Physiological consequences of urbanization to Sonoran Desert birds
Author(s):
- Bobby Fokidis, School of Life Sciences
- Pierre Deviche
Abstract:
As cities expand worldwide, understanding how species adapt to novel urban habitats will become increasingly important to conservation. The adrenocortical stress response enables vertebrates to cope with novel environmental challenges to homeostasis. We examined baseline and stress-induced corticosterone (CORT) concentrations in three songbird species within and around Phoenix, Arizona. We tested whether baseline and stress-induced CORT patterns differed among species living at varying densities in Phoenix and tested the hypothesis that, for species capable of successfully colonizing cities, individuals living in urban areas have a decreased acute stress response compared to individuals living in native desert. Baseline CORT levels were generally similar in urban and desert birds. Capture and handling stress typically produced greater total CORT responses in urban birds than in desert birds, although these responses differed as a function of sampling date. Urban birds showed less seasonal variability in stress responses than desert birds. We propose that more predictable resources in the city than in rural areas may decrease the need to vary stress responsiveness across life history stages. The results highlight the species-specific effects of urbanization on stress physiology and the difficulty to predict how urbanization impacts organisms.
Keywords:
Temporal Coverage:
2006-01-12 to 2008-08-22Geographic Coverage:
Geographic Description: area in phoenixBounding Coordinates:
Longitude:-112.40 to -111.47
Latitude:+33.57 to +33.23
Contact:
Information Manager, Global Institute of Sustainability, Arizona State University,POB 875402,TEMPE
caplter.data@asu.edu
Methods used in producing this dataset: Show
Data Files (1) :
Tabular: Morphometric and stress data
Description: Tabular data on variation in body size and stress markers between urban and desert songbirds
Column | Description | Type | Units |
---|---|---|---|
record | primary key and table index |
integer | dimensionless |
species | Four letter ABA species code |
string |
Enumeration:
|
time | Time of bird capture in format hh:mm |
time | Format: hh:mm |
date | Date of bird capture in format dd-mm-yyyy |
date | Format: DD/MM/YYYY |
location | Description of capture location |
string | |
site | Whether site was urbanized or undisturbed desert habitat |
string |
Enumeration:
|
wing_chord | Length of the wing (mm) |
float | millimeter |
tarsus | Length of the tarsus (mm) |
float | millimeter |
mass | Weight of the bird (g) |
float | gram |
H:L_ratio | The ratio of heterophil to lymphocyte white blood cells as determined by visual examination of blood smears |
float | dimensionless |
wbc | The number of total white blood cells per 10,000 red blood cells as determined by visual examination of blood smears |
integer | dimensionless |
baseline_cort | The basal concentration of the stress steroid (corticosterone) in ng/ml of plasma |
float | nanoGramsPerMilliLiter |
stress_cort | The concentration of the stress steroid (corticosterone) in ng/ml of plasma after 30 minutes of capture and handling stress |
float | nanoGramsPerMilliLiter |