Ornithology I Spring 1999 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). It is also critical that you visit field trip sites on your own if you can't make the actual trips. There is no substitute for actual field experience; and you are expected to be familiar with the birds seen on the trips.

Highlight of this morning's walk in Briones was a stunning full-sized gopher snake. Bird life was below average but included superb views of Lazuli Bunting, Black-headed Grosbeak, Chipping and Lark sparrows. The full list is here.

• 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.
• Mockingbirds sing to attract females. Those with larger repertoires are more successful at breeding.
• Geographic variation in the American Dipper was used to illustrate neoteny (retention of juvenile characters into adulthood) as an evolutionary mechanism.
• Flocking behavior in the Cedar Waxwing can be linked to its food requirements which are unreliable as it is an obligate frugivore.
• 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.
• 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.
• Please preregister if you plan to enroll in the Fall. Click here for details.

• We reviewed the birds seen on the Rhododendron Dell trip. We added one new species to the list, Steller's Jay. Other highlights included White-throated Swifts, nesting Downy Woodpecker, and a family of racoons. Click here for the complete list.
• We covered chickadees, verdins, bushtits, creepers, nuthatches, wrens, and thrushes.
• 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 postulated that the Winter Wren may be a fairly recent arrival to Eurasia from North America.
• 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.
• A picnic lunch is suggested for the May 22 field trip to Briones Regional Park. More information and a good map of the park can be found here.
• Next week is the final evening class of the semester!

• We finished woodpeckers, flycatchers, larks, swallows, corvids and wrentits.
• 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. 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. Rapid rates of evolutionary change were linked to small population sizes.
• Possible reasons for the male mimicry in juvenile woodpeckers were discussed.
• The Western Flycatcher has recently been split into the Pacific-coast Flycatcher and the Cordilleran Flycatcher. These are examples of "sibling species," i.e. biological species which do not differ morphologically.We finished flycatchers, larks, swallows, and corvids.
• The Horned Lark illustrated the differences in diversity of larks in North America vs. Eurasia. Why are there so 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.
• The ability of a raven to seemingly count up to six was discussed in terms of the dangers in methodology of measuring intelligence.
• The extraordinary adaptability of the Raven was compared to that of the Crow and the distribution of these two closely related species was presented in terms of the concept of "competitive exclusion.

• We finished hummingbirds, kingfishers, and started woodpeckers.
• The correct mixture for a hummingbird feeder is 1 part sugar to 4 parts water.
• Niche partitioning in tropical kingfishers illustrated Gauss's Law of Competitive Exclusion.
• Speciation in the Northern Flicker complex was discussed. The vicariance model was compared with the Founder Principal.
• Biochemical techniques in systematics including DNA hybridization studies were described.
• Evolutionary gradualism was contrasted with punctuated equilibria.
• Diversity was linked to fragmentation of small peripheral populations resulting in speciation.

• We finished cuckoos, owls, nightjars, swifts and began hummingbirds.
• Discussed feather ruffling, fluffing, panting and other mechanisms of thermoregulation.
• We discussed the nature and evolutionary implications of sexual size dimorphism in owls and other raptors and also the possible evolutionary basis for asynchronous hatching in owls. An explanation for the former is related to the long incubation by female owls. Maximizing the number of offspring in the face of unreliable food supplies is a possible explanation for the latter.
• Hibernation in the Poor-will was discussed.
• Mechanisms for backwards flight in the hummingbird were explained.

• We finished falcons, grouse, chachalacas, pigeons, parrots, trogons, and cuckoos.
• The Field Trip to Rodeo Lagoon was a success. Lincoln's Sparrow was added to the cumulative list. The full list is here.
• 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 and Bald Eagle noting that the banning of DDT has not resulted in significant increases in shell thickness. I showed a short clip from "All Bird TV" showing the use of radio telemetry to track Peregrine migration.
• Discussed the evolution of leks using the Sage Grouse as an example. Advantages and disadvantages of this breeding strategy were discussed.  
• 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.

• We discussed the relationships between Brown-headed Cowbird brood parasitism and their hosts.
• We also discussed the adaptive significance of mimicry in the Northern Mockingbird and other species.
• We completed New World Vultures and Hawks.
• We speculated that 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 discusses as was visual acuity in the Golden Eagle.
• Remember the Rodeo Lagoon field trip on April 10th.
• If you have not yet registered for this quarter, please do so AS SOON AS POSSIBLE. This is important.

March 23

• We covered.stilts, plovers, sandpipers, gulls and alcids.
• We also discussed the possible evolution of distraction displays in shorebirds and rooftop nesting in the Killdeer and spent time on the behavior of the Herring Gull and the interactions between chicks and their parents.
• We discussed the general rules of geographic variation. Body size increases and extremity length decreases in response to colder climates (Bergman's Rule and Allen's Rule). Pigment saturation increases in moist climates (Gloger's Rule). These rules apply to all warm-blooded vertebrates and are believed to be thermoregulatory adaptations.  
• End of the quarter. Remember the Rodeo Lagoon field trip on April 10th. I hope to see you all in two weeks! Please don't forget to preregister. Thank you very much for a great quarter!

March 20

Today's trip to the Cliff House was quite successful. We added three new species to the cumulative trip list: Turkey Vulture, Bullock's Oriole and Hooded Oriole. These were all seen at the end of the trip. The Turkey Vulture was soaring over the residential area just east of Sutro Heights Park. The two orioles were adult males well seen foraging in flowering Eucalyptus at the west end of Geary Blvd. Other highlights included an Osprey circling over the west end of Geary, a Golden-crowned Kinglet in the cypresses at Sutro Heights, and two Wandering Tattlers on the rocks below the Cliff House. Black Oystercatchers and Ruddy Turnstones were also evident on the rocks. Some of the Red-throated Loons were in breeding plumage. The full list is at http://fog.ccsf.edu/~jmorlan/seal.htm

March 16

• Finished cranes, waterfowl, limpkins, coots, jacanas, oystercatchers, and stilts.
• Discussed regulation of animal numbers a la Malthus and Lack. It's the carrying capacity of the environment that ultimately determines population levels.
• Geographic variation in the coot was discussed relative to the the validity of Caribbean Coot and Hawaiian Coot.
• 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.
• Color vision in birds was discussed. Diurnal birds have keen color vision and can see ultraviolet.
•  Next week is the last class of the quarter.  Please preregister for part B when we will finish the book!.

March 9

• Finished herons, storks, flamingos, and ibises.
• Discussed morphology using a sunning Great-blue Heron as an example.
• Discussed polymorphism in the Great-blue Heron.
• 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.

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March 6

Today's trip to the Chain of Lakes was about average. However birds were so scarce at Middle Lake that we were forced to check several adjacent areas and do much more walking than in past years. We added two new forms to our cumulative list for this trip, Ring-billed Gull and Small falcon. We saw an adult and immature Ring-billed Gull at the north end of North Lake and the small falcon was at the north end of the Buffalo Paddock. It was not seen particularly well, and at first I thought it might be a Merlin. However the long tail and deep wing beats are more typical of kestrel. It might be worth it to go back out to that area and try to get a better look at that bird. I don't believe I've ever seen a definite kestrel in Golden Gate Park before. The full list is here.

March 2

• Discussed 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).
• Finished pelicans, boobies, anhingas, and cormorants. Discussed vagrancy in boobies and other birds; molt in anhingas; and breeding success as correlated with age in cormorants. Also discussed advantages and disadvantages of wettable feathers in cormorants and anhingas.
• Discussed size illusion.

February 23

• Reviewed birds seen at Lake Merritt.
• Discussed bird anatomy with reference to a Red Crossbill specimen.
• Families: Albatrosses, Shearwaters, Storm-Petrels, Frigatebirds and Tropicbirds.
• A video demonstrated the flight style of albatrosses and other tubenosed birds.
• Dynamic soaring and Bernoulli's Principal, how birds fly.
• Discussed polymorphism in the Northern Fulmar and the distinction between polymorphism and other types of plumage variation.

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February 20

This morning's trip to Lake Merritt was a great success with close views of many land and water birds despite the rain. We added three new species to the composite list since 1985, Herring Gull, Thayer's Gull and Turkey Vulture. Other highlights included Redhead and the perennial Cattle Egret. A distant Barrow's Goldeneye was seen before the class started. The full list is here. Remember you are responsible for these birds even if you were not able to attend the field trip. Future field trips will be open to members of other classes.

February 16

• Discussed binoculars and optics.
• Some good sites that deal with optics for birding:
• Better View Desired: http://www.biddeford.com/~sing/BVD.html
• Optics for Birding: http://www.optics4birding.com/
• New Jersey Audubon: http://www.njaudubon.org/genlmenu/optics.html
• Eagle Optics: http://www.eagleoptics.com/
• Discussed bird anatomy, particularly feather tracts of the wing and head.
• Families: Loons, grebes.  
• Review the Lake Merritt online checklist in preparation for this Saturday's Field Trip. Please bring some stale bread to attract some of the birds on the field trip. All trips are expected to be held as scheduled regardless of weather.

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February 9

• 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.
• 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.
• World Diversity - Click here.
• Assignments - Memorize the parts of a bird on pages 10-11 of National Geographic Guide and bring your questions to class.
• Bring binoculars to class next week for optics discussion: