Tag Deployment

Everything you need to know about deploying tags

Tag Management

This chapter pertains to tag deployment methods in the field. For information on the management of tag deployment metadata withing the Motus system, see Tag Management.

How to tag animals

This section is still in development as we develop guidelines and videos on various methods for tagging animals safely and effectively.

Draft guidelines and SOPs

The following documents are drafts and should be used with caution until the final documents are published. That said, we have opted to make these documents available due to the number of requests from the research community. If you plan to share the documents, we recommend sharing links to this page to minimize circulation of outdated versions once the final documents are published.

Instructional videos

Instructional videos on how to tag videos can be found in the next section.

pageInstructional Videos

Trimming tags

There are a number of researchers who opt to cut the antennas of tags when deploying on smaller animals. Basic antenna theory suggests it will decrease the effective power of the transmitter, but more testing is needed to determine the magnitude of this decrease when deployed on animals. Controlled tests have shown that OOK tags (166.380 MHz) will decrease in power with length, but are most effective when cut to specific lengths (harmonics of the nominal frequency). On the other hand, FSK tags (434 MHz) appear to decrease continuously with length, not showing better performance at specific lengths like OOK tags. These tag tests were not done on animals and will likely be different in real deployments.

That being said, if you're planning on trimming one of your Lotek tags, you should aim for one of these lengths to maximize the effect power:

FrequencyLengths

166.380 MHz

18.0 cm, 15.0 cm, 12.9 cm, 11.3 cm, 10.0 cm, 9.0 cm, 8.2 cm, 7.5 cm, 6.9 cm, 6.4 cm, 6.0 cm, 5.6 cm

151.5 MHz

19.8 cm, 16.5 cm, 14.1 cm, 12.4 cm, 11 cm, 9.9 cm, 9 cm, 8.2 cm, 7.6 cm, 7.1 cm, 6.6 cm, 6.2 cm

150.1 MHz

20 cm, 16.6 cm, 14.3 cm, 12.5 cm, 11.1 cm, 10 cm, 9.1 cm, 8.3 cm, 7.7 cm, 7.1 cm, 6.7 cm, 6.2 cm

Tag Harness sizes

This table lists harness sizes for the pre-fabricated ‘figure eight’ leg loop harness method based on real sizes used on individuals tagged in the field. Sizes include the length of a single leg-loop, not include overlap with the tag. Weights can be used to help specify which harness size to use.

Please note that these are guidelines. Regardless of what sizes you find here, the harness should always be fitted to the individual. Please see a How to Tag Animals above for more information.

SpeciesHarness Size (mm)Weight (g)Wing (mm)Sample size

Yellow-billed Cuckoo

50-61

43-80

10

Black-billed Cuckoo

52

34

1

Hammond's Flycatcher

29

9.5

1

Dusky Flycatcher

34

1

Say's Phoebe

37

23.5

1

White-eyed Vireo

28-34

9-12

5

Warbling Vireo

33-35

13-14

3

Red-eyed Vireo

39-42

15-20

100+

Bank Swallow

32-34

10-13

50+

Barn Swallow

34-37

17-19

80+

House Wren

33

11

1

Eurasian Reed Warbler

30

9-13

60+

Gray-cheeked Thrush

50-54

26-37

30+

Bicknell's Thrush

46-50

24-30

12

Swainson's Thrush

48-52

25-36

100+

Brown Thrasher

62

67

1

Golden-winged Warbler

27-30

58-65

51

Orange-crowned Warbler

29-32

8-10

4

Kentucky Warbler

34-35

12-15

2

Hooded Warbler

30-34

9-14

4

Cerulean Warbler

26-28

Magnolia Warbler

24-28

?

Blackpoll Warbler

33-36

10-22

200+

Black-throated Blue Warbler

26-28

?

Palm Warbler

26-34

9-12

5

Yellow-rumped Warbler (Myrtle)

31-34

10-15

100+

Prairie Warbler

26-29

7-10

7

Canada Warbler

34

10-12

?

Yellow-breasted Chat

40-42

22-25

4

Saltmarsh Sparrow

36-39

18-20

60+

Clay-colored Sparrow

30-31

9-12

7

Field Sparrow

30-32

12-13

6

Lark Sparrow

32-42

20-28

1

White-crowned Sparrow

44

31

1

White-throated Sparrow

45-50

23-31

100+

Savannah Sparrow (Ipswich)

38-44

21-30

100+

Eastern Towhee

50

40

1

Summer Tanager

39-40

26-27

2

Blue Grosbeak

37

26

1

Indigo Bunting

34-36

14-17

10

Painted Bunting

34

1

Dickcissel

38-44

22-32

3

Orchard Oriole

40-42

19-22

2

How to avoid tag aliasing

Aliasing can occur when multiple tags emit a signal at the same time. Sometimes these interacting signals can produce a pattern which match a different tag that is not actually present. This is due to the nature of how the unique tag ID is encoded in the signal. However, the parameters used to define these IDs are quite stringent, making aliasing only an issue in specific conditions.

Strategic tag deployment

To help mitigate aliasing, we recommend keeping numbers low at any given tagging site. This can be done by staggering deployments, either spatially or temporally. Most aliasing is caused by tags which have the same burst interval but a different Lotek ID. That means if you have more than one burst interval in your selection of tags, you can deploy more tags at any given site with a reduced risk of aliasing. However, do not deploy more than one tag with the same Lotek ID, even if they have different burst intervals!

Read more about how to avoid tag aliasing.

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