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Measuring Productivity Part I

FIELD BIOLOGY & METHODOLOGY Fall 2013 Althoff. Lecture 19. Measuring Productivity Part I. Population Biology 101. Pop n = For pop n to _____ : births+emigration > deaths + immigration

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Measuring Productivity Part I

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  1. FIELD BIOLOGY & METHODOLOGYFall 2013 Althoff Lecture 19 Measuring Productivity Part I

  2. Population Biology 101 • Popn = • For popn to _____: births+emigration > deaths + immigration • ________________: adult population fails to replace itself with self-sustaining individuals… ___________________…must be sustained by excess from other subpopulations

  3. Key Definitions ______________ = number of offspring (young) produced during a reproductive cycle (season)by a population ______________ = number of young produced in a popn that reach sexual maturity ______________ = rate at which an individual produces offspring (young)

  4. 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

  5. BIRDS ? ?

  6. 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

  7. 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

  8. 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

  9. 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

  10. Waterfowl nest predated before hatching

  11. 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

  12. 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)

  13. 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). • Determine chronology of breeding season and monitor the stages. Requires detailed records including mapping

  14. Piping plover mapping • Note: • Location of nests, no. eggs, etc. • No. of adults (1,2, or 3…i.e., breeding pairs • Behaviors (on nest?, courtship displays?, vocalizatons?)

  15. 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

  16. Breeding Chronology Piping Plover Territory Establishment 3 Nest building 1 Fledge Egg laying 4e, 4-5 d 2 Incubation 25-27 d Precoccial chicks 18-21 d MAY JUNE JULY AUG

  17. 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 > 1 chick fledged per adult 1 2 3 steady or increasing

  18. 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

  19. 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

  20. 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.

  21. 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?

  22. 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.

  23. 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

  24. 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 (1st brood) 6 = evidence of fledgling success in either brood, plus evidence of success in other 7 = evidence of fledgling success in both broods

  25. Indirect method --basically spot mapping

  26. Indirect Method

  27. 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.

  28. 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

  29. 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

  30. Point count example

  31. 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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