, off-peak. Daigram taken from the Birds of North America account (Frederick, P. C., and D. Siegel-Causey. 2000. Anhinga (Anhinga anhinga). In The Birds of North America, No. 522 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.)
• Discussed breeding success as correlated with age in cormorants.
• Niche partitioning in cormorants illustrated Gause's Law of Competitive Exclusion.

• Families: frigatebirds, tropicbirds, boobies, & pelicans.
• Reviewed molt and plumage terminology. Natal down, juvenal, basic, alternate plumages. Prebasic, prealternate molts. Prebasic molts are complete; prealternate molts are partial. Basic plumage = winter; alternate plumage = summer (usually).
• We discussed external bird topography using a recently dead White-crowned Sparrow as an example.
• Reviewed the general rules of geographic variation in warm-blooded animals..
  1. Allen's Rule - an animal's extremities are shorter in colder parts of its range than in warmer parts.
  2. Bergman's Rule - an animal's body size is smaller in warmer parts of its range than in colder parts.
  3. Gloger's Rule - dark pigments increase in warm and humid habitats.
• Discussed post-breeding dispersal & vagrancy in boobies and other colonial waterbirds.
• Discussed the local decline in breeding Brown Pelicans as related to egg-shell thinning from DDT.

  This was the last class for Part A. Please register for Part B as soon as possible if you have not already done so.

• We discussed factors contributing to bird abundance and the attributes of a healthy ecosystem.
• The interesting hybrid zone between the two subspecies groups of Yellow-rumped Warbler was outlined.
• The controversy regarding the possible detrimental effects of flowering eucalyptus to birds was outlined. Further information and references are here.
• Families: albatrosses, shearwaters, storm-petrels & frigatebirds.
• Dynamic soaring and Bernoulli's Principle, how birds fly and soar. Dynamic soaring in the albatross was demonstrated.
• Discussed polymorphism in the Northern Fulmar and the distinction between polymorphism and other types of plumage variation.

• We discussed vagrancy in migratory birds and mirror-image misorientation. We also discussed the Grinnell hypothesis which we rejected because it invokes the discredited theory of "group selection." The possibility of balanced polymorphism was discussed.
• Discussed the procedures and purposes of the California Bird Records Committee.
• Families: loons and grebes.
• Geographic variation and the subspecies concept were assayed. Although much variation is clinal, subspecies still have a place in ornithological taxonomy.
• The taxonomic implications of avian hybridization was outlined with special emphasis on "hybrid zones" and "zones of overlap and hybridization." See article by Short for full details.
• The biological species concept was reviewed and the situation with Clark's and Western grebes was used as an example. Positive assortative mating prevents gene flow between the populations.

• Discussed polymorphism in the Great Blue Heron and the distinction between polymorphism and other types of plumage variation.
• Abundance terminology: Abundant, common, fairly common, uncommon, rare, casual and accidental.
• Families: grouse and quail.
• We discussed the evolution of leks using the Sage Grouse as an example. Advantages and disadvantages of this breeding strategy were discussed.  
• The decline of California Quail in Golden Gate Park was correlated to increases in feral cat colonies in the park. For information on the American Bird Conservancy's "Cats Indoors!" program, click here.

• Discussed the definition of subspecies = geographic race.
• Discussed predator avoidance behavior in birds.
• Discussed the cryptic species of the Western Flycatcher and Wood-Pewee species pairs. The Western Flycatcher has recently been split into the Pacific-coast Flycatcher and the Cordilleran Flycatcher. These are examples of "cryptic species," i.e. biological species which do not differ morphologically.
• The possible functions of rictal bristles in flycatchers was discussed.
• Families: Waterfowl, guans.
• Discussed types of feather coloring including iridescence.
• Introduced molt and plumage terminology. Natal down, juvenal, basic, alternate plumages. Prebasic, prealternate molts. Prebasic molts are complete; prealternate molts are partial. Basic plumage = winter; alternate plumage = summer (usually).
• Eclipse plumage in ducks is not a separate or special plumage, but part of the normal plumage cycle in all birds.
• My thinking on the use of the term "eclipse plumage" is in the Cinnamon Teal photo caption here.

• Discussed binoculars and optics.
• Some good sites that deal with optics for birding:
  • Better View Desired
  • Cornell
  • Optics for Birding
  • Eagle Optics
  • Laura's Optics Guide
• Click here for my brief review of new entry level binoculars from Bushnell.
• Click here for my tips on digiscoping.
• World Diversity - Click here.
• Families: Waterfowl.

• We start at 7pm sharp with your observations and questions.
• Theme of class- What are the factors contributing to avian diversity in the face of Natural Selection?
• Definition of "bird" - Feathered vertebrate. Five major vertebrate classes.
• Types of feathers - Vane, contour, down, semiplume, filoplume, aftershaft.
• Parts of a feather - Shaft or rachis, barbs, barbules.
• Discussed types of feather coloring including iridescence.
• Earliest Bird - Archaeopteryx - Could it fly?
• Breeding strategies - Altricial, Precocial. Energetic costs and benefits of each strategy. Herons are "Semi-altricial 1".
• Bring binoculars to class next week, for optics discussion.
• Assignment - Memorize the parts of a bird on pages 10-12 of the National Geographic Guide (5th edition) and bring your questions to class.