1. By: Jared Hall Biology 5331 Conservation Biology
Importance of Native Seeds in White-Winged Dove Diets Dominated by Agricultural Grains
By: Jared Hall
Biology 5331
Conservation Biology

2. Background Ground-feeding granivores (Lewis 2005)
Do not supplement diet with insects (Lack 1968)
Altricial young (Mirarchi 2005)
High nutrient requirements
Spring and fall migrators (Tomlinson 2005)
Abundant species (Oldenburger 2015)
9.76 million breeding individuals in Texas
1.77 million harvested annually

3. Introduction
WWDO population decreased throughout 1900s (Waggerman 2002)
Currently rebuilding, although still below historic size
Increase in agriculture (McKay 1980)
Decreases native forage
Alters habitat from small to landscape scale
Agriculture grains are similar to candy for humans (Dolton 1975)
High in energy only
Low in protein, minerals, vitamins
Examples: milo, corn, sesame seeds, wheat, barley, etc.

4. Associated Issues Agriculture and urbanization Cultivation (TPWD 2012)
95% of native vegetation removed in the LRGV (swanson and rappole 1993)
Cultivation (TPWD 2012)
Loss of native habitats
Fencing agriculture fields (Primack 2014)
Increases encroachment, decreases native vegetation

5. Objectives and Hypotheses
Objective was to determine necessity of native seeds compared to ag grains on productivity of captive white-winged doves
Hypothesized that low protein in ag grains would limit doves ability to fledge young and attempt multiple nestings during a single breeding season.
Also hypothesized that native forage is necessary for doves to nest successfully multiple times.

6. Methods Captured 104 WWDO Placed pairs in 52 individual cages
Kleberg and Hidalgo Counties
September February 2004
Sexed using Cloacal characteristics (Miller and Wagner 1955)
Placed pairs in 52 individual cages
26 pairs received treatment 1
Sorghum only
26 pairs received treatment 2
Sorghum and native seed (Croton sp. and Helianthus sp.)

7. Methods Cont.
Recorded
Dry mass of feed consumed per week
Eggs per pair
Hatchlings per pair
Fledglings per pair
Weighed young at 10, 14, 21, and 56 days post-hatch
Young were considered fledged at 14 days post-hatch (Cottam and Trefethen 1968)
Removed from parent cage 21 days post-hatch

8. Statistical Analyses Alpha= 0.05 for all analyses Students t-test
Used to compare two means for significant differences
Nestling mass between diet treatment by nestling age
Number of eggs, clutches, hatchlings, fledglings per pair by treatment
Daily feed consumption between treatments within each nesting period
Chi-square
Demonstrates how likely it is that an observed distribution is due to chance
Test the effect of diet on a pair's ability to produce >3 eggs, hatchlings, and fledglings

9. Statistical Analyses Cont.
Analysis of Variance (ANOVA)
Method of testing equality of three of more population means by analyzing sample variances
Compared total dry matter intake between nesting periods
Post hoc Tukey test
Separate differences among nesting periods
Linear Regression
Relationship between two variables
Typically depicted by scatter plots with a best fit line
Proportion of sorghum/native seed in diet based on age

10. Significant Results Sorghum + Native Seed
Chicks weighed 27-32% more than sorghum alone throughout the entire 56 day period
Fledged 1.0 more chicks/pair
Produced 0.29 more fledglings/total egg
Produced 0.31 more fledglings/hatched eggs
Sorghum alone did not produce any values higher than sorghum + native seed

11. Results Cont.
ANOVA
t-tests

12. Results
Chi-square
Linear Regression

13. Discussion
WWDO productivity is significantly greater when doves have access to native seeds as hypothesized
Number of clutches per treatment was not significant
Not supported by the second hypothesis
Increased agriculture in Texas may explain decrease in WWDO from (Hayslette et al. 1996)
All granivorous species are impacted similarly

14. Going Forward
Test whether nutrient imbalances reduce white-winged dove productivity, thus, limit population size in agricultural environments
Adjust current management strategies to account for lack of native seeds
Utilize WMAs

15. Literature Cited
Cottam, C, and J. B. Trefethen, editors Whitewings: the life history, status, and management of the white-winged doves. D. Van Nostrand, Princeton, New Jersey, USA.
Dolton, D. D Patterns and influencing factors of white-winged doves feeding activity in the Lower Rio Grand Valley of Texas and Mexico. Thesis, Texas A&M University, College Station, USA.
Hayslette, S. E., T. C. Tacha, and G. L. Waggerman Changes in white-winged doves reproduction in southern Texas, Journal of Wildlife Management 60:
Lewis, J. C Foods and Feeding Ecology. Pages in T. S. Baskett, editor. Ecology and Management of the Mourning Dove. Stackpole Books, Pennsylvania, USA.
McKay, W. D The influence of agriculture on avian communities near Villaviciencio, Columbia. Wilson Bulletin 92:
Miller, W. J., and F. H. Wagner Sexing mature Columbiformes by cloacal characters. Auk 72:
Mirarchi, R. E., Energetics, Metabolism, and Reproductive Physiology. Pages in T. S. Baskett, editor. Ecology and Management of the Mourning Dove. Stackpole Books, Pennsylvania, USA.
Oldenburger, S. L., M. Frisbie, J. Purvis, N. S. Heger, J. Roberson, and D. Morrison Eurasian-collared, Mourning, and White-winged Doves Texas Population Status and Harvest Texas Parks and Wildlife Department, Texas, USA.
Primack, R. B., Habitat destruction, fragmentation, degradation, and global climate change. Pages in Essentials of Conservation Biology, Sixth Edition. Sinauer Associates Inc, Massachusetts, USA.
Swanson, D. A., and J. H. Rappole Status of the white-winged doves in southern Texas. Southwestern Naturalist 37:93-96.
Texas Parks and Wildlife Department Texas Conservation Action Plan : Cross Timbers Handbook. Editor, Wendy Connally, Texas Conservation Action Plan Coordinator. Austin, Texas.
Tomlinson R. E., Migration. Pages in T. S. Baskett, editor. Ecology and Management of the Mourning Dove. Stackpole Books, Pennsylvania, USA.
Waggerman, G. L White-winged and white-tipped dove density, distribution, and harvest. Texas Parks and Wildlife Department, Texas Federal Aid Project Report W-128-R-10, Austin, USA.

16. Questions?