Animalia > Chordata > Aves > Accipitriformes > Accipitridae > Circus > Circus cyaneus

Circus cyaneus (Northern Harrier; Hen Harrier)

Synonyms: Falco cyaneus (homotypic)
Language: French; Spanish


Circus cyaneus cyaneus (Eurasian marsh hawk)
Circus cyaneus hudsonius (American marsh hawk) (Attributes)

EDGE Analysis

Uniqueness Scale: Similiar (0) 
 Unique (100)
Uniqueness & Vulnerability Scale: Similiar & Secure (0) 
 Unique & Vulnerable (100)
ED Score: 5.21795
EDGE Score: 1.82744


Adult Weight [1]  436 grams
Birth Weight [3]  24 grams
Female Weight [5]  1.153 lbs (523 g)
Male Weight [5]  346 grams
Weight Dimorphism [5]  51.2 %
Breeding Habitat [2]  Temperate grasslands, Freshwater marshes, Coastal saltmarshes, Agricultural
Wintering Geography [2]  Widespread U.S./Mexico
Wintering Habitat [2]  Temperate grasslands, Coastal saltmarshes, Agricultural
Diet [4]  Carnivore (Invertebrates), Carnivore (Vertebrates)
Diet - Ectothermic [4]  10 %
Diet - Endothermic [4]  70 %
Diet - Invertibrates [4]  10 %
Diet - Scavenger [4]  10 %
Forages - Ground [4]  100 %
Clutch Size [6]  4
Clutches / Year [3]  1
Fledging [5]  36 days
Global Population (2017 est.) [2]  1,600,000
Incubation [3]  31 days
Mating Display [7]  Non-acrobatic aerial display
Maximum Longevity [3]  17 years
Raptor Research Conservation Priority [8]  155
Snout to Vent Length [5]  18 inches (46 cm)
Speed [9]  20.356 MPH (9.1 m/s)
Wing Span [9]  3.608 feet (1.1 m)
Female Maturity [3]  1 year
Male Maturity [3]  1 year


Protected Areas

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Important Bird Areas

Biodiversity Hotspots

Prey / Diet

Prey / Diet Overlap


Aquila chrysaetos (Golden Eagle)[12]
Haliaeetus leucocephalus (Bald Eagle)[12]


Range Map

External References


Attributes / relations provided by
1Storchová, Lenka; Hořák, David (2018), Data from: Life-history characteristics of European birds, Dryad, Dataset,
2Partners in Flight Avian Conservation Assessment Database, version 2017. Accessed on January 2018.
3de Magalhaes, J. P., and Costa, J. (2009) A database of vertebrate longevity records and their relation to other life-history traits. Journal of Evolutionary Biology 22(8):1770-1774
4Hamish Wilman, Jonathan Belmaker, Jennifer Simpson, Carolina de la Rosa, Marcelo M. Rivadeneira, and Walter Jetz. 2014. EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology 95:2027
5Nathan P. Myhrvold, Elita Baldridge, Benjamin Chan, Dhileep Sivam, Daniel L. Freeman, and S. K. Morgan Ernest. 2015. An amniote life-history database to perform comparative analyses with birds, mammals, and reptiles. Ecology 96:3109
6Jetz W, Sekercioglu CH, Böhning-Gaese K (2008) The Worldwide Variation in Avian Clutch Size across Species and Space PLoS Biol 6(12): e303. doi:10.1371/journal.pbio.0060303
7Terje Lislevand, Jordi Figuerola, and Tamás Székely. 2007. Avian body sizes in relation to fecundity, mating system, display behavior, and resource sharing. Ecology 88:1605
8Buechley ER, Santangeli A, Girardello M, et al. Global raptor research and conservation priorities: Tropical raptors fall prey to knowledge gaps. Divers Distrib. 2019;25:856–869.
9Alerstam T, Rosén M, Bäckman J, Ericson PGP, Hellgren O (2007) Flight Speeds among Bird Species: Allometric and Phylogenetic Effects. PLoS Biol 5(8): e197. doi:10.1371/journal.pbio.0050197
10Ecology of Commanster
11SPECIES ASSESSMENT FOR BAIRD’S SPARROW (AMMODRAMUS BAIRDII) IN WYOMING, ROBERT LUCE AND DOUG KEINATH, United States Department of the Interior, Bureau of Land Management, December 2003
12Jorrit H. Poelen, James D. Simons and Chris J. Mungall. (2014). Global Biotic Interactions: An open infrastructure to share and analyze species-interaction datasets. Ecological Informatics.
13Cirtwill, Alyssa R.; Eklöf, Anna (2018), Data from: Feeding environment and other traits shape species' roles in marine food webs, Dataset,
14SPECIES ASSESSMENT FOR PYGMY RABBIT (BRACHYLAGUS IDAHOENSIS) IN WYOMING, DOUGLAS A. KEINATH AND MATTHEW MCGEE, United States Department of the Interior Bureau of Land Management Wyoming State Office Cheyenne, Wyoming (2004)
15Lafferty, K. D., R. F. Hechinger, J. C. Shaw, K. L. Whitney and A. M. Kuris (in press) Food webs and parasites in a salt marsh ecosystem. In Disease ecology: community structure and pathogen dynamics (eds S. Collinge and C. Ray). Oxford University Press, Oxford.
16Snowy Plover (Kentish Plover) Charadrius alexandrinus, K. Boula, 1996, U.S. Forest Service
17The Sagebrush Sea by Cornell Lab of Ornithology
18The Breeding Ecology of Least Bitterns (Ixobrychus exilis) at Agassiz and Mingo National Wildlife Refuges, Karen Elizabeth Arnold, Thesis for Master of Science Major in Wildlife and Fisheries South Dakota State University 2005
19Microtus breweri, Robert H. Tamarin and Thomas H. Kunz, MAMMALIAN SPECIES No. 45, pp. 1-3 (1974)
20Microtus californicus (Rodentia: Cricetidae), NICHOLE L. CUDWORTH AND JOHN L. KOPROWSKI, MAMMALIAN SPECIES 42(868):230–243 (2010)
21Microtus montanus, Wendy E. Sera and Cathleen N. Early, MAMMALIAN SPECIES No. 716, pp. 1–10 (2003)
22Microtus pinetorum, Michael J. Smolen, Mammalian Species No. 147, pp. 1-7 (1981)
23Comparative breeding biology of Hen Harrier and Montagu’s Harrier: an 8-year study in north-eastern France, A. MILLON, J.-L. BOURRIOUX, C. RIOLS & V. BRETAGNOLLE, Ibis (2002), 144, 94–105
24Exploring the Denali Food Web, ParkWise, National Park Service
25Neofiber alleni, Dale E. Birkenholz, MAMMALIAN SPECIES No. 15, pp. 1-4 (1972)
26Oryzomys palustris, James L. Wolfe, Mammalian Species No. 176, pp. 1-5 (1982)
27Scapanus latimanus, B. J. Verts and Leslie N. Carraway, MAMMALIAN SPECIES No. 666, pp. 1–7 (2001)
29Spermophilus brunneus, Eric Yensen and Paul W. Sherman, MAMMALIAN SPECIES No. 560, pp. 1-5 (1997)
30Spermophilus richardsonii, Gail R. Michener and James W. Koeppl, Mammalian Species No. 243, pp. 1-8, (1985)
31Gibson, D. I., Bray, R. A., & Harris, E. A. (Compilers) (2005). Host-Parasite Database of the Natural History Museum, London
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 Wildfinder Database
Biodiversity Hotspots provided by Critical Ecosystem Partnership Fund
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset accessed via on 2023-06-13; License: CC BY 4.0