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Below, I am pasting a short paper on winter occurances of Franklin's Gulls 
in Kansas during the 1988-89 winter, which I co-authored with Lloyd Moore, 
Ted Cable and Mick McHugh.  The paper was presented to KOS. (The FRGU that I 
saw at Smithville Lake on January 7th of this year was also in nuptial 
plumage. I am writing it up for the MBRC.) I am attaching the table of 
occurrences to a second post. Please note the MO records mentioned in the 
second post..

                                            WINTER RECORDS OF FRANKLIN'S 
GULLS IN NUPTIAL PLUMAGE
R. Fisher, L. Moore, T. Cable, E. McHugh

During the winter of 1988-89, at least 21 Franklin Gulls (Larus pipixcan) 
were found in Kansas, Missouri, Iowa, and Illinois. Strangely, all were in 
high breeding plumage.


Franklin Gulls are common fall migrants in Kansas and western Missouri. They 
are less abundant but regular fall migrants in Missouri, Iowa and Illinois. 
However, most Franklin's Gulls are gone from these latitudes by 
mid-November, and during migration they are in winter plumage or molting 
into it. Their normal winter range is "the Pacific from Guatemala south to 
the Gull of Panama, the Galapagos Islands, and Chile, and along the Gulf of 
Mexico from Texas to Louisiana" (AOU 1957). Blake (1977) and Oberholser 
(1974) both report that Franklin's Gull overwinters only "casually" on the 
Gulf Coast. Records of single Franklin's Gulls wintering north of their 
normal range are not unprecedented. For example, prior to the winter of 
1988-89 there had been eight winter records for Franklin's Gull in Iowa 
(T.H. Kent, pers. comm. 30 March 1989) and six winter records for Illinois 
(R.E. Goetz pers. comm. 27 March 1989). However, the number of Franklin's 
Gulls wintering far north of their normal range during the winter of 1988-89 
was unprecedented as was the fact that they were all in nuptial plumage.


Thirty-three Franklin's gulls were reported in the four state area (Kansas, 
Missouri, Iowa, and Illinois) from December 1988 to February 1989. 
Conservatively estimated, at least 21 of these were different individuals. 
Eleven of the Kansas birds were seen on the same day, 10 together and the 
eleventh 20 miles away. Five others in Kansas and western Missouri, though 
seen on different dates, were 30 to 135 miles away. The Iowa and Illinois 
birds were also widely scattered, making it unlikely that the same 
individuals were counted twice. Table 1 presents the specific locations and 
dates of Franklin's Gull records for the winter of 1988-89.


All the reports were of birds in nuptial plumage, having bright red bills, 
full black hoods, thick white crescents above and below the eye, and whitish 
separation of the dark gray mantle from the black tips of the primaries. The 
feathers of the birds were reported as being fresh and immaculately clean. 
In bright light the breasts of several birds were distinctly pink-flushed.


The freshness of the birds' nuptial plumage appears to rule out the 
possibility of a delayed molt from the plumage of the previous spring and 
raises interesting questions why the birds remained north as though ready to 
breed when they should have gone south in winter feather. Although there 
have been previous winter records of Franklin's Gulls in nuptial plumage 
(e.g., four of the Iowa records and at least two of the Illinois records), 
the presence of so many records in a single year suggests an unusual causal 
event. Grant (1982) reports that Franklin's is the only gull to molt in both 
spring and autumn. He describes the timing of the molts as follows: autumn 
molt occurs "prior to the southward migration (from July to October) and the 
molt into summer plumage as "prior to northward migration (from November to 
April)." The period of adult/second summer plumage is given as February to 
September.


It is interesting to speculate whether physiological factors responsible for 
the unusual plumage were also responsible for the deviation from the normal 
migratory behavior. The physiological mechanisms involved in molt and 
migration are extremely complex and poorly understood. There is evidence 
that many environmental factors (e.g., length of daylight, temperature, 
alternation of wet and dry seasons, breeding stimuli, and even fright) may 
play a role in stimulating molt, and that molt may be physiologically linked 
to stages of the reproductive cycle (Welty 1975).

The unusually mild December and January may have allowed the birds to remain 
hundreds of miles farther north than usual. However, warm weather in those 
months cannot alone explain why eighteen of the birds had already completed 
the molt by Mid-January, some as early as December.


Another abnormal environmental phenomenon that may have been a stimulus for 
abnormal molt was the 1988 drought. Much of the breeding range of Franklin's 
Gulls was severely affected, resulting in habitat loss. Because molt seems 
to be related to breeding cycles and stress, attributing the abnormal 
plumage to the drought seems to be a plausible hypothesis. However, the 
hypothesis raises more interesting questions than it answers. Exactly how 
did the drought interrupt the birds' normal cycle? Did the birds undergo two 
accelerated molts (i.e. first to basic plumage, then to spring plumage) or 
did they substitute the spring molt for the one supposed to occur in fall?


The winter of 1988-89 appears to have produced an unusual number of 
exceptions to the published molt schedules and winter ranges of Franklin's 
Gull. Whatever its cause, this event may be symptomatic of profound 
environmental stresses affecting other species. Therefore, it warrants 
additional investigation.

                                                                             
                    LITERATURE CITED

American Ornithologists Union. 1957. Check-list of North American birds. 5th 
ed. A.O.U., Baltimore, MD 691 pp.

              Blake, E.R. 1977. Manual of neotropical birds. Vol. 1, 
Spheniscidae (Penguins) to Laridae (Gulls and Allies).

                              Univ. Chicago Press. Chicago. 647 pp.Grant, 
P.J. 1982. Gulls - a guide to identification. Buteo Books. Vermillion, SD. 
280 pp.

Oberholser, Harry C. 1974. The bird life of Texas, Vol. U. Texas Press. 
Austin, TX. 530 pp.

Welty, J.C. 1975. The life of birds. 2nd ed. W.B. Saunders. Philadelphia. 
623 pp.


Bob Fisher
Independence, Missouri
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