Polar Biology

, Volume 36, Issue 11, pp 1587–1599 | Cite as

Seasonal observations and machine-learning-based spatial model predictions for the common raven (Corvus corax) in the urban, sub-arctic environment of Fairbanks, Alaska

  • A. P. Baltensperger
  • T. C. Mullet
  • M. S. Schmid
  • G. R. W. Humphries
  • L. Kövér
  • F. Huettmann
Original Paper


The common raven (Corvus corax) is an abundant generalist of the northern hemisphere, known to congregate and roost near human-related food sources. Due to a growing human-footprint and associated anthropogenic food subsidies, raven populations have increased dramatically over the past several years throughout the USA. The sub-arctic region has also witnessed increased urbanization and industrialization, and ravens have taken advantage of these changes. During 2004 and 2006, we surveyed parking lots on a bi-weekly basis in the city of Fairbanks in interior Alaska, showing an influx of ravens in winter. Between 2010 and 2012, we documented the presence and absence of ravens at a permanent set of 30 suspected raven locations and 21 randomized locations within the city limits of Fairbanks. We used machine learning (RandomForests) and 12 spatial GIS datasets from the Fairbanks North Star Borough to accurately model-predict the relative occurrence of ravens during winter and summer in Fairbanks. Our research showed a positive correlation between raven occurrence and commercial and residential zones in both winter and summer, as well as an inverse geographic relationship between ravens and the waste transfer station in the study area in winter, and a direct correlation near restaurants in summer. These results emphasize the link that ravens have with commercial, anthropogenic food sources, and how Fairbanks and its subsidized, urban habitat may be shaping part of the wider sub-arctic biodiversity landscape.


Common raven Fairbanks Alaska Distribution model Machine learning Subsidized predator 



This project represents unfunded natural history work conducted by northern raven enthusiasts. A collaborative effort, this research was initiated during supermarket trips by FH between 2004 and 2006, and was continued from 2010 until 2012 as a graduate student project under the leadership of AB. We gratefully acknowledge the help of many volunteer observers and helpers in the Fairbanks and UAF community, including S. and J. Linke, H. Gundersen and family, R. Barry, as well as D. Holyoke of the UAF Student Chapter of The Wildlife Society (TWS) for spatial surveys, and for sharing sightings and details. This is EWHALE lab publication #116.

Supplementary material

300_2013_1376_MOESM1_ESM.docx (109 kb)
Online Resource 1 Year-round urban raven surveys in Fairbanks, Interior Alaska 2004–2006 (DOCX 109 kb)
300_2013_1376_MOESM2_ESM.docx (107 kb)
Online Resource 2 Spatial survey datasets of ravens in Fairbanks, Alaska 2010–2012 (DOCX 106 kb) (251 kb)
Online Resource 3 ESRI ArcGIS GRID data layer: Spatial prediction of relative index of occurrence (ROI) of ravens in Fairbanks, AK in winter (ZIP 251 kb) (252 kb)
Online Resource 4 ESRI ArcGIS GRID data layer: Spatial prediction of relative index of occurrence (ROI) of ravens in Fairbanks, AK in summer (ZIP 252 kb)


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • A. P. Baltensperger
    • 1
  • T. C. Mullet
    • 1
  • M. S. Schmid
    • 2
  • G. R. W. Humphries
    • 3
  • L. Kövér
    • 4
  • F. Huettmann
    • 1
  1. 1.EWHALE Lab, Department of Biology and WildlifeUniversity of Alaska FairbanksFairbanksUSA
  2. 2.Takuvik Joint International Laboratory, Département de BiologieUniversité LavalQuebec CityCanada
  3. 3.Department of ZoologyUniversity of OtagoDunedinNew Zealand
  4. 4.Department of Nature Conservation Zoology and Game ManagementUniversity of DebrecenDebrecenHungary

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