The Ohio Cardinal, Fall 2009 & Winter 2009-2010

Lichen Composition in Introduction Blue-gray Gnatcatcher Lichens are the product of an intri- and Ruby-throated cate symbiosis: composite organisms that contain both an alga (sometimes Hummingbird Nests a cyanobacterium) and a fungus. The fungal component is known as a mycobiont, which creates the color By Jim McCormac and Ray E. and structure of the lichen. The Showman algal partner is the photobiont, which photosynthesizes and produces food for the lichen. Lichens are not com- Jim McCormac monly used as construction material 2314 Sandman Drive in North American nests (Box Columbus, OH 43235 1). However, two well-known and [email protected] notable exceptions are the Blue-gray Gnatcatcher and the Ruby-throated Ray E. Showman Hummingbird. Because these spe- cies are common and widespread in 59335 Randerson Road eastern , including McArthur, OH 45651 Ohio (McCormac and Kennedy 2004), their nests are often seen and described. Literature references to these two species’ nests abound. Per- haps every published nest description Abstract mentions the presence of lichens as Blue-gray Gnatcatchers ( exterior shingling on gnatcatcher caerulea) and Ruby-throated Hum- and hummingbird nests. mingbirds (Archilochus colubris) heavily We can find no study that docu- utilize macrolichens in their nests. ments lichen species and their rela- We are unaware of any study that tive abundance in nest composition. documents the species and composi- At best, the presence of lichens in tion of lichens that are used by these nests is described in very general two bird species. This paper reports terms, such as this reference for the the results of a detailed study of Blue-gray Gnatcatcher: “…decorated 26 gnatcatcher and hummingbird with large quantities of crustose lichens nests, mostly from Ohio. Lichens (Parmelia spp., Physcia spp.)” (Ellison found on these nests were common 1992). It should be noted that crus- foliose (leaf-like) species that grow tose lichens are in general crustlike and tightly appressed to their growth on twigs and branches. Further, they substrate. Sometimes crustose lichens all had lobe tips that were somewhat even grow within the substrate. It is loosely attached to the bark. Tightly highly unlikely that crustose lichens appressed lichen species were not are harvested by hummingbirds or found on any of the nests. gnatcatchers, and Ellison’s refer- ence to their use is undoubtedly in 72 The Ohio Cardinal, Fall 2009 & Winter 2009-2010

Figure 1. Ruby-throated Hummingbird nest in Black Maple (Acer nigrum), Knox County, Ohio, July 2010. Decoration of Flavoparmelia caperata provides camouflage. Photo by Jim McCormac error and underscores the issues with ing used material in second nesting lichen identification. attempts (Root 1969). There are A few bird species are known at least three documented cases in to use plant material with insecti- which gnatcatchers avoided the re- cidal properties in nest construction. use of materials in nests that were Among these are Red-shouldered infested with mites (Ornithonyssus Hawks (Buteo lineatus), which often sylviarum), even though their second use black cherry (Prunus serotina) nesting was quite near the infected (Dykstra et al. 2009). A recent study nests (Root 1969), suggesting that also suggests that Carolina Chicka- lichens employed in gnatcatcher nest dees (Poecile carolinensis) might select construction are ineffective at repel- moss species that have insecticidal ling common nest parasites. properties (Andreas 2009). Some Bird species that routinely utilize lichen species are known to produce lichens in nest construction prob- secondary chemical metabolites that ably do so primarily for purposes of can inhibit invasion by potentially camouflage. Ruby-throated Hum- predacious small (Lawrey et mingbirds and Blue-gray Gnat- al. 1999). However, chemical proper- catchers typically site their nests on ties in lichens that might inhibit nest small branches of trees, often at the parasites are unknown, and little if axil of two branches (Baicich and any research has been done in this Harrison 2005). Arboreal habitats area. selected by these species are often Some evidence suggests that liberally encrusted with lichens. The lichens routinely used in Blue-gray copious shingling of the nests with Gnatcatcher nests do not serve as lichens clearly helps them to blend parasite repellants. Gnatcatchers are with their surroundings (Figure 1), well known for frequently decon- and the nests often resemble lichen- structing their nests and incorporat- covered knots (Figure 2).

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Figure 2. Blue-gray Gnatcatcher nest in Fraser Magnolia (Magnolia fraseri), Fayette County, West Virginia, 26 April 2010. A shingling of Parmelia sulcata blends the nest with its surroundings. Photo by Jim McCormac.

Materials and Methods specimens varied from a few years to several decades in age—rendering Fourteen Ruby-throated Hum- color largely useless as an identifica- mingbird nests were examined. Nests tion character. However, identifica- were from the Ohio State Mu- tion of most lichens was possible seum of Biodiversity, the Cleveland based on lobe size and shape, surface Museum of Natural History, Lake characteristics, the presence of cilia, County Metroparks, Dawes Arbo- and undersurface color (Showman retum, Huston-Brumbaugh Nature and Flenniken 2004). Center, and various individuals as listed in the acknowledgments. Of Results and Discussion these, 11 were from various locations in Ohio, two were from Pennsylva- Table 1 lists the lichen species nia, and one came from Indiana. All found and the estimated composi- of these locations are in the heart of tion of each nest examined. Lichens the eastern deciduous forest biome identified on the nests included the and do not differ appreciably in following: regards to vegetative habitat charac- Hammered Shield Lichen (Parmelia teristics. All of the nests were heavily sulcata): 23 nests (88%) ornamented with lichens. Twelve Common Greenshield Lichen (Flavo Blue-gray Gnatcatcher nests were parmelia caperata): 15 nests (58%) examined. All came from various Speckled Shield Lichens (probably sites within Ohio. These nests were Punctelia subrudecta; may also in all heavily shingled with lichen lobe clude P. rudecta): 13 nests (50%) tips. Ruffle Lichen (Parmotrema spp.): 4 Nests were examined with the aid nests (2%) of a dissecting microscope, and the Powdery Axil-bristle Lichen (Myelo lichens incorporated in the nests chroa aurulenta): 1 nest (<1%) were identified to species when possi- Both gnatcatchers and humming- ble. Most of the lichens had faded to used many of the same lichen a uniform brownish color—the nest species in their nests, but there was

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Box 1. North American bird species, other than gnatcatchers and hummingbirds, that regularly use lichens in nest construction

Eastern Wood-Pewee: Lichens 2005). However, this largely southern often figure prominently in the exterior species heavily utilizes Spanish moss, shingling of nests of this species Tillandsia usneoides (Moldenhauer et al. (McCarty 1996). We would have liked to 1996). The specific epithetusneoides have had a large sample size of pewee means “resembles Usnea,” and nests to analyze, but they apparently references to beard lichens in Northern are not well represented in collections, Parula nest construction, especially in due to the difficulty of accessing nest the in southern parts of its range, may sites. Two nests were made available actually refer to the moss. to us, both from Lake County, Ohio, collection dates unknown. In both cases, Yellow-rumped Warbler: Hammered Shield Lichen, Parmelia Unspecified lichens (Hunt and sulcata, was the only species used. Flaspohler 1998).

Olive-sided Flycatcher: Beard Blackburnian Warbler: Usnea lichens, genus Usnea* (Altman and lichens (Griscom and Sprunt 1957). Sallabanks. 2000) Blackpoll Warbler: Usnea lichens Vireo species: Most, if not all, (Baicich and Harrison 2005). species found in eastern North America regularly use lichens in nest building, at American Redstart: unspecified least sparingly. But they do not generally lichens (Griscom and Sprunt 1957). heavily shingle the exterior (Baicich and Harrison 2005). Red Crossbill: Usnea lichens and “black tree lichen” (genus Bryoria) Golden-crowned and Ruby- (Adkisson 1996). crowned Kinglet: Beard lichens, genus Usnea (Baicich and Harrison White-winged Crossbill: 2005). Unspecified lichens (Benkman 1992).

Cedar Waxwing: May sometimes use Evening Grosbeak: Unspecified Usnea lichens (Baicich and Harrison lichens (Gillihan and Byers 2001). 2005). However, an exhaustive study of waxwings that examined dozens *Beard lichens in the genus Usnea reach of nests in Ottawa County, Ohio, fails peak abundance in boreal regions in to mention lichens as nest material North America, hence their prevalence (Putnam 1949). Moss is often mentioned in the nests of northern nesting bird as a component of Cedar Waxwing species that typically use lichens in nest nests, and bryophytes (mosses) are construction. In Ohio, there are nine probably fairly often confused with Usnea species, but most have a limited lichens, especially prominently tufted distribution and none are abundant. species such as Usnea, by generalists. Thus, they do not figure prominently in nest construction of Ohio species or : Reported using species breeding south of the boreal Usnea lichens (Baicich and Harrison forest in general.

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a notable difference in the size of and branches, as well as the trunks lichen pieces harvested by the two of trees, and none are tightly ap- species. Lichen fragments incor- pressed to bark (at least the lobe tips porated into Ruby-throated Hum- are not). All but one of the lichen mingbird nests averaged 3 to 4 mm species documented in this study in diameter; gnatcatcher fragments prefer sunny tree bark as a substrate averaged 4 to 6 mm in diameter. In (the exception, Myelochroa aurulenta, all cases, the lichen pieces are exfo- liating lobe tips of the lichens—the prefers shaded tree bark, but only strap-like outer portions that curl a small quantity was incorporated away from the bark and are the easi- into one of our study nests). Ruby- est portions of the lichen for the bird throated Hummingbirds presumably to grasp and remove (see Figure 3). choose a nearby lichen to camou- All of the hummingbird nest flage their nests, making horizontal lichens share several characteristics. branches with sufficient sunlight Parmelia sulcata was the most heavily that are festooned with lichens good utilized lichen, followed by Flavopar- places to seek the nests. melia caperata and Punctelia spp. They As with Ruby-throated Hum- are all common foliose lichens, pres- mingbird nests, Parmelia sulcata was ent in most Ohio counties (Show- a favored material for Blue-gray man and Flenniken 2004; Figure 4). Gnatcatchers. Flavoparmelia cape- Each lichen species grows on twigs rata and Parmotrema spp. were also

Figure 3. Hammered Shield Lichen (Parmelia sulcata), Vinton County, Ohio, February 2010. The recurved lobe tips that are readily harvestable by hummingbirds and gnatcatchers are apparent. Photo by Ray Showman. 76 The Ohio Cardinal, Fall 2009 & Winter 2009-2010 frequently used on some nests. The latter two species have broader lobes than Parmelia sulcata, and the choice of these species may reflect the gnatcatcher’s preference for slightly larger lichen pieces. Blue-gray Gnat- catchers tend to heavily armor the exterior of their nests with lichens, whereas hummingbirds tend to plate their nests more sparingly. Gnat- catcher nests might be considered to be shingled with lichens (Figure 5), whereas hummingbird nest exteriors could be considered as being decorated with lichens (Figure 6). It is unknown whether this preference reflects a need for appropriate camouflage of the nest, the strength of the birds’ bills (presumably the stouter bill of gnatcatchers could manipulate larger, tougher pieces of lichen than hummingbirds), or other pressures. Certain lichens are clearly favored over other readily available species. Selection is almost certainly based on morphological traits of the lichen that enable the birds to harvest them. The lichens used in nest construc- tion are species that can be removed by the tiny bill of a hummingbird or gnatcatcher. Other common twig and branch lichens either have tiny lobes (Physcia millegrana) or are tightly appressed and not easily removed (P. aipolia and P. stellaris; Figure 7). The only published reference we located that mentions specific lichen species utilized in nest construction was Ellison’s (1992) monograph of the Blue-gray Gnatcatcher. He cites Physcia spp. (Rosette Lichens) as be- Figure 4. Ohio distributions of the three lichen ing used, but we found no evidence species most commonly found in this study. Maps that any of the nine Physcia species courtesy of the Ohio Moss and Lichen Association: http://www.ohiomosslichen.org 77 The Ohio Cardinal, Fall 2009 & Winter 2009-2010

5 aurulenta Myelochroa Myelochroa

10 sp. Parmotrema - 5 5 45 30 50 40 50 20 40 lia caperata Flavoparme

5 95 10 20 10 10 80 sp.* Punctelia Table 1. Table Estimated percent ofEstimated percent lichen species on each nest. 90 45 75 60 50 40 50 60 100 100 100 100 sulcata Parmelia additional informationadditional Nest location, date and Ruby-throated Hummingbird: Ruby-throated maple. 1. Medina C0., OH. 29 September 2009. Silver 1908. American beech. 29 May PA. 2. Waynesburg, 1907. 04 June PA. Co., 3. Green Arboretum. OH. Dawes 4. Licking Co., 1994 OH 19 August 5. Coshocton Co., OH. 2007 6. Mahoning Co., OH. Co., 7. Delaware OH. Co., 8. Delaware OH Co., 9. Delaware OH Co., 10. Delaware 1935. 11. Indiana. July 1985. Maple. OH. November 12. Summit Co., 1944. OH. 02 July Co., 13. Portage OH, area. 14. Athens Co.,

78 The Ohio Cardinal, Fall 2009 & Winter 2009-2010 aurulenta Myelochroa Myelochroa

5 40 10 sp. Parmotrema - 45 30 60 90 20 50 lia caperata Flavoparme

5 5 5 30 50 10 sp.* Punctelia Estimated percent ofEstimated percent lichen species on each nest. 5 45 30 95 80 50 40 100 100 100 100 Table 1, continued. Table sulcata Parmelia additional informationadditional Nest location, date and Blue-gray Gnatcatcher: OH. A. Hancock Co., Arboretum OH. Dawes Licking Co., B. OH. Granville. C. Licking Co., OH. 20 October 1909. Hancock Co., D. OH. 1994. E. Summit Co., OH. 2006. Scioto Co., F. OH. Co., Delaware G. OH Co., H. Delaware 2003 or 2004 I. Summit Co., OH area Summit Co., J. OH, area. K. Athens Co., OH, area. L. Athens Co.,

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found in Ohio were used. The most common of these is Physcia mille- grana, Mealy Rosette Lichen, which is abundant near typical gnatcatcher and hummingbird nest sites but has quite tiny lobes and is probably unacceptable as nest material. Lichens are a critical component of Blue-gray Gnatcatcher and Ruby- throated Hummingbird nests. All 26 nests that we obtained for this study had lichens as a co-dominant component, forming an integral part of nest camouflage. Of the 223 mac- Figure 5. Blue-gray Gnatcatcher nest rolichen species known from Ohio showing heavy lichen shingling. Composition: (Showman and Flenniken 2004), Flavoparmelia caperata 60%; Punctelia only a few appear to be acceptable spp. 30%; Parmotrema spp. 10%. Nest for nest construction. Fortunately, collected in Scioto County, Ohio in 2006. these are common and widespread in lichens (Showman 1973). Since species. Excessive air pollution can 1972, there has been a dramatic have profound effects on lichen com- resurgence of lichens in formerly munities. Many species are especially polluted areas (Showman 1997). The sensitive to high levels of sulfur diox- influence of lichen availability on ide (Showman and Flenniken 2004). nesting success has not been stud- Prior to passage of the Clean Air ied. Two species commonly used Act in 1972, heavily industrialized in gnatcatcher and hummingbird regions, such as parts of the Ohio nests, Parmelia sulcata and Punctelia River Valley, were virtually lacking subrudecta, are somewhat tolerant of air pollution. Two others, Flavopar- melia caperata and Punctelia rudecta, are quite sensitive to airborne toxins. Increases in air pollution, especially sulfur dioxide, may have deleterious consequences on the nesting suc- cess of Blue-gray Gnatcatchers and Ruby-throated Hummingbirds.

Acknowledgments The authors thank the following individuals for providing nests for Figure 6. Ruby-throated Hummingbird this study or otherwise offering their nest showing lichen decoration. Composition: expertise: John Condit (Ohio State Flavoparmelia caperata 50%; Parmelia sulcata 50%. Nest collected in Delaware County, University), Patrick Coy, Julie Davis, Ohio, date unknown. Ron Gamble, Mary Huey (Lake 80 The Ohio Cardinal, Fall 2009 & Winter 2009-2010

County Metroparks), Andy Jones (Cleveland Museum of Natural His- Benkman, C. W. 1992. White- tory), Tim Mason (Dawes Arbore- winged Crossbill (Loxia leucoptera). tum), Robert Scott Placier, Heather In: The Birds of North America Nagy, R. Seiler, Lori Totman (Dawes Online (A. Poole, Ed.). Ithaca: Arboretum), and Bonnie Twaddle Cornell Lab of Ornithology; (Huston-Brumbaugh Nature Cen- Retrieved from the Birds of North ter). Robert Klips provided the distri- America Online: http://bna.birds. bution maps from the Ohio Moss cornell.edu/bna/species/027 and Lichen Association. Dykstra, C. R., J. L. Hays, and M. Literature Cited M. Simon. 2009. Selection of fresh vegetation for nest lining by Red- shouldered Hawks. Wilson Journal Adkisson, C. S. 1996. Red Crossbill of Ornithology 121: 207-210. (Loxia curvirostra). In: The Birds of North America Online (A. Ellison, W. G. 1992. Blue-gray Poole, Ed.). Ithaca: Cornell Lab Gnatcatcher (Polioptila caerulea). In: of Ornithology; Retrieved from The Birds of North America the Birds of North America Online (A. Poole, Ed.). Ithaca: Online: http://bna.birds.cornell. Cornell Lab of Ornithology; edu/bna/species/256 Retrieved from the Birds of North America Online: http://bna.birds. Altman, B. and R. Sallabanks. 2000. cornell.edu/bna/species/023 Olive-sided Flycatcher (Contopus cooperi). In: The Birds of North Gillihan, S. W. and B. Byers. 2001. America Online (A. Poole, Ed.). Evening Grosbeak (Coccothraustes Ithaca: Cornell Lab of vespertinus). In: The Birds of North Ornithology; Retrieved from the America Online (A. Poole, Ed.). Birds of North America Online: Ithaca: Cornell Lab of http://bna.birds.cornell.edu/bna/ Ornithology; Retrieved from the species/502 Birds of North America Online: http://bna.birds.cornell.edu/bna/ Andreas, B. K. 2009. Use of species/599 bryophytes by Carolina chickadees (Poecile carolinensis) in Griscom, L. and A. Sprunt (Eds.). nest construction. Evansia 27 (1): 1957. The warblers of North America. 23-29. The Devin-Adair Company, New York. Baicich, P. J. and C. J. O. Harrison. 2005. Nests, eggs, and nestlings Hunt, P. D. and D. J. Flaspohler. of North American birds (2nd Ed.). 1998. Yellow-rumped Warbler Princeton University Press, (Dendroica coronata). In: The Birds Princeton, New Jersey. of North America Online (A.

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Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from Showman, R. E. and D. G. the Birds of North America Flenniken. 2004. The macrolichens Online: http://bna.birds.cornell. of Ohio. Ohio Biological Survey, edu/bna/species/376 Columbus, Ohio.

Lawrey, J. D., A. P. Torzilli, and Showman, R. E. 1973. The V. Chandhoke. 1999. Destruction foliose and fruticose lichen flora of chemical defenses by a fungal of the Ohio River Valley between pathogen. American Journal of Botany Gallipolis, Ohio and Parkersburg, 186: 184-189. West Virginia. Ohio Journal of Science 73: 357-363. McCarty, J. P. 1996. Eastern Wood- Pewee (Contopus virens). In: The Showman, R. E. 1997. Continuing Birds of North America Online lichen colonization in the upper (A. Poole, Ed.). Ithaca: Cornell Ohio River Valley. The Bryologist Lab of Ornithology; Retrieved 100: 478-481. from the Birds of North America Online: http://bna.birds.cornell. edu/bna/species/245

McCormac, J. S. and G. Kennedy. 2004. Birds of Ohio. Lone Pine Publishing International Inc., Edmonton, Alberta, Canada.

Moldenhauer, R. R. and D. J. Regelski. 1996. Northern Parula (Parula americana). In: The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell. edu/bna/species/215

Putnam, L. S. 1949. The life history of the Cedar Waxwing. Wilson Bulletin 61: 141-182.

Root, R. B. 1969. The behavior and reproductive success of the Blue- gray Gnatcatcher. Condor 71:16-31.

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