An examination of interactions between bird and foundation plants in an arid ecosystem.

Positive interactions between plants and animals create habitat infrastructure on which many species rely, especially when the promotion of foundation species is involved. Mutualistic interactions between plants and birds (like pollination or seed dispersal) are dependent on both plant and bird phenology or cyclic/seasonal changes. However, phenology is plastic as photoperiod and temperature largely determine flowering & fruiting for plants and migration & breeding for birds. As our climate changes and habitats degrade, we must understand what interactions are at risk. That's why, in this study, we examined the relationships between birds, their community, their behavior, and their microhabitat associations.

Transcript

1. An examination of interactions between bird and foundation plants in an arid ecosystem. Malory Owen & Christopher Lortie
5. Positive interactions, Facilitation, & Mutualism
6. Phenology
7. Goals
8. A review of allocation in Cactaceae reproductive structures Chapter 1
9. Progress to date: • Second round of data extraction • Reviewed 424 studies for relevancy • +132 studies • Only 23 studies relevant (N=23) • Multiple records per studies (n=132) • Often missing important data necessary for meta-analysis
14. Bird microhabitat associations and behaviors are linked via phenology Chapter 2
15. Purpose and Hypothesis Purpose: This study aims to explore the influence of a shift in desert bird community on foundation plant association and bird behavior to inform our understanding of potential phenological mismatches in desert ecosystems. Hypothesis: Phenology shifts in foundation plants (i.e. shrubs and cacti) and birds are linked and determine bird behavior.
16. Research Questions 1. How does desert bird community change between migratory/flowering seasons (hereafter referred to as spring) and breeding/fruiting seasons (hereafter referred to as summer)? 2. How do birds associate with available plant microhabitats or exhibit different behaviors in different seasons? 3. Are microhabitats fostering certain behaviors among birds?
17. Predictions 1. Spring and summer seasons change the desert bird community and their associations with the microhabitat plants. 2. Taxonomic and functional diversity of bird species differ when in association with microhabitat plant species relative to other microhabitats. 3. Bird behaviors are expressed at different frequencies in different microhabitats.
18. Field methods • Two-hour surveys walking on two 500m transects (N=2, n=20/season) • Species, behavior, microhabitat, coordinates, time of sighting, & distance from transect
19. Data manipulation • Behaviors and microhabitats were compressed • Behaviors: Active movement, Inactivity, Foraging, Cleaning, & Territorial/Mating behavior • Microhabitats: Shrub, Cactus, & Other • Taxonomic and Functional Diversity • Species • Trophic guild • Migratory class
20. Statistical Analysis • Difference in community between seasons? • LM/GLM and PCA • Diversity influence on behavior or microhabitat? • One-way ANOVA • Tukey HSD posthoc • Next steps: GLMs • Microhabitat influence on behavior? • Pearson’s Chi-squared test • Bonferroni posthoc
21. Key Findings to Date • 463 birds seen & 755 birds heard • 39 species • 8 trophic guilds • 4 migratory classes
22. * * * * * * p-value < 0.0001
24. v v v
25. Mean ± SD (spring, summer) p-value F Species Microhabitat Shrub 5.88 ± 14.4, 2.00 ± 8.4 0.122 1.758 Cactus 2.30 ± 6.69, 1.77 ± 7.84 Other 4.35 ± 8.03, 1.26 ± 5.02 Behavior Active movement 3.63 ± 6.44, 1.51 ± 6.17 <0.001 3.304 Cleaning 0.09 ± 0.37 Feeding 0.79 ± 1.57, 0.74 ± 3.26 Inactivity 2.02 ± 3.14, 1.00 ± 5.35 Territorial/mating 6.00 ± 15.31, 1.74 ± 8.21 Trophic Microhabitat Shrub 28.11 ± 42.96, 9.56 ± 18.10 0.345 1.155 Cactus 11.00 ± 13.64, 8.44 ± 16.33 Other 20.78 ± 26.84, 6.00 ± 10.09 Behavior Active movement 17.33 ± 19.94, 7.22 ± 13.46 0.038 2.11 Cleaning 0.44 ± 1.01, 0.11 ± 0.33 Feeding 3.78 ± 5.78, 3.56 ± 6.71 Inactivity 9.67 ± 10.62, 4.78 ± 11.41 Territorial/mating 28.67 ± 45.16, 8.33 ±17.30 Migratory Microhabitat Shrub 63.25 ± 60.92, 21.50 ± 35.95 0.631 0.699 Cactus 24.75 ± 36.65, 19.00 ± 36.67 Other 46.75 ± 66.79, 13.50 ± 25.68 Behavior Active movement 39.00 ± 45.74, 16.25 ± 28.03 0.352 1.165 Cleaning 1.00 ± 1.15, 0.25 ± 0.50 Feeding 8.50 ±6.61, 8.00 ± 12.78 Inactivity 21.75 ± 23.87, 10.75 ± 21.50 Territorial/mating 64.50 ± 88.19, 18.75 ± 36.17
26. (Pearson’s Chi-squared Test, X2=26.47, df=6, p<0.001)
27. Implications • Hypothesis partially supported • Birds’ relationships (as exhibited by behavior) do change as foundation plant species’ phenology changes. • Infrastructure-creating foundational species influence bird behavior
28. Deserts are experiencing habitat degradation too…
29. Looking ahead in our changing world
30. Thanks! Let’s chat