Correlated Ivory-billed Woodpecker Molt and Breeding Phenology; Florida 1968, More Evidence that Ivory-billed Woodpecker Survived Post Singer Tract
Molt is commonly used by bird banders and ornithologists to gauge a bird's health and age, and aid in specie's identification. The observed molt phenology can be determinate in identification between even closely related species. After recently discovering a synchronous molt on the Ivory-billed Woodpecker in Louisiana (M. Collins, 2008 video, Virrazzi, 2022), I examined the circumstances of the 1968 Ivory-billed feather from Florida associated with those published sightings.
A correlated molt and breeding phenology was deduced to research the subject feather (see table below). The exact date the specific fresh, secondary feather was found is consistent with the breeding and normal molt phenology for Ivory-billed and not a Pileated Woodpecker.
H. Norton Agey and George M. Heinzman reported eleven detections, including sightings of Ivory-billed Woodpeckers in central Florida from 1967 to 1969 by several people. The sighters became aware of the birds after an inexperienced youngster described a large woodpecker with field marks that only fit an Ivorybill.
Several capable people subsequently saw or heard these birds and identified them as Ivory-billed Woodpeckers. A feather discovered near a fallen nest tree was professionally identified as an Ivory-billed feather. Other feathers from a very young bird were found attached to splinters in the cavity. This was not a one day, one observer event, or one without physical evidence, quite the contrary. The years of evidence were described and published in The Florida Naturalist, 1971.
The Ivory-bills were reported from a large cattle ranch with locked gates west of U.S. Route 27 in Hardee and Highlands Counties, north of Highlands Hammock State Park (P. Sykes, 2016). The authors had permission to be on the ranch and the landowner was aware of the Ivory-billed Woodpeckers presence for ~ 10 years prior. Ivory-bills were seen in Highland Hammock State Park several times per reports of multiple witnesses in the 1960's. Birds were reported in the area in the 1930's.
Gradually during the multi-year Bald Eagle census for Florida Audubon they began to accumulate insight into the wary birds' movements while hiking this seasonally flooded forest. Ivory-bills are documented to often breed in locations that are flooded (Tanner, 1942). They noticed Ivory-billed sized, fresh tree holes in the general area and bark scaling in certain trees. They heard various Ivory-billed like calls and strong knocks
In 1968 a tree they suspected as recently having a nest was blown down, breaking at the cavity hole. The pertinent tree sections were collected and measured; the hole was comparable to an Ivory-billed nest hole and not Pileated.
Three feathers found at the broken tree were collected and sent to Alexander Wetmore, PhD, ornithologist and Secretary at The Smithsonian Institute. Several taxa of birds have been named in Wetmore's honor. Nothing indicating the feathers or nest hole were not collected in the field on the stated date was noted. The largest feather was identified as the innermost secondary (S8) of an Ivory-billed Woodpecker by Wetmore. Jerome Jackson confirmed prior to 1995 that the feather was indeed an S8 of an Ivory-billed Woodpecker (P. Sykes, 2016).
During a confidential conversation with a professional who had spoken to J. Jackson, Jackson could not recall any details about which Ivory-billed specimen was missing secondary 8. He had not taken or had lost the notes. The professional went to the subject museum and could not find any Ivory-billed specimen missing S8. There was a very old, damaged specimen that Wetmore should have certainly noted the feather condition had he ever seen a feather from that skin.
In this article the molting phenology of Ivory-billed Woodpeckers is examined to see if it coincides with the date this exact secondary feather was found. Feathers are partially consumed in days by bacteria, other animals and other processes.
The 1971 article was silent on whether the innermost secondary (S8) they found at a fallen Ivory-billed nesting hole in April, 1968 coincided with the proper timing for an Ivory-billed to drop that particular secondary. The feather had been formally identified as an Ivory-billed by an ornithologist as mentioned. Neither the authors nor the ornithologist may have found a reference on the IBWO molting sequence since no summary likely existed in 1968. They may have not realized molt timing can contribute to species identification between the two larger species of SE USA Picidae; regardless they had the S8 feather of an Ivory-billed.
For the first time the 1968 feather is looked at with the benefit of modern literature on the molt timing of Ivory-billeds. The 2008 Ivory-billed video (Pearl River, LA Collins) was found to have a synchronously molting bird.
The molting sequence of Ivory-bills was determined by examining up to 204 specimens; this established that the innermost primary (P1) is dropped soon after the breeding season ends and then innermost secondary (S8) is shed soon after P1 or P2. In this video from March 29, 2008 primary 1 in both wings is missing and that matches well with the expected specific molt sequence as proposed by J. Jackson.
Most North American Picidae also start their flight feather molt right after the breeding season. Pileateds breeding season ends approximately 2 months later than Ivory-bills; for a respective calendar day an Ivory-billed should not have the same feather or feathers molted vis-a vis a Pileated. The same is actually true for molts of other species; the Ivory-billed molts flight feathers earlier than many North American bird species.
The Pearl River, LA 2008 Ivory-billed had both P1s missing on March 29, 2008 (see video showing that above). The S8 Florida feather was found on April 21, 1968.
Both dates are respectively consistent with the known Ivory-billed molt phenology for P1 and S8. This is further and new evidence supporting that the exact feather found in Florida, S8, coincides with the literature for that feather's temporal molt.
The only observed date for Ivory-bills mating is on November 29, 2019. Ivory-bills first clutch eggs have been found in January, February and March.
Note that Heinzman's name is apparently misspelled throughout The Florida Naturalist article, (1971). (Heinzmann [sic] and Agey, 1971; Heinzman’s name is misspelled throughout the article per P. Sykes, 2016)
Conclusions: Examining evidence of Ivory-bills should include comparing the observations with the molt and breeding phenology of the species. Molt and breeding phenology can be used to assist in confirming or questioning reports of Ivory-bills.
Some Reference Excerpts:
Spring--At what time the winter groups of ivorybills break up and spring activities commence is rather difficult to state, for there seems to be considerable irregularity to the breeding season. Judged from published records of its nests, the period of greatest activity would seem to be late March and early April. According to Audubon, (1842): "The ivory-billed woodpecker nestles earlier in spring than any other species of its tribe. I have observed it boring a hole for that purpose in the beginning of March." Scott (1881) reports taking an incubating female in Florida on January 20, 1880, and (1888) of finding a nest containing one young female about one third grown on March 17, 1887. Ridgway (1898) likewise speaks of shooting a male that left its nest hole February 15, 1898, and Hoyt (1905) states that "in Florida they begin building the latter part of January, and if undisturbed the eggs are laid by February 10th."
In 1937 James Tanner discovered a nest in Louisiana from which the fledgling left on March 30, fully 2 months earlier than any previous records from the same locality, and in 1938 apparently the same pair of birds had young the last week in February. In contrast to these dates we find 10 records of April nesting, 5 for May, and 1 (Beyer, 1900) of a young bird just out of the nest in July. The latter records might well constitute second attempts at nesting. The Florida birds, in general, start earlier than those in Louisiana, but at best there seems to be less regularity to the commencement of the nesting period than is found with most of our North American woodpeckers. In this, the ivorybill may register its affinity with tropical birds in general, the ivorybill being the most northern representative of an otherwise tropical or semitropical genus. There is some evidence for believing that ivorybills wander over considerably larger territories in winter than those to which they confine their activities in the spring, but little definite information has thus far been recorded on any of their before and after breeding activities.
Courtship--Nothing seems to have been written on the courtship of the ivorybill except the observations of Allen and Kellogg (1937):
Our only observations were made in Florida about 6 a. m., on April 13, 1924. We had discovered this pair of Ivorybills at about the same time the preceding morning when they came out of the cypress swamp and preened their feathers and called a few times from the top of a dead pine before going off together to feed. They had made such a long flight the previous day that we were unable to find them again, but that night, still traveling together, they had returned to the same group of medium-sized cypress trees which they had apparently left in the morning and In which there was one fresh hole In addition to four or five other old ones In the near vicinity. On the morning of the 13th, they called as they left these cypress trees and flew to the top of a dead pine at the edge of the swamp, where they called and preened. Finally the female climbed up directly below the male and when she approached him closely he bent his head downward and clasped bills with her. The next instant they both flew out on to the "burn," where we followed their feeding operations for about an hour.
Nesting--As before stated, while there are a few records of February nesting, the most definite records are for March, April, and early May, as follows:
April 6, ____. M. Thompson, Okefinokee swamp, Georgia. Laying.
April 9, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Three fresh eggs.
April 10, ____. Dr. S. W. Wilson, Altamaha swamp, Georgia. Four eggs.
April 15, 1893. A. Wayne, Florida. A young female about 2 weeks out of the nest.
April 19, 1893. Ralph Collection, Lafayette County, Fla. Three eggs.
May 2, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Three eggs.
May 19, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Four eggs, a second laying.
May (early) 1894. E. A. Mcllhenny, Avery swamp., Louisiana. Five young, 3 days old.
May 3, 1885. Capt. B. F. Goss, Jasper County, Tex. Three eggs.
July 1897. George G. Beyer, Franklln Parish, La.
March 4, 1904. Brown brothers (Hoyt), feeding young.
March 16, 1904. H. D. Hoyt, Taylor County, Fla. Large young.
March 4, 1905. H. D. Hoyt, Claremont County, Fla. Two eggs, incubation advanced.
March 24, 1905. R. D. Hoyt, Claremont County, Fla. Two eggs slightly Incubated (second laying of the preceding).
April 13, 1924. A. A. Allen, Taylor Creek, Fla. Nest completed. Incubation not yet started.
April (early) 1931. J. J. Kuhn, northern Louisiana. Incubating.
May 13, 1934. J. 3. Kuhn, northern Louisiana. Probably small young.
April 6, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Incubating.
April 9, 1935. A. A. Allen and P. P. Kellogg, northern LouIsiana. Building.
April 25, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Incubating.
May 10, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Small young.Again quoting from the report of Allen and Kellogg (1937):
The site of the Ivorybill's nest seems to vary considerably. Audubon states: "The hole is, I believe, always made in the trunk of a live tree, generally an ash or a hackberry, and is at a great height." There are, however, records of their nesting in live cypress, partially dead oaks, a dead royal-palm stub,"an old and nearly rotten white elm stump," etc., indicating about as great a variety as shown by the pileated woodpecker. The lowest authentic nest of which we have found a record, was that described by Beyer (1900) "about 25 feet up in a living over-cup oak," although Scott (1881) mentions what he considered "an old nest evidently of this species," in a palmetto stub only fifteen feet from the ground. The nest which we discovered in Florida, in 1924, was about thirty feet up in a live cypress and there were other holes in the vicinity in similar trees that had apparently been used in years past. The bark had healed over in some cases and scar tissue was apparently trying to close the wounds. Of the four nests examined in Louisiana, three were in oaks and one in a swamp maple. The maple, seven and a half feet in circumference (breast high), was partially alive, but the top where the nest was located, 43 feet from the ground, was dead and pithy. Of those in oak trees, one was in a dead pin-oak stub about ten feet in circumference and about fifty feet high, standing in more or less of a clearing. The nest was 47 feet 8 inches from the ground. The other two were not measured accurately but were certainly over forty feet from the ground. About the middle of May when it was determined that the first two trees had been deserted, they were cut down, careful measurements taken, and the contents of the holes preserved. The hole in the maple was 5 inches in vertical diameter and 4 1/8 inches laterally, and was slightly irregular at the bottom, as shown in the photographs; that in the oak was more symmetrical with a similar vertical diameter of 5 inches and a transverse diameter of 4 inches. The depth of the maple nest from the top of the entrance hole was 19 1/8 inches, of which 3 inches was filled with chips and "sawdust." This nest cavity was 8 1/8 inches in diameter at the egg level, and the tree itself 18 1/2 inches in diameter at the level of the hole. The nest cavity in the oak was 20 inches from top to bottom with a diameter of 8 1/4 inches at the egg level. The entrance hole went in 3 inches before it turned abruptly downward; the tree at this point was 22 inches in diameter. There was a stub just above the hole in the maple about 4 inches long representing a branch that had apparently died and been broken off years before and started to heal over. The oak was perfectly smooth at the entrance hole, not on either side, slightly above, were the bases of two large branches that could not have given the opening any protection from the weather. The opening in the maple faced north, two of those in the oaks east, and one west. Audubon states: 'The birds pay great regard to the particular situation of the tree and the inclination of the trunk; first, because they prefer retirement, and, again, because they are anxious to secure the aperture against the access of water during beating rains. To prevent such a calamity the hole is generally dug immediately under the juncture of a large branch with the trunk." None of the nests examined by us showed this desire for protection from rain, and the chips at the bottom of the cavity were perfectly dry, though we had had some very heavy rains shortly before they were examined.
Audubon further states: "The average diameter of the different nests which I examined was about 7 inches within, although the entrance, which is perfectly round, is only just large enough to admit the bird." Beyer (1900) says: "The entrance measures exactly 4 1/2 inches in height and 3 7/8 inches in width," and McIlhenny (Bendire, 1895) gives the measurements of a typical hole as "oval and measures 4 1/8 by 5 3/4 inches," and Scott (1888) as "3 1/2 inches wide and 4 1/2 inches high." The corresponding measurements of the nests of Pileated Woodpeckers are given by Bendire (1895) as follows: "The entrance measures from 3 to 3 1/2 inches in diameter, and it often goes 5 inches straight into the trunk before it is worked downward." The additional one to two inches in diameter of the nest hole should he kept in mind when searching for reasons why the Ivorybill has proven less successful than the Pileated Woodpecker in its struggle for existence. Thompson (1885) states: "The depth of the hole varies from three to seven feet, as a rule, but I found one that was nearly nine feet deep and another that was less than two." He also claims that they are always jug-shaped at the lower end.
Of two nests discovered by Hoyt (1905) in Claremont County, Fla., one was 58 feet up in a live cypress about 20 yards from a nest discovered in 1904 by the Brown brothers; the second nest built by the same pair after the first eggs had been taken was in a cypress stub about 70 yards distant from the first and 47 feet from the ground. The opening of the first nest was 6 3/4 inches by 3 1/4 inches, with the trunk of the tree 15 inches in diameter at the nest cavity, which was 14 inches deep. The second nest hole measured 6 by 3 3/4 inches and was likewise 14 inches deep. "The opening in both nests was uneven and rough, and just inside the hollow was much enlarged, being 9 inches across, and unlike the nests of other woodpeckers, was smaller at the bottom than at the top. * * * * One marked feature of the nest tree of which I have seen no mention made is that the outer bark of those I have examined was torn to shreds from a point some distance below the nest site to 15 or 20 feet above it. This made the nest tree noticeable for quite a distance. The last nest taken this season had little of this work done."
Change of season or daylight hours stimulates molting, migrating, and breeding. Other factors that influence the timing of the molt include temperature and available nutrition, as well as the bird's general health and reproductive state. In this article the season and date factors only are examined to see if they correlate with the expected date for a normal Ivory-billed Woodpecker molt for the specific feather found.
H. Norton Agey and George M. Heinzman reported eleven detections, including sightings of Ivory-billed Woodpeckers in central Florida from 1967 to 1969 by several people. The sighters became aware of the birds after an inexperienced youngster described a large woodpecker with field marks that only fit an Ivorybill.
Several capable people subsequently saw or heard these birds and identified them as Ivory-billed Woodpeckers. A feather discovered near a fallen nest tree was professionally identified as an Ivory-billed feather. Other feathers from a very young bird were found attached to splinters in the cavity. This was not a one day, one observer event, or one without physical evidence, quite the contrary. The years of evidence were described and published in The Florida Naturalist, 1971.
The Ivory-bills were reported from a large cattle ranch with locked gates west of U.S. Route 27 in Hardee and Highlands Counties, north of Highlands Hammock State Park (P. Sykes, 2016). The authors had permission to be on the ranch and the landowner was aware of the Ivory-billed Woodpeckers presence for ~ 10 years prior. Ivory-bills were seen in Highland Hammock State Park several times per reports of multiple witnesses in the 1960's. Birds were reported in the area in the 1930's.
Gradually during the multi-year Bald Eagle census for Florida Audubon they began to accumulate insight into the wary birds' movements while hiking this seasonally flooded forest. Ivory-bills are documented to often breed in locations that are flooded (Tanner, 1942). They noticed Ivory-billed sized, fresh tree holes in the general area and bark scaling in certain trees. They heard various Ivory-billed like calls and strong knocks
In 1968 a tree they suspected as recently having a nest was blown down, breaking at the cavity hole. The pertinent tree sections were collected and measured; the hole was comparable to an Ivory-billed nest hole and not Pileated.
Three feathers found at the broken tree were collected and sent to Alexander Wetmore, PhD, ornithologist and Secretary at The Smithsonian Institute. Several taxa of birds have been named in Wetmore's honor. Nothing indicating the feathers or nest hole were not collected in the field on the stated date was noted. The largest feather was identified as the innermost secondary (S8) of an Ivory-billed Woodpecker by Wetmore. Jerome Jackson confirmed prior to 1995 that the feather was indeed an S8 of an Ivory-billed Woodpecker (P. Sykes, 2016).
During a confidential conversation with a professional who had spoken to J. Jackson, Jackson could not recall any details about which Ivory-billed specimen was missing secondary 8. He had not taken or had lost the notes. The professional went to the subject museum and could not find any Ivory-billed specimen missing S8. There was a very old, damaged specimen that Wetmore should have certainly noted the feather condition had he ever seen a feather from that skin.
In this article the molting phenology of Ivory-billed Woodpeckers is examined to see if it coincides with the date this exact secondary feather was found. Feathers are partially consumed in days by bacteria, other animals and other processes.
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| Top L Dorsal IBWO, Top R Ventral IBWO, Bottom L Dorsal PIWO, Bottom R Ventral PIWO, Note that the IBWO wing is not properly "laid out" compared to the PIWO's |
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| NBP-Florida woodpecker holes |
The 1971 article was silent on whether the innermost secondary (S8) they found at a fallen Ivory-billed nesting hole in April, 1968 coincided with the proper timing for an Ivory-billed to drop that particular secondary. The feather had been formally identified as an Ivory-billed by an ornithologist as mentioned. Neither the authors nor the ornithologist may have found a reference on the IBWO molting sequence since no summary likely existed in 1968. They may have not realized molt timing can contribute to species identification between the two larger species of SE USA Picidae; regardless they had the S8 feather of an Ivory-billed.
For the first time the 1968 feather is looked at with the benefit of modern literature on the molt timing of Ivory-billeds. The 2008 Ivory-billed video (Pearl River, LA Collins) was found to have a synchronously molting bird.
The molting sequence of Ivory-bills was determined by examining up to 204 specimens; this established that the innermost primary (P1) is dropped soon after the breeding season ends and then innermost secondary (S8) is shed soon after P1 or P2. In this video from March 29, 2008 primary 1 in both wings is missing and that matches well with the expected specific molt sequence as proposed by J. Jackson.
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| Study Results of Ivory-billed specimens |
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| Highland Hamock State Park details of study |
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| This was the first announcement of the sightings and proceeded the paper in the Florida Naturalist soon after. |
Most North American Picidae also start their flight feather molt right after the breeding season. Pileateds breeding season ends approximately 2 months later than Ivory-bills; for a respective calendar day an Ivory-billed should not have the same feather or feathers molted vis-a vis a Pileated. The same is actually true for molts of other species; the Ivory-billed molts flight feathers earlier than many North American bird species.
The Pearl River, LA 2008 Ivory-billed had both P1s missing on March 29, 2008 (see video showing that above). The S8 Florida feather was found on April 21, 1968.
Both dates are respectively consistent with the known Ivory-billed molt phenology for P1 and S8. This is further and new evidence supporting that the exact feather found in Florida, S8, coincides with the literature for that feather's temporal molt.
The only observed date for Ivory-bills mating is on November 29, 2019. Ivory-bills first clutch eggs have been found in January, February and March.
Note that Heinzman's name is apparently misspelled throughout The Florida Naturalist article, (1971). (Heinzmann [sic] and Agey, 1971; Heinzman’s name is misspelled throughout the article per P. Sykes, 2016)
Ivory-billed Woodpeckers in Florida
Conclusions: Examining evidence of Ivory-bills should include comparing the observations with the molt and breeding phenology of the species. Molt and breeding phenology can be used to assist in confirming or questioning reports of Ivory-bills.
On April 21, 1968, a secondary 8 feather (S8) of an Ivory-billed Woodpecker was found at Highland Hammocks State Park, Florida by multiple people. April 21 is temporally consistent with the phenology of a normal molt of S8 feather for an Ivory-billed and not a Pileated Woodpecker or many other species.
The presence of feathers from a very young bird and an older Ivory-billed on April 21, 1968, is consistent with the known breeding cycle of Ivory-billeds.
The feathers found in 1968 are consistent with two separate complex biological cycles which statistically is strong bivariate evidence of Ivory-bills. The feathers' discovery date coincides with the molting and breeding phenology of the species. This adds to the evidence that the Ivory-billed Woodpecker survived well past 1944 in the United States.
The presence of feathers from a very young bird and an older Ivory-billed on April 21, 1968, is consistent with the known breeding cycle of Ivory-billeds.
The feathers found in 1968 are consistent with two separate complex biological cycles which statistically is strong bivariate evidence of Ivory-bills. The feathers' discovery date coincides with the molting and breeding phenology of the species. This adds to the evidence that the Ivory-billed Woodpecker survived well past 1944 in the United States.
A synchronous molt of P1 on the Ivory-billed Woodpecker videoed in Louisiana (M. Collins, 2008 video, Virrazzi, 2022), is consistent with the phenology of a normal molt of these feathers for an Ivory-billed and not a Pileated Woodpecker or many other species.
Both the 1968 (FL) and 2008 (LA) Ivory-billed reports, supported by correlation with breeding and molt phenology are strong evidence that the Ivory-billed Woodpecker survived well past 1944 in the United States.
Some Reference Excerpts:
Spring--At what time the winter groups of ivorybills break up and spring activities commence is rather difficult to state, for there seems to be considerable irregularity to the breeding season. Judged from published records of its nests, the period of greatest activity would seem to be late March and early April. According to Audubon, (1842): "The ivory-billed woodpecker nestles earlier in spring than any other species of its tribe. I have observed it boring a hole for that purpose in the beginning of March." Scott (1881) reports taking an incubating female in Florida on January 20, 1880, and (1888) of finding a nest containing one young female about one third grown on March 17, 1887. Ridgway (1898) likewise speaks of shooting a male that left its nest hole February 15, 1898, and Hoyt (1905) states that "in Florida they begin building the latter part of January, and if undisturbed the eggs are laid by February 10th."
In 1937 James Tanner discovered a nest in Louisiana from which the fledgling left on March 30, fully 2 months earlier than any previous records from the same locality, and in 1938 apparently the same pair of birds had young the last week in February. In contrast to these dates we find 10 records of April nesting, 5 for May, and 1 (Beyer, 1900) of a young bird just out of the nest in July. The latter records might well constitute second attempts at nesting. The Florida birds, in general, start earlier than those in Louisiana, but at best there seems to be less regularity to the commencement of the nesting period than is found with most of our North American woodpeckers. In this, the ivorybill may register its affinity with tropical birds in general, the ivorybill being the most northern representative of an otherwise tropical or semitropical genus. There is some evidence for believing that ivorybills wander over considerably larger territories in winter than those to which they confine their activities in the spring, but little definite information has thus far been recorded on any of their before and after breeding activities.
Courtship--Nothing seems to have been written on the courtship of the ivorybill except the observations of Allen and Kellogg (1937):
Our only observations were made in Florida about 6 a. m., on April 13, 1924. We had discovered this pair of Ivorybills at about the same time the preceding morning when they came out of the cypress swamp and preened their feathers and called a few times from the top of a dead pine before going off together to feed. They had made such a long flight the previous day that we were unable to find them again, but that night, still traveling together, they had returned to the same group of medium-sized cypress trees which they had apparently left in the morning and In which there was one fresh hole In addition to four or five other old ones In the near vicinity. On the morning of the 13th, they called as they left these cypress trees and flew to the top of a dead pine at the edge of the swamp, where they called and preened. Finally the female climbed up directly below the male and when she approached him closely he bent his head downward and clasped bills with her. The next instant they both flew out on to the "burn," where we followed their feeding operations for about an hour.
Nesting--As before stated, while there are a few records of February nesting, the most definite records are for March, April, and early May, as follows:
April 6, ____. M. Thompson, Okefinokee swamp, Georgia. Laying.
April 9, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Three fresh eggs.
April 10, ____. Dr. S. W. Wilson, Altamaha swamp, Georgia. Four eggs.
April 15, 1893. A. Wayne, Florida. A young female about 2 weeks out of the nest.
April 19, 1893. Ralph Collection, Lafayette County, Fla. Three eggs.
May 2, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Three eggs.
May 19, 1892. E. A. Mcllhenny, Avery swamp, Louisiana. Four eggs, a second laying.
May (early) 1894. E. A. Mcllhenny, Avery swamp., Louisiana. Five young, 3 days old.
May 3, 1885. Capt. B. F. Goss, Jasper County, Tex. Three eggs.
July 1897. George G. Beyer, Franklln Parish, La.
March 4, 1904. Brown brothers (Hoyt), feeding young.
March 16, 1904. H. D. Hoyt, Taylor County, Fla. Large young.
March 4, 1905. H. D. Hoyt, Claremont County, Fla. Two eggs, incubation advanced.
March 24, 1905. R. D. Hoyt, Claremont County, Fla. Two eggs slightly Incubated (second laying of the preceding).
April 13, 1924. A. A. Allen, Taylor Creek, Fla. Nest completed. Incubation not yet started.
April (early) 1931. J. J. Kuhn, northern Louisiana. Incubating.
May 13, 1934. J. 3. Kuhn, northern Louisiana. Probably small young.
April 6, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Incubating.
April 9, 1935. A. A. Allen and P. P. Kellogg, northern LouIsiana. Building.
April 25, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Incubating.
May 10, 1935. A. A. Allen and P. P. Kellogg, northern Louisiana. Small young.Again quoting from the report of Allen and Kellogg (1937):
The site of the Ivorybill's nest seems to vary considerably. Audubon states: "The hole is, I believe, always made in the trunk of a live tree, generally an ash or a hackberry, and is at a great height." There are, however, records of their nesting in live cypress, partially dead oaks, a dead royal-palm stub,"an old and nearly rotten white elm stump," etc., indicating about as great a variety as shown by the pileated woodpecker. The lowest authentic nest of which we have found a record, was that described by Beyer (1900) "about 25 feet up in a living over-cup oak," although Scott (1881) mentions what he considered "an old nest evidently of this species," in a palmetto stub only fifteen feet from the ground. The nest which we discovered in Florida, in 1924, was about thirty feet up in a live cypress and there were other holes in the vicinity in similar trees that had apparently been used in years past. The bark had healed over in some cases and scar tissue was apparently trying to close the wounds. Of the four nests examined in Louisiana, three were in oaks and one in a swamp maple. The maple, seven and a half feet in circumference (breast high), was partially alive, but the top where the nest was located, 43 feet from the ground, was dead and pithy. Of those in oak trees, one was in a dead pin-oak stub about ten feet in circumference and about fifty feet high, standing in more or less of a clearing. The nest was 47 feet 8 inches from the ground. The other two were not measured accurately but were certainly over forty feet from the ground. About the middle of May when it was determined that the first two trees had been deserted, they were cut down, careful measurements taken, and the contents of the holes preserved. The hole in the maple was 5 inches in vertical diameter and 4 1/8 inches laterally, and was slightly irregular at the bottom, as shown in the photographs; that in the oak was more symmetrical with a similar vertical diameter of 5 inches and a transverse diameter of 4 inches. The depth of the maple nest from the top of the entrance hole was 19 1/8 inches, of which 3 inches was filled with chips and "sawdust." This nest cavity was 8 1/8 inches in diameter at the egg level, and the tree itself 18 1/2 inches in diameter at the level of the hole. The nest cavity in the oak was 20 inches from top to bottom with a diameter of 8 1/4 inches at the egg level. The entrance hole went in 3 inches before it turned abruptly downward; the tree at this point was 22 inches in diameter. There was a stub just above the hole in the maple about 4 inches long representing a branch that had apparently died and been broken off years before and started to heal over. The oak was perfectly smooth at the entrance hole, not on either side, slightly above, were the bases of two large branches that could not have given the opening any protection from the weather. The opening in the maple faced north, two of those in the oaks east, and one west. Audubon states: 'The birds pay great regard to the particular situation of the tree and the inclination of the trunk; first, because they prefer retirement, and, again, because they are anxious to secure the aperture against the access of water during beating rains. To prevent such a calamity the hole is generally dug immediately under the juncture of a large branch with the trunk." None of the nests examined by us showed this desire for protection from rain, and the chips at the bottom of the cavity were perfectly dry, though we had had some very heavy rains shortly before they were examined.
Audubon further states: "The average diameter of the different nests which I examined was about 7 inches within, although the entrance, which is perfectly round, is only just large enough to admit the bird." Beyer (1900) says: "The entrance measures exactly 4 1/2 inches in height and 3 7/8 inches in width," and McIlhenny (Bendire, 1895) gives the measurements of a typical hole as "oval and measures 4 1/8 by 5 3/4 inches," and Scott (1888) as "3 1/2 inches wide and 4 1/2 inches high." The corresponding measurements of the nests of Pileated Woodpeckers are given by Bendire (1895) as follows: "The entrance measures from 3 to 3 1/2 inches in diameter, and it often goes 5 inches straight into the trunk before it is worked downward." The additional one to two inches in diameter of the nest hole should he kept in mind when searching for reasons why the Ivorybill has proven less successful than the Pileated Woodpecker in its struggle for existence. Thompson (1885) states: "The depth of the hole varies from three to seven feet, as a rule, but I found one that was nearly nine feet deep and another that was less than two." He also claims that they are always jug-shaped at the lower end.
Of two nests discovered by Hoyt (1905) in Claremont County, Fla., one was 58 feet up in a live cypress about 20 yards from a nest discovered in 1904 by the Brown brothers; the second nest built by the same pair after the first eggs had been taken was in a cypress stub about 70 yards distant from the first and 47 feet from the ground. The opening of the first nest was 6 3/4 inches by 3 1/4 inches, with the trunk of the tree 15 inches in diameter at the nest cavity, which was 14 inches deep. The second nest hole measured 6 by 3 3/4 inches and was likewise 14 inches deep. "The opening in both nests was uneven and rough, and just inside the hollow was much enlarged, being 9 inches across, and unlike the nests of other woodpeckers, was smaller at the bottom than at the top. * * * * One marked feature of the nest tree of which I have seen no mention made is that the outer bark of those I have examined was torn to shreds from a point some distance below the nest site to 15 or 20 feet above it. This made the nest tree noticeable for quite a distance. The last nest taken this season had little of this work done."
