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Harvard Forest Data Archive


Mark-Recapture of Rodent and Shrew Populations in a Declining Hemlock Stand at Harvard Forest 2012

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  • Lead: Allyson Degrassi, Aaron Ellison
  • Investigators: Elizabeth Kennett
  • Contact: Information Manager
  • Start date: 2012
  • End date: 2012
  • Status: complete
  • Location: Simes Tract (Harvard Forest)
  • Latitude: +42.47 to +42.48 degrees
  • Longitude: -72.22 to -72.21 degrees
  • Elevation: 215 to 300 meter
  • Datum: WGS84
  • Taxa: Blarina brevicauda (northern short-tailed shrew), Clethrionomys gapperi (gapper's red-backed vole), Glaucomys volans (southern flying squirrel), Microtus pennsylvanicus (meadow vole), Napaeozapus insignis (woodland jumping mouse), Peromyscus maniculatus (deer mouse), Peromyscus leucopus (white-footed mouse), Sorex fumeus (smoky shrew), Sorex cinereus (masked shrew), Tamias striatus (eastern chipmunk)
  • Release date: 2023
  • Language: English
  • EML file: knb-lter-hfr.208.7
  • DOI: digital object identifier
  • EDI: data package
  • DataONE: data package
  • Related links:
  • Study type: long-term measurement
  • Research topic: biodiversity studies; physiological ecology, population dynamics and species interactions
  • LTER core area: population studies
  • Keywords: hemlock, hemlock woolly adelgid, mammals, populations, species richness
  • Abstract:

    Eastern Hemlocks (Tsuga canadensis) are foundation species, which are known to have a large influence on the species composition and ecosystem dynamics. The purpose of this study was to understand how rodent species richness and composition differed among different hemlock treatments consisting of intact forest, logged forest, and invaded hemlock stands in the Harvard Forest of Petersham, MA. Sherman live traps were arranged on 7x7m grids covering 0.49ha in four different hemlock treatments that were established in 2003: 1) the logged treatment, where commercial trees were removed 2) the girdled treatment, where the hemlocks were girdled using a chainsaw, thus killing the trees, and mimicking the effects of the woolly adelgid, an invasive insect 3) the hemlock control which is where hardwoods are at least 70% hemlocks, and 4) the hardwood control, where other hardwood species are dominate. Animals were marked and recaptured from June-July. Using Schnabel methods for population estimate, there appeared to be a shift in the population from more abundant Gapper’s Red-backed vole, Clethrionomys gapperi in the logged and girdled treatments to white-footed and deer mice (Peromyscus spp) in the hemlock and hardwood control plots. This shift in population may indicate that hemlocks support Peromyscus spp over voles. The species richness and overall population dynamic of these rodents surveyed may lead to a greater understanding as to the potential affect they may have on the seed dispersal in these plots and could account for many interactions between the vegetation and the animals also present.

  • Methods:

    We set out Sherman traps in 7 by 7 grids that were spaced 10 meters apart in all eights Simes plots (Logged, Girdled, Hardwood control, and Hemlock Control). Plot 7 includes only 34 traps (rather than 49) across approximately 0.35 ha. We would check in intervals of two nights in a row, doing one block per trapping period (see trapping schedule on flash drive). We would start by setting the traps in the afternoon, and then we would go out a 4am to check the traps by walking the grids. If there was no capture we would spring the trap to shut it. If there was a capture we would take the weight of the animal, mark it, see if it was a recap or not, determined its age, sex, reproductive status, and the number of slugs in the trap. If the animal appeared to be a deer mouse or white-footed mouse we would also take an amylase sample by squirting distilled water in their mouths because the two species are almost visually indistinguishable. The amylase will be analyzed in the fall to see the exact ratios and distributions. As far as analysis we used the Schnabel method to find the estimated population size.

  • Organization: Harvard Forest. 324 North Main Street, Petersham, MA 01366, USA. Phone (978) 724-3302. Fax (978) 724-3595.

  • Project: The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. (ROR).

  • Funding: National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210.

  • Use: This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

  • License: Creative Commons Zero v1.0 Universal (CC0-1.0)

  • Citation: Degrassi A, Ellison A. 2023. Mark-Recapture of Rodent and Shrew Populations in a Declining Hemlock Stand at Harvard Forest 2012. Harvard Forest Data Archive: HF208 (v.7). Environmental Data Initiative:

Detailed Metadata

hf208-01: rodent data

  1. dateset: date trap set
  2. datecheck: date trap checked
  3. block: block ID
    • Valley: valley
    • Ridge: ridge
  4. plot: plot ID
    • Logged: logged
    • Girdled: girdled
    • Hemlock: Hemlock
    • Hardwood: hardwood
  5. night: night, one of 1 through 10 (integer); dummy variable
  6. moonphase: moon phase
    • Full: full moon
    • Half: half moon
    • New: new moon
  7. moonface: moon face, % visible (integer) (unit: dimensionless / missing value: NA)
  8. trap: trap identification label
  9. trap.status: status of the trap upon checking
    • SPRUNG: trap was tripped, but no animal
    • DISTURBED: trap was disturbed (moved, bait removed, or cotton removed)
    • USED: trap did not capture an animal, was not sprung, but there was evidence of animal use (feces or urine)
    • CAPTURE: trap captured an animal
  10. species: species code
    • PE: Peromyscus species
    • PEMA: Peromyscus maniculatus, deer mouse
    • PELE: Peromyscus leucopus, white-footed mouse
    • NAIN: Napaeozapus insignis, Woodland Jumping mouse
    • GLVO: Glaucomys volans, Southern Flying Squirrel
    • TAST: Tamias striatus, Eastern Chipmunk
    • CLGA: Clethrionomys gapperi, Gapper’s Red-backed Vole
    • MIPE: Microtus pennsylvanicus, Meadow Vole
    • SHREW: shrew species unknown
    • SOFU: Sorex fumeus, Smoky Shrew
    • BLBR: Blarina brevicauda, Northern Short-tailed Shrew
    • SOCI: Sorex cinereus, Masked shrew
    • NA: no data (trap was sprung, disturbed, or used)
  11. species.status: species status
    • ALIVE: alive
    • DEAD: dead
    • NA: no data
  12. color1: marking color
    • BK: black
    • BL: blue
    • PR: purple
    • GR: green
    • OR: orange
    • RD: red
    • NA: no data (no animal or unmarked animal)
  13. color2: marking number (range: 1-20). NA: no data (no animal or animal not marked)
  14. recapture: recapture
    • N: no
    • Y: yes
    • NA: no data (no animal or unmarked animal)
  15. remark.color: color used for marking recaptures
    • BK: black
    • BL: blue
    • PR: purple
    • GR: green
    • NA: no data (no animal or unmarked animal)
  16. age: age
    • A: adult
    • SA: sub adult
    • J: juvenile
    • NA: no data (no animal or unmarked animal)
  17. sex: sex
    • F: female
    • M: male
    • NA: no data (no animal or unmarked animal)
  18. rs: reproductive status
    • N: non-reproductive
    • R: reproductive
    • NA: no data (no animal or unmarked animal)
  19. wt: weight (unit: gram / missing value: NA)
  20. slugs: initial slug presence indication or number of slugs present
    • S: small number of slugs present (1-4)
    • M: medium number of slugs present (5-10)
    • L: large number of slugs present (more than 10)
    • Y: slugs present
    • N: slugs absent
    • NA: no data (presence or absence of slugs not checked)
  21. slug.presence: slug presence
    • Y: slugs present
    • N: slugs absent
    • NA: no data (presence or absence of slugs not checked)
  22. amy: amylase, saliva sample taken from PE, PEMA, or PELE
    • N: no
    • Y: yes
    • NA: no data (sample not needed)