Seasonal and year-round use of the Ramsar-listed Kushiro Wetland by sika deer (Cervus nippon yesoensis)
- Published
- Accepted
- Subject Areas
- Animal Behavior, Conservation Biology, Ecology
- Keywords
- seasonal migration, cross-ecosystem movement, ecosystem maintenance and recovery project, GPS collar, net squared displacement, seasonal home range overlap
- Copyright
- © 2017 Takafumi et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Seasonal and year-round use of the Ramsar-listed Kushiro Wetland by sika deer (Cervus nippon yesoensis) PeerJ Preprints 5:e3048v1 https://doi.org/10.7287/peerj.preprints.3048v1
Abstract
The sika deer (Cervus nippon yesoensis) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact these sika deer are having on the ecosystem. However, their seasonal movement patterns, i.e., when and how the deer inhabit the wetland, remain unclear. Thus, we examined seasonal movement patterns and the population structure of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The overlap areas of population-level home ranges among capture sites were calculated for both the entire year and for individual seasons. Our results showed that approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 64 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81–100% of their annual home range was within the wetland area. The movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, nomadic, and atypical. Even among individuals captured at the same site, various seasonal movement patterns were identified. Annual population-level home ranges showed little to no overlap, and seasonal population-level home ranges were completely segregated among capture sites. Individual deer used the wetland either seasonally or year-round, and some populations inhabiting the wetland had sub-populations with different seasonal movement patterns, which need to be considered to achieve more effective ecosystem management including deer management in the wetland.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Seasonal population-levelhome range area of sika deer (Cervusnippon yesoensis) of Kushiro Wetland in (A) first winter, (B) summer, and(C) second winter in a year at each capture site
The home range area was estimated by pooling all recorded locations of deer at each capture site and determining the 95% local convex hull for them. The location data used during migration periods excluded the seasonal home range estimation. The periods were defined as all migrant individuals that had not yet initiated migration to next home range as estimated by NSD the method. Red outline, Takkobu home ranges; green outline, Kottaro home ranges; blue outline, embankment home ranges; shaded grey area, Kushiro Wetland; filled blue areas, sea; solid lines, municipality boundaries.
Dates of spring and autumn migration initiation of sika deer (Cervus nippon yesoensis) classified as seasonal migrants in 2014 and 2015, the first day of snow cover*, and loss of snow cover†.
Raw location data of the COAs shown in Figures 2 and 3.
COA location for each individual. COAs were calculated using seasonal home ranges. The X and Y coordinates (in UTM; m) of individual COAs are shown for each season. Seasons are labeled as winter 1 (first winter), summer, and winter 2 (second winter) with period defined via the NSD method (see the Methods section in the manuscript).
Shapefile raw data ofannual population-level home range each capture site for Figure 4
Home range area of deer of Kushiro Wetland in a year each capture site. The home range area was estimated by a 95% local convex hull using all pooled deer location data for a year at the same capture site.
Shapefile containing the raw data of seasonal population-level home ranges for deer collared at each capture site shown in Figure S1
Seasonal population-level home range area of Kushiro Wetland deer in (a) first winter, (b) summer, and (c) second winter for one year at each capture site. The home range area was estimated by a 95% local convex hull using all pooled deer location data at each capture site.
Raw data used tocalculate the values in Table1, Table 2 and conduct the wetland utilizationanalysis
Annual home range size (km 2 ); home range in wetland (km 2 ), amount of the annual home range comprised of wetland habitat (km 2 ); home range outside wetland, amount of home range comprised of non-wetland habitat (km 2 ), percent wetland (%), home range in wetland / annual home range size for each individual. These data are summarized in Table 2 and were statistically analyzed using the R code found in the file “wetland use.r”.
R code for the analysis of wetland use among movement patterns and capture sites.
This script uses the data file “Raw_data_of_Table1_and2_migration_type_and_wetland_use_area.csv” and applies a generalized linear mixed model (GLMM) to the data. The results are summarized and shown in the manuscript.
Raw migration initiation data used to generate the values in Table S1
Migration initiation date for each individual exhibiting movement classified as migration.
Raw seasonal migration distance data.
Spring and autumn migration distances for each individual exhibiting movement classified as seasonal migration. These data are summarized and shown in the manuscript.