Data from - Ecological insights from three decades of animal movement tracking across a changing Arctic

We provide here the data used in analysis of 3 test cases, presented in the manuscript "Ecological insights from three decades of animal movement tracking across a changing Arctic". We utilized the new Arctic Animal Movement Archive (AAMA), a growing collection of 201 standardized terrestrial and marine animal tracking studies from 1991–present. The AAMA supports public data discovery, preserves fundamental baseline data for the future, and facilitates efficient, collaborative data analysis. With three AAMA-based case studies, we document climatic influences on the migration phenology of eagles, geographic differences in adaptive response of caribou reproductive phenology to climate change, and species-specific changes in terrestrial mammal movement rates in response to increasing temperature.  

Methods
Arctic Animal Movement Archive (AAMA)

The AAMA enables the discovery and use of Arctic and Subarctic animal movement data. The AAMA is hosted on Movebank (movebank.org), a global research platform for animal tracking and bio-logging data. Current information about participating studies, how to download or request data, and how to join the archive and provide new datasets is available at the AAMA landing page (https://www.movebank.org/cms/movebank-content/arctic-animal-movement-archive). 

The data presented here is processed from raw movement data in AAMA. This data publication provide the data used in 3 case studies that analyze ecological changes in animal movement, phenology and demography in response to environmental conditions in the arctic.

Case Study 1. Long-term data reveal influence of decadal climate patterns on summering behavior in a migratory raptor

We used 569,720 location estimates collected from 146 golden eagles (Aquila chrysaetos) in 12 AAMA studies across western North America (Table 1). Records were imported into R via the move package. We assigned all individuals to one of three age categories: juvenile (survived up to the onset of its 2nd southbound migration), sub-adult (surviving up to the onset of its 4th southbound migration), or adult (surviving past the onset of its 4th southbound migration). We incorporated into analyses instances where individuals were observed during an age-class transition. Breeding status was not considered in analyses because it was not determined for all individuals. We identified the onset of golden eagle summering behavior via a mechanistic range shift analysis in R with the marcher package. The model was fit with the maximum likelihood method, and we used the Ornstein-Uhlenbeck model option to estimate ranging behavior. We modified the MRSA slightly by forcing the model to fail if a data gap of >30 days occurred. We inspected start dates and locations to remove spurious model results due to tag deployments that ended during spring migration or began during summer. This process yielded 179 summering onset estimates with modelled start and end dates made by 103 eagles.

Table 1.

Studies used in Case Study 1, ‘long-term data reveal importance of decadal climate patterns on summering behavior in a migratory raptor’.

Study

Start

End

Animals

Summering onsets

ABoVE: USFWS R6 Golden Eagles

2015

2017

2

6

ABoVE: USGS/WVU Raptors

2013

2013

1

1

Adult Golden Eagle Satellite Tracking

2012

2017

10

18

Alaska Golden Eagles

2014

2017

33

61

Aquila chrysaetos interior west N. America, Craigs, Fuller

1993

1996

6

6

Beringia South Migrant Golden Eagle

2013

2015

1

3

Eagles Wintering in Bitterroot Valley

2013

2017

17

30

Eastern Montana Golden Eagles

2013

2017

11

20

Golden Eagle Migration, Denali, Alaska, McIntyre

1998

2000

6

6

Golden Eagles of Interior Alaska; Lewis

2015

2017

10

15

HawkWatch International Golden Eagles

2003

2008

4

9

Western GOEA Conservation

2015

2017

2

4

Case Study 2. Large-scale geographic differences in parturition timing of caribou

We used caribou movement data in 13 AAMA studies (Table 2). Among the caribou in our study, woodland caribou (Rangifer tarandus caribou) are considered a separate subspecies from barren-ground caribou (R. t. groenlandicus), which are known for their long-distance calving migrations. Woodland caribou are further classified as belonging to different ecotypes, including boreal and mountain, which differ by habitat and behavioral phenotype. Following exploratory analysis, we further partitioned woodland caribou by geographic area into northern and southern mountain and boreal caribou. Barren-ground caribou data were partitioned into their largely coherent reproductive subpopulations (herds).

Parturition dates were estimated by adapting methods described in DeMars et al. (2013) for each of the two subspecies. For R. t. caribou, we analyzed movements between April 28 and June 30 and found times when movement activity decreased suddenly and persistently below 5 threshold speeds (10, 15, 20, 25, and 30 m/h), and conservatively retained those parturitions where three of five thresholds agreed within a day of each other. For barren-ground caribou, which calve significantly later and shortly after completing a long-distance migration, we adapted the individual-based method (DeMars et al. 2013; Gurarie et al. 2019), which fits a non-calving model, in which movement rates remain constant throughout the study period, and a calving model, where there is a sudden drop in movement rate followed by a progressive increase.

Table 2.

Studies used in Case Study 2, ‘large-scale geographic differences in parturition timing of caribou’.

Study

Start

End

Animals

Parturitions

ABoVE: BC Atlin Caribou

2000

2001

7

7

ABoVE: NWT Dehcho Boreal Woodland Caribou

2007

2017

80

164

ABoVE: NWT Inuvik Barren Ground Caribou

2006

2017

193

387

ABoVE: NWT Inuvik Boreal Woodland Caribou

2002

2012

23

56

ABoVE: NWT North Slave Barren Ground Caribou: Bathurst

2006

2017

90

142

ABoVE: NWT North Slave Boreal Caribou

2017

2017

15

15

ABoVE: NWT Sahtu Barren Ground Caribou: Bluenose-East

2006

2017

103

165

ABoVE: NWT Sahtu Boreal Woodland Caribou

2007

2011

11

22

ABoVE: NWT Sahtu Mountain Woodland Caribou

2008

2010

3

4

ABoVE: NWT South Slave Barren Ground Caribou: Beverly and Ahiak

2006

2017

109

224

ABoVE: NWT South Slave Boreal Woodland Caribou

2006

2017

122

219

ABoVE: Yukon Caribou

2000

2017

71

98

Mountain caribou in British Columbia

2001

2015

90

127

Case Study 3: Temperature and precipitation response in movement rates of terrestrial mammals

We compiled movement paths for 1,720 individuals representing five mammalian species from 22 AAMA studies: black bear, Ursus americanus; grizzly bear, U. arctos; caribou, R. tarandus ssp.; moose, Alces alces; and wolf, Canis lupus (Table 3). We calculated step lengths (m) and location sampling interval (min) along each movement time series, excluding locations with sampling intervals longer than 24 hours. We annotated movement data with daily maximum temperatures (°C) and summertime precipitation or winter snow water equivalent (SWE) estimates using the Daymet data product (https://daymet.ornl.gov/). To match the temporal scale of Daymet, we aggregated movements by estimating daily mean step lengths and sampling intervals for each day within an individual’s time series. In order to reduce the influence of seasonally dependent behaviors (e.g., migration or parturition), we partitioned data into January-only (peak winter) and July-only (peak summer) datasets. As in case study 2, we treated the two subspecies of caribou (R. t. groenlandicus and R. t. caribou) as distinct groups within our analysis due to anticipated differences in daily movement rates. We also excluded bears from the winter analyses due to lack of data; however, the very nature of their hibernation represents a reduced overwinter movement rate.

Table 3.

Studies used in Case Study 3, ‘temperature and precipitation response in movement rates of terrestrial mammals’.

Study

Start

End

Animals

Species

ABoVE: BC Atlin Caribou

2000

2002

10

Rangifer tarandus caribou

ABoVE: Boutin Alberta Grey Wolf

2013

2014

20

Canis lupus

ABoVE: Boutin Alberta Moose

2010

2012

24

Alces alces

ABoVE: Hebblewhite Alberta-BC Wolves

2000

2011

53

Canis lupus

ABoVE: NPS Denali Wolves

2004

2016

68

Canis lupus

ABoVE: NPS Wolves in Yukon-Charley Rivers National Preserve

2003

2015

47

Canis lupus

ABoVE: NWT Dehcho Boreal Woodland Caribou

2007

2018

85

R. tarandus caribou

ABoVE: NWT Inuvik Barren Ground Caribou

2006

2018

264

R. tarandus groenlandicus

ABoVE: NWT Inuvik Boreal Woodland Caribou

2002

2012

26

R. tarandus caribou

ABoVE: NWT North Slave Barren Ground Caribou: Bathurst

2009

2019

172

R. tarandus groenlandicus

ABoVE: NWT North Slave Boreal Caribou

2017

2018

20

R. tarandus caribou

ABoVE: NWT Sahtu Barren Ground Caribou: Bluenose-East

2006

2019

120

R. tarandus groenlandicus

ABoVE: NWT Sahtu Boreal Woodland Caribou

2004

2011

15

R. tarandus caribou

ABoVE: NWT Sahtu Mountain Woodland Caribou

2008

2010

3

R. tarandus caribou

ABoVE: NWT South Slave Barren Ground Caribou: Beverly and Ahiak

2006

2019

156

R. tarandus groenlandicus

ABoVE: NWT South Slave Boreal Woodland Caribou

2006

2018

174

R. tarandus caribou

ABoVE: Peters Hebblewhite Alberta-BC Moose

2008

2010

18

Alces alces

ABoVE: Yukon Caribou

2000

2019

219

R. tarandus caribou

Brown and Black bear (Ursus spp.), Jerry Belant, Alaska

1998

2000

40

Ursus spp.

Latham Alberta Wolves

2006

2007

7

Canis lupus

Mountain caribou in British Columbia

2001

2016

172

R. tarandus caribou

NWT South Slave Boreal Wolves

2016

2018

7

Canis lupus