Chris Butler

Yellow Rails are secretive, nocturnal birds that breed in the northern US and Canada and winter along the coast, from Texas to North Carolina

Bookhout, T. A. 1995. Yellow Rail (Coturnicops noveboracensis). In The Birds of North America, No. 139 (A. Poole, and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists’ Union, Washington, D.C.

7 Mar 1842◦ First Yellow Rail collected

1950s – one record 1960s – one record 1970s – three records 1980s – no records 1990s – four records 21st century – Arbour found Yellow Rails to

be regular in extreme southeastern OK during autumn migration

Heck, B. A. and W. D. Arbour. 2008. The Yellow Rail in Oklahoma. Bulletin of the Oklahoma Ornithological Society 41: 13-15.

Began banding Yellow Rails in Oklahoma in 2008 in order to◦ 1.) Estimate population sizes◦ 2.) Use stable isotopes to identify where these

birds originated◦ 3.) Examine age/sex ratios◦ 4.) Examine fat deposition across months

In 2009, began collaboration with Jennifer Wilson and Charles Brower at Texas mid-Coast NWR to compare OK and TX rails

Spotlight birds and then catch them with handheld nets

Birds were banded, aged according to Pyle (2008), scored for fat, and two rectrices (tail feathers) were removed for stable isotope analysis and genetic analysis

Mark-recapture history analyzed using POPAN in program MARK

Rectrices from MB were obtained with the aid of Kristen Martin and Derek Furutani, while SK feathers came from Kiel Drake

To date, more than 100 Yellow Rails have been banded at Red Slough WMA◦ In addition, Yellow Rails have also been

encountered at other locations in SE OK during mid-winter, including Grassy Slough (McCurtain Co.) and Hugo WMA (Choctaw Co)

During 2009-10, 176 Yellow Rails were banded at San Bernard NWR, TX◦ There were 17 recaptures during this time

Date New Recaptures

10 Nov 2009 13

17 Nov 2009 5

28 Nov 2009 4

4 Jan 2010 1

5 Jan 2010 9

16 Jan 2010 25

2 Feb 2010 14 3

7 Feb 2010 14 2

13 Feb 2010 25 1

1 Apr 2010 15 3

8 Apr 2010 7 4

10 Apr 2010 17 3

13 Apr 2010 17 1

20 Apr 2010 10

Some of the birds that we banded in November were re-encountered as late as March, so we estimated the population size at Red Slough for late Nov 2009 – Mar 2010

POPAN estimate is 68 ± 18 individuals at Red Slough, 976 ± 234 Yellow Rails overwintered at San Bernard NWR

At both locations, ~4 individuals/ha

H

Per

cent

of T

otal

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5

10

15

20

25

-180 -160 -140 -120 -100

OK

0

5

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25

TXDeuterium results for Oklahoma (n = 45) and TX (n = 21) suggest that rails in TX generally came from areas with a deuterium excess of -141 ± 5 while rails from Oklahoma came from areas with a deuterium excess of -131 ± 4

However, the differences were not significant (Mann-Whitney, p = 0.17)

Deuterium

Pe

rce

nt o

f T

ota

l

0

5

10

15

20

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-180 -160 -140 -120 -100

Feather sample from MB suggests no offset

Coastal

Coastal

We obtained DNA sexes from 92 individuals , 52 of which were male and 40 of which were female.

The sex ratio for both locations combined was slightly male-biased (sign test, p = 0.038).  

However, there was not a significant difference in sex ratios between OK and TX (sign test, p = 0.5).

Of the birds captured during January through April, 133 out of 178 (74.7%) could not be assigned to a SY/ASY age class, as they showed a mixture of SY/ASY characteristics ◦ Instead, we compared the ratios of birds caught during

November and December (i.e. we compared the ratio of HY:AHY birds).

Seven of 19 birds (36.8%) captured at San Bernard NWR during this period were aged as HY, while six of 14 birds (42.9%) captured at Red Slough WMA during this period were aged as HY.

The ratio of HY:AHY (after hatch-year) birds was not significantly different between the two locations (Fisher’s exact test, p =0.99).

Birds in Oklahoma maintained more fat reserves than birds in TX◦ Out of 124 birds

banded in TX, only 1(!) had fat, which was scored as a “1” (the lowest score)

The density of Yellow Rails (~4 rails / ha) wintering in southeastern Oklahoma is comparable to the density in San Bernard NWR◦ However, drought during 2011/12 & 2012/13 greatly

reduced the number encountered in OK. The SIA results suggest that birds wintering in

OK & TX breed primarily on the Canadian prairies◦ Many samples remain to be run◦ Need to re-run samples from SK

The sex ratio was slightly male-biased with approximately equal numbers of HY/AHY birds detected

Birds in OK apparently store more fat during the winter than birds in TX

Kissimmee Prairie

PreserveSP

1.) Surveys to determine winter distribution and density of Yellow Rails should be undertaken◦ If they overwinter in southeastern Oklahoma, where else

may they occur? 2.) Winter habitat requirements should be

determined ◦ Does habitat structure or species composition affect

occupancy? What are the effects of various fire regimes? How does hydrology affect density? How may climate change affect this species?

3.) Extent of migratory connectivity in this species should be examined◦ Where do birds breeding in the eastern portion of the

range overwinter?◦ What is the best way to track movements of this species?

Thanks to ◦ UCO’s Office of Research & Grants◦ USDA Forest Service◦ USFWS◦ OSU Forest Resources Center, SW LA Refuge Complex,

and MS Sandhill Crane NWR for providing accommodation◦ David Eason, Katrina Hucks, Daniel Whalen, Nat Burgess,

Eric and Erica Judd, Jill Stinedurf, Stephen Frazee, John Polo, Monte Stone, Erica Davis, Lisa Pham, Robert and Cameron Bastarache, Emily Stine, Craig Koenigs, Son Nguyen, Erica Becker, Chris Roy, David Arbour, Berlin Heck, Kim McBride, Jennifer Curtis, Shay Still, Jeremy Young, Bryan Wilcox, Brad Rising, Paul Bjornen, Gloria Caddell, the UCO Ornithology class of 2010 & 2012, Doug Wood and Dr. Wood’s ornithology class for assistance with fieldwork