Split Bird Rings

Porzana makes a full range of split bird rings from sizes 2.0 mm diameter to 22.0 mm, plus clip rings and special rings for Guillemot, Razorbill and others. Rings for use on smaller short-lived species are made from a magnesium-aluminium alloy, and incoloy (a nickel-chromium alloy) is used for most large long-lived species and where excessive abrasion or exposure to saline or alkaline water would shorten ring life. For cost reasons, stainless steel is used for rings with a diameter greater than 12.5 mm. Although incoloy is a more expensive metal it is more durable than stainless steel and is also preferred by our customers due to its better handling qualities, the rings being easier to close and less susceptible to 'spring-back' than pure steel. Most of our aluminium alloy rings are 'C' shaped whereas the harder incoloy and steel rings are 'V' shaped for easier and better closing.

Porzana also supplies a range of specialised pliers designed for use with our rings (see Equipment).The BTO Ringer's Manual includes a useful section on closing rings which can be downloaded using the following link: Fitting Rings (PDF) Download

The table below shows the standard ring sizes produced, along with the equivalent British Trust for Ornithology (BTO), Australian Bird and Bat Banding Scheme (ABBBS) and US Fisheries and Wildlife Service (USFWS) reference codes. The internal diameter is the diameter of the ring when closed.

Internal Diameter

BTO
Ref

ABBBS
Ref

USFWS
Ref

Metal Height
& Gauge

Ring
Shape

Number
Height

Rings per Packet

1. Aluminium Alloy Rings

2.0 mm

AA

01

0A

5.5 x 0.38 mm

C

1.6 mm

100

2.3 mm

A

02

1

5.5 x 0.38 mm

C

1.6 mm

100

2.8 mm

B

03

1B

5.5 x 0.50 mm

C

1.6 mm

100

3.3 mm

04

1A

5.5 x 0.50 mm

V

1.6 mm

100

3.5 mm

CC

1D

5.5 x 0.50 mm

V

1.6 mm

100

4.0 mm

05

2

5.5 x 0.50 mm

V

1.6 mm

100

4.3 mm

C

2A

7.0 x 0.60 mm

V

1.6 mm

100

4.5 mm

06

7.0 x 0.60 mm

V

1.6 mm

100

5.25 mm

D

3B

7.0 x 0.60 mm

V

1.6 mm

100

2.5/4.0 mm

SO

K

4.0 x 0.38 mm

1.6 mm

50

2. Incoloy Rings

2.3 mm

A2

1

5.5 x 0.35 mm

V

1.6 mm

100

2.8 mm

B2

03

1B

5.5 x 0.35 mm

V

1.6 mm

100

3.3 mm

B+

04

1A

5.5 x 0.35 mm

V

1.6 mm

100

4.0 mm

05

2

5.5 x 0.35 mm

V

1.6 mm

100

4.3 mm

C2

2A

5.5 x 0.35 mm

V

1.6 mm

100

4.5 mm

06

5.5 x 0.35 mm

V

1.6 mm

100

4.75 mm

3

5.5 x 0.35 mm

V

1.6 mm

100

5.25 mm

D2

3B

7.0 x 0.56 mm

V

2.4 mm

100

5.5 mm

07

3A

7.0 x 0.56 mm

V

2.4 mm

100

6.35mm

4

7.0 x 0.56 mm

V

2.4 mm

100

7.0 mm

Esp

4A

7.0 x 0.56 mm

V

2.4 mm

50 or 100

8.0 mm

5

9.0 x 0.85 mm

V

3.2 mm

50 or 100

9.0 mm

FV

9.0 x 0.85 mm

V

3.2 mm

50 or 100

9.5 mm

6

9.0 x 0.85 mm

V

3.2 mm

50 or 100

11.0 mm

G

7A

9.0 x 0.85 mm

V

3.2 mm

50 or 100

12.5 mm

H

7

9.0 x 0.85 mm

V

3.2 mm

50

9.0 mm

FC

8.7 x 0.60 mm

C

3.2 mm

50

Razorbill

Raz

5R

9.0 x 0.85 mm

3.2 mm

50

Guillemot

Guil

6M

9.0 x 0.85 mm

3.2 mm

50

16.0 mm

8.7 x 0.60 mm

Clip

3.2 mm

10

19.0 mm

8.7 x 0.60 mm

Clip

3.2 mm

10

22.0 mm

8.7 x 0.60 mm

Clip

3.2 mm

10

26.0 mm

M. Inc

8.7 x 0.60 mm

Clip

3.2 mm

10

3. Stainless Steel Rings

11.0 mm

GG

11

7A

12.0 x 1.00 mm

V

3.2 mm

50

12.5 mm

27

7

12.0 x 1.00 mm

V

3.2 mm

50

14.0 mm

J

12

7B

12.0 x 1.00 mm

V

3.2 mm

50

16.0 mm

K

13

7D

12.0 x 1.00 mm

V

3.2 mm

50

18.0 mm

28

8

12.0 x 1.00 mm

V

3.2 mm

50

19.0 mm

L

14

12.0 x 1.00 mm

V

3.2 mm

50

22.0 mm

15

9

12.0 x 1.00 mm

V

3.2 mm

50

26.0 mm

Mb

15

9

12.0 x 1.00 mm

Clip

3.2 mm

10

Although the standard list of products should cover most requirements, special orders for unusual ring sizes, shapes or numbering requirements can also be considered on request. In recent months these special orders have included field-readable rings for Puffin, Greater Flamingo, Roseate Tern and Blue-footed Booby.

For full pricing information and quotes please contact Shane Muggridge (porzana@bto.org)


ADDRESSES AND NUMBERING

Although a few customers require just a simple number to be stamped on the rings, most also require an address. The amount of information that can be stamped on a ring is dependent on the size of the ring, and the table below describes the limits. For example a 2.0 mm diameter ring can have two lines of address each with a maximum of 9 characters plus a 6 character number. Typically the number will comprise of a one or two character prefix and then the number (e.g. A00001 or AB0001). It should be emphasised that these are the maximum characters and numbers that can be shown on the ring, and for clarity it is advisable to keep the address and numbering system as simple as possible.

Address Die

Numerator

Internal
Diameter

Metal
Height

Max
Lines

Max
Characters

Max
Height

Number
Size

Max
Digits

Alloy Rings

Die 1

2.0
mm

5.5
mm

2

9

1.0

1.6

6

Die 2

2.3-2.8
mm

5.5
mm

2

11

1.0

1.6

7

Die 3

3.3-5.25 mm

5.5 & 7.0
mm

2

16

1.0

1.6

7

Die 4

2.5-4.0
mm

4.0
mm

1

11

1.0

1.6

7

Incoloy
& Stainless
Steel
Rings

Die 5

2.3-2.8
mm

5.5
mm

2

11

1.0

1.6

7

Die 6

3.3-4.75 mm

5.5 & 7.0
mm

2

16

1.0

1.6

7

Die 7

5.25-7.0 mm

7.0
mm

2

23

1.25

2.4

7

Die 8

8.0-12.5 mm

8.7 & 9.0
mm

2

28

1.75

3.2

7

Die 9

14.0-22.0 mm

12.0 x 1.00
mm

2

36+

2.5

3.2

7

The standard numerator used on 8.0 mm rings and above is 3.2 mm in height but a larger 5.0 mm numerator can be used on the wider stainless steel rings of 11.0 mm diameter upwards on request, however this numerator has a maximum of 5 digits.

To cover the complete range of ring sizes a total of nine address dies is optimal, although smaller dies can be used on larger rings of the same metal type (for example a die made for a 5.25 mm incoloy ring could be used on a 12.5 mm incoloy ring). The manufacture of address dies has to be subcontracted to a specialist engraving company but a quotation for the cost of producing these dies can be obtained on request. The dies are retained at the factory for future orders.

New customers deciding on a numbering scheme should give careful consideration to the number of characters that they wish to use, and whether they wish to differentiate between the various ring sizes by using prefixes. It is advisable to avoid the use of characters that are easily confused with similar letters or numbers, for example if 'E' is used then 'F' should be avoided, or if 'C' is used then 'G' should be avoided. On smaller rings, suggested letters to avoid are: F, G, I, M, O, Q, S, U, W and Z wherever possible.