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 within the Motus system, see Tag Management.
Tag Deployment - Best Practices
Before you deploy your tags, consider the following:
Ensure local stations and any other stations you may rely on are active and working. Never assume that stations are working. Communicate with collaborators that manage stations from which you may expect detections. You may need to regularly check on stations yourself to confirm stations are functional.
Tag deployments are most effective when made in close proximity to an active station. Detections on a local station allow you to confirm your tags are working.
Be sure that tags are activated prior to their deployment using a receiver or an active Motus station.
Create a deployment with an anticipated start date prior to deployment. See Anticipated deployment date.
Plan to record the required metadata during deployment and update it as soon as you can following deployment. See Tag Metadata.
Always keep animal welfare at top of mind whenever you deploy tags. See note below:
Animal welfare should be the number one priority when tagging any species
Tag weight must include the weight of all harness materials. For lightweight species, this is especially important. Adding loops to tags for adjustable or backpack harnesses adds about 0.25-0.30 g, for instance. Due to manufacturing variance, estimating tag + harness weight is not enough on its own and fitted tags should also be individually weighed in the field before deployment.
Tags should not exceed the 3% weight rule for most bird species and 5% for bats as a general rule. However, we strongly recommend you estimate the lean (or fasting) weight of the individual for this rule. It should be possible to determine this weight using literature, or by examining your own historical banding data of this species, using wing length as a rough comparison metric.
You should consider the how fat loading may impact the size of the bird when fitting a tag to a bird using any of the 3 harnessing methods listed below. In other words, you should consider putting tags on as loosely as possible for individuals that are expected to gain a lot of fat after tagging occurs.
How to tag animals
As is the case for any new measurement technique for wild animals, researchers should always have in-person training on any tagging method before deploying tags on their own. In addition, tagging animals is hard and requires extensive experience handling birds of various sizes and species before learning how to tag.
This section is still in development as we continue to create guidelines and videos on various methods for tagging animals safely and effectively.
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.
Figure-8 Leg Loop Harness
Methods
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 for more information.
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
29
8
1
Orange-crowned Warbler
29-32
8-10
4
Kentucky Warbler
34-35
12-15
2
Hooded Warbler
30-34
9-14
4
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
Fox Sparrow
48-50
37-44
20
White-crowned Sparrow
44
31
1
White-throated Sparrow
45-50
23-31
100+
Savannah Sparrow (Typical)
38-40
20-25
84
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
Cerulean Warbler
26-28
?
?
Video
Adjustable Leg Harness
Methods
There is currently no SOP drafted for this method, but researchers can follow instructions published in:
Video
Backpack Harness
Glue on
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:
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 for more information.
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
29
8
1
Orange-crowned Warbler
29-32
8-10
4
Kentucky Warbler
34-35
12-15
2
Hooded Warbler
30-34
9-14
4
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
Fox Sparrow
48-50
37-44
20
White-crowned Sparrow
44
31
1
White-throated Sparrow
45-50
23-31
100+
Savannah Sparrow (Typical)
38-40
20-25
84
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
Cerulean Warbler
26-28
?
?
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!
Tag AliasingLast updated
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