Linking foraging decisions to residential yard bird composition
Publication date: 2016-11-30
Bounding Coordinates:
Longitude:-113.34 to -111.59
Latitude:34.01 to 32.91
PO Box 875402,Tempe
caplter.data@asu.edu
Author(s):
- Susannah Lerman, USDA Forest Service Northern Research Station
Abstract:
Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We measured the amount of resources remaining, or giving-up densities (GUD) for final foragers on artificial food patches in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the patch. Birds foraging in mesic yards depleted patches to a lower level (i.e. had lower GUDs) than birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, yard design affected individual species behavioral responses. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in the missed opportunity (alternative resources more abundant in xeric yards) and the digestive cost (moist conditions in mesic yards) both contributed to our results while predation costs did not. Enhancing the GUD method with our statistical model provided insights into how individual species and bird densities influenced the GUD. If the described differences we found in foraging behavior are indicative of differences in habitat quality, then this would lend additional support for native landscapes to help reverse the loss of urban bird diversity.
Keywords:
urban, biodiversity, community structure, conservation disturbance patterns, population studies residential yards, native landscaping, giving-up densities cap lter, cap, caplter, central arizona phoenix long term ecological research, arizona, az, arid land
Temporal Coverage:
2010-02-13 to 2010-05-03Geographic Coverage:
Geographic Description: CAP LTER study areaBounding Coordinates:
Longitude:-113.34 to -111.59
Latitude:34.01 to 32.91
Contact:
Data Manager, Julie Ann Wrigley Global Institute of Sustainability, Arizona State University,PO Box 875402,Tempe
caplter.data@asu.edu
Methods used in producing this dataset: Show
Data Files (2) :
Tabular: 639_species_density_c8396bf588fb003f7a20fba1a145731b.csv
Description: study site (residential yards) details, and bird foraging patterns of study seed-trays
Column | Description | Type | Units |
---|---|---|---|
Location | Name of homeowner where experiment took place |
string | |
Yard Type | Landscape design of yard: Mesic = turf and exotic plants, Xeric = crushed gravel and drought tolerant vegetation |
string |
Enumeration:
|
Treatment | Placement of the seed tray: Bush = next to plants, Open = 3 meters away from plants |
string |
Enumeration:
|
Species | AOU bird code |
string | |
SpDensity | Total number of individuals for the species observed foraging on seed tray |
float | number |
GUD (g) | GUD = Giving-up densities, the amount of seed remaining after foraging experiment ends in the seed tray |
float | gram |
ExpModel_GUDlog_0=20 | Predicted GUD based on an exponential model of the GUD data |
float | gram |
SeedConsumed | Total number of seeds consumed per tray |
float | number |
total Pecks | Total number of pecks for the species |
float | number |
Peck % | Percent of pecks by the species for the seed tray |
float | dimensionless |
GUD pecks | Total number of pecks for the seed tray when the species stopped pecking on seed tray |
float | number |
Order | Order the species stopped pecking on seed tray |
float | number |
Total Tray Pecks | Total number of pecks for the seed tray (all species, all visits) |
float | number |
Minimum Individuals | Total number of individual birds observed foraging on seed tray |
float | number |
Total Species | Total number of species observed foraging on seed tray |
float | number |
Tabular: 639_predation_3fc65738044a7753a56425db96214a09.csv
Description: study site (residential yards) details, and bird predation patterns
Column | Description | Type | Units |
---|---|---|---|
Location | Name of homeowner where experiment took place |
string | |
TYPE | Landscape design of yard: Mesic = turf and exotic plants, Xeric = crushed gravel and drought tolerant vegetation |
string |
Enumeration:
|
S - Date | Start date |
date | Format: YYYY-MM-DD |
E - Date | End date |
date | Format: YYYY-MM-DD |
S - Time | Start time |
date | Format: HH:MM:SS |
E - Time | End time |
date | Format: HH:MM:SS |
Experiment | Placement of the seed tray: Bush = next to plants, Open = 3 meters away from plants |
string |
Enumeration:
|
T-min | Minimum temperature |
float | celsius |
T-max | Maximum temperature |
float | celsius |
GUD | GUD = Giving-up densities, the amount of seed remaining after foraging experiment ends in the seed tray |
float | gram |
Notes? | Notes for the experiment |
string | |
Last Species | Last species observed foraging on the seed tray |
string | |
2nd Last Species | Second to last species observed foraging on the seed tray |
string | |
3rd Last Species | Third to last species observed foraging on the seed tray |
string | |
4th Last Species | Fourth to last species observed foraging on the seed tray |
string | |
5th Last Species | Fifth to last species observed foraging on the seed tray |
string | |
6th Last Species | Sixth to last species observed foraging on the seed tray |
string | |
Total Species | Total number of species observed foraging on seed tray |
float | number |
Minimum Individuals | Total number of individual birds observed foraging on seed tray |
float | number |
Species configuration | Total number of individuals for each species observed foraging on seed tray |
string |