DOCSLIB.ORG

Construction and Analysis of a Giant Gartersnake (Thamnophis Gigas) Population Projection Model

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Construction and Analysis of a Giant Gartersnake (Thamnophis Gigas) Population Projection Model Prepared in cooperation with the California Department of Water Resources Construction and Analysis of a Giant Gartersnake (Thamnophis gigas) Population Projection Model Open-File Report 2017–1164 U.S. Department of the Interior U.S. Geological Survey Cover: Photograph showing an adult female giant gartersnake (Thamnophis gigas), Sacramento Valley, California, representing the importance of large adult female snakes for population persistence. Photograph by Alexandria M. Fulton, U.S. Geological Survey, May 10, 2017. Construction and Analysis of a Giant Gartersnake (Thamnophis gigas) Population Projection Model By Jonathan P. Rose, Julia S.M. Ersan, Glenn D. Wylie, Michael L. Casazza, and Brian J. Halstead Prepared in cooperation with the California Department of Water Resources Open-File Report 2017–1164 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior RYAN K. ZINKE, Secretary U.S. Geological Survey William H. Werkheiser, Deputy Director exercising the authority of the Director U.S. Geological Survey, Reston, Virginia: 2018 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit https://www.usgs.gov/ or call 1–888–ASK–USGS (1–888–275–8747). For an overview of USGS information products, including maps, imagery, and publications, visit https:/store.usgs.gov. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Rose, J.P., Ersan, J.S.M., Wylie, G.D., Casazza, M.L., and Halstead, B.J., 2018, Construction and analysis of a giant gartersnake (Thamnophis gigas) population projection model: U.S. Geological Survey Open-File Report 2017–1164, 98 p., https://doi.org/10.3133/ofr20171164. ISSN 2331-1258 (online) Acknowledgments We thank the California Department of Water Resources for supporting this project. We also thank the U.S. Fish and Wildlife Service and the Natomas Basin Conservancy for funding projects whose data were used in this report. We thank the Natomas Basin Conservancy, Colusa National Wildlife Refuge, Wildlands, Inc., and several cooperative landowners for access to the study sites. We also thank the giant gartersnake Technical Review Committee for providing feedback and guidance for this study, Julie Yee and Brian Prochazka for reviewing this report, and Tim Tinker and Elizabeth Gallegos for reviews of sections 1 and 2, respectively. We are grateful to Eric Hansen, Rick Scherer and Maxwell Joseph for sharing data and model results on giant gartersnake reproduction. Dr. Ray Wack of the University of California, Davis and the Sacramento Zoo conducted the X-rays and interpreted the number of embryos in each radiograph for the fecundity analysis. We thank Lisa Parker for administrative support. This study would not have been possible without the work of numerous biological technicians who collected field data on giant gartersnakes for the U.S. Geological Survey for many years. This work was performed under Institutional Animal Care and Use Committee protocol WERC-2014-01 and as stipulated in California Department of Fish and Wildlife Scientific Collecting Permit 10779 and U.S. Fish and Wildlife Service Recovery Permits TE- 020548-5 and TE-157216-2. iii This page left intentionally blank iv Contents Acknowledgments ................................................................................................................................................... iii Abstract .................................................................................................................................................................... 1 Background .............................................................................................................................................................. 1 Purpose and Scope ................................................................................................................................................. 3 Giant Gartersnake Biology ....................................................................................................................................... 3 Study Area ............................................................................................................................................................... 4 Goals and Objectives ............................................................................................................................................... 4 Section 1: Fitting a von Bertalanffy Growth Model for Giant Gartersnakes .............................................................. 5 Introduction ........................................................................................................................................................... 5 Methods ................................................................................................................................................................ 6 Data Collection ................................................................................................................................................. 6 Growth Analysis ............................................................................................................................................... 9 Results................................................................................................................................................................ 12 Discussion .......................................................................................................................................................... 17 Section 2: Reproductive Frequency and Size-Dependence of Fecundity in the Giant Gartersnake ....................... 19 Introduction ......................................................................................................................................................... 19 Methods .............................................................................................................................................................. 20 Data Collection ............................................................................................................................................... 20 Statistical Analysis ......................................................................................................................................... 23 Results................................................................................................................................................................ 24 Litter Size, Neonate Size, and Maternal Size ................................................................................................. 25 Annual Proportion of Gravid Females and Reproductive Frequency.............................................................. 29 Discussion .......................................................................................................................................................... 30 Section 3: Integrating Growth and Capture-Mark-Recapture Models to Estimate Size-Dependent Survival in Giant Gartersnakes. ....................................................................................................................... 33 Introduction ......................................................................................................................................................... 33 Methods .............................................................................................................................................................. 35 Data Collection ............................................................................................................................................... 35 Hierarchical Cormack-Jolly-Seber Model ....................................................................................................... 38 Environmental Covariates .............................................................................................................................. 39 Model Comparison and Model Averaging ...................................................................................................... 40 Results................................................................................................................................................................ 40 Capture Data Summary.................................................................................................................................. 40 CJS Survival Model ........................................................................................................................................ 41 Environmental Covariates of Survival............................................................................................................. 48 Discussion .......................................................................................................................................................... 50 Conclusions ........................................................................................................................................................ 54 v Section 4: Development and Elasticity Analysis of an Integral Projection Model for the
Load more

Recommended publications
  • Cfreptiles & Amphibians
    WWW.IRCF.ORG/REPTILESANDAMPHIBIANSJOURNALTABLE OF CONTENTS IRCF REPTILES & IRCFAMPHIBIANS REPTILES • VOL 15,& NAMPHIBIANSO 4 • DEC 2008 •189 20(4):166–171 • DEC 2013 IRCF REPTILES & AMPHIBIANS CONSERVATION AND NATURAL HISTORY TABLE OF CONTENTS FEATURE ARTICLES Differential. Chasing Bullsnakes (Pituophis catenifer sayiHabitat) in Wisconsin: Use by Common On the Road to Understanding the Ecology and Conservation of the Midwest’s Giant Serpent ...................... Joshua M. Kapfer 190 . The Shared History of Treeboas (Corallus grenadensis) and Humans on Grenada: A WatersnakesHypothetical Excursion ............................................................................................................................ (Nerodia sipedonRobert W. Henderson) 198 Lorin A.RESEARCH Neuman-Lee ARTICLES1,2, Andrew M. Durso1,2, Nicholas M. Kiriazis1,3, Melanie J. Olds1,4, and Stephen J. Mullin1 . The Texas Horned Lizard in Central and Western Texas ....................... Emily Henry, Jason Brewer, Krista Mougey, and Gad Perry 204 1Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois 61920, USA . The Knight Anole (Anolis equestris) in Florida 2 Present ............................................. address: DepartmentBrian of Biology,J. Camposano, Utah Kenneth State L. University, Krysko, Kevin Logan, M. Enge, Utah Ellen 84321,M. Donlan, USA and ([email protected]) Michael Granatosky 212 3Present address: School of Teacher Education and Leadership, Utah State University, Logan, Utah 84321, USA CONSERVATION4Present
    [Show full text]
  • Improved Conservation Plant Materials Released by NRCS and Cooperators Through December 2014
    Natural Resources Conservation Service Improved Conservation Plant Materials Released by Plant Materials Program NRCS and Cooperators through December 2014 Page intentionally left blank. Natural Resources Conservation Service Plant Materials Program Improved Conservation Plant Materials Released by NRCS and Cooperators Through December 2014 Norman A. Berg Plant Materials Center 8791 Beaver Dam Road Building 509, BARC-East Beltsville, Maryland 20705 U.S.A. Phone: (301) 504-8175 prepared by: Julie A. DePue Data Manager/Secretary [email protected] John M. Englert Plant Materials Program Leader [email protected] January 2015 Visit our Website: http://Plant-Materials.nrcs.usda.gov TABLE OF CONTENTS Topics Page Introduction ...........................................................................................................................................................1 Types of Plant Materials Releases ........................................................................................................................2 Sources of Plant Materials ....................................................................................................................................3 NRCS Conservation Plants Released in 2013 and 2014 .......................................................................................4 Complete Listing of Conservation Plants Released through December 2014 ......................................................6 Grasses ......................................................................................................................................................8
    [Show full text]
  • The Vascular Plants of Massachusetts
    The Vascular Plants of Massachusetts: The Vascular Plants of Massachusetts: A County Checklist • First Revision Melissa Dow Cullina, Bryan Connolly, Bruce Sorrie and Paul Somers Somers Bruce Sorrie and Paul Connolly, Bryan Cullina, Melissa Dow Revision • First A County Checklist Plants of Massachusetts: Vascular The A County Checklist First Revision Melissa Dow Cullina, Bryan Connolly, Bruce Sorrie and Paul Somers Massachusetts Natural Heritage & Endangered Species Program Massachusetts Division of Fisheries and Wildlife Natural Heritage & Endangered Species Program The Natural Heritage & Endangered Species Program (NHESP), part of the Massachusetts Division of Fisheries and Wildlife, is one of the programs forming the Natural Heritage network. NHESP is responsible for the conservation and protection of hundreds of species that are not hunted, fished, trapped, or commercially harvested in the state. The Program's highest priority is protecting the 176 species of vertebrate and invertebrate animals and 259 species of native plants that are officially listed as Endangered, Threatened or of Special Concern in Massachusetts. Endangered species conservation in Massachusetts depends on you! A major source of funding for the protection of rare and endangered species comes from voluntary donations on state income tax forms. Contributions go to the Natural Heritage & Endangered Species Fund, which provides a portion of the operating budget for the Natural Heritage & Endangered Species Program. NHESP protects rare species through biological inventory,
    [Show full text]
  • Progress Report for the San Joaquin Valley Giant Garter Snake
    PROGRESS REPORT: 2003 SAN JOAQUIN VALLEY GIANT GARTER SNAKE CONSERVATION PROJECT Prepared by: Todd Williams, Wildlife Biologist Veronica Wunderlich, Biological Science Technician U.S. Fish & Wildlife Service San Luis National Wildlife Refuge Complex Box 2176 Los Banos, CA 93635 INTRODUCTION & BACKGROUND: The giant garter snake, Thamnophis gigas (Rossman & Stewart 1987), was designated as a federally threatened species throughout its range in October 1993 and (USFWS 1993). Giant garter snakes are endemic to the Central Valley of California, and historically occurred throughout the San Joaquin and Sacramento Valleys (Hansen and Brode 1980). They are thought to have occurred as far north as Butte County and south to Kern County, within the boundaries of the foothills of the Coastal and Sierra Nevada ranges. The current range of the giant garter snake is confined to the Sacramento Valley and isolated portions of the San Joaquin Valley (USFWS 1999). The giant garter snake is primarily an aquatic species that feeds on small fishes, tadpoles, and frogs (Fitch 1941). Historically, prey items included thick-tailed chub (Gila crassicauda), Sacramento blackfish (Orthodox microlepidus), and the California red- legged frog (Rana aurora draytoni), all of which have been extirpated from the giant garter snake’s current range (Rossman et al 1996). The habitat requirements of giant garter snakes include wetland areas with sufficient emergent vegetation for cover, openings in the vegetation for basking, and access to rodent burrows for shelter and winter periods of reduced activity (USFWS 1993). Giant garter snakes tend to be absent from rivers that support populations of large predatory fish as well as watercourses that have sand, gravel or rocky substrates (Hansen 1980).
    [Show full text]
  • Thamnophis Sauritus (Eastern Ribbon Snake)
    Maine 2015 Wildlife Action Plan Revision Report Date: January 13, 2016 Thamnophis sauritus (Eastern Ribbon Snake) Priority 2 Species of Greatest Conservation Need (SGCN) Class: Reptilia (Reptiles) Order: Squamata (Lizards And Snakes) Family: Colubridae (Colubrids) General comments: Small wetland specialist; existing habitat regulations inadequate but new SVP protection a plus; both sub species listed together Species Conservation Range Maps for Eastern Ribbon Snake: Town Map: Thamnophis sauritus_Towns.pdf Subwatershed Map: Thamnophis sauritus_HUC12.pdf SGCN Priority Ranking - Designation Criteria: Risk of Extirpation: NA State Special Concern or NMFS Species of Concern: Thamnophis sauritus is listed as a species of Special Concern in Maine. Recent Significant Declines: NA Regional Endemic: NA High Regional Conservation Priority: Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Status: T, Last Examination: 11/1/2012, Change: No Change, Canada Occurence: NS Northeast Endangered Species and Wildlife Diversity Technical Committee: Risk: No, Data: Yes, Area: Yes, Spec: No, Warrant Listing: No, Total Categories with "Yes": 2 Northeast Partners In Amphibian and Reptile Conservation (NEPARC): Regional Responsibility:< 50 % US Distribution, Concern: >= 75% of States Listed in WAP High Climate Change Vulnerability: NA Understudied rare taxa: NA Historical: NA Culturally Significant: NA Habitats Assigned to Eastern Ribbon Snake: Formation Name Agricultural Macrogroup Name Agricultural Habitat System Name: Pasture-Hay Notes: secondary
    [Show full text]
  • Reptiles of Phil Hardberger Park
    ALAMO AREA MASTER NATURALISTS & PHIL HARDBERGER PARK CONSERVANCY REPTILES OF PHIL HARDBERGER PARK ROSEBELLY LIZARD→ REPTILE= Rosebelly Lizard (picture by author) TERRESTRIAL Fred Wills is the author of this piece. VERTEBRATE Animals with backbones (vertebrates) fall into several classes. We all recognize feathered birds and hairy mammals. But what is a reptile? An easy defini- tion of reptiles is that they are terrestrial, vertebrate animals with scales or plates covering the body. However, this definition simplifies their great diversity. WITH SCALES In Texas alone, there are four major groups of reptiles: lizards, snakes, turtles, and crocodilians (alligators). Hardberger Park is home to lizards, snakes, and turtles. OR PLATES Common lizards of the park include the Rosebelly Lizard, Texas Spiny Lizard, and Ground Skink. Common snakes of the park include the Texas Rat Snake, Rough Earth Snake, and Checkered Garter Snake. Can you name any other lizards and snakes found in the area? Hint: One lizard can change color, and PHP: one snake can produce sound. ROSEBELLY LIZARD Like many birds and mammals, reptiles are predators. Small ones like the Rosebelly Lizard and Rough Earth Snake eat invertebrate animals such as insects. TEXAS SPINY LIZARD Medium-sized snakes such as the Checkered Garter Snake often eat frogs. Larger snakes, including the Texas Rat Snake, typically eat small mammals and GROUND SKINK birds. TEXAS RAT SNAKE Where do reptiles live? The various species occupy almost all kinds of habitats, from dry prairie to moist woodland, and even wetlands and streams. Re- ROUGH EARTH SNAKE lated species often divide up the habitat through differing behaviors.
    [Show full text]
  • Lake Erie Watersnake (Nerodia Sipedon Insularum) in Canada
    PROPOSED Species at Risk Act Management Plan Series Adopted under Section 69 of SARA Management Plan for the Lake Erie Watersnake (Nerodia sipedon insularum) in Canada Lake Erie Watersnake 2019 Recommended citation: Environment and Climate Change Canada. 2019. Management Plan for the Lake Erie Watersnake (Nerodia sipedon insularum) in Canada [Proposed]. Species at Risk Act Management Plan Series. Environment and Climate Change Canada, Ottawa. 2 parts, 28 pp. + 20 pp. For copies of the management plan, or for additional information on species at risk, including the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) Status Reports, residence descriptions, action plans, and other related recovery documents, please visit the Species at Risk (SAR) Public Registry1. Cover illustration: © Gary Allen Également disponible en français sous le titre « Plan de gestion de la couleuvre d’eau du lac Érié (Nerodia sipedon insularum) au Canada [Proposition] » © Her Majesty the Queen in Right of Canada, represented by the Minister of Environment and Climate Change, 2019. All rights reserved. ISBN Catalogue no. Content (excluding the illustrations) may be used without permission, with appropriate credit to the source. 1 www.canada.ca/en/environment-climate-change/services/species-risk-public-registry.html MANAGEMENT PLAN FOR LAKE ERIE WATERSNAKE (Nerodia sipedon insularum) IN CANADA 2019 Under the Accord for the Protection of Species at Risk (1996), the federal, provincial, and territorial governments agreed to work together on legislation, programs, and policies to protect wildlife species at risk throughout Canada. In the spirit of cooperation of the Accord, the Government of Ontario has given permission to the Government of Canada to adopt the Blue Racer, Lake Erie Watersnake and Small-mouthed Salamander and Unisexual Ambystoma (Small- mouthed Salamander dependent population) – Ontario Government Response Statement (Part 2) under Section 69 of the Species at Risk Act (SARA).
    [Show full text]
  • Giant Garter Snake: the Role of Rice and Effects of Water Transfers
    Giant Garter Snake: The Role of Rice and Effects of Water Transfers Report of Point Blue Conservation Science May 2017 W. David Shuford Giant Garter Snake: The role of rice and effects of water transfers May 2017 Point Blue Conservation Science W. David Shuford Suggested Citation: Shuford, W. D. 2017. Giant Garter Snake: The role of rice and effects of water transfers. Report of Point Blue Conservation Science, 3820 Cypress Drive #11, Petaluma, CA 94954. Point Blue Contribution No. 2133. Point Blue Conservation Science – Point Blue’s 140 staff and seasonal scientists conserve birds, other wildlife and their ecosystems through scientific research and outreach. At the core of our work is ecosystem science, studying birds and other indicators of nature’s health. Visit Point Blue on the web www.pointblue.org. Main Points Effects on the federally and state threatened giant garter snake are a major concern under a long-term (10-year) plan to transfer water from sellers in the Sacramento Valley to users south of the Delta or in the San Francisco Bay Area. Water will be made available for transfer from cropland idling, crop shifting, groundwater substitution, reservoir release, and conservation. A maximum of 60,693 acres of rice land would be fallowed each year if the full amount of 565,614 acre feet of surface water is transferred annually. This level of idling potentially could have major impacts on this snake given the current importance of the rice landscape in the Sacramento Valley to the species’ continued survival. Giant garter snakes in the Sacramento Valley have a strong association with natural wetlands and aquatic agricultural habitats, particularly rice and associated water conveyances.
    [Show full text]
  • Expanded Description of a Chinese Endemic Snake Opisthotropis Cheni (Serpentes: Colubridae: Natricinae)
    Asian Herpetological Research 2010, 1(1): 57-60 DOI: 10.3724/SP.J.1245.2010.00057 Expanded Description of a Chinese Endemic Snake Opisthotropis cheni (Serpentes: Colubridae: Natricinae) LI Cao1, LIU Qin1 and GUO Peng 1, 2* 1 Department of Life Sciences and Food Engineering, Yibin University, Yibin 644000, Sichuan, China 2 Chendgu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China Abstract Based on seven newly-collected specimens, we provide an expanded description for the rare Chinese snake Opisthotropis cheni. The new specimens are consistent with the type series in scale counts and body dimensions. How- ever, two individuals lack yellow cross-bands that are apparent in the type specimens. A key to the ten Chinese species of Opisthotropis is provided. Keywords snake, Opisthotropis cheni, morphology, China 1. Introduction 070140, 071041, 071046-071050) (Table 1), collected from the Nanling National Nature Reserve in Ruyuan The genus Opisthotropis Gǘnther (1872) is comprised of County, Guangdong Province, China (Figure 1), were 17 currently recognized species, and is widely distributed morphologically examined in this work. The specimens in eastern, southern, and southeastern Asia (Uetz, 2010). were preserved in 8% formalin for initial fixation, and Members of this genus are all small aquatic snakes, later transferred to 75% ethanol. All specimens were de- mainly inhabiting rapidly flowing streams or small rivers. posited at Yibin University (YBU), Sichuan Province, Ten species of Opisthotropis occur in China (Zhao, China. 2006). Snout-vent length (SVL) and tail length (TL) were Zhao (1999) described Opisthotropis cheni based on measured using a meter ruler to the nearest millimeter, four specimens collected from Mt.
    [Show full text]
  • Giant Garter Snake Habitat Quantification Tool
    Giant Garter Snake Habitat Quantification Tool Part of the Multispecies Habitat Quantification Tool for the Central Valley Habitat Exchange Scientific Rationale and Methods Document, Version 5 Multispecies Habitat Quantification Tool: Giant Garter Snake Acknowledgements The development of the scientific approach for quantifying impacts and benefits to multiple species for use in the Central Valley Habitat Exchange (Exchange) would not have been possible without the input and guidance from a group of technical experts who worked to develop the contents of this tool. This included members of the following teams: Central Valley Habitat Exchange Project Coordinators John Cain (American Rivers) Daniel Kaiser (Environmental Defense Fund) Katie Riley (Environmental Incentives) Exchange Science Team Stefan Lorenzato (Department of Water Resources) Stacy Small-Lorenz (Environmental Defense Fund) Rene Henery (Trout Unlimited) Nat Seavy (Point Blue) Jacob Katz (CalTrout) Tool Developers Amy Merrill (Stillwater Sciences) Sara Gabrielson (Stillwater Sciences) Holly Burger (Stillwater Sciences) AJ Keith (Stillwater Sciences) Evan Patrick (Environmental Defense Fund) Kristen Boysen (Environmental Incentives) Giant Garter Snake TAC Brian Halstead (USGS) Laura Patterson (CDFW) Ron Melcer (formerly DWR; with Delta Stewardship Council as of February 2017) Chinook Salmon TAC Alison Collins (Metropolitan Water District) Brett Harvey (DWR) Brian Ellrott (NOAA/NMFS) Cesar Blanco (USFWS) Corey Phillis (Metropolitan Water District) Dave Vogel (Natural Resource
    [Show full text]
  • NJ Native Plants - USDA
    NJ Native Plants - USDA Scientific Name Common Name N/I Family Category National Wetland Indicator Status Thermopsis villosa Aaron's rod N Fabaceae Dicot Rubus depavitus Aberdeen dewberry N Rosaceae Dicot Artemisia absinthium absinthium I Asteraceae Dicot Aplectrum hyemale Adam and Eve N Orchidaceae Monocot FAC-, FACW Yucca filamentosa Adam's needle N Agavaceae Monocot Gentianella quinquefolia agueweed N Gentianaceae Dicot FAC, FACW- Rhamnus alnifolia alderleaf buckthorn N Rhamnaceae Dicot FACU, OBL Medicago sativa alfalfa I Fabaceae Dicot Ranunculus cymbalaria alkali buttercup N Ranunculaceae Dicot OBL Rubus allegheniensis Allegheny blackberry N Rosaceae Dicot UPL, FACW Hieracium paniculatum Allegheny hawkweed N Asteraceae Dicot Mimulus ringens Allegheny monkeyflower N Scrophulariaceae Dicot OBL Ranunculus allegheniensis Allegheny Mountain buttercup N Ranunculaceae Dicot FACU, FAC Prunus alleghaniensis Allegheny plum N Rosaceae Dicot UPL, NI Amelanchier laevis Allegheny serviceberry N Rosaceae Dicot Hylotelephium telephioides Allegheny stonecrop N Crassulaceae Dicot Adlumia fungosa allegheny vine N Fumariaceae Dicot Centaurea transalpina alpine knapweed N Asteraceae Dicot Potamogeton alpinus alpine pondweed N Potamogetonaceae Monocot OBL Viola labradorica alpine violet N Violaceae Dicot FAC Trifolium hybridum alsike clover I Fabaceae Dicot FACU-, FAC Cornus alternifolia alternateleaf dogwood N Cornaceae Dicot Strophostyles helvola amberique-bean N Fabaceae Dicot Puccinellia americana American alkaligrass N Poaceae Monocot Heuchera americana
    [Show full text]
  • Survey of Caledon Natural Area State Park
    Survey of Caledon Natural Area State Park David A. Perry 316 Taylor Ridge Way Palmyra, VA 22963 Introduction Caledon Natural Area was originally established as Caledon plantation in 1659 by the Alexander family, founders of the city of Alexandria, Virginia. It remained in private hands until it was donated to the Com- monwealth in 1974 by Mrs. Ann Hopewell Smoot. In 1981, the Caledon Task Force was appointed by Governor Robb to develop a management plan for Caledon to help protect the summering bald eagle popu- lation. A no-boating zone along the Potomac shoreline, limited public access trails and buffer zones were created to help protect bald eagle habitat. These limits have remained basically in place through August 2012, with some amendments. With the delisting of the bald eagle as an endangered species, plans were developed and approved on April 25, 2012 to expand public access at Caledon. Most likely these plans will be initiated in 2013. Located in King George County, Caledon Natural Area is approximately 37 km (23 miles) east of Freder- icksburg and about 97 km (60 miles) northwest of the confluence of the Potomac River and Chesapeake Bay. Within the park boundaries are a total of 1,044 hectares (2,579 acres) of diverse habitat; 953 hectares (2,355 acres) are forested (majority are mixed hardwood with some isolated softwood stands), 10.1 hect- ares (25 acres) are in old fields, 26.3 hectares (65 acres) are ponds and streams, 28.3 hectares (70 acres) are marshes, 6.1 hectares (15 acres) in Potomac shore and beach and 19.4 hectares (48 acres) are considered the original home site.
    [Show full text]