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Measuring Productivity – Part I Ecological MethodologyLEC-11 Althoff
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Population Biology 101 Pop n = For pop n to _____: births+emigration > deaths + immigration ________________: adult population fails to replace itself with self-sustaining individuals… ___________________…must be sustained by excess from other subpopulations
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Key Definitions ______________ = number of offspring (young) produced during a reproductive cycle (season) by a population ______________ = number of young produced in a pop n that reach sexual maturity ______________ = rate at which an individual produces offspring (young)
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Key Definitions…BIRDS ________________ = number of eggs that hatch per nest (or group of nests). Not equivalent to nesting/ fledging success. -- egg per nest hatches or -- ____ of eggs hatching per nest __________ = young still in nest and/or unable to fly to leave natal site __________ = young left nest and/or natal site, able to fly _____________ > 1 nestling/hatchling fledges
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BIRDS ? ?
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Key papers: Martin, T.E. and G.R. Geupel. 1993. Nest- monitoring plots: methods for locating nests and monitoring success. Journal of Field Ornithology 64(4):507-519. (on CLASSNOTES) Winter, M., S.E. Hawks, J.A. Shaffer, and D.H. Johnson. 2003. Guidelines for finding nests of passerine birds in tallgrass prairie. Prairie Naturalist 35(3):197-211 (on CLASSNOTES) BIRDS…nest searching & monitoring
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Key considerations: T & E species Human impact on searches & monitoring Brood parasitism factor Imperfect/uncertain nest/fledgling fate BIRDS…nest searching & monitoring 1 2 3 4
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T & E Species 1 Few left…. Don’t want to mark/band nestlings if can avoid it…but doesn’t help monitoring effort Always error to the side of caution… Examples: California condor ____________ Kirtland’s warbler
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Human Impact on Nesting Success 2 Nest often well camouflaged or cryptic… ___________ ______________ to nest site “provides path” for ground predator (i.e., snakes, small mammals) or visual cues to aerial predators (i.e., crows) or retard growth of nestlings
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Waterfowl nest predated before hatching
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Brood parasitism 3 Affects determination of number of fledglings of host species ____ _____ Could _____ “nest” success results….sometimes cowbirds mature/ fledge before host species young…or nest is abandoned prematurely
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Brood parasitism …con’t 3 In some areas, for impacted host species, brood parasitism is ______...so probably not that big impact on estimation of productivity In some areas, for impacted host species, brood parasitism is ______...so significant impact on estimation of productivity Decision: is metric one uses…??? a) __________________________ (more helpful for determining recruitment) b) __________________________per unit of area (cruder estimate of productivity)
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Detailed Protocols….from nest initiation to fledgling Murphy, Robert K., Brian G. Root, Paul M. Mayer, J. Paul Goossen, and Karen A. Smith. 1999. A draft protocol for assessing piping plover reproductive success on Great Plains alkali lakes. Pages 90-107 in K.F. Higgins, M.R. Brashier, and C.D. Kruse (eds.), Proceedings, piping plovers and least terns of the Great Plains and nearby. South Dakota State University, Brookings. Jamestown, ND: Northern Prairie Wildlife Research Center Online.http://www.npwrc.usgs.gov/resource/birds/pplover/index.htm (Version 08Oct99).http://www.npwrc.usgs.gov/resource/birds/pplover/index.htm Determine chronology of breeding season and monitor the stages. Requires detailed records including mapping
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Note: 1)Location of nests, no. eggs, etc. 2)No. of adults (1,2, or 3…i.e., breeding pairs 3)Behaviors (on nest?, courtship displays?, vocalizatons?) Piping plover mapping
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Piping Plover monitoring…con’t Start in early May Visit individual alkaline lakes every _____ days Cannot “flag” nest….so use _____ (stone markers….10-30 ft/paces from nest location) Determine _____ of eggs, then… Determine _____ of chicks (pre- fledging), then… Follow sites/lakes until all birds “gone”…usually by early August
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Territory Establishment Nest building Egg laying 4e, 4-5 d Incubation 25-27 d Precoccial chicks 18-21 d Fledge MAYJUNEJULYAUG Breeding Chronology Piping Plover 1 2 3
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Piping Plover reporting…con’t Density of pairs (but “challenge” being a “shoreline” species) Clutch size (mean, median, mode) Nest success - % Egg /Hatching success - % Chick survival post hatching - trend Fledging success -% Young produced per adult 1 chick fledged per adult steady or increasing 1 2 3
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Nest Survival/Success Analysis Most commonly used approach is the _________ METHOD (1961, 1975): Mayfield, H.F. 1961. Nesting success calculated from exposure. Wilson Bulletin 73:255-261. Mayfield, H.F. 1975. Suggestions for calculating nest success. Wilson Bulletin 87:456-466. Attempted to deal with “incomplete info” and provide guidelines (and consequences of those guidelines) for what to include in the analysis
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Post-fledging Survival For most species, this is _____ most important piece of information to know For most species, this is _____ most difficult piece of information to obtain a) challenge of tagging/marking individuals ___________________ them b) challenge of __________ them examples: piping plovers: “gone” in 18-21 d grasshopper sparrows: out of adult territory in 7-21 d dabbling ducks: move from lake to lake in some regions
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Proportional survival of _______________ (0-20 days) wood thrushes during years of low, moderate, and high rodent abundance southeastern New York. Schmidt, K.A., S.A. Rush, and R.S. Ostfeld. 2008. Wood thrush nest success and post- fledgling survival across a temporal pulse of small mammal abundance in an oak forest. Journal of Animal Ecology 77:830-837.
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Interpret the wood thrush data What does the y-axis scale mean? What are the “vertical lines” extending from each “point” expressing? Why are all 3 “lines/trends” decreasing? Based on 18-20 d post-fledgling survival data, which, condition (high, moderate, or low) of small mammal abundance appears to negatively influence wood thrush survival the most?
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Spot Mapping Requires ________ visits to a site/plot (usually 10 or more) Requires ability to detect species via _______ or _________ or both Aided by ability detect males vs. females (__________________________________) Aided by _________ (banded and/or radio- marked) of individuals Aided by knowing _____________________ associated with nest building, egg laying, incubating, feeding of young, alarm calls, etc.
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Indirect Method – Reproductive Index ___________ Method: Vickery, P.D., Hunter, M.L. & Wells, J.V. 1992. Use of a new reproductive index to evaluate relationship between habitat quality and breeding success. Auk 109:697-705. Basic premise: _____________ reflect stage of breeding cycle and that for species with hard-to- find nest, this may be next best thing Specialized form of spot mapping Used for grasshopper, savannah, and vesper sparrows in Maine
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Indirect Method “Scoring” System Can score for entire breeding season or for individual days Rankings 0 = no territorial male present 1 = territorial male present 4+ weeks 2 = territorial male & female present 4+ weeks 3 = pair found nest building, laying, incubating, or giving distraction display 4 = adults carrying food to presumed nestlings 5 = evidence of fledgling success (1 st brood) 6 = evidence of fledgling success in either brood, plus evidence of success in other 7 = evidence of fledgling success in both broods
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Indirect method --basically spot mapping
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Indirect Method
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Evaluation of the Vickery Method Dickcissels -- too much brood parasitism in KS Rivers, J.W., D.P.Althoff, P.S. Gipson, and J.S. Pontius. 2003. Evaluation of a reproductive index to estimate dickcissel reproductive success. Journal of Wildlife Management 67:137-144. Grasshopper Sparrows & E. Meadowlarks shows promise for general trends in KS Althoff, D.P., P.S. Gipson, J.S. Pontius, and R.D.Japuntich. 2009. Evaluation of a index to estimate grasshopper sparrow and eastern meadowlark reproductive success. Wildlife Biology in Practice 5(1):33-44.
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Surveying -- Breeding Birds Only _______________ vs. _______________ May get __________…may get ________ to breeding bird abundance Greater the ____________ effort, more likely the better estimates. Either more plots, more visits to plots/points…or both Has been used for some species to estimate _______________ produced
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Standard Protocol ______________: 5-, 6-, or 10 minutes “_______” conditions: Beaufort wind scale <3, little to no wind Typically start around sunrise to 10am, but some evening survey for some species. Owls and other nocturnal species would be conducted at night Sometimes employee “______________” approach
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Point count example
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Basic Utility of Data Monitor for many years…get __________ Compare productivity/breeding activity by ___________ and/or _____________ type Compare productivity/breeding activity by ______________________. Ex. Burning patches every 1, 2, or 3 years Ex. Removing mesopredators vs. control Measure ________________________ (natural or anthropogenic)
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