North American Bird Bander Oct-Dec 2015 Vol. 40 No. 4 Jan-Mar 2016 Vol. 41 No. 1

Feature Articles

Observations From 24 Years, 1991-2014, of Banding an Adirondack Breeding Population of Ruby-throated Hummingbirds (Archilochus colubris).

Robert P. Yunick

Abstract- Ruby-throated Hummingbirds (Archilochus colubris) were banded at an Adirondack mountain location in the state of New York over the period 1991-2014 producing 1221 birds banded and 429 returns and recaptures in the years following banding.  Mist netting was used as the capture method for the first eight years, 1991-1998, yielding 232 bandings and 24 returns.  A more efficient capture method using a modified Sargent trap (Russell and Russell 2001) was employed for the following 16 years, 1999-2014, resulting in 989 bandings and 405 return recaptures out as far as eight years after banding.

During this latter 16-year period, numbers of hummingbirds banded annually ranged from 23 to 128 representing 48.9-87.9% of the total annual captures, while returns ranged 11 to 57 or 12.1-51.7% of total annual captures.  Among 814 adults banded, females were 63.0% of the total, males 37.0%; but females represented 78.7% of the return recaptures, males 21.3%.  The percentage of banded females ever recaptured at least once as a return was 38.2% while only 22.2% of banded males were ever recaptured as a return.  Among 166 banded immatures, males outnumbered females 52.4% to 47.6%, while females returns slightly outnumbered males 51.2 to 48.7%.  As with adults, the percentage of banded immature females ever recaptured as a return exceeded males by 25.3% to 21.8%.

Except for the first capture period in early May when male scaptures exceeded fmales, the number of females banded as well as returned exceeded similar male caputres over the entire remaining breeding season.  Over the 24-year duration, the ratio of adult female bandings to adult males was 1.94:1, while among returns it averaged 3.40:1 and was as high as 4.80:1 by the fourth year after banding.  No adult male was ever recaptured beyond four years after banding making it five years of age, while one adult female was recaptured every year a total of 25 times out to eight years after banding making her at least nine years old, tying the North American age record then posted on the Bird Banding Laboratory website (Bird Banding Laboratory 2015).  Among banded immatures, females outnumbered males 1.08:1; while as returns, females outnumbered males 2.05:1, no male banded as an immature was recaptured beyond three years, while the oldest recaptured female banded as an immature was eight years old.

MAPS (Monitoring Avian Productivity and Survivorship) Data Provide Inferences on Demographic Drivers of Population Trends for 158 Species of North American Landbirds

Steven K. Albert, David F. DeSante, Danielle R. Kaschube and James F. Saracco

The Monitoring Avian Productivity and Survivorship (MAPS) Program is a continent-wide bird banding and data collection effort among public agencies, non-governmental organizations, and individuals to assist the conservation of birds and their habitats through demographic monitoring.  We analyzed MAPS data from 1992 through 2006 to provide temporal (annual) and spatial (at the scale of Bird Conservation Regions [BCRs]) estimates or indices for key vital rates, including population change, population density, adult apparent survival, recruitment, productivity, and other demographic parameters for 158 species of landbirds.  We presented results, along with pair-wise correlations among vital rates, for all 158 species and provided detailed discussions of results and research and management suggestions for 60 of the species (discussions for the remaining 98 species are currently being drafted) on a newly released website, Vital Rates of North American Landbirds (www.vitalratesofnorthamericanlandbirds.org).  The results and accompanying discussions provide inferences about which vital rate(s) appear to be driving population change and could significantly improve strategies for reversing population declines that are occurring in many of these species.  Here we provide a summary of the information provided on the website and illustrate how the information is presented and interpreted through one example species, Wood Thrush (Hylocichla mustelina).