Boyd Deep Canyon Desert Research Center

28 Dec, 04 AM - 31 Dec, 04 AM

I will study the selective forces acting on Costa?s Hummingbird song by comparing male reproductive success (paternity) in the population with song characteristics and physical displays. I am asking if there is a relationship between song characteristics (like loudness, repetition, frequency and tone) and male reproductive success in Costa?s hummingbirds; and if so, which song characteristics are preferred? Also, does a relationship exist between certain physical displays (like diving and shuttling) and male reproductive success? I predict that one or more of the song characteristics and physical displays will be correlated with reproductive success; and males who have the preferred song characteristics and physical displays will have more offspring than males that lack the preferred song characteristics and physical displays. I expect these relationships, because it is energetically expensive to sing loudly, repeatedly, and with high frequency and pure tone. It is also costly to dive repetitively. I will collect songs, behavioral observations and feathers for paternity analysis from at least 40 males during the 2010 and 2011 breeding season. Feathers will also be collected from at least 20 females and nestlings hummingbirds from each season. A number of twenty nests should be a sufficient representation of the population, because based off of previous studies that tested paternity, three-fourths of the studies used less than 50 nests (Griffith et al. 2002). I will capture birds using drop-door traps and potter traps. Drop-door traps will have a feeder suspended in a cage and a string will be pulled to keep the door open. Once a hummingbird flies into the trap, the string will be released and the door will drop, capturing the hummingbird. Potter traps are similar to the drop-door traps except that the door is propped up on a lever and when the bird flies into the cage the string will release the lever and the door will shut. The potter traps and drop-door traps will be placed in the shade and monitored the entire time to ensure the birds? safety. Using forceps, I will pluck 2 to 3 feathers from the breast all individual birds captured (Chan et al. 2008). The feathers will be stored in sterile cryotubes containing 95% ethanol (EtOH); (modified from Taberlet and Bouvet 1991). Birds will be banded using federal government aluminum bands. Males will also be marked with passive integrated transponder (PIT) tags, which will be injected subcutaneously under the skin on the back between the wings or under the wing using a syringe implanter. Nicolaus et al. (2008) found no negative affects when PIT tags were implanted on the back between the wings of Great Tits (Parus major) for either nestlings or adults. Birds will be identified using PIT tag readers that will be attached to a feeder. To make individual identification in the field away from feeders easier, I will apply non-toxic paint patterns to the back of both males and females (Clark and Feo 2008). I will observe each male for three, 1-h observation periods. During each observation period, the number of dives that a male performs will be noted. Also, song will be recorded when the male is perched. I will record the number of bouts, and number of songs in each bout (repetition of songs within 1/2 second of the previous song) to determine if these behaviors influence reproductive success. The seven song characteristics that I will measure are: peak frequency (the frequency with the most energy), maximum frequency (highest frequency reached), duration of song elements (as described in Williams and Houtman 2008), amplitude, song length, bout length, and the mean and variance between the inter-clicks which compose the first element in the song. I will extract nuclear DNA from the feathers (adapted from De Volo et al. 2008) and 4 or 5 microsatellite markers will be isolated and characterized and appropriate primers will be tested to amplify the microsatellites for paternity analysis using PCR. The amplified DNA will be run on an electrophoresis agarose gel. If the offspring share 100% of the microsatellites of a male, the offspring will be labeled that individual male?s progeny (Rosivall et al. 2009). If the male does not share 100% of the microsatellites with the nestlings, then the male is not labeled as the father of the chicks (Balenger et al. 2009). I will also run maternal DNA alongside offspring DNA to verify microsatellite marker amplification was successful (100% shared microsatellites between mother and young).

Visit #20030 @Boyd Deep Canyon Desert Research Center

Approved

Under Project # 19878 | Research

Reproductive Success and Song in Costa's hummingbirds

graduate_student - California State University (CSU), Fullerton

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Erin Chin Dec 28 - 31, 2009 (4 days)

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Mayhew housing facilities 1 Dec 28 - 31, 2009