Assessing migration patterns in Passerina ciris using the world's bird collections as an aggregated resource

Area of Science:

• Ecology
• Ornithology
• Conservation Biology

Background:

• Natural history museum collections (NHCs) offer valuable data on species' demography and historical movements.
• Abundance indices, derived from corrected NHC specimen records, can estimate relative population densities.
• Understanding migratory bird behavior is crucial for effective conservation strategies.

Purpose of the Study:

• To investigate the migratory behavior of the New World migratory passerine, *Passerina ciris*.
• To demonstrate the utility of NHC data and abundance indices in inferring migratory patterns.
• To integrate NHC data with remote sensing to understand ecological associations.

Main Methods:

• Georeferenced NHC specimen data were used to calculate abundance indices over a 12-month period.
• Abundance index values were analyzed across regions and months to identify movement patterns.
• Enhanced Vegetation Index (EVI) from remote sensing data was correlated with specimen abundance.

Main Results:

• A statistically significant quasi-circular movement pattern was observed in *Passerina ciris* across its non-breeding range.
• Specimen record abundance showed a non-random association with areas of high primary productivity, indicated by EVI.
• NHC data successfully inferred previously unknown migratory behaviors.

Conclusions:

• Abundance indices from NHC specimens are a powerful tool for understanding migratory behavior and population dynamics.
• Integrating NHC data with remote sensing enhances ecological and demographic insights.
• This approach provides a deeper understanding of behavioral ecology across space and time.