EA 105 – Field Ornithology, Class VII – Last class :(

Tuesday was the last class of the 14-class Field Ornithology series I’ve been taking since January, and I must say I’ll really miss it! It’s been extremely informative, Joe Morlan is a great teacher, and our weekend field trips netted me the following 14 life birds and provided countless tips on identification!

– Black-throated Gray Warbler
– Cassin’s Vireo
– Green Heron
– Northern Rough-winged Swallow
– Pacific Loon
– Purple Finch
– Pygmy Nuthatch
– Red-throated Loon
– Redhead
– Tricolored Blackbird
– Vaux’s Swift
– Warbling Vireo
– White-breasted Nuthatch
– White-throated Swift

Following are my notes from class.

• Book recommendation: “The Song of the Dodo” – Joe’s favorite bird-related book
• We tore through the remainder of the National Geographic Field Guide to North American Birds at a blistering pace, and I was scrambling to keep up with notetaking
• Babblers:
  • The Wrentit is the only North American member of this family
    • short-winged, non-migratory bird
    • doesn’t like to fly, prefers to hop from branch to branch
    • can be seen in the Marin Headlands (Rodeo Lagoon) and Bayview Hill (SF)
    • both the male and female sing, which is unusual
•  Chickadees and Titmice:
  • Titmice have crests, Chickadees have dark caps and white cheeks
  • Chickadee identification is easy in San Francisco – we only have Chestnut-backed Chickadees
  • like the Wrentit, they’re non-migratory
  • Chestnut-backed Chickadees in Marin County are a Marin endemic subspecies neglecta
    • Geographic barriers prevent much/any interbreeding with the rufescens ssp. to the north
  • Are cavity nesters, often using woodpecker holes
• Penduline Tits & Verdins:
  • The Verdin is the sole representative of this family in North America
  • It pierces the base of flowers with its sharp bill and drinks the nectar from there;  too bad for the flower, as this behavior side-steps the flower’s pollination strategy
  • Also non-migratory
• Bushtits & Long-tailed Tits:
  • The Bushtit is the only member of this family in the US
  • Bushtits:
    • live in woodlands, foothills and juniper
    • often seen in flocks of 15-25 birds
    • only the adult female has a light-colored eye
    • build a sock-shaped nest of flexible materials – lint, cotton, spiderwebs, etc.
• Creepers
  • Again, just one in the US, the Brown Creeper
  • has long curved bill to probe in bark crevices for spiders and soft-bodied insects
  • have spiky tail feathers, much like woodpeckers, which help brace them against trees
  • since tail feathers R1 & R2 are very important to them, they don’t molt in the normal numerical order, but rather R2 R3 R4 R5 R6, then R1.  This allows them to keep using the old R1 while the other feathers molt in, then by the time R1 is molted, the other feathers are all fresh.
  • next behind pieces of loose bark
• Nuthatches
  • ID tips: White-breasted has all-white face around the eye, Red-breasted has a black eye stripe, and Pygmy has a black cap extending to the eye
  • White-breasted Nuthatch is mostly seen in oak savannahs
  • Pygmy Nuthatch is the only likely Nuthatch in SF, as they prefer coastal and lowland habitats
  • Red-breasted moved into the SF Bay Area in the 1940s, and lives here in the narrow gaps between White-breasted and Pygmy Nuthatch territory
  • All 3 Nuthatches can been seen at Glacier Point in Yosemite
• Wrens
  • strictly New World except for the Winter Wren, which also exists in the Old World
    • this shouldn’t be too surprising, since only the Winter Wren lives in the Aleutians, and so can cross over
  • build globe-shaped nest with a hole in the side, or use boxes, gutters, etc.
  • Male Wrens build multiple nest “frames”
    • One theory is that this is to  avoid nest predation, but this is not the case
    • Male Wrens are polygamous, and so build multiple nests in hopes that they’ll get multiple partners
    • When a female “moves in,” she finishes the nest
  • Marsh Wrens have a repertoire of 100+ of songs in the West, but sing only a few dozen in the Eastern US
• Factoid: Brightly-colored birds sing less than dull ones, since their color is used to attract females, while the song of duller birds does this
• Dippers
  • Again, just 1 species in the US – the American Dipper
  • Lives in mountainous streams and follows creeks’ courses
  • prefer clear unpolluted mountain streams (don’t we all?)
  • are famous for walking underwater
  • nest behind waterfalls or in crevices, culverts or under bridges
  • feed on cadisfly and dragonfly larvae
  • used to be called the Water Ouzel
  • nests are Wren-like spheres w/a hole in the side
  • their eyes sometimes flash white – is this their nictitating membrane (a “third eyelid”)?
• Factoid: the pink flesh at the corners of human eyes is our vestigal nictitating membrane
• Kinglets
  • 2 species in North America, Ruby-crowned and Golden-crowned
  • have wing bars
  • GC Kinglet is in the Bay Area year-round, but the RC Kinglet is a winter visitor.
  • GC Kinglet is hard to see since it prefers the tops of tall trees and its song is extremely high-pitched
• Gnatcatchers
  • Strictly New World, but in the same family as Old World Warblers
  • Blue-Gray Gnatcatcher is the only one in northern California
    • used to be fairly rare, but has increased
• Thrushes
  • widespread family world-wide
  • have a booted tarsus (no scales on the front of their legs)
  • American Robin is the best-known thrush in the US
    • don’t call it a Red-breasted Robin – that is a different bird, which lives only in the Old World
    • are abundant pretty much everywhere
    • some populations (the ones in colder climates) are more migratory than others
    • build a very strong mud and straw nest
    • eggs are … wait for it … robin’s egg blue
    • Robins recognize Cowbird eggs laid in their nests, and puncture and/or eject them.
      • Cowbirds then retaliate by killing the Robin eggs and/or young.  This has been referred to as “Mafia behavior” in Cowbirds, since it’s very much a protection racket!
    • Robins follow Glodger’s Rule (birds in wetter climates have more/darker pigment)
    • contrary to popular belief, they do not get drunk eating berries, although some suffer mild paralysis from the neuro-toxin-rich berries they feed on.
    • they catch worms by sight
• Mimids
  • Mockingbird and Thrashers
  • strictly American birds
  • as their name suggests, they mimic other sounds
  • They arrived in California in the 1920s after the Central Valley Water Project cleared out all of the native habitat, which is totally unsuitable for Mockingbirds
  • Why do they mock?
    • is it to keep out other species by imitating their alarm or territorial calls?
      • no evidence for this, and why would they care, since like most animals, they have their niche and don’t really compete with other species
    • Studies have found that males with a larger repertoire of songs have an easier time attracting mates than ones with a small repertoire.
      • generally speaking, the way one would acquire more songs is through living a longer life, and so it shouldn’t be surprising that females would prefer a mate who has good survivability
    • M & F look alike
    • feed on insects
    • they skylark (singing while flying) as mating and territorial displays
• Starlings
  • all Starlings are non-native
  • European Starling is the only one that has become established (and how!)
  • are also mimics
  • often associate with blackbirds
  • have roosts of up to millions of birds
  • their breeding plumage is acquired by feather wear, and not by molt!
    • The white tips of their winter feathers wear off to reveal the glossy irridescence of their breeding plumage
  • are obligate cavity nesters.  Entering and exiting their cavities helps to wear their feathers
  • competition from Starlings has decimated the populations of bluebirds, woodpeckers, and other native obligate cavity nesters
  • when Starlings become agricultural pests, permits are issued, and the roosts are sprayed with a biodegradable detergent, which penetrates their feathers, causing them to become wet and then die of hypothermia
  • they were purposely introduced into NYC’s Central Park in 1890
    • homesick immigrants began a program of introducing all birds mentioned in Shakespeare
    • it took numerous attempts for them to take
  • in Europe, Starlings have not spread to Africa nor Asia, and are actually in decline
    • Why haven’t they spread?
      • The Ural Mountains may block them to the east, but the US Starlings weren’t fazed at all by either the Rocky Mountains or the Sierra Nevada.
    • Perhaps the breeding pairs that succeeded in the NYC release were particularly aggressive and/or adaptable individuals.  Since these few pairs formed the gene pool for all resulting US Starlings, perhaps ours are made of sterner stuff than their European brethren
• Pipits
  • American Pipit is a winter resident in the SF Bay Area, and it’s expanding
• Waxwings
  • Crested w/yellow-tipped tails
  • Cedar Waxwing is the only one in California, Bohemian Waxwing is a rarity in the northern US
  • are obligate fruitavores
    • flock behavior is more common in fruitavores than other birds, since trees ripen fruit as a progression, rather than all at once
    • young feed on insects, as they need the protein
• Sily-flycatchers
  • Phainopepla is the only one in NA
    • unusual in that it breeds on both its wintering grounds and its summer grounds!
    • can be seen in the Livermore valley, on Mines Rd.
    • are one of the only birds that can digest the miseltoe berry
• Wood Warblers
  • a large family with 57 species in the US
  • highly migratory
  • most are all or partly yellowish
  • usually build a cup-shaped nest
  • the Yellow Warbler has disappeared from California as a breeding bird due to nest parasitism by the Brown-headed Cowbirds
    • most parasites that drive their host to extinction would themselves become extinct, however, the BH Cowbird parasitise 100s of species, so the loss of one doesn’t affect them much
    • BH Cowbird eggs hatch 1-2 days earlier than Warblers, so they get a leg up on eating
    • BH Cowbird young are much larger and have brighter gapes than the host species young, so they tend to get fed more, often to the exclusion of the host’s young, which then starve
• Tanagers
  • North American Tanagers were recently found to belong in the Cardinal Grosbeak family
  • Western Tanager is the only San Francisco Tanager species.
• Emberizids
  • White-crowned Sparrow
    • has 4 sub-species
      • oriantha breeds in the high Sierras
      • nuttalli breeds in the San Francisco Bay Area, and is a permanent resident along the coast
        • predation by feral cats has all but eliminated them from SF
      • Why do they breed only on the coast and in the high Sierra?
        • good question!
      • each population has its own song dialect, so birds from, say, Lake Merced sing a different song from thos in, say, Alcatraz
      • birds in the nest hear the songs in their neighborhood, are silent for their first year, then sing the song they heard while nestlings
      • A study that raised WCS chicks in isolation to see what their “basic” song was found that the basic song is very tuneless and not very pleasant
• Cardinals, Saltators and Allies
  • are seed eaters with thick bills
  • males sing from the nest while incubating, an unusual behavior since it would tend  to advertise where the nest is!
• Icterids
  • Brown-headed Cowbird
    • How did their famous nest parasitism evolve?
      • The “Bison Theory”: they follow bison/cattle, which are very mobile, and thus couldn’t stop to build a nest and raise young
        • No, because 1) the Shiny Cowbird lives only in areas that have never had bison and 2) during nesting time, Cowbirds don’t follow cattle or bison
    • one species of Cowbird lays its eggs in abandoned nests and raises its young normally
• Frigilline and Carduelline Finches
  • Female does all of the work, Male stands by and sings (oh, and brings her food when she’s on the nest)
  • House Finch feeds seeds to its young, and they can digest them, which most young birds cannot
    • Brown-headed Cowbird chicks cannot digest them either, so any Cowbirds hatched in a House Finch nest starve to death!  BH Cowbirds, unsurprisingly, tend to avoid laying eggs in House Finch nests – this implies that BH Cowbirds monitor their “nesting” success
• Old World Sparrows
  • House Sparrow was introduced from Europe
    • introduced in San Francisco in 1870, in Boston in 1850, and by 1900 they were everywhere.
    • They’re tied in to human structures and have little/no impact on native species
    • like the Starling, their breeding plumage is acquired by feather wear and they do not have a pre-alternate molt

Wheeew! Lots of birds covered in this class!  Now I have to decide if I want to take the extremely in-depth, long-term series of Field Identification classes that Joe also teaches, where they go through one species per class, and it takes around 5 years of Fall/Winter/Spring classes to get through the book!

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