Raptor Population Index

Regional Population Trend Summaries - 2011


Only sites with more than 10 years of hourly data available in HawkCount.org were analyzed. Trends are shown only for species consistently recorded at a watch site. Data are presented in two manners, “long-term” which represents the extent of hourly data available in HawkCount.org (see trend graphs), and “recent 10-years” representing the trend for the period 2001 to 2010 (displayed on trend map).


Black Vulture (Coragyps atratus)


Eastern: Black Vultures continue to expand their range north in eastern North America leading to increasing counts at many watch sites. Of the 9 eastern sites analyzed, Black Vultures increased significantly at 8 sites over the long-term (88%). Recent ten-year trends (2001 to 2010) were predominantly nonsignificant although one spring site showed a significant increase, Fort Smallwood, MD. Overall, it appears range expansion may have slowed with only some areas showing continued increases.


Central: Black Vultures are not regularly reported at the Central region watch sites.


Western: Insufficient data for analysis.


Gulf Coast: Population indices showed inconclusive trend data for Black Vultures with a nonsignificant trend measured at Corpus Christi, TX.



Turkey Vulture (Cathartes aura)


Eastern: Northward range expansion continues for the Turkey Vulture throughout the east. Significant increases in Turkey Vultures were recorded at 9 of the 13 eastern watch sites analyzed. Increases were particularly notable at northern sites such as Eagle Crossing, QC and Franklin Mountain, NY. A significant decline was observed in the recent decade at Cape May, NJ but was not detected in the previous RPI analysis (Farmer et al. 2008). It may represent a recent change in migration tendency or short-stopping, but further research is needed.


Central: Of the five central sites, all showed an increase in Turkey Vultures, consistent with the northward range expansion pattern observed in the east.


Western: Significant long-term increases were shown for Chelan Ridge, WA (since 1998) and Goshute Mountains (since 1983). Turkey Vultures increased primarily from the 1980s through the late 1990s for these sites, whereas other watch sites reported nonsignificant trends (Farmer et al. 2008). At Manzano Mountains, NM, the upward trend was interrupted at the turn of the millennium and has stabilized in recent years. Bonnie Butte, OR, reported nonsignificant increases since 1994, stabilizing during the last ten years. Drought conditions starting in 1999 may have played a role in the stabilization or decline observed in the recent decade.


Gulf Coast: Migration counts of Turkey Vultures near the Gulf Coast in Texas (Corpus Christi) showed stable trends but large fluctuations in counts between years.



Osprey (Pandion haliaetus)


Eastern: Two of the 13 eastern sites analyzed displayed a significant increase of Osprey over the long-term whereas the majority of sites showed nonsignificant declines or stable numbers. In recent years, some sites had significant declines in numbers, most notably Cape May, NJ. These trends warrant note as Osprey are more abundant at Cape May compared to most eastern sites. Localized population declines or changes in migration patterns may be occurring in coastal populations. Greater understanding of Osprey migration ecology may assist in interpreting these trends.


Central: Osprey in the central region rebounded from prior lows through the 1990s into the recent decade (Farmer et al. 2008). One site reported a long-term significant increase while other central region watchsites showed stable numbers over the long-term. In contrast, from 2001 through 2010, two sites show significant declines in Osprey, Hawk Ridge, MN, and Lake Erie Metro Park, MI. It appears that long-term population gains have leveled off in the recent decade (Farmer et al. 2008) and the RPI analyses suggest some regional declines could be occurring.


Western: Similar to the east, Osprey showed a steady post-DDT era increase throughout the west, however in the late 1990s and early 2000s the upward trend became more moderate or turned negative at several sites perhaps as a result of the recent drought in western North America (Farmer et al. 2008). Trend analyses over the last ten years revealed significant declines at Chelan Ridge, WA, and the Goshute Mountains, NV. For the latter, the recent decrease reverses a long upward trend from the 1980s. Trends at other western sites included nonsignificant declines at Manzano Mountains, NM, and Bonney Butte, OR, and a nonsignificant increase at Bridger Mountains, MT, however sample sizes are small at these sites.


Gulf Coast: Trends for Ospreys counted at Corpus Christi, TX, remained significantly positive during the last ten years continuing a pattern seen since the inception of the site. See Farmer et al. (2008) for discussion of trends at other Gulf sites.



Swallow-tailed Kite (Elanoides forficatus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: Swallow-tailed Kites increased over the long-term at Corpus Christi, TX, the only site reporting sufficient numbers for analysis.



White-tailed Kite (Elanus leucurus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: White-tailed Kites showed stable numbers at Corpus Christi, TX, with indications of a significant increase in numbers during the last decade of data collection.




Mississippi Kite (Ictinia mississippiensis)


Eastern: Two sites reported sufficient sightings of Mississippi Kites for analysis, Pilgrim Heights, MA and Fort Smallwood, MD. However at both sites, the trends were nonsignificant.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: Mississippi Kites increased over the long-term at Corpus Christi, TX, the only site reporting sufficient numbers for analysis. See Farmer et al. (2008) for discussion of trends at other Gulf sites.



Bald Eagle (Haliaeetus leucocephalus)


Eastern: Bald Eagles showed a strong increase during the 1980s and 1990s across the region. Significant increases were recorded at 12 of 13 eastern sites over the long-term and many sites show increases into the recent decade as well (e.g., Fort Smallwood, MD). Bald Eagle numbers may be stabilizing in some areas as some watch sites report no trend for the recent decade (e.g., Cape May, NJ).


Central: Central sites also showed increasing Bald Eagle numbers in the RPI long-term trend analyses (e.g., Hawk Ridge, MN). These trends are consistent with the widespread increase in Bald Eagle populations documented by RPI analyses in 2008 (Farmer et al. 2008). Similar to the eastern regional trends, analyses of the recent decade of data from central sites, suggests the increase is slowing and some populations may be stabilizing.


Western: Bald Eagle populations were relatively stable in the west based on previous analyses, however low count numbers and the challenges associated with covering their later migration season limited our ability to examine trends (Farmer et al. 2008). Current analyses for western watch sites showed stable numbers at Chelan Ridge, WA, Bonney Butte, OR, Bridger Mountains, MT, and the Manzano Mountains, NM using fall migration data. Near significant declines were seen at Sandia Mountains, NM, during the past 25 years with a significant decline during the last ten years. The Goshute Mountains, NV, watchsite also reported near significant declines, but only for the last decade. Overall, low samples size of eagles at these sites warrents caution when examining trends and we suggest use of breeding and winter surveys to help clarify these western trajectories.


Gulf Coast: Bald Eagle populations migrating along the Gulf flyway appeared to be increasing based on data from Corpus Christi, TX.




Northern Harrier (Circus cyaneus)


Eastern: Trends are mixed across the region with many sites reporting nonsignificant or stable patterns for this species. Although Eagle Crossing, QC showed significant increases in Northern Harrier since the 1980s, some eastern sites report significant long-term declines (e.g., Franklin Mountain, NY, Montclair Hawkwatch, NJ, Hawk Mountain, PA, Lighthouse Point, CT, and Fort Smallwood, MD). Some sites indicate a continued decline into the last decade as well. While declines in eastern populations are evident within the United States, it is unclear if changes in migration tendencies or short-stopping may be contributing to declines observed. Recent 10-year trends show nonsignificant declines for a few sites and further research or additional northern watch sites added to the network could help clarify the status of this species.


Central: Harrier trends remain mixed for central sites, with most showing no significant change for the long-term or recent decade (e.g., Hawk Ridge, MN, and Holiday Beach, ON). Whitefish Point, MI, shows a significant increase in the last ten years. Overall, harriers appear variable but stable through the region with some localized declines or possible changes in migration pattern occurring. As more south-central sites are added to the network we may gain a clearer picture of this broad front migrant’s status south of the Great Lakes region.


Western: After initial increases across the American West throughout the 1980s and 1990s, Northern Harrier populations have markedly decreased in the region, possibly in connection with drought conditions (Farmer et al. 2008). Near significant declines at watch sites in the Pacific Northwest on Chelan Ridge, WA, and Bonney Butte, OR, starting in the mid-1990s have been tempered during the last ten years. Previously significant declines at Goshute Mountains, NV, and Manzano Mountains, NM, that commenced around the turn of the millennium have been reduced in strength in the recent decade. Goshutes showed nonsignificant patterns for the recent ten years, whereas Manzanos Mountains had a near significant increase. Other western watch sites reported nonsignificant trends for the species. Future drought events and possible changes in migration patterns should be evaluated to clarify Northern Harrier population trends.


Gulf Coast: Nonsignificant positive trends for Northern Harriers were witnessed during fall counts at Corpus Christi , TX.



Sharp-shinned Hawk (Accipiter striatus)


Eastern: Sharp-shinned Hawk population trends varied among sites as six of the 13 eastern sites recorded significant decreases and many showed no significant pattern. For several sites, the RPI analyses revealed long-term declines in counts (e.g., Cape May, Montclair and Picatinny Peak, NJ, Lighthouse Point, CT, and Fort Smallwood, MD). Lighthouse Point showed steep declines in the recent decade as well. The remainder of eastern watch sites analyzed by RPI showed nonsignificant changes in the recent decade. Farmer et al. (2008) noted that long-term declines could represent short-stopping by mid-Atlantic and New England populations but may indicate population declines for northern populations. Mid-Atlantic and southern New England populations were stable or increasing according to Christmas Bird Count reports and recent trend analyses (Farmer et al. 2008). An increase in spruce budworm in parts of Quebec since 2006 may explain a localized upswing in this songbird specialist noted at Waggoner’s Gap, PA, in recent years. A better understanding of migration geography and ecology in this species and more sites reporting hourly counts to HawkCount.org will help clarify trends in the future.


Central: Three of the five sites showed significant declines over the long-term (Hawk Ridge, MN, Holiday Beach and Grimsby, ON, whereas the other watch sites in the region displayed nonsignificant patterns. For the period 2001 to 2010, Lake Erie Metropark, MI, also showed a significant decline whereas other sites displayed nonsignificant patterns of change. Central region Sharp-shinned Hawk populations appear to be stable in recent years although some populations may be declining or changing migration geography along the Great Lakes. Further data from central sites for recent years may help clarify patterns.


Western: Past analyses of Sharp-shinned Hawk populations in western North America have generally been stable until the late 1990s when declines were observed at Chelan Ridge, WA, the Goshute Mountains, NV, the Wellsville Mountains, UT, and at Grand Canyon (Lipan Point), AZ (Farmer et al. 2008). This recent downward trend faded and trend analyses for the last ten years showed nonsignificant declines for western watch sites. However, continuing longterm migration monitoring throughout the American West is important to ensure the detection of further downturns or significant declines at more severe rates.


Gulf Coast: Count data from the coastal site at Corpus Christi, TX, showed a near significant population increase for Sharp-shinned Hawks. For further discussion see Farmer et al. (2008).




Cooper’s Hawk (Accipiter cooperii)


Eastern: Of the 13 eastern sites analyzed, six sites displayed significant increases in Cooper’s Hawks over the long-term and two sites showed significant declines. In the recent decade, Lighthouse Point, CT also recorded significant increases in Cooper’s Hawks. Most remaining count sites show no change for this species in recent years. Trends suggest that increases reported in Farmer et al. (2008) may be starting to stabilize in the mid-Atlantic region and that Cooper’s Hawks could be declining in their northern range. Continued increases particularly in the Piedmont and Atlantic coastal region may represent continued expansion of this species into eastern urban and suburban areas as this species has increasingly adapted to living in eastern cities and suburban neighborhoods.


Central: Of the five central sites, one exhibited a significant increase and one a significant decline over all years analyzed (Hawk Ridge, MN, and Grimsby, ON, respectively). Other sites showed no long-term pattern. There were no significant declines or increases in the recent decade. Long-term data analyses suggest that Cooper’s Hawks rebounded from the pesticide era from the 1970s through 1990s but more recently populations have stabilized. The recent RPI analyses also suggest this species may be decreasing in the northern part of its range. Whether this represents a stabilization period after a recent range expansion or more serious challenges for this highly adaptable bird is unclear.



Western: Cooper’s Hawk populations were among the raptors increasing in numbers throughout the 1980s and 1990s across their western distribution with an onset of declines when drought conditions became more severe at the turn of the millennium (Farmer et al. 2008). Significant declines followed in the early 2000s at Bridger Mountains, MT, the Goshute Mountains, NV, the Wellsvilles, UT, and at the Grand Canyon, AZ, but they have leveled in recent years according to the latest analyses. Data from the last ten years indicated nonsignificant declines at Bonney Butte, OR, Goshutes Mountains, NV, and the Manzanos Mountains, NM. During the same period, counts at the Bridger Mountains showed nonsignificant increases in Cooper’s Hawks and Chelan Ridge, WA, reported significant increases. Further monitoring in connection with climatic fluctuations and drought cycles will be necessary to fully understand their population status.


Gulf Coast: Significant increases for Cooper’s Hawks were detected at Corpus Christi, TX across all count years (since 1997). See Farmer et al. (2008) for further discussion of trends in this region.



Northern Goshawk (Accipiter gentilis)



The Northern Goshawk is considered a partial migrant as some proportion of their North American population migrates annually (Squires and Reynolds 1997). However some populations also undergo pronounced irruptions or invasions to the south when food supplies are scarce. These irruptions can be detected in some migration count datasets as periodic spikes in numbers, particularly at northern sites. Migration count trends should be interpreted with caution given this species' complex migration behavior.


Eastern: Ten of the 13 eastern sites analyzed monitor Northern Goshawks in sufficient numbers to detect trends. Of those, four sites show a significant decrease over the long-term, whereas one site (Mount Peter, NY) shows a significant decline since 2001. Two additional sites, Hawk Mountain and Waggoner’s Gap, PA, display near significant declines for recent years as well (p<0.10). Goshawks remain difficult to monitor using migration counts (see Farmer et al. 2008); however the decrease in sightings at eastern watch sites south of Canada warrants investigation. Further research is needed to clarify what these declining patterns represent.


Central: Northern Goshawk counts declined at Grimsby, ON since the 1980s, however the majority of central region hawk watches show nonsignificant patterns for this species. Grimsby also exhibits a significant decline in the recent decade. This trend may suggest central populations of this species have either declined or become less migratory. Further research may be warranted to examine health of goshawk populations in the central and eastern regions.


Western: Regional declines of Northern Goshawk populations in the western United States were observed since the 1980s. Negative trends continued regionally yet with marginal significance through the early 2000s (Farmer et al. 2008). Since 1992, the beginning of standardized counts at Bridger Mountains, MT, trends of Northern Goshawk populations have been declining at near significant rates. Although trends were still negative when analyzing the most recent ten years of count data, the downturn was not significant. Significant negative trends since the early 1980s were observed at Goshute Mountains, NV. However for the last ten years, analyses found nonsignificant trends for this watch site perhaps indicating a moderation of the previous population downturn. All other western sites showed nonsignificant trends with the exception of Chelan Ridge, WA, where counts declined. See Farmer et al. (2008) for further discussion of trends.


Gulf Coast: Insufficient records for analysis.





Harris’s Hawk (Parabuteo unicinctus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: The only site recording Harris’s Hawk in sufficient numbers for analysis, Corpus Christi, TX, reported nonsignificant trends.



Red-shouldered Hawk (Buteo lineatus)


Eastern: Thirteen of the eastern sites reporting sufficient hourly data to HawkCount tallied Red-shouldered Hawks and most showed no significant trends. One site, Montclair Hawkwatch, NJ, showed a significant increase in Red-shouldered Hawk over the long-term. In contrast, Hawk Mountain, PA showed a significant decrease along with Franklin Mountain, NY. In the recent decade, two sites in the central Appalachians of Pennsylvania show strong declines (Hawk Mountain and Waggoner’s Gap). RPI analyses appear to indicate an increase in counts of Red-shouldered Hawk in the Piedmont or Coastal Plain or the eastern part of the region and a parallel decrease in inland populations. Whether these represent regional populations shifts or a possible change in migration pathway remains a question. Further research on migration dynamics of this species and examination of Christmas Bird Counts and other surveys may be useful in understanding these patterns. See Farmer et al. (2008) for further details.


Central: All five of the watch sites in this region tallied this species. Of them, three sites showed significant decreases over the long-term (Hawk Ridge, MN, and Holiday Beach and Grimsby, ON) and one reported a significant increase (Whitefish Point, MI). No significant change was observed in the recent decade for any site. Although this may indicate that the monitored populations are stable, we believe that high inter-annual variability of counts renders trend detection challenging for this species. Additional sites with hourly count data in HawkCount should enhance our ability to monitor this species within this region. See Farmer et al. (2008) for further information.


Western: One site, Chelan Ridge, WA, reported nonsignificant trends for Red-shouldered Hawks, other sites did not record sufficient numbers for analysis.


Gulf Coast: Insufficient records for analysis.



Broad-winged Hawk (Buteo platypterus)


Eastern: Most eastern sites reported highly variable numbers of Broad-winged Hawks year to year, consistent with this species’ variable migration pattern. There were no significant increases in Broad-winged Hawks in recent years but two long-term sites, Hawk Mountain, PA, and Montclair, NJ, showed significant long-term decreases. Two other sites, Fort Smallwood, MD and Lighthouse Point, CT, showed near significant long-term declines (p<0.10) as well. Trends from the recent decade show stable numbers at most sites, with three additional sites showing an increase (Montclair, NJ, Franklin Mountain and Mount Peter in NY) and no sites showing declines. The reversal in trends from long-term declines to a recent upswing at several sites is encouraging and may speak to a rebound in eastern numbers. Shifts in migration geography also may have affected site trends in the east. See Farmer et al. (2008) for a full discussion of migration patterns.



Central: None of the five central sites showed a significant increase over the long-term. Trends for all sites in the recent decade remain variable but stable. These results are similar to those reported in the prior RPI analyses (Farmer et al. 2008), which noted “the Broad-winged Hawk appears to be stable or increasing in North America” although some regional declines could be occurring in the east. See Farmer et al. (2008) for more details.



Western: Broad-winged Hawk breeding populations have likely expanded into the western regions of North America since the 1980s (Farmer et al. 2008) and the upward trend continued until the late 1990s. This trend was confirmed across many western watch sites with particularly pronounced increases at the Goshute Mountains, NV, Bridger Mountains, MT, and at the Grand Canyon (Lipan Point), AZ. However, count numbers are fairly low at these sites and may be hard to interpret. During the last ten years, the upward trend moderated across the west and appeared to be nonsignificant at all western count sites. Broad-winged Hawk seems to be relatively stable across the west


Gulf Coast: Broad-winged Hawk population trends at Corpus Christi TX were negative, but not significant for the last ten years or since the mid-1990s. Further discussion of Broad-winged Hawk trends in the region can be found in Farmer et al. (2008).



Swainson’s Hawk (Buteo swainsoni)


Eastern: Only Cape May, NJ recorded Swainson’s Hawks in sufficient numbers to allow analysis. No significant trend was shown.


Central: Only two of the five central region sites detected Swainson’s Hawks in numbers sufficient for analysis. Both Lake Erie Metropark and Whitefish Point, MI showed nonsignificant increases although the numbers detected were small. Farmer et al. (2008) reported Swainson’s Hawks increased through 2004 rebounding from population lows experienced during 1980s as a result of pesticide kills on wintering areas.


Western: Populations of Swainson’s Hawks increased in the western United States during the 1980s and 1990s. A large increase in counts was observed at Goshute Mountains, NV, over the long-term. The increase may be attributed to a significant recovery after declines from detrimental pesticide use originating on wintering grounds in Argentina (Farmer et al. 2008). The trends were observed along both the Intermountain and Rocky Mountain flyways and were potentially limited regionally by drought conditions during the early 2000s (Farmer et al. 2008). In recent years (2000-2010), a nonsignificant increase persisted across the west. RPI analyses showed relative stability at Chelan Ridge, WA, a slight increase at the Goshute Mountains, NV, and a disproportionally high yet nonsignificant increase at the Manzano Mountains, NM. The discrepancy detected in New Mexico may be explained by the variable migration pattern observed in this species.


Gulf Coast: In the late 1990s, a significant increase in population numbers for Swainson’s Hawks along the Gulf of Mexico was observed in Corpus Christi, TX, but the increase slowed in the recent decade. A discussion of trends at other Gulf sites can be found in Farmer et al. (2008).



White-tailed Hawk (Buteo albicaudatus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: White-tailed Hawk increased significantly at Corpus Christi, TX over the long-term. This was the only site recording this species sufficiently for analysis.



Zone-tailed Hawk (Buteo albonotatus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Zone-tailed Hawks have maintained stable count numbers since the mid-1980s at the Sandia Mountains, New Mexico, a spring migration watch site. Additional monitoring sites are needed for this species.


Gulf Coast: Zone-tailed Hawks increased significantly at Corpus Christi, Texas during the period of monitoring. Further monitoring may reveal if this represents a range expansion for the species.



Red-tailed Hawk (Buteo jamaicensis)


Eastern: Migrating Red-tailed Hawk trends were variable among sites with two sites, Lighthouse Point in CT and Eagle Crossing in QC showing significant long-term increases and four sites showing long-term decreases (e.g., Hawk Mountain and Rose Tree Park in PA, Picatinny Peak and Montclair Hawkwatch in NJ). In the most recent decade, three sites showed significant declines, while two sites showed near significant declines (p<0.1), and most other sites show stable numbers. In contrast, Christmas Bird Counts during the same time period suggest stable or increasing numbers across the east (Farmer et al. 2008). The two analyses combined suggest that Red-tailed Hawks may be becoming less migratory or changing their migration behavior. See Farmer et al. (2008) for further discussion.


Central: Holiday Beach, ON was the only site reporting a long-term declining trend for central region Red-tailed Hawks. One site, Grimsby, ON showed an insignificant decline. A recent significant decline also was found at Hawk Ridge, MN. Similar to the eastern region, we suspect declines may represent decreasing migration tendency rather than a decline in populations as Christmas Bird Counts report stable numbers. However, further survey data could prove helpful in determining the status of northern Red-tailed Hawks. See Farmer et al. (2008) for more information.


Western: Red-tailed Hawks are among the most widespread Buteos in the west and appear secure throughout their range (Farmer et al. 2008). In contrast, recent analyses show possible regional declines in migration counts. Fall migration counts from the Manzano Mountains, NM, over the last 25 years did not reveal any significant trend, however when focused on the past ten years, a negative trend became apparent. Near significant negative population trends were also measured at Bonney Butte, OR, not only for the most recent ten years, but also since the inception of this migration monitoring site in 1994. The remainder of count locations reported nonsignificant trends for Red-tailed Hawks during both fall and spring migration counts in the western United States. Climate change may be reducing the migration tendencies, and analyses the USFWS Breeding Bird Survey and Audubon Society’s Christmas Bird Count may clarify the trend for this species.


Gulf Coast: Nonsignificant negative trends for Red-tailed Hawk populations were witnessed at Corpus Christi in TX.



Ferruginous Hawk (Buteo regalis)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Monitoring population trends for the Ferruginous Hawks from current western migration sites is limited given the low numbers encountered at ridge top sites. Only three western locations provided enough data for analyses and sample sizes are small. Bridger Mountains, MT, and Manzano Mountains, NM, showed nonsignificant increases over the past decade. However, for the Manzano site, Ferruginous Hawk population trends also showed a long-term decrease for all count years (since 1985). A significant decrease was observed at the Goshute Mountains, NV, in recent years, but the trend was nonsignificant for the long-term (since 1982). Ferruginous Hawk declines may be connected to habitat loss and changes in prey base across large parts of their distribution. See Farmer et al. (2008) for more information.


Gulf Coast: The coastal watch site in Corpus Christi, TX, had a significant increase in population counts during the last 10 years. However, the trends were nonsignificant since the inception of the project.



Rough-legged Hawk (Buteo lagopus)


Eastern: Two eastern sites showed significant declines in Rough-legged Hawks over the long-term, none showed significant increases. During the past decade, Eagle Crossing, QC, and Stone Mountain, PA, showed significant declines in Rough-legged Hawk counts whereas Hawk Mountain, PA, and Franklin Mountain, NY, reported nonsignificant declines. Other sites reporting showed no trends. Declines have also been observed in Christmas Bird Counts and are likely due to birds remaining farther north than in previous years (Farmer et al. 2008). Further research is needed to clarify the reasons for decreases in migrant and wintering birds.


Central
: Two of five sites analyzed by RPI showed changes in Rough-legged Hawks. Holiday Beach, ON, showed significant decline in recent years and Hawk Ridge, MN, showed a nonsignificant decline. As noted above, declines may represent decreases in breeding population or changes in migration extent. Christmas Bird Count analyses suggest birds are not migrating as far as prior years (Farmer et al. 2008).


Western: Count data for Rough-legged Hawk are difficult to obtain in the west due to their passage in late fall and early winter when western count operations are often limited by winter-like weather (Farmer et al. 2008). However, migration counts at the watch sites at Chelan Ridge, WA, Bonney Butte, OR, Bridger Mountains, MT, and the Goshute Mountains, NV, indicated nonsignificant decreases for Rough-legged Hawk populations over the last ten years as well as over the long-term. Due to seasonal limitations for migration monitoring of Rough-legged Hawks especially on mountain ridges, surveys throughout their wintering ranges may provide a more comprehensive perspective on population trends for the species.


Gulf Coast: Insufficient data for analysis.



Golden Eagle (Aquila chrysaetos)


Eastern: Of the 11 sites reporting sufficient numbers of Golden Eagles for analysis, five sites showed significant long-term increases and six showed no significant change. In the last 10 years, most eastern sites display stable numbers of this species although Cape May, NJ showed recent significant declines. The stable or declining numbers at watch sites in recent years suggest that eastern eagle increases may be stabilizing. See Farmer et al. (2008) for further discussion.


Central: Of the six central sites in the RPI analyses, four sites showed significant increases: Grimsby and Holiday Beach, ON, Hawk Ridge, MN, and Whitefish Point, MI. Stable numbers were observed for all central sites in the last decade mimicking patterns shown in the eastern region. See Farmer et al. 2008 for further discussion of eagle trends.


Western: Golden Eagle migration counts show declines at several western migration monitoring sites. While count indices were relatively stable throughout the late 1990s and early 2000s (Farmer et al. 2008), Golden Eagle counts have started to decrease in recent years at sites in the Pacific Northwest and the northern Rocky Mountains. Chelan Ridge, WA, Bonney Butte, OR, and Bridger Mountains, MT, all showed a significant downward trend during the last decade. For the latter two sites, the negative trends were significant for the long-term. Similar curves on population indices were shared by the monitoring sites at the Goshute Mountains, NV, and Manzano Mountains, NM, with an initial decline during the 1980s, a period of stabilization in the 1990s, followed by an apparent decline in recent years. However trends at the New Mexico site were less pronounced. Considering the relative longevity of the Goshutes, NV project, near significant declines were detected not only for the Golden Eagle population trends of the last ten years, but also during the 1980s. With increasing evidence of declines in Golden Eagle migration counts, particularly at interior ridge tops in recent years, further extensive monitoring and investigation of potential causes for population downturns are important. Some researchers suspect short-stopping or changes in migration behavior, possibly influenced by changing global climate, may be contributing to these patterns. Resident populations should be surveyed using other methods.


Gulf Coast: Corpus Christi recorded a nonsignificant increase in Golden Eagle counts in recent years. See Farmer et al. (2008) for further information.



Crested Caracara (Caracara cheriway)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Insufficient records for analysis.


Gulf Coast: Counts of Crested Caracara remained stable at the Corpus Christi, TX, watch site since the count started in 1997. Further monitoring sites are needed for this species.



American Kestrel (Falco sparverius)


Eastern: Of the 12 eastern sites reporting, only Eagle Crossing, QC, showed a significant increase in the American Kestrel. Eight sites showed significant declines over the long-term and two sites showed nonsignificant long-term decreases in migrating kestrels. From 2001 to 2010, only Picatinny Peak and Cape May, NJ show a continued significant decline while most sites showed nonsignificant or stable patterns. The trends in counts for this species continue to raise alarms as numbers remain lower than those recorded during the 1980s and 1990s and no population rebound is evident. One small positive note is the stability in counts since 2005 at many sites and over the long-term in Quebec. Despite these glimmers of hope, there is cause for conservation concern for this species across the region. For further discussion of kestrel conservation status see Farmer et al. (2008).


Central: Of the seven sites reporting, Hawk Ridge, MN reported a significant long-term increase in American Kestrels since the 1970s whereas Holiday Beach and Grimsby, ON, both showed significant long-term decreases. Whitefish Point, MI, displayed a nonsignificant increase while other sites showed no trend. From 2001 to 2010, two sites showed significant declines including Lake Erie Metropark, MI, and Holiday Beach, ON. Hawk Ridge also showed a nonsignificant recent decline (p<0.1). These analyses indicate that kestrels in the Great Lakes region may be undergoing recent declines that were not detected in past RPI analyses (Farmer et al. 2008). Conservation concern remains high for this species.


Western: Population trends for the American Kestrel across the west show decreasing or stable patterns in recent years. Using the recent RPI analyses, kestrel populations in the Pacific Northwest and the northern Rocky Mountains showed a significant long-term decline as represented by Chelan Ridge, WA, Bonney Butte, OR, and Bridger Mountains, MT, (see Farmer et al. 2008). However, during the past 10 years, count indices in this region remained relatively stable with negative trends lacking significance and some sites displaying possible increases in the last two years. Trend curves at count sites in Nevada and New Mexico indicate a different pattern altogether. Long-term data for kestrels from the Goshute Mountains, NV, between 1982 and today do not show any significant trends. Count indices climbed between 1982 and the late 1990s. After reaching a peak approximately ten years ago, the trends changed markedly with a population decrease through today. Count indices from the Manzano Mountains, NM, have been relatively steady from 1985 to the early 2000s, but trends over the last ten years indicate a significant decline in population numbers. Spring counts performed at Sandia Mountains, NM, showed an early increase in population numbers in the early years of the project and a nonsignificant decrease for the last 10 years. Indications of declines across the the kestrel range in combination with emerging evidence of factors potentially leading to reduced reproductive success warrant increased efforts in monitoring American Kestrel populations range-wide and identifying causes of the decline.


Gulf Coast: At the Corpus Christi site near the Gulf in Texas, American Kestrel counts have increased significantly since the count started in 1997. Other gulf site trends can be examined in Farmer et al. 2008.



Merlin (Falco columbarius)


Eastern: Of the 13 datasets analyzed, there were four significant long-term increases including Cape May and Montclair, NJ, Hawk Mountain, PA, and Mount Peter, NY. For the period 2001 through 2010, a nonsignificant increase was observed at Waggoner’s Gap, PA. All other eastern sites showed stable numbers in the recent decade. Patterns shown for this species suggest an increase since the 1990s although numbers may be stabilizing in recent years. For further discussion see Farmer et al. (2008)


Central: Hawk Ridge, MN, Whitefish Point, MI, and Holiday Beach, ON, showed significant increases in Merlin since the 1980s. None of the sites showed declining counts and most report stable counts since 2001. The recent RPI analyses support previous suggestions that Merlin population growth has slowed across both eastern and central regions. See Conservation Status Report for further discussion (Farmer et al. 2008).


Western: Merlin populations have shown increases at various locations throughout its western range. At the Goshute Mountains, NV, and the Manzano Mountains, NM, steady significant increases in counts occurred over the last three decades. Similarly, significant positive increases were seen during spring migration counts at Sandia Mountains in NM. Northern watch sites at Chelan Ridge, WA, Bonney Butte, OR, and Bridger Mountains, MT, also showed increases in count numbers, but at nonsignificant rates. Trend analyses over the last ten years revealed moderate increases or relative stability of count numbers across all watch sites in western mountain ranges.


Gulf Coast: Merlin counts from Corpus Christi, TX, indicated significant population increases along the Gulf flyway, particularly during the last decade. In light of climatic changes in temperate and boreal regions of the species distribution, continued monitoring of population trends remain important for this falcon.



Peregrine Falcon (Falco peregrinus)


Eastern: Peregrine Falcons significantly increased at six sites over the long-term with count data extending from 1970s and 1980s to present (Lighthouse Point, CT, Mount Peter, NY, Cape May, Montclair and Picatinny Peak, NJ, and Hawk Mountain, PA). In the recent decade, peregrines show significant increases at three sites, Fort Smallwood, MD, Picatinny Peak, NJ and Lighthouse Point, CT. Other long-term sites show a stable trend in counts during recent years. For further discussion of trends see Farmer et al. (2008).


Central: Four sites show significant increases in Peregrine Falcons since the 1970s (Hawk Ridge, MN, Whitefish Point, MI, Grimsby and Holiday Beach, ON). Trends from the recent decade showed stable numbers at all sites. Peregrine populations may be stabilizing after a long period of steady growth throughout eastern and central North America. For further information see Farmer et al. 2008.


Western: Steady increases or population stability was observed in previous analyses for the Peregrine Falcon in western North America (Farmer et al. 2008). Significant increases persisted for the Goshutes Mountains, NV, and the Manzano Mountains, NM, over the entire duration of the projects since the 1980s. In the last decade, watch sites across its range in the west reported relative stability for the species. Most sites indicated positive but nonsignificant increases during recent years. Continued efforts at migration sites for this quintessential migratory raptor species may indicate if the recovery from population declines in the 1960s and 1970s continues in the future.


Gulf Coast: Along the Gulf flyway, Corpus Christi, TX reported significant population increases during the last 14 years of fall counts. Trends from other gulf sites may be found in Farmer et al. 2008.



Prairie Falcon (Falco mexicanus)


Eastern: Insufficient records for analysis.


Central: Insufficient records for analysis.


Western: Populations of Prairie Falcons increased or remained stable throughout the 1980s and 1990s in western North America (Farmer et al. 2008). Declines were detected by RPI between 1995 and 2005 at the Goshute Mountains, NV, and the Manzano Mountains, NM. Recent analyses show evidence of population stability at most western watch sites. Count indices from the Goshutes showed nonsignificant declines for the most recent ten years of data. Significant and relatively steep declines persisted at the Manzanos along the Rocky Mountain flyway and warrant close attention for future analyses. In contrast, spring counts at the Sandia Mountains, NM, indicated nonsignificant increases in population indices for Prairie Falcons.


Gulf Coast: Counts for Prairie Falcons at Corpus Christi, TX, showed nonsignificant declines although numbers detected are small.





Citations: Farmer, C.J., L.J. Goodrich, E. Ruelas I., and J.P. Smith. 2008. Conservation Status of North America.s Birds of Prey. Pp. 303-420 in K.L. Bildstein, J.P. Smith, E. Ruelas I., and R.R. Veit (eds). State of North America.s Birds of Prey. Nuttall Ornithological Club and American Ornithologists. Union Series in Ornithology No. 3. Cambridge, Massachusetts, and Washington, D.C. [TP-07]


Squires, J.R. and R. T. Reynolds. 1997. Northern Goshawk (Accipiter gentilis). In: The Birds of North America, No. 298. (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists Union, Washington, D.C.



Authors and Reviewers: Julie Brown, Markus Mika, Laurie Goodrich, Steve Hoffman, Ernesto Ruelas Inzunza, David Hussell.