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W.B. Krohn

Publications and source records attributed to W.B. Krohn.

27 records · Page 2Linked to original sources
USGS1977

Band recovery distribution of eastern Maine woodcock

A total of 9,643 American woodcock (Philohela minor) was banded in eastern Maine during the summers of 1962-74. The fall migration of these woodcock, based on 620 recoveries, occurred along a broad front between the Appalachian Mountains and Atlantic Ocean. Most birds wintered in a region extending from southern Virginia to northern Florida; a few woodcock moved as far west as Louisiana and eastern Texas. The band-recovery distribution of Maine woodcock, and band-recovery records from birds wintering in Louisiana published by other investigators, support the idea of Atlantic and Central flyways. However, recoveries from woodcock banded in breeding localities other than eastern Maine must be studied to more precisely relate major breeding and wintering grounds

Wildlife Society Bulletin↗
USGS1975

Search for blood protozoans in the American woodcock

Smears were prepared from heart blood of 55 woodcock collected in central Maine between spring and fall, 1972 and 1973. Peripheral blood taken from the wings of 41 of these birds also was examined. Examination of stained films revealed no infected blood cells. Samples of heart blood from 35 of the 41 woodcock were injected into young ducks, quail, and a gull. Plasmodia were not seen in inoculated birds.

Maine↗
USGS1973

Molt patterns and weight changes of the American woodcock

A study of molt and changes in body weight of American Woodcock was conducted to better understand the summer and fall behavior of these birds and to indicate periods of physiological stress. The postnuptial molt of adults was a complete molt beginning in late June and ending by the middle of October. In contrast, the postjuvenal molt was a less intensive partial molt beginning in mid-July but also extending to the middle of October. Both male and female adult birds experienced weight loss in August during peak molt. Young birds gradually gained weight throughout the summer. Fat deposition was negatively correlated with molt while fall body weights were positively correlated with fat deposition. The data indicated that the majority of Maine woodcock are not physiologically prepared for migration until mid-October. Weights of adult males during the spring suggested that this is an important period of stress for these birds.

The Wilson Bulletin↗
USGS1971

Some patterns of woodcock activities on Maine summer fields

Certain aspects of woodcock usage of summer fields were studied in Maine. Findings were as follows: ....1. On two study fields in 1968, numbers of woodcock first began spending nights in the fields during the second week of June. During 1968 and 1969, the number of birds flushed from the fields varied greatly between nights. Use of fields continued into the first week of November......2. Woodcock started flying into summer fields approximately 26 minutes after sunset. Unless disturbed, birds remained on fields throughout the night and started departing for diurnal covers about 48 minutes before sunrise. The duration of evening and morning flight periods averaged 13 to 15 minutes.....3. Woodcock did not necessarily use the same field throughout the summer. Five of the 36 birds taken as repeats were caught on fields other than where originally banded. However, it was believed that flights to and from fields were essentially local movements.....4. Vegetation appeared to have been a critical factor influencing the distribution of woodcock in fields. Areas of low ground cover interspersed with taller and denser cover were used most frequently.....5. Immatures, especially immature males, were the predominant age-sex class captured on Maine summer fields. The question of whether the age-sex composition of birds using summer fields is atypical of the total woodcock population requires additional study.

The Wilson Bulletin↗
USGS1970

Woodcock feeding habits as related to summer field usage in central Maine

In 1968 and 1969, 60 American woodcock ( Philohela minor ) were collected before and after alighting on summer fields in central Maine. A comparison of stomach contents from these birds showed that woodcock fed prior to entering fields at dusk. No evidence was found to indicate that any substantial amount of food was eaten by birds remaining on fields throughout the night. In 1968, the availability and abundance of known woodcock foods were measured in 30 soil samples from one field. Few woodcock foods were found in samples located randomly and at flush sites, thus providing no evidence that birds selected sites where soil invertebrates were concentrated.

Maine↗