Agassiz Association. Wilson Ornithological Chapter.

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Ducks; Effect of Postponed Moult in Certain Passerine Birds; Prelim-
inary Pheaant Studies. By C. William Beebe, Curator of Birds. Zoo-
logical Scientific Contributions of the New York Zoological Society,
Vol. 1, Nos. 12-15.

The Extermination of America's Bird Fauna. By E. W. Shufeldt.
Separataftryk Af, "Nyt Magaziu for Xaturvidenskaberne. " Chris-
tiania. 1914.

Osteology of the Passenger Pigeon (Ectopistes migratorius). By
R. W. Shufeldt. From "The Auk," Vol. XXXI, No. 3, July, 1914. Pp.
358-362.

Notes on the Louisiana Clapper Rail (Rallus crepitans saturatus) in
Texas. By George Finlay Simmons. From "The Auk," Vol. XXXI,
No. 3, July, 1914. Pp. 363-384.



Correspondence 157

okxitiiological journals eeceived.

The Auk, A'ol. XXXI, April aud July, 1914.

Bird-Lore, A^l. XVI, Nos. 2, 3, 4. 1914.

Bluebird, Vol. VI, Nos. 10 and 11. 1914.

The Condor, Vol. XVI, Nos. 2, 3, 4. 1914.

The Oregon Sportsman, Vol. II, Nos. 4, 5, 6, 7. 1914.

The Oriole, Vol. II, Nos. 1, 2. 1914.

The Taxidermist, Vol. 2, No. U. 1914.

Our Feathered Friends, Vol. I, No. 4. 1914.



CORRESPONDENCE

A REJOINDER.
By T. C. Stephens.

There appears in a recent number of the Auk" a criticism by W. L. M.
of some -work which has appeared from time to time by students of the
Macbride (Iowa) Lakeside Laboratory. Inasmuch as the present writer
is largely responsible for this work, and iuasmucli as similar work may
appear in the future, it becomes a duty to ascertain to what extent the
criticisms are groundeil.

The criticism is directed wholly at such parts of the work as relate to
the food of nestling birds, a field which seems to be guarded zealously
by the critic as the peculiar domain of the Biological Survey.

Let us examine specifically some of the objections raised. He charges
the workers with "over-enthusiasm" (a statement rather too vague to
detain us), and goes on to say that it is a grievous fault "to publish
identifications that could not possibly have been made under the
circumstances. ' '

Truly, this is a bold and sweeping accusation. Upon wliat does our
rash reviewer base- his confidence ? W. L. M. further says, ' ' Now the
positive identification of a mosquito, and the distinguishing of the house
and stable flies, two obscurely marked species of the same family, require
far closer and more definite observation than could possibly be made on
specimens in process of being fed to nestling birds."

This criticism is directed at Gabrielson's work on the catbird (Wils.
Bull., XXV, Dec, 1913, pp. 179-180), where, in Table III, 99 "Flies"
were recorded as being fed to the young over a period of ten days; and
in which the text says ' ' The flies were mostly fish flies, tliough house and
stable flies were also noted. ' '

* The Auk, XXXX. July, 1914, pp. 420-421. "W. L. M." presumably stands
for W. Li. McAtee, of the Biological Survey, but inasmuch as his name does
not appear on the editorial staff, and not having been introduced by the
Editor of The Auk, the writer regrets to be compelled to refer, in the present
note, simply to the initials as signed.



158 The Wilson Bulletin — No. 88

Now the uest of the catbirils was in a bush located on a stee}- hillside.
The blind being higher, enabled the observer to see over and around the
bushes. Flies SAvarmed aliout on the foliage of these bushes, and the
observer in the blind could see the catbird capture them and feed them
To the young birds in the nest. A number of these flies were caught and
submitted to an entomologist from Ames College, who was teaching that
subject at the laboratory, and who named the tiies as above. The paper
did not state that every fly fed to the young birds was recognized as to
kind. In the tables II and III they are simply listed as "Flies." The
enumeration in the text may have been based upon specific data, or it may
have been a general estimate leased upon memory, and still lie an
accurate statement.

The original statement is perfectly safe, and scientifically accurate,
notwithstanding the obstinate misinterpretation by the critic.

Now, in regard to the mosquitoes, which are also denied by AV. L. ]\[.
in the statement above quoted. The one mosquito recorded in the cat-
bird paper (page 179) was obser\ed under the following circumstances,
as communicated to me by the author of that paper: "The old bird was
on the nest, and I was in the blind. As it was only 8:00 a.m., a few
mosquitoes were still about. One in the blind buzzed around my face,
and I struck at it with my hand. It flew out of the peep-hole, and as
I idly followed its flight it lighted on a leaf within six or eight inches of
the nest. The old bird immediately snapped it up and fed it to one of
the nestlings. ' '

With reference to the mosquito records in the Yellow Warbler study
(Wils. Bull., XXV, June, 1913, p. 5.5), I can only call the reader's atten-
tion to the fact that as the observer sat in the blind, the nest was almost
as close to his eyes as is a newspaper while being read — not over two
feet away. The bill of a Yellow Warbler is only 3.5 mm. wide at its
base, while the terminal third of it is not over a single millimeter in
width. Thus even the body of a mosquito could scarcely be entirely con-
cealed in the bill of such a bird. I am well aware that it is almost
a waste of time to be discussing the question whether .a mosquito was ac-
tually seen or not; lint I would simply remark that when the possibility
of it is so evident, it would seem that the critic is rather forcing an issue.
When we admit the possiliility of seeing one mosquito, the repetition
of it, even to sixty-five times, should give us no greater concern.

Our captious reviewer displays a lack of knowledge of this kind of
field work, and its methods, when he questions an observer 's ability to
count 5, 6, or 7 Mayflies in the beak of a Brown Thrasher at the nest.
May I be permitted to call attention to a few elementary facts ?

The date on which these seemingly large numbers of Mayflies were
recorded was June 28, at which time the Mayfly swarms Avere at their
maximum. In the evening dense clouds of them filled the air, and during
the day the grass was full of them. Frequently the old l)irds fed in the



Correspondence 159

grass ill c-losc proximity to the nest, where they \\ere uiider observation.
In a few instances the Mayflies were counted as they were being gathered.
On this date 244, counted, Mayflies were fed to the young.

Usually the old bird pauses an instant at tlie nest before feeding,
during which time there is au excellent opiiortunity for counting. In
fact, Mr. Gabrielson tells me that this summer, while watching a Eose-
breasted Grosbeak's nest, he was able, by making a slight noise, to hold
the male on the edge of the nest for three minutes, by the watch, while
trying to determine the contents of its beak. I wish I might assure the
critic that it is not surprising for the bird to have so many Mayflies in its
beak; neither is it, under the circumstances, particularly difficult to
count that number of them.

The ants may be discussed in a similar way. I think no more than
three ants were recorded at any single visit. In all of these records, it
is understood, I had supposed as a matter of course, that the number
recorded were seen and counted; but it was not claimed, nor was it in-
tended to convey the impression, that no more were in the bird 's bill.
For instance, if the old bird visits the nest with a beak full of ants,
and the observer could distinguish the bodies of three individuals, it
would be ridiculous to assume that no more than three were in the
bird's mouth. This is so elementary!

It will be found that in Gabrielson 's report on the Brown Thrasher
study, in Table I, the plus sign was frequently used to indicate that a
certain number of individual insects were recognized out of a larger
number. In this report (Wils. Bull., XXIY, June, 1912, p. S4) there will
be found the following statement : "It Avill be noticed in the tabulated
data that the number of insects was not always determined exactly, but
was entered in this manner, '6+ Mayflies,' etc. In all such cases
the minimum number was used in computing the tables. As all of the
persons who assisted were cautioned especially to note the number of
insects exactly, it is safe to assume that if there be any error in the data
it is in having recorded too few insects, rather than too many. ' '

The reviewer then believes he has given sufficient illustrations of the
inaccuracy of the work to demolish it completely, and proceeds with this
ex cathedra pronouncement : "It should be recognized that reporting on
the food of nestling birds on the basis of field observation is work for
accomplished entomologists, not for amateur ornithologists, ' ' with em-
phasis, perhaps, on the "amateur." Of course, no one will dispute this
statement, although the work is more likely to be done by an ornitholo-
gist who knows some entomology, than by an ' ' accomplished entomolo-
gist." The only fault with such a remark is the animus revealed by it,
which does not beget confidence or friendliness. The reviewer is expected
to give more conclusive proof of inaccuracy before indulging in such
caustic comment.

The very excellent pioneer report on the nest study of the Chipping



160 The Wilson Bulletin — No. 88

Sparrow by Dr. C. M. AVeed* is cited as a model, because of the iu-
definiteness of identification of the food fed to the young sparrows. This
nest of tlie chippy Avas "near" a window, from which it was watched;
but nothing further was stated to enable one to know whether the
distance was two feet or ten feet, or whetlier it was watched through an
open or closed window. It is only fair to the authors of this paper to
quote from page 109 as follows: "The precise determination of the
most of the food brought was, of course, impossible, the observations
having been undertaken especially to learn the regularity of the feeding
habits of the adult birds. ' ' Since this study was not undertaken for the
purpose of determining the nature of the food, it hardly seems proper, in
fairness to the author, to set it up as an example of this line of work.

The reviewer's proposal to tie bags over the anal orifices of nestling
birds for the purpose of collecting the excreta will be highly amusing
to anyone who has noticed young birds in the nest. However, any sug-
gestion coming from so well qualified a critic deserves attention, and the
writer will endeavor to try out this new method at some future time.

As another suggestion that the authors of the several papers reviewed
may have been deceived in their observations the reviewer has said, "A
great many birds feed by regurgitation and the food is at no time
visible. ' ' We take it that the reviewer here has in mind passerine birds,
since no other order was involved in the discussion.

In our studies on the passerine birds we have succeeded in following
the feeding of at least one out of a brood, from the moment it left the
egg until it left the nest, in the cases of the yellow warbler, the catbird,
and the meadowlark (report on the last having not yet been published) ;
and in each of these instances there has been no feeding by regurgita-
tion. This is known simply from the fact that the food has been
visible in the bird's bill. It is quite possible, of course, that regurgi-
tation may be found to be practiced by certain passerine birds, such as
the flycatchers and the grosbeaks, and it is just such questions which can
be settled by field observation. (I am not now considering the carry-
ing of berries in the throat of a waxwing as coming under the definition
of regurgitation.)

The reviewer's confession of limited experience in field work of this
kind is sufficient reason in itself to make him more cautious of such
vigorous, though quibbling, criticism.

It would seem that he is very skeptical of the value of field observa-
tions on the food of nestling birds in any case. It is to be assumed
that he relies wholly upon the examination of stomach contents. But
there are limitations to that method also. The examination of a stomach
will give, at best, the story of only three or four hours of the bird's
life. Even with the food mass in a watch glass, some of the material
must be macerated beyond recognition. What is unrecognizable cannot

* Weed Clarence M. An Observation on the Feeding Habits of the
Chipping Sparrow. X. H. Agric. Exp. Sta. Bull. 5.j, 1898, pp. 101 -llo.



Correspondence 161

be taken into account, except as "unknown" or as "miscellaneous."
If the tables or diagrams do not show this must we not conclude that
the writer has discarded the unidentified material? Wilcox,^ v,ho ex-
amined over 200 stomachs of the robin in one year, says: "The
determination of insect remains in the stomachs of birds is a very
difficult and i^erplexing task, and one which is not all pleasant, since
nearly all the material is in the very worst condition imaginable, and
mutilated and jiartly digested fragments of several species of insects
being mixed up in utter confusion. The elytra, mouth parts and tarsi
are, of course, usually left to tell their tales, as are also the harder parts
of all other insects, snails, myriapods and the seeds of the various fruits;
but the soft bodied larvae and earthworms are too often macerat>id almost
beyond recognition." (p. 118.)

Too often the adherent of stomach examination publishes only his
percentage results, without the detailed data upon which his percentages
are based, which are necessary in a strictly scientific piece of work.

Most ornithologists. will concede that field observations on the food of
birds possess certain advantages; those who have had much practice
in this method will understand that it yields results with far greater
accuracy than its critics are ready to admit.

No field worker, I presume, would claim that field observations alone
would give us a full knowledge of the economic status of a species. It
will be claimed, however, that such observations contribute to such knowl-
edge very largely, if not with parity, in comparison with other methods.
Furthermore, this method is not destructive of life, which would become
a fact of importance in the study of any rare species. It is not par-
ticularly reassuring to read the boast of having killed so many thousands
of nestling birds in order to determine what their food had been for
the last two or three hours. The writer recognizes that under certain
circumstances it may be justifiable, but nevertheless, in the judgment of
many this criticism will apply to the stomach method.

It would seem, when a careful review is made, that the hypercritical
apostle of stomach examination ought to be more cautious whither he
slings. To paraphrase the revie^^er's closing remark, what is needed
above all on the part of iconoclastic reviewers is more certainty and less
quibbling, and more hard work in the field and laboratory that there
may be developed an appreciation of the difficulties to be encountered
in productive efl^^ort.

Sioux City, Iowa.

* Wilcox, E. V. Bull. 43, Ohio Agric. Exp. Sta., 1892, pp. ll.j-1.31.





_ ,.€S^iiisZi>,2Si




The Site of the Roost.

Upper, from the South-east. Middle, from the North-east.

Lower, from the West.



THE

WILSON BULLETIN

NO. 89.

A QUARTERLY JOURNAL OF ORNITHOLOGY

VOL. XXVI DECEMBER, 1914. NO. 4



OLD SERIES VOL. XXVI. NEW SERIES VOL. XXI.



NOTES ON A NORTHERN ROBIN ROOST.^

BY ARTHUR R. ABEL.

The Robin roost to be here described w^as located within
the city Hmits of Sioux City, Iowa, in fact in a rather closely
built up district of the city. The flight to the roost was first
noticed about August 7, 1914, although no record was made
at this time.

However, by the fifteenth the regularity of the flight had
been noted and it was decided to determine its origin and des-
tination. At this time the birds were flying in considerable
numbers, from northeast to southwest, over Newton St. and
the College Campus. On this evening the flight was watched
on Newton St. from 7 :lo to 7 :28 when the flight practically
ceased, and eighty-five birds had been counted.

On the evening of August 16th, the birds were first noticed
at 6 :50, and from this time to 7 :30 110 birds flew over the
route. By the thirtieth the numbers were considerably aug-
mented, and I had planned to work over toward the north-
east in hope of ascertaining how far they came.

Accordingly I left about six o'clock and went northeast-
ward until I reached the ravines north of ^Morningside known
as North Ravines. The country here was very hilly and the

' Read before The Sioux City Bird-Stiuly Club, Nov. .^d. 1014.



166 The Wilson Bulletin — No. 89

flocks were seen first as they came over the ridge of the hills.
I kept on going northeastward thinking that each hill con-
cealed the ravines where the flocks formed. Each time how-
ever I was disappointed and was forced to go still farther on,
until at last about dark I saw a few flocks fly out of a ravine
about one and one-half miles from Newton St. This how -
ever did not prove to be the source of the supply for the next
day about noon this ravine was deserted, proving that the
flocks stopped only for a brief rest. On the same evening (the
30th.) we were surprised to find many kingbirds flying over
the same route. The kingbirds, however, flew somewhat earl-
ier than the Robins, although part of the time the flight was a
mixed one. The last of the flight consisted entirely of robins,
which flew until it became dark.

The Robins flew faster and with more rapid wingbeats than
the Kingbirds. The observations of this evening made clear
that the flocks gathered over a very large territory, and were
formed by additions from the many ravines east of town. A
word of explanation might be made as to the use of the term
" flocks " in this connection. At the best time of the flight
the birds came stringing in almost continuously, sometimes
singly or in pairs, and sometimes in groups of from ten to
twenty ; often it required alertness to keep the count correctly.
On the evening of the thirtieth, at a point about two miles
west of where the roost was subsequently found. I counted
226 robins and 93 kingbirds.

On the next evening I went in the opposite direction, and
found at some distance southwest of the college, the robins
were flying in a direction reverse to that of the night before ;
this suggested that the roost might be nearer to the college.

On the evening of Sept. 1st, the roost was located in a small
wooded hollow adjoining the athletic field. The central clump
was composed of about fifty rather tall box-elder trees, pretty
well crowded together so that the foliage was dense enough
and high enough to afiford protection and shelter. To the
north there were a good many scattered trees, but on the east
there was a large open space occupied by the athletic field,



Abel — A Winter RornN Roost 167

which afforded an excellent place for counting. ' To the south-
east there were a good many trees but they seemed to disre-
gard them and fly directly over. At 6 :27 p. m. most of the
birds had congregated, and a few Kingbirds were also seen
among the robins.

On the evening of Sept. 2, the roost was visited at 6 :30
and only four Robins were counted in the trees. The first
birds to fly in from the east came at 6 :43 and from this on
they came in from the east with rapidity until 7 :30 when it
became too dark to see or count them. By this turn we had
counted 302 Robins entering the roost from the north and east.




Territory where the Flocks Gathered.
Typical ravine in wliicli Robins feed during tlie day.

The Kingbirds had vanished — none were to be seen, although
a single one was seen in the roost 'early the next morning.
The cold night of Sept. 1st, had probably been too much for
them. It was decided to visit the roost early the next morn-
ing in order to see how it would break up. So at 3 :45 A. M.
we were on the ground, but everything was so quiet and dark
and cold that we sought shelter. Returning at 4:55, we
heard the first Robin chirp at 5 :05. At 5 :10 several flew si-
lently from outside trees to the main roost. At 5:15 we



168 The Wilson Bulletin — No. 89

could say that morning had dawned, and a chorus of chirps
and calls beg-an which did not quiet down until the roost had
been vacated. At 5 :21 the first bird flew out. At 5 :32 the
calling became much louder, and we heard the call which can
be best expressed by " whe-ap." At 5 :25 the disturbance be-
came quite general and there was considerable uproar, and
much flying about among the trees.

At intervals about twenty-one mourning doves flew from
outside trees and the main roost. At 5 :20 a Blue Jay called
and was answered two or three times by other Blue Jays ; this
seemed to stir the Robins up a little, and they began to leave
in large numbers. Among other birds heard in and about
the roost at this time might be mentioned the Baltimore Ori-
ole, several Goldfinches, a Downy Woodpecker, and several
Chickadees ; while on Sept. 24th, about 100 Blue-bi-rds' rested
there over night. At 5 :45 about a hundred Chimney Swifts
appeared, probably coming from a large chimney of a nearb)'
schoolbuilding. By 6 :50 the roost was practically deserted
except for two or three Robins which had been stunned by
flying into telephone wires. The great majority of the Robins
on leaving the roost, flew out a short distance, alighting in
other trees or on wires, where they seemed to take a brief
rest before proceeding to the feeding grounds. On the way
from the roost the Robins were seen on all sides, on the Col-
lege Campus, in private yards ; many were on the ground
feeding, others were perched in trees and on the roofs of
houses. No doubt the birds gradually dispersed to the outer
limits of their feeding range, for by ten o'clock they had dis-
appeared from the immediate neighborhood.

On Sept. 4th, an effort was made to count the Robins ar-
riving from the south, as well as from the north ; at this time
362 birds were counted, in a similar manner 558 were counted
on the evening of the eighth.

On Sept. 9th, a heavy rain fell throughout the day, in fact
it was said to be the heaviest rain in sixteen years ; dark-
ness settled rather early in consequence of the cloudiness.
Although watching under these circumstances was uncom-



Abel — A Winter Robin Roost 169

i'ortable it seemed advisable to ascertain what effect the
weather conditions would have upon the flight. The first
Robin flew into the roost at 5 :47 ; they now followed regular-
ly at intervals of two or three minutes, at G :06 thirty birds
flew in. The watch was now discontinued, as it seemed that
the only noticeable change was that the flight started fifteen
or twenty minutes earlier than usual. But as there was no
cessation in the steady and almost uniform downpour this is
attributed to the earlier twilight.

It was thought desirable to attempt a complete census of
the birds arriving from all directions. Accordingly on the
evening of Sept. 11, a number of members of the Sioux City
Bird Study Club visited the roost and assisted in the count-
mg. It was thought that all the birds could be observed by
establishing three stations, as follows : the writer undertook
to watch the flight from the west ; the southeast quadrant was
watched by Dr. Stephens and Mr. Fields ; and the northeast
quadrant w^as watched by Mrs. Fields and Miss Hood. Al-
together 761 Robins were counted as they entered the roost
from all directions.

The following table sho^\s the only complete census that
we made :

Time West Northeast Southeast Total

6:04 2 2

6 :08 2 2

6:15 3 2 5

6:16 2 2

6:17 5 5 10

6:18 1 1 2

6 :19 2 2 4

' 6 :20 16 1 17

6:21 6 6

6 :22 19 1 20

6 :23 2 2

6 :24 7 7

6 :2.5 3 3

6 :26 15 15

6 :27 2 2

6 :28 4 4



170 The Wilson Bulletin — No. 89

Time West Northeast Southeast Total

6 :29

6 -.30 1

6 :31

6 :32 6

6 :33

6 :34 1

6 :35 1

6 :36

6 :37

6 :38

6 :40

6 :41

6 :42

6 :43 1

6 :44

6 :45

6 :46 4

6 :47 2

6 :48

6 :49

6 :50

6 :51

6 :52

6 :53

6 :54

6 :55 3

6 :56

6 :58

6 :59

7 :03

7 :05

7 :06

7 :09

Total 7G1

It is believed that this count is approximately correct, i.e.,
probably not more than a hundred birds were missed in the
counting-. Of course to one who is witnessing the flight,
without attempting to make a count, there would probably
come temptation to estimate them by the " thousands " ; a
flock of even several hundred birds presents quite an imposing


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