A nest trap designed for ground nesting birds, specifically Snowy Plovers (Charadrius alexandrinus), is described. The trap is inexpensive to construct, easy to operate, and lightweight for ease of use under field conditions. The trap is designed to operate most efficiently under lightly or non-vegetated habitats, typical of Snowy Plover nesting sites

Conway, Warren C.

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Stephen F. Austin State UniversitySFA ScholarWorksFaculty Publications Forestry2000A Nest Trap for Snowy PloversWarren C. ConwayArthur Temple College of Forestry and Agriculture, Stephen F. Austin State Universtiy, Nacogdoches, Texas 75962,wconway@sfasu.eduFollow this and additional works at: http://scholarworks.sfasu.edu/forestryPart of the Forest Sciences CommonsTell us how this article helped you.This Article is brought to you for free and open access by the Forestry at SFA ScholarWorks. It has been accepted for inclusion in Faculty Publicationsby an authorized administrator of SFA ScholarWorks. For more information, please contact cdsscholarworks@sfasu.edu.Recommended CitationConway, Warren C., "A Nest Trap for Snowy Plovers" (2000). Faculty Publications. Paper 303.http://scholarworks.sfasu.edu/forestry/303A Nest Trap for Snowy Plovers Warren C. Conway and Loren M. Smith Department of Range, Wildlife, and Fisheries Management Texas Tech University Lubbock, TX 79409-2125 Emaih WCONWAY @ TTACS.TTU.EDU ABSTRACT A nest trap designed for ground nesting b!rds, specifically Snowy Plovers (Charadrius alexandrinus), is described. The trap is inexpen- sive to construct, easy to operate, and lightweight for ease of use under field conditions. The trap is designed to operate most efficiently under lightly or non-vegetated habitats, typical of Snowy Plover nesting sites. INTRODUCTION Various nest trap designs have been developed for ground-nesting birds, including shorebirds (Dorio et al. 1978, Gartshore 1978, Grau11979, Mills and Ryder 1979, Sordahl 1980). Because of the relatively open habitats in which Snowy Plovers are found nesting (Page et al. 1995), nest trap concealment is difficult. Other drop-door box nest traps have been used to capture this species (Paton and Edwards 1996). However, in this paper, we describe a different nest trap that was effective in capturing 70 female and seven male Snowy Plovers nesting in saline lake wetlands in Lynn, Terry, and Bailey counties, Texas, during 1999. METHODS Trap Design and Placement * The trap consists of two 1.83 m lengths of 1.25 cm electrical conduit, four 16 cm pieces of 1 cm wooden dowels, and two medium-weight strap hinges. A 1.83 m x 1.83 m section of 2.54 cm mesh netting (such as retired mist nets or rocket netting) is also needed to construct this trap. Dowels are secured into each end of conduit lengths. Dowels should be somewhat difficult to place in the conduit, but this insertion can be accomplished effectively using a hammer to pound dowels into conduit ends. The two pieces of conduit are bent physically, either by hand or by using a pipe tool, into equal "U" shapes (Figures l a and lb). Hinges are attached to the dowels at the ends of the conduit, such that when the trap is closed, the two "U" shaped conduit lengths lay flat on the ground (Figure la). When the trap is open, the two "U" shaped conduit lengths should lay on top of one another (Figure lb). Hinges are secured effectively by drilling holes through the conduit, but only barely drilling into the dowel. Once holes are drilled, the hinges can be secured by screwing hinge screws through the conduit into the dowels. The dowel serves to secure the hinges, a requirement to ensure that the trap functions. Once the trap frame is finished, netting is secured to the perimeter of the trap while in the closed (i.e., flat) position. This will ensure that when the trap is deployed there is enough slack in the netting to allow the trap to lay flat on the ground. The netting can be secured to the trap frame using heavy twine. The amount or length of twine needed to properly secure netting to the trap frame will vary. After netting is attached, black spray paint can be used to reduce glare from the aluminum conduit. It is more effective to paint the conduit after netting has been attached. Two lengths of twine (about 1.5 m) are secured at 10 and 2 o'clock positions on the top piece of conduit. These lengths are secured together and then tied to at least 50 m of twine which serves as the pull cord to operate the trap (Figures la and lb). The trap is set in the open position (i.e., the two "U" conduit pieces laying on top of one another) around a Snowy Plover nest (Figure lb). The bottom piece of conduit should be secured to the ground using stakes (e.g.,re-bar stakes work well). Apr. - Jun. 2000 North American Bird Bander Page 45 Once secured, the operator should walk at least 50 m away from the nest unraveling the pull cord, keeping the line taught. During the nesting season, especially in hot weather, Snowy Plovers will approach the nest usually within 15 min. Depending on stage of incubation and tempera- ture, some birds will approach as the operator backs away from the nest. Consequently, it is important to know incubation stage, and focus trapping efforts during the second week of incubation. Eggs can be left in the nest. No artificial eggs are necessary. Operating the Trap - The operator should be far enough away from the nest such that the bird returns to the nest in a relatively short period of time. This distance varies with stage of incubation and weather conditions. In some instance, binoculars will be needed to see the bird approaching and entering the nest area. Once the bird enters the trap area, it will generally take a few minutes to become settled on eggs. It is important not to become impatient. If the bird is not completely settled when the trap is deployed, the bird may fly vertically (rather than sit tight) and could be caught in netting as the trap is moving into the flat position, and be thrown to the ground, potentially causing injury, death, or nest abandon- ment. Generally, wait 1 to 2 min after the bird settles on the eggs before pulling the cord. Once the bird is settled, the operator must pull the pull cord to close the trap. The pull cord is attached to the top piece of conduit which, when triggered, carries the netting over the top of the bird and lands flat on the ground (Figure la). At this point, the bird will become moderately tangled if using larger heavier-mesh rocket netting, more so if using lighter-weight mist netting. The operator should practice triggering the trap to determine how much effort and torque is needed to close the trap satisfactorily. Each trap will be different, so practice is important for rapid and successful capture events. Once the trap is deployed, immediately retrieve the bird and remove the trap from the nest area. This allows for rapid return of the bird after processing (i.e., banding, measuring, etc.) and minimizes the number of times the nest is approached and potentially disturbed. No birds were injured during 77 successful capture events during this study. The main advantages of this trap are that it (1) is inexpensive and easy to assemble, (2) takes minimal tools to construct, (3) is lightweight and three or four traps may be carried by one person easily, and (4) can be operated by a single person. The main disadvantages are that it (1) requires manual triggering and (2) always needs to be monitored. I Nest locatio i Anchørs I I Pull cord Hinge Location Fig. la. Snowy Plover nest trap in closed/deployed position. Note location of actual nest at opposite nd of nest trap from where the nest trap operator is located. Page 46 North American Bird Bander Vol. 25 No. 2 I Nest location To nest trap o erator Pull cord. At•hed tothe top half of the frame. Electrical conduit frame. Notice how the top half of the frame lays on top of the anchors and the bottom half of the frame. Furled up netting. Notice how netting is set beyond the back end of the plover nest. Hinge location Fig. lb. Snowy Plover nest trap in open/set position. Note how the netting is furled behind the nest to allow the bird to sit back down on nest without interference. ACKNOWLEDGMENTS We thank the various landowners who allowed access to their property during this study. Research was funded in part by the Texas Parks and Wildlife Department and the Playa Lakes Joint Venture. L. M. Smith was supported by the Caesar Kleberg Foundation for Wildlife Conservation. This is manuscript T-9-862 of the College of Agricultural Sciences and Natural Resources, Texas Tech University. This work was performed under Texas Tech University Animal Care and Use Committee Approved Protocol 99825A and 00933B. LITERATURE CITED Dorio, J. C., J. Johnson, and A. H. Grewe. 1978. A simple technique for capturing Upland Sandpipers. Inland Bird Banding News 50:57-58. Gartshore, M. E. 1978. A noose trap for catching nesting birds. N. Am. Bird Bander3:1-2. Graul, W. D. 1979. An evaluation of selected capture techniques for nesting shorebirds. N. Am. Bird Bander 4:19-21. Mills, J. A. and J.P. Ryder. 1979. Trap for cap- turing shore and seabirds. Bird-Banding 50:121-123. Page, G. W., J. C. Warriner, and P. W. C. Paton. 1995. Snowy Plover (Charadrius alexandrinus). In The birds of North America, No. 154 (A. Poole and F. Gill, eds.). Philadelphia, PA: Acad. Nat. Sci.; Washington, DC: Am. Ornithol. Union. .Paton, P. W. C. and T. C. Edwards, Jr. 1996. Factors affecting interannual movements of Snowy Plovers. Auk 113:534-543. Sordahl, T.A. 1980. A nest trap for recurvirostrids and other ground-nesting birds. N. Am. Bird Bander 5:1-3. Apr. - Jun. 2000 North American Bird Bander Page 47 

A Nest Trap for Snowy Plovers

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A Nest Trap for Snowy Plovers

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