Ornithology 1A Spring 2012 Calendar
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. The class calendar from last spring is available here.
Click here for field trip
information. Please check this site before the trip in case of last minute changes!
Please register at eBird and email me
your eBird ID. I can then offer to share field trip lists with you.
Click here
for a summary of bird name changes from the 52nd AOU supplement.
February 7, 2012
- 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.
- Naming Birds - Hierarchical categories, Class, Order, Family, Genus, Species, etc.
- Twenty seven traditional orders of birds.
- The taxonomic implications of avian
hybridization with special emphasis on "hybrid zones" and "zones of overlap and hybridization."
See article by Short for full details.
- The biological
species concept.
- Types of feathers - Vane,
contour, down, semiplume, filoplume, aftershaft.
- Parts of a feather - Shaft
or rachis, barbs, barbules.
- Earliest Bird - Archaeopteryx
- Could it fly?
- Breeding strategies
- Altricial, Precocial. Energetic costs and benefits of each strategy. Herons are "Semi-altricial 1".
- The "Morlan Method" gull identification key with full text is here.
Adobe acrobat reader required. An abridged html version is here.
- Assignment - Memorize the parts of a bird on pages 10-11 of the National Geographic Guide (6th edition)
and bring your questions to class.
Spring 2011
May 17
- Families: shrikes, vireos, corvids, swallows, silvid warblers, 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.
- 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.
- 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.
This was be the last class for the semester. Please preregister, after July 1st
if you plan to enroll in the Fall. Click here for details.
May 10
- Families: nightjars, swifts, hummingbirds, trogons, kingfishers, woodpeckers & flycatchers.
- Differences between Allen's and Rufous Hummingbirds are slight with more overlap in characters than differences.
Allen's Hummingbird is close to being unidentifiable in the field.
- Trogons were used to highlight a discussion on the ethics of song playback in birding.
- Niche partitioning in tropical kingfishers illustrated Gause's Law of Competitive Exclusion.
- 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.
- 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.
May 3
- Families: Pigeons, Parrots and Cuckoos & Owls.
- 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.
- Discussed "reversed sexual size dimorphism" is owls and other raptors.
- We visited the Palace of Fine Arts to look for the nesting Barn Owls. We saw one adult Barn Owl and heard a
young owl calling. Also seen were Black-crowned Night Herons and Mexican Free-tailed Bats.
April 26
- Families: Sandpipers, Gulls, Jaegers & Alcids
- 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.
- Discussed the historical dynamics of the population of Common Murres.
April 19
- Families: cranes, plovers, jacanas, oystercatchers & stilts
- The vocal structure of cranes was described.
- Cross fostering between Whooping and Sandhill cranes failed because of hybridization.
- We discussed the possible evolution of distraction displays in shorebirds.
- A photo of a Killdeer chick generated discussion of the ethics of birding and bird photography. We agreed that
nesting birds should not be unduly disturbed by such activity.
- 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.
- 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.
April 12
- Families: Ospreys, hawks, falcons, limpkins and coots.
- Visual acuity in the Golden Eagle was discussed.
- 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.
- Discussed variability in the pattern of frontal shield in the American Coot. Geographic variation in the coot was discussed relative to the the validity of Caribbean Coot and
Hawaiian Coot.
- Discussed regulation
of animal numbers a la Malthus and Lack. It's the carrying capacity of the environment that ultimately
determines population levels.
- View nesting Peregrines in San francisco here.
- Reviewed the general rules of geographic variation
in warm-blooded animals..
- Allen's Rule - an animal's extremities are shorter in colder parts of its range than in warmer parts.
- Bergman's Rule - an animal's body size is smaller in warmer parts of its range than in colder parts.
- Gloger's Rule - dark pigments increase in warm and humid habitats.
April 5
- Families: Herons, ibises, storks, flamingos and vultures.
- Golden Gate Raptor Observatory provides an opportunities for Citizen Science in Ornithology.
- 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.
- 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.
March 22
March 15
- Discussed similarities and differences of Downy and Hairy Woodpeckers. Click here
and here
for David Sibley's essays on the subject.
- Outlined the general rules of geographic variation
in warm-blooded animals..
- Allen's Rule - an animal's extremities are shorter in colder parts of its range than in warmer parts.
- Bergman's Rule - an animal's body size is smaller in warmer parts of its range than in colder parts.
- Gloger's Rule - dark pigments increase in warm and humid habitats.
- Families: shearwaters, frigatebirds, tropicbirds, boobies, & pelicans.
- Discussed polymorphism in the Northern Fulmar and the distinction between polymorphism and other types of plumage
variation.
- 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.
March 8
- Families: Grebes and albatrosses.
- Mockingbirds sing to attract females. Those with larger repertoires are more successful at breeding.
- Niche partitioning in illustrated Gause's Law of Competitive
Exclusion.
- 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 and the distinction between polymorphism and other types of plumage variation.
- Dynamic soaring and Bernoulli's Principle,
how birds fly and soar. Dynamic
soaring in the albatross was demonstrated.
March 1
- Families: Grouse, quail and loons.
- 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.
- 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).
February 22
- We discussed external bird topography using a recently dead Yellow-rumped Warbler as an example.
- Defined subspecies as a method of describing geographic variation using nomenclature.
- Families: Waterfowl, guans and, grouse
- We discussed the possible reasons that male ducks are in bright plumage in the winter and drab in the summer.
February 15
- Discussed binoculars and optics.
- Some good sites that deal with optics for birding:
- Click here for my brief
review of new entry level binoculars from Bushnell.
- Click here for my tips on digiscoping.
February 8
- 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.
- Naming Birds - Hierarchical categories, Class, Order, Family, Genus, Species, etc.
- Twenty seven traditional orders of birds.
- The taxonomic implications of avian
hybridization with special emphasis on "hybrid zones" and "zones of overlap and hybridization."
See article by Short for full details.
- The biological
species concept.
- Types of feathers - Vane,
contour, down, semiplume, filoplume, aftershaft.
- Parts of a feather - Shaft
or rachis, barbs, barbules.
- Earliest Bird - Archaeopteryx
- Could it fly?
- Breeding strategies
- Altricial, Precocial. Energetic costs and benefits of each strategy. Herons are "Semi-altricial 1".
- The "Morlan Method" gull identification key with full text is here.
Adobe acrobat reader required. An abridged html version is here.
- Assignment - Memorize the parts of a bird on pages 10-12 of the National Geographic Guide (5th edition)
and bring your questions to class.