Bald eagle research data-Bird Initiative: National Midwinter Bald Eagle Survey

The mission of the U. Fish and Wildlife Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. Since the bald eagle was listed under the Endangered Species Act, the number of nesting bald eagle pairs and productivity number of young fledged per nest have been monitored throughout the lower 48 states. This effort was a partnership of state and federal surveyors, and produced an excellent data set which was used to develop the population table, map and chart in the links below. Follow these links to see how bald eagle numbers have responded since DDT was banned and the Endangered Species Act was passed.

Bald eagle research data

Bald eagle research data

Bald eagle research data

Responses of wintering Bald Eagles Bald eagle research data boating activity. Not all routes are surveyed every year. Acknowledgments I would like to thank Ronald Wright, Dan Kunkle, Donald Kramer, Laurie Goodrich, and one anonymous reviewer for insight and help with revisions of this manuscript. As noted in the methods section, the passage time for each subpopulation can vary according to number of factors including breeding success, weather, and Bald eagle research data availability Buehler, Productivity rates were low and both nest abandonment and relocation rates were very high. Balf, M. Version Statistical analysis All statistical analysis was performed Medalist thermal underwear R version 3. Reliable Bald Eagle age classification data were collected in —,—, and

Drug bust pan am jfk. Associated Data

The female lays eggs, which usually hatch in late April and early May. Eagel, of the 28 nests rechecked, only 3 produced young. Explore This Park. Last Lever enlargement July 16, In the U. How can you help eagles? Click here to view the Virginia breeding bald eagle annual survey project Bald eagle research data. Among other actions, "take" includes disturbance of bald eagles. William D. Bryan Watts has Can lick herself the survey for 18 years. This mature bald eagle is ready to take flight. The second survey flights are conducted in late April through May to check occupied nests for productivity and to recheck occupied territories for breeding. This national Bald eagle research data is a year-round resident dats the park, and Bakd sight of one soaring over the open water adds to the park's beautiful scenery.

We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles Haliaeetusleucocephalus within the conterminous 48 United States from to

  • Voyageurs is one of the few national parks in the continental U.
  • The mission of the U.
  • Section Navigation Section Navigation.
  • The approved rule revisions became effective in June, , and eliminate the need for applicants to obtain both a state and federal permit for activities with the potential to take or disturb bald eagles or their nests.

Download Metadata. Didn't find what you're looking for? Suggest a dataset here. Metadata Updated: October 10, Restricted: This dataset can only be accessed or used under certain conditions. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.

Government Work. Access to this information by the public is very limited. Visit page. Brent Frakes.

Bryan Watts has conducted the survey for 18 years. Click here to view the Virginia breeding bald eagle annual survey project page. Last updated: July 30, Comply with campsite and Day use site closures, which may occur during the breeding season if a nest is within meters of a site. West, Suite Bloomington, MN Characteristics The bald eagle is the largest raptor in the park, with a height of 35 inches and a lengthy wingspan of six to eight feet. The approved rule revisions became effective in June, , and eliminate the need for applicants to obtain both a state and federal permit for activities with the potential to take or disturb bald eagles or their nests.

Bald eagle research data

Bald eagle research data. Laws that Protect the Bald Eagle

The taxonomic family that includes bald eagles gained protection by the Migratory Bird Treaty Act in when the United States and Mexico agreed to a supplement to the migratory bird convention they first signed in The Migratory Bird Treaty Act is the law that implements treaties for the protection of shared migratory bird resources signed by the United States with Canada, Japan, Mexico and Russia.

William D. Ruckelshaus, Administrator of the Environmental Protection Agency, issued an order canceling nearly all remaining Federal registrations of DDT products. In the U. Federal Register Proposed Rule: reopening of public comment period with new information. West, Suite Bloomington, MN The bald eagle, our national bird and a symbol of the United States, is a conservation success story.

Today, Florida, has one of the densest concentrations of nesting bald eagles in the lower 48 states. While no longer listed under the U. Endangered Species Act or the Florida Endangered and Threatened Species rules, bald eagles remain protected by both the state eagle rule 68A This plan replaces the Bald Eagle Management Plan.

A non-regulatory conservation plan, the Species Action Plan outlines actions necessary to continue to maintain a stable or increasing population of bald eagles in Florida. The Species Action Plan will be reviewed at 7 year intervals, and progress towards actions will be updated on the FWC eagle webpages and through annual reports.

The U.

Midwinter Bald Eagle Survey - SciStarter

We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles Haliaeetusleucocephalus within the conterminous 48 United States from to Using hierarchical mixed model methods, we report trends in counts from 11, surveys along routes in 44 states.

Nationwide Bald Eagle counts increased 0. After accounting for potential biases resulting from temporal and regional differences in surveys, we believe trends reflect post-DDT recovery and subsequent early effects of density-dependent population regulation.

The winter population of Bald Eagles in the contiguous 48 states includes migrants from Canada and Alaska, as well as migratory and nonmigratory breeding eagles at mid-latitudes e.

In , when Bald Eagle populations were beginning to recover after the ban on use of DDT in Grier , the National Wildlife Federation NWF initiated nationwide coordinated counts in an effort to document their populations changes. Initial NWF survey objectives were to establish an index to the total wintering Bald Eagle population in the contiguous 48 states, to determine eagle distribution during a standardized survey period, and to identify previously unrecognized areas of important winter habitat Pramstaller Since that time, every January, several hundred individuals have counted eagles as part of a nationwide Midwinter Bald Eagle Survey.

The surveys have continued under the oversight of several federal agencies including the Bureau of Land Management , National Biological Survey , U. Geological Survey U.

Army Corps of Engineers U. The Bald Eagle was removed from the E. The E. Fish and Wildlife Service U. Continuing other established eagle monitoring efforts is also encouraged to document progress toward post-delisting goals for the Bald Eagle U.

In this report, we evaluate national trends in wintering Bald Eagle counts from by interpreting data collected in key regions during the period of eagle recovery. We evaluated reliability of data sets through careful data screening and modeling relevance of survey covariates on trends. Beginning in , NWF officials asked participants in each state to count eagles only along standard, non-overlapping routes to establish a basis for monitoring count trends. Standard survey routes were defined as clearly described areas where eagles had been previously observed.

NWF guidelines stipulated that standard surveys be conducted by the same number of experienced observers using the same method e. Steenhof et al. Methods used during winter Bald Eagle surveys from to and years thereafter were described by Steenhof et al. Methods included observers conducting surveys on standard routes during the first 2wk of January each year, usually on one of two target days. Coordinators from each state organized local counts, enlisted survey participants, and compiled data to eliminate duplicate sightings and overlapping routes.

The size of areas surveyed range from single fixed points to km survey routes. Survey methods from differed from those reported by Steenhof et al. Due to weather and staffing limitations, not all standard routes were surveyed every year. Twenty-five states identified and began surveying standard routes in ; other states did not begin standard surveys until the mids. Some states stopped participating in the count in the late s and early s Michigan and Virginia, respectively and some states started counting eagles annually after Mississippi, Ohio, West Virginia and Wyoming.

The number of states participating each year has ranged from , and the number of standard survey routes per state ranged from Data screening, classification, and evaluation closely followed Steenhof et al.

At least 4 yr of data were needed forestimating trends Steenhof et al. Because counts were conducted only once annually, we assumed that detectability on each route remained consistent over time, depending on the survey mode. Ground surveys were modeled separately from water surveys as separate and distinct routes to account for potential differences in detectability.

We did not consider weather conditions e. We fit a hierarchical mixed model to estimate trends using the logged counts Steenhof et al. Route sizes, regions, concentration area, and year were modeled as fixed effects, with route modeled as the random effect.

To facilitate comparison with the prior analyses Steenhof et. Also known as a random coefficients regression model, the structure allows covariance between random slope and intercept terms to account for within-route variation.

We assumed this within-route variation was the same for all routes, and that routes were independent of each other. We examinedresidual plots to ensure the appropriateness of this model. We assessed the sensitivity to changes in routes used between the analysis and the current analysis using influence diagnostics Cook's Distance on fixed effects and covariance parameters, and restricted likelihood distance; West et al. We used the final model to estimate total, regional Northeast, Northwest, Southeast, Southwest , and state-level trends in midwinter eagle counts over the 25yr of the survey.

We adjusted the P -values for each estimate using a Bonferroni step-down procedure Holm All analyses were conducted in SAS version 9. Our analysis of data from was based on , observations of wintering eagles during 11, surveys along routes in 44 states Table 1.

Our analysis incorporated 94routes new since 70 in the Northwest, 8 in the Southeast, and 16 in the Southwest but surveys were apparently not conducted on routes used in the analysis 13 in the Northeast, 14 in the Northwest, 32 in the Southeast, and 54 in the Southwest. Notably, Wyoming began participating in the survey in 64 routes , and Michigan 3 routes and Virginia 4 routes did not provide counts after New Mexico only provided information on 1 route down from 54 routes last analysis period.

When the model was re-run omitting all newly included routes, there was no material change and by visual inspection we concluded there was no meaningful difference in regional or national estimates. The final model retained the three-way interaction of region, route size, and year, but concentration area did not interact with any other model terms Table 2.

Number of survey routes and surveys used in the analysis, with estimated trends in the eagles counted, midwinter, by state. Significance of fixed effects and estimated covariance in the hierarchical mixed model used to estimate trends in midwinter counts of Bald Eagles, a.

Counts of wintering Bald Eagles increased nationwide at an estimated rate of 0. Regional trends were highest in the Northeast 3. Counts in the Southwest decreased significantly by Model-based trend estimates revealed statistically significant declining trends in Arizona, Colorado, Nebraska, and Texas Table 1.

We did not detect trends in counts increasing or decreasing for the remaining 28 states during Fig. Map of the conterminous United States with midwinter Bald Eagle count trends by state, Dark green and dark red represent states with significant positive and significant negative count trends, respectively.

Light green, light red and white represent states with non-significant positive, non-significant negative, and no change count trends, respectively e. Yellow represents states with no data. P -value adjusted for multiple testing using the Bonferroni step-down procedure. Counts of adult Bald Eagles increased nationwide, at an estimated rate of 0. Counts of adult and immature Bald Eagles, respectively, increased significantly in 12 states: Idaho 1. As in the first 15yr, increasing count trends were greatest in the Northeast; however, estimated rate of increase was lower than that calculated for Table 4.

Eagle counts from the Westand Southeast were stable during the first 20yr, but with the addition of the last 5yr of data the trend in the Southwest now indicates a significant decrease in eagle counts Table 4. Percent change per yr in the midwinter Bald Eagle count by region for yr, yr and yr analysis periods. The yr analysis continued to show overall increasing count trends; however, our yr estimate of trend in the North and East shows a rate of increase that was lower than the previous analyses.

The increase in counts of wintering Bald Eagles throughout the contiguous U. By the mids, when the Midwinter Bald Eagle Survey was initiated, increasing Bald Eagle nesting was documented in a variety of study areas e. Recent analyses of nationwide counts from the Breeding Bird Survey Sauer et al. Bart unpubl. Increases in counts during winter also have been documented independently of the Midwinter Bald Eagle Survey Fielder and Starkey , Zwank et al. Bald Eagle migration patterns are complex and dependent on age immature or adult , location of breeding, local climate, and food availability Buehler , and likely have some influence on count trends.

For example, decreasing count trends in the south and increasing count trends in the north could reflect increased eagle breeding populations in Canadian provinces and Alaska, increased breeding among breeding eagles in northern latitudes in the contiguous U. Additionally, evidence that migration behavior may be changing, possibly due to climate change, has been documented for Bald Eagles Buskirk and several other raptors as well Rosenfield et al.

Slower rates of increase and approximately stable counts of nesting Bald Eagles and reproductive rates have been noted at breeding areas across the continent e. Stinson et al. Differences among counts from geographic areas probably reflect, in part, differences in regional population dynamics that, in turn, are affected by different environmental factors. Of particular interest is the yr tendency for declining winter counts from the Southwest region that became significant with the addition of the last 5yr of data, despite an increasing local breeding population in Arizona Allison et al.

Recently, Harvey et al. Additional monitoring and specific studies are needed to understand how climate change Cayan et al. Stabilization of eagle populations as they reach carrying capacity would be expected as a consequence of density-dependent population regulation due to limited resources.

For example, Bald Eagle nesting and wintering populations along the southern coast of British Columbia increased then stabilized. Elliott et al. The availability of food also influences the daily and seasonal use of areas by wintering Bald Eagles Stalmaster et al. Varying water levels can influence eagle foraging Hunt et al.

The presence of birds on an individual route on a single daycould vary from year to year depending on food availability and foraging behavior Stalmaster et al. As Steenhof et al. Second, survey routes were added and deleted during the last 5yr of the study with potential effects on trends.

For example, in the Northeast, 13 routes used in prior analyses were dropped: all of Michigan, and at least two in Iowa with fairly large trends in the last analysis. In the Southeast, all routes from Virginia were dropped, and in the Southwest, only one route from New Mexico continues to be counted. Similarly, for the other regions, where new routes were added since , the pattern was similar among periods.

The annual Midwinter Bald Eagle Survey can be particularly important because it provides information about Bald Eagle distribution, local abundance, and age class, and thus, informs the post-delisting national, regional and local status of the Bald Eagle.

We suggest that careful consideration be given to continuing this winter survey for Bald Eagles in the contiguous U. Continued monitoring will benefit risk assessment from existing factors such as contaminants Bowerman et al.

Without their cooperation and commitment to Bald Eagle conservation and long-term data collection, these records would not have been possible.

Kirk Bates, Lynda Leppert, and Leah Dunn also provided important data management and quality control services.

Bald eagle research data