Cameron Freshwater
Department of Biology
University of Victoria
Victoria, British Columbia, Canada
E-mail: camfresh@uvic.ca

Cameron K. Ghalambor
Department of Biology and Graduate Degree Program in Ecology
Colorado State University
Fort Collins, Colorado, USA
E-mail: cameron.ghalambor@colostate.edu

Paul R. Martin
Department of Biology
Queen's University
Kingston, Ontario, Canada
E-mail: pm45@queensu.ca

Adult_Survival.csv (MD5: b05142c8e4f507949a0de4448fd1b268)

Arrival_Date.csv (MD5: cbbf8fa18b115e9f3c05fd70f5896150)

Biogeography.csv (MD5: 627fe84e1ffb74d55065f06abc2cec12)

Breeding_Date.csv (MD5: 1ab82e4d46ff6703251af676248fa1a8)

Brood_Number.csv (MD5: 6cda71ced7d80623f71bddd506904632)

Clutch_Size.csv (MD5: 5e1fd440ef3eea8046ce1e7eddc64735)

Diet_Breadth.csv (MD5: ebc8b7663bd97a86f2b64a84b12033ec)

Egg_Mass.csv (MD5: 00af1875f709dfe307fa4b688cd716b6)

Foraging_Behaviour_Breadth.csv (MD5: 34d2fec478134a29c3143b8de278af85)

Habitat_Breadth.csv (MD5: 32ed27214f2580fa521f9661807e67dc)

Nest_Site_Breadth.csv (MD5: 96ac8ff7223e5e623d2449cd1a897744)

These files contain species- and location-specific information for each of the ecological traits that we investigated.

Columns found in all files are as follows:

• Comparison: Independent comparison number, sequentially numbered, following the taxonomic order of Gill and Donsker (2010).
• Dominance: Whether species was classified as dominant or subordinate based on outcome of aggressive interactions (see Supplement 1 for details).
• Record: Unique record number for each site, year, or study from which data on a pair was gathered.
• Genus: Taxonomic genus of focal species, following Gill and Donsker (2010).
• Species: Focal species, following Gill and Donsker (2010).
• Mass: Mean mass values for each species.
• Location: Region where data were collected according to original references.
• Reference: Original reference from which ecological data were collected.

Columns unique to Arrival_Date.csv and Breeding_Date.csv

• Julian.Date: Julian date calculated from first arrival or first egg dates in original reference (mean if original reference spanned multiple years).
• Date: Original date of first arrival or first egg in original reference (mean if original reference spanned multiple years).
• Details: how first arrival or egg date was defined in original reference.

Columns unique to Clutch_Size.csv

• Clutch.Size: Clutch size from original reference (mean if original reference spanned multiple years).

Columns unique to Egg_Mass.csv

• Calculated.Fresh.Egg.Mass: Egg mass as calculated in original reference.

Columns unique to Brood_Number.csv

• Number.of.Broods.per.Year: Most common number of broods (excluding renests) produced annually for each species, from original reference.

Columns unique to Survival.csv

• Annual.Survivorship: Average probability of a breeding-age bird surviving from one year to the next from original reference (mean if original reference spanned multiple years).
• N: Number of individuals used to estimate annual survivorship.
• Notes: Method used to estimate annual survivorship and which individuals were included in original reference.

Columns unique to Diet_Breadth.csv, Foraging_Behaviour_Breadth.csv, Nest_Site_Breadth.csv, and Habitat_Breadth.csv

• X.Diversity: Calculated Shannon-Weaver index of diversity for trait of interest (mean if original reference spanned multiple years).
• X.Richness: Number of unique categories of the trait of interest observed in the original reference (mean if original reference spanned multiple years).
• N: Number of individuals included in original reference
• Notes: How the ecological trait of interest was defined in the original reference.

Columns unique to Biogeography.csv

• Breeding.Range.Size: Size of breeding range within Americas in km2 as calculated in BirdLife International and NatureServe (2011) using a Lambert Azimuthal Equal Area projection.
• Wintering.Range.Size: Size of wintering range within Americas in km2 as calculated in BirdLife International and NatureServe (2011) using a Lambert Azimuthal Equal Area projection.
• Breeding.Range.Latitude: Latitude of the centroid of breeding range within Americas in degrees as calculated from maps in BirdLife International and NatureServe (2011).
• Wintering.Range.Latitude: Latitude of the centroid of wintering range within Americas in degrees as calculated from maps in BirdLife International and NatureServe (2011).
• Breeding.Range.Longitude: Longitude of the centroid of breeding range within Americas in degrees as calculated from maps in BirdLife International and NatureServe (2011).
• Wintering.Range.Longitude: Longitude of the centroid of wintering range within Americas in degrees as calculated from maps in BirdLife International and NatureServe (2011).
• Migration.Distance: Distance in km between centroid of the breeding range and the centroid of the wintering range, estimated using an online calculator (http://www.csgnetwork.com/gpsdistcalc.html).

LITERATURE CITED

BirdLife International and NatureServe. 2011. Bird species distribution maps of the world.BirdLife International, Cambridge, UK, and NatureServe, Arlington, Virginia, USA.

Gill, F., and D. Donsker. Editors. 2010. IOC World Bird Names (Volume 2.6). Available at http://worldbirdnames.org.