Urban Ecology: A Primer on Urban Birds Summer Institute 2009

1. Urban Ecology: A Primer on Urban BirdsSummer Institute 2009 The red tailed hawk, Pale Male, perches above his territory amidst the din of New York City.

2. Birds are useful indicators of ecological conditions; long-term bird surveys can provide a window into the ecosystem health of the city, while teaching students important concepts in urban ecology. In 2003, a student on an Audubon field trip to Mount Auburn Cemetery photographed this young male red-tailed hawk perched on a headstone with a baby turtle clamped in its bill.

3. Ecology of Urban Birds Urban avifauna are noted for adaptability with respect to foraging behavior, territory size and social structure Clockwise from upper left: House sparrow (Passer domesticus) - actually not a true sparrow, part of the Old World guild of weaver finches (introduced in 1851 - now 150,000,000); European starling (Sturnus vulgaris) was introduced in 1890 (now 200,000,000); Brown headed cowbird (Molothrus ater) is our only common nest parasite - originally tied to bison populations; Common grackle (Quiscalus quiscula) is the common bird of park lawns; American crows (Corvus brachyrhyncos) are very adaptable to cities but may soon be wiped out by West Nile Virus,

4. Peregrine Falcons - An Urban Success Story! Placed on the Endangered Species list nearly thirty years ago, the peregrine falcon has made an incredible recovery from the point of near extinction. Impacted by DDT it was extirpated from the eastern United States and nearly wiped out nationwide. Historically, approximately 4000 nesting pairs represented a stable population prior to DDT. That number fell to 275 nesting pairs in 1975. Strict controls on the use of DDT, plus a dedicated reintroduction effort has brought the population back to nearly 4000 nesting pairs - many in urban areas such as Boston and New York. Peregrine falcons (top), and other members of the Falconidae, such as kestrels and merlins are the acrobatic predators of the urban skyline. Peregrines are capable of level flight that exceeds 50mph and can dive (stoop) at 200mph in pursuit of avian prey. Their ecological niche as cliff dwellers - and taste for pigeons and house sparrows - make them urban neighbors.

5. Introduced avian species can expand their range dramatically over short periods of time. Starlings were introduced into New York City in 1890 - they are now now nearly cosmopolitan. Mynas, although similar have not expanded their range. Left: Common mynas (Acridotheres tristis) are also introduced urban Icterids (family that includes starlings) - but have a much more confined range in North America.

6. Analysis of trends suggest that most successful urban birds are likely to have been pre-adapted to mixed environments. Top: Data for 45 common species of birds found in urban habitats reveal that most are naturally found in wooded or mixed habitats - grassland specialists are rare. Bottom: National trends show both increases and decreases in urban bird populations on a species-specific basis. Bottom line… there are great opportunities for student science research and with meaningful contributions to conservation!

7. Right: Island biogeography provides an intriguing theoretical way to investigate urban bird communities. Data from cities all over Europe suggest that urban habitats really are like islands. Bottom: Even urban parks can become saturated with avian territories - forcing residents out onto the street! from: Esteban & Jukka (2001), Biodiversity & Conservation 10:2023-2043.

8. Bird species richness in Madrid is negatively associated with the amount of paved ground within the park boundaries Biodiversity declines as fraction of pavement increases Typically, parks are designed with either an impervious landscape design - or with a “naturalistic” landscape relief. The latter design enhances avian biodiversity by allowing for a more heterogeneous environment.

10. Data from long-term Christmas counts suggest that crows successfully exploit urban habitats and thrive in cities Christmas Counts provide a reliable window into the population trends of urban bird populations. In Seattle, the crow population has grown in response to increased human domination of the landscape. Data from Massachusetts indicate that urbanized habitat support larger social groups* *from: Auger, Auger & Strauss (1990), Wilson Bulletin 102(4):615-622.

11. A crow family group. American Crows form cohesive social groups of related family members that help the adult breeding pair raise young. In urban territories, ecological niches are saturated and reproductive success is often gained indirectly via inclusive fitness The way a crow Shook down on me The dust of snow From a hemlock tree Has given my heart A change of mood And saved some part Of a day I had rued Robert Frost - Dust of Snow Crows appear to be the victims of the disease - not the critical hosts. In order to be good hosts, they need to maintain viremia for at least 20-100 days, so that they could pass on the virus to others.

12. Ovenbirds limited by habitat fragmentation Researchers in Canada observed lower rates of pairing between male and female birds in altered habitats. Contiguous forest: 96% Agricultural lands: 86% Data from Missouri found road effects on pairing: >300 meters from road: 76% <300 meters from road: 22% Bayne & Hobson (2001), Auk 118(2):380-388. Van Horn, et al. (1995), Auk:759-768.

13. Waterbirds can serve as bioindicators of changes in trophic dynamics… Great-crested grebe (P. cristatus) Black-necked grebe (P. nigricollis) Changes in great-crested & black-necked grebes wintering in grebes in Mar Menor Lagoon (Spain) as it relates to nitrogen flow within the lagoon from: Viaroli, et al (2005) Hydrobiologia, 550:221-235.

14. Researchers in Phoenix investigated bird biodiversity in neighborhoods and parks - and measured the wealth of diversity and the human wealth of the neighborhoods Paige Warren and her research colleagues looked at the urban mosaic in a new way… shifting from traditional urban-to-rural gradients, to the city as a patchwork of neighborhoods - each with different economic conditions. From: Kinzig, et al. (2005), The effects of human socioeconomic status and cultural characteristics on urban patterns of diversity, Ecology and Society 10(1):On-line .

15. Research in urban neighborhoods in Phoenix suggest that bird diversity and human wealth are positively correlated Similar to data from plant communities, wealthier neighborhoods had more species of birds. Some species such as the cactus wren (left) and hooded oriole (right) were only found in wealthy neighborhoods.

16. Warren and her colleagues believe that human influence occurs at two scales: bottom-up and top-down

17. Conceptual framework for enhancing avian biodiversity in our cities Cape May warbler - one of our “rare” neotropical migrants.

18. Lyme Disease System • Introduction to ecology • Agent: bacterium (Borrelia bergdorferi) • Vector: deer tick (Ixodes scapularis) • Hosts: white footed mouse (Peromyscus leucopus) and white-tailed deer (Odocoileus virginianus) • Incidental hosts: birds, voles, red foxes, coyotes, humans Left: Sedated red fox being fitted with a radio-telemetry collar. Middle (2): Spirochete bacteria responsible for causing Lyme Disease. Upper right: Adult, nymphal and larval stages of the deer tick Lower right: Common yellowthroat found to be a competent host in Ontario

19. West Nile Virus Disease System • Agent: Virus (Flavivirus) • Vector: Mosquitoes (Culex spp.), found in 43 species • Hosts: wild birds, possibly ducks and pigeons critical to maintaining life cycle • Incidental hosts: mammals, bats, frogs (Rana ridibunda), possibly horses Culex sp female, laying eggs

20. Great tits (Parus major) use a variety of acoustic signals - some are to establish boundaries. This European songbird lives in variable social groups. Part of the year, the adult males establish territories and sing elaborate courtship calls in order to attract female mates. Bird biodiversity is generally lower in urban areas due to habitat fragmentation - and quite possibly - anthropogenic noise!

21. Slabbekoorn, H., and M. Peet. 2003. Birds sing at a higher pitch in urban noise. Nature 424(July 17):267. The data the team have analyzed come from recordings of 32 males in various parts of Leiden. The researchers also took a series of recordings and background-sound measurements in each location before, during, and after rush hour. The average minimum frequency of the males' songs, ranging from 2.82 to 3.77 kilohertz, was lower in quieter neighborhoods than in noisier ones. Urban noise, mostly from engines in cars, trucks, boats, and modern conveniences such as leaf blowers, encroached on birds' lower frequencies in the loud neighborhoods. http://acp.eugraph.com/news/news03/slabb.html

22. Bioacoustics of Chickadee (Poecile atricapillus) song contests reveal hierarchies between competing males Subordinate males alter the frequency of their territorial calls in response to playback songs of dominant males from nearby territories. Subordinate males sing at a higher frequencies. Daniel Mennill & colleagues, Auburn University and Queens College in Kingston, Ontario

23. Piping Plover Shore Birds • Federally Endangered Species • migratory- breeds along eastern seaboard and Great Lakes • monogamous, ground nesting • easily disturbed by humans • Utilizes beachfront corridors for nesting • Reproductive success reduced by human disturbance • Vehicle disturbance must be minimized during the fledging phase of the reproductive cycle.

24. Piping Plovers respond to management at Sandy Neck: Increased reproductive fitness Sandy Neck Beach