THE WESTERN POND TURTLE: HABITAT AND HISTORY FINAL REPORT Prepared by: Dan C. Holland, PhD Wildlife Diversity Program Oregon Department of Fish and Wildlife Portland, OR Prepared for: U. S. Department ofEnergy Bonneville Power Administration Environment, Fish and Wildlife P. O. Box 3621 Portland, OR 97208-3 62 1 Project Number 92-068 Contract Number DE-BI79-92BP62 137 August 1994 TABLE OF CONTENTSf1 TABLE OF CONTENTS Chapter Pat,:e Chapter 1 A Brief Overview of the Evolution of the Willamette-Puget Sound Hydrographic Basin Introduction .1-3 The Biotic Landscape ofthe Willamette Valley in the Holocene .1-7 The Historical Appearance of the Willamette Valley ca: 18 10- 1860 .1-15 The Influence ofHumans on the Biotic Landscape ofthe Willamette Valley .1-19 Changes in the Biotic Landscape: 1840's-1940' .1-22 Literature Cited .1-31 Chapter 2 A Synopsis of the Natural History of the Western Pond Turtle Taxonomy 2-3 Description , 2-3 Range 2-4 Distribution-Oregon 2-4 Behavior 2-5 Diet 2-5 Home Range 2-6 Activity '" 2-6 Habitat Requirements--Aquatic Habitats .2-7 Habitat Requirements--Terrestrial Habitats .2-8 Overland Movements 2-9 Reproduction 2-9 Growth and Survivorship .2-11 Predation and Mortality 2-11 Disease 2-13 Parasites 2-14 Drought. .2-14 Literature Cited .2-15 Chapter 3 Methods 3-1 Chapter 4 Status of the Western Pond Turtle in the Willamette Drainage Historical Background 4-3 Recent Studies 4-4 Survey Effort Goals 4-4 Overall Results 4-5 Other Studies 4-5 Locality Data 4-6 Population Structure 4-6 Population Size 4-8 TABLE OF CONTENTS/2 Population Density 4-8 Changes in Population Size and Density 4-9 Discussion 4-1 0 Summary 4-13 Literature Cited 4-15 Chapter 5 Reproductive Ecology ofthe Western Pond Turtle 5-1 Chapter 6 Description of Study Sites Site CA 010 K 6-3 Site CA 014 K 6-3 Site OR 002 U 6-3 Site OR 017 U 6-4 Site OR 050 U 6-4 Site OR 039 W 6-4 Site OR 082 W 6-5 Site OR 082 W 6-5 Site OR 103 W 6-5 Site OR 163 W 6-6 Site OR 001 C 6-6 West Eugene Site(s) 6-6 Literature Cited 6-7 Chapter 7 Aquatic Movemeuts of the Western Pond Turtle Introduction 7-3 Methods 7-3 Results: Site CA 014 K 7-7 Site CA 010 K 7-9 SiteOROl7U 7-12 Site OR 002 U 7-14 Site OR 050 U 7-17 Site OR 039 W 7-19 Site OR 103 W 7-20 Site OR 082 W 7-21 Site OR 097 W 7-21 Site OR 001 C 7-22 Site OR 163 W 7-23 West Eugene Sites 7-24 Discussion 7-25 Movements Within:. Riverine Habitats 7-26 LacustrinelPalustrine Habitats 7-28 Large-Scale Artificial Lacustrine Habitats 7-30 Disturbed Wetland Habitats 7-30 TABLE OF CONTENTS/3 General Considerations Regarding Movement 7-31 Literature Cited .7-33 Chapter 8 Overwintering in the Western Pond Turtle Introduction 8-3 Results: Riverine/Stream Habitats 8-3 Pond/lake Habitats 8-5 Altered WeHand Habitats 8-9 Discussion _.8-11 Literature Cited 8-15 Chapter 9 The Effect of Introduced Turtle Species on the Status of the Western Pond Turtle (Clemmys marmorata) in a Central California Pond Introduction 9-3 Materials and Methods 9-3 Results 9-5 DiscussioD 9-7 Literature Cited 9-10 Chapter 10 Molecular Genetics of the Western Pond Turtle Introduction 10-3 Results .1 0-5 Discussion .10-5 Recommendations .1 0-6 Addendum 10-7 Literature Cited 10-9 Chapter 11 Translocation as a Mitigation Strategy 11-1 Appendices CHAPTER 1 A Brief Overview of the Evolution of the Willamette-Puget Sound Hydrographic Basin 1·2 A Brief Overview of the Evolution of the Willamette-Puget Sound Hydrographic Basin Table of Contents Section Introduction 1-3 The Biotic Landscape ofthe Willamette Valley in the Ho1ocene .1-7 The Historical Appearance ofthe Willamette Valley ca: 1810-1860 1-15 The Influence ofHumans on the Biotic Landscape ofthe Willamette Valley 1-19 Changes in the Biotic Landscape: 1840's-1940's .1-22 Literature Cited .1-3 1 1-3 INTRODUCTION Like many prominent physiographic features ofthe landscape ofthe Pacific northwest, the Willamette-Puget Sound (hereafter WPS) hydrographic basin has a relatively recent origin, and a moderately complex evolutionary history. This area was largely a marine terrace/continental shelf environment during the Eocene and Oligocene. Formation ofthe area was initiated by the development ofa volcanic archipelago part ofa larger system extending along much ofthe west coast ofthe North American continent. This chain ofvolcanoes served as the foundation for development ofa forearc basin, which in turn induced accretion ofmarine sediments through at least the Pliocene. In the Oligocene, a marine environment existed as far south as present-day Salem. During the middle-late Miocene, intense vulcanism in the area ofthe Columbia plateau produced massive incursions oflava, which covered many ofthese sediments. The general pattern from the Miocene onward was recession ofthe marine environment, and a shift from marine-dominated processes, such that by the late Pliocene other forces were the primary factors involved in the subsequent evolution ofthe landscape. The uplifting and tilting of the Coast Range, coupled with the intensive orogenic activity (both volcanic and uplift) in the Cascades province resulted in the formation ofthe large lowland "basin" we now know as the WPS trough. By the late Pliocene-early Pleistocene, the combination and interaction of vulcanism with a high erosion & accretion potential set the stage for the evolution ofthe landform as we currently recognize it. For the purposes ofthis report, the major processes of interest occurred from the Pliocene-Pleistocene boundary onward Initial displacement ofthe Willamette River to the east side ofthe basin by uplift and vulcanism in the Coast Range was essentially complete by the onset ofthe Pleistocene. Subsequent rapid erosion ofthe uplifting Cascades, particularly during periods ofsea-level recession and glaciation, produced extensive and complex deposits of sediments from the rivers draining the west slope ofthe range. The coalescence ofthese alluvial fans covered much ofthe southern two-thirds ofthe Willamette Valley, and displaced the course ofthe river to the general area of its present channel(s) between Eugene and Cotvallis. Coupled with minor intrusive landforms derived from the Coast Range formations and localized volcanic/pyroclastic events (particularly in the northern part ofthe system) , much ofthe subdivision ofthe valley occurred during this time. Further north, the river ran to the east of its current channel. In the area of Oregon City, the river ran to the southeast and was joined by an extension ofthe Tualatin River southeast ofits current confluence. Continuing declines in sea level led to a shift in the drainage ofthe Tualatin through Lake Oswego, while the Willamette continued downcutting through the Columbia River basalts near Oregon City. This action eventually produced the falls. Spread ofthe Boring lava flows shifted the channel ofthe Willamette northward, and subsequent flood events reconnected the Tualatin to the Willamette at or near their current confluence. The influence ofPleistocene glaciation on the dynamics and distribution ofentire biotas was profound, perhaps more so than any other geological event in the last few million years. The ecosystems of the WPS trough are no exception. The four major glaciations will not be reviewed in detail here, but their effects will be briefly discussed. 1-4 The extent ofthe advance ofthe ice sheets varied between epochs, with the most extensive glaciation occurring during the last period, the Wisconsonian. In the area to the north ofthe Columbia River the Cordilleran continental ice sheet extended into the northern end ofthe WPS trough, such that the southern end ofPuget Sound was buried under several hundred meters of ice. Locally, glaciers ofvarying size occurred in most if not all ofthe major drainages on the west slope ofthe Cascades. A large sheet of ice extended from the Mt. Hood glacier complex down the Sandy River channel almost to its current confluence with the Columbia River (Orr et aI, 1992). Concurrent with the advance ofthe glaciers, the general climate became more cool and moist. In part, this allowed a major southerly extension ofthe boundaries ofthe Arcto-Tertiary geoflora (Axelrod, 1958). This also decreased significantly the lower elevation limits ofmany mesic/cool adapted forn1s, such as currently typifY the flora ofhigher elevations. As such, at the height ofthe glacial period the total extent and altitudinal range ofxeric-adapted biotas (typical Madro-Tertiary communities like oak forests and grasslands) were considerably less in the WPS trough than in very recent history. Procession and recession ofthe two basic biotas in this area - one a moist-forest conifer dominated system and the other a more xeric-adapted hardwood/mixed forest and grassland system - probably occurred on a cyclic basis in the basin over the last 700,000 years. The advance and retreat ofthe Arcto-Tertiary and Madro-Tertiary geofloras occurred over a vast area ofthe western North American continent. The influence of this situation was significant on both the local and total distribution ofmany elements ofthese landscape biota, producing spatially disjunct relict populations or communities ofspecies in many areas. This pattern is apparent in many areas along the west coast, and as such many situations in the WPS trough are arguably not unique. However, other events were to playa major role in the evolution ofthe biota ofthe Willamette landscape, producing in effect a ecological tabla rasa ofa nature and on a scale that was truly unique. This influence ofthis phenomenon extends across 15,000 years to the present.