DOI: 10.25349/d9m31j
title: Tejon Ranch Exclosure Experiment - Tick (family Ixodidae: subclass Acari) and Small Vertebrate Responses

description: Large-bodied wild ungulates are declining worldwide, while domestic
 livestock continue to increase in abundance. Such changes in large
 herbivore communities should have strong effects on the control of ticks
 and tickborne disease as they can indirectly modify habitat and directly
 serve as final hosts for ticks’ lifecycles. Numerous studies have now
 linked changing ungulate communities to changes in tick populations and
 disease risk. However, the effects of changing large herbivore communities
 are variable across studies, and the effect of climate as a mediating
 factor of this variation remains poorly understood. Also, studies to date
 have largely focused on wildlife loss without considering the extent to
 which livestock additions may alter tick populations, even though
 livestock replacement of wildlife is the global norm. In this study, we
 used a large-scale exclosure experiment replicated along a topo-climatic
 gradient to examine the effects on tick populations of both large
 herbivore removal and livestock additions. We found that while questing
 ticks increased modestly, by 21%, when large herbivores were removed from
 a system they decreased more substantially, by 50%, when livestock (in the
 form of cattle) were added. Importantly, in addition to the direct effects
 of climate on tick populations, climate also mediates the effect of
 ungulates on questing tick density. Particularly the addition of livestock
 under the most arid conditions decreased tick presence, likely due to
 changes in ground-level microclimates away from those beneficial to ticks.
 Overall, the work contributes to our understanding of tick population
 responses to globally common human-induced rangeland alterations under the
 concurrent effects of climate change.
description: ## Data Files **Tejon_MeanComparisons_Dataset.csv**: contains tick drag
 data aggregated by *year*, *month*, *site*, *block*, and *plot*. The tick
 drag data includes a *total* column of all tick species collected and
 additionally, four columns representing the three tick species collected
 via drags *deoc* (*Dermacentor occidentalis*), *ipac* (*Ixodes
 pacificus*), *deva* (*Dermacentor variabilis*), and *other* (for
 non-identified ticks). Finally, it contains a unique numerical ID for each
 of the 27 exclosure treatments of TREE, *plotID*. This data was used in
 the manuscript's analyses, which investigated the individual and
 interactive impacts of climate level and herbivore treatment on tick
 abundance. **Tejon_MixedModels_Dataset.csv**: in addition to tick drag
 data, it contains columns liz_estimate and mam_estimates created by the
 results located in the **tejon_mamliz_popestimates.csv** file detailed
 below. This data set analyzes climate and herbivore treatment impact on
 lizard and small mammal populations. These results and figures are
 included in the Appendix. NAs in the liz_estimate and mam_estimates
 columns indicate when model estimates were omitted because the resulting
 estimations were unrealistic. **Total_Ticks_2016_to_2018.csv**: raw data
 from field tick drags from 2016 - 2018. **Tick_19.csv**: raw data from
 field tick drags occurring in 2019. **lizardcounts_02172021.csv**: raw
 data file containing lizard surveys completed in the field. Lizard surveys
 were completed by mark and recapture surveys that took place at only the
 Arid and Intermediate climate level plots (N=18). The plots were sampled
 for three consecutive days, and when a lizard was spotted, they were
 sprayed with a scale-safe paint. Each day, there was a different color of
 paint. For example, in a row in the data set, a lizard spotted on day 1
 will have a 1 in the column *day1*. If it were not spotted on day 2, there
 would be a zero in the *day2* column. And if it were spotted on day 3,
 there would be a 1 in the *day3* column. **mammal_counts_02182021.csv**:
 raw data file containing small mammal trapping data completed in the
 field. Small mammal surveys were completed using mark and recapture
 surveys. Each plot was surveyed for three consecutive days. When an animal
 was caught, they were given a metal ear tag (IACUC # 904.1). The column
 *tag* in the data file indicates the tag number assigned to the animal.
 Each row indicates how many times *day1*, *day2*, and *day3* that animal
 was caught over our sampling period. Those with an NA in the *tag* column
 were, for some reason (e.g., juvenile or deformity), unable to be tagged.
 **tejon_mamliz_popestimates.csv**: data file containing the abundance
 estimate results for small mammal and lizard populations using
 `Rcapture` to evaluate the raw data (two data files directly mentioned
 above) recorded in the field. **Dataset Clarifications** *site* = Climate
 Level, a factorial column denoting three climate levels of the study -
 Arid, Intermediate, and Mesic. *plot* = Herbivore treatment, a factorial
 column denoting three herbivory treatment types used in the study. Within
 the data set, they are referred to as Open, Partial, and Total. For data
 figures and discussion of results and analyses within the manuscript,
 these are changed to: * Open = *Cattle and Wildlife* (CW) * Partial =
 *Wildlife* (W) * Total = *Minus Cattle and Wildlife* (-CW)