Cope's gray treefrog

Edward Drinker Cope described the species in 1880. The specific name, chrysoscelis, is from Greek chrysos, gold, and scelis, leg.[http://www.sel.barc.usda.gov/Diptera/people/FCT_pdf/FGNAMES.pdf Family Group Names in Diptera] {{webarchive|url=https://web.archive.org/web/20080411095829/http://www.sel.barc.usda.gov/Diptera/people/FCT_pdf/FGNAMES.pdf |date=2008-04-11 }}

Microscopic inspection of the chromosomes of D. chrysoscelis and D. versicolor reveals differences in chromosome number. D. chrysoscelis is diploid, having two complete sets of chromosomes, the usual condition in vertebrates. D. versicolor is tetraploid, having double the usual number of chromosomes. Generally, D. versicolor is believed to have evolved from D. chrysoscelis in the last major ice age, when areas of extremely low temperatures divided populations. Despite currently sharing habitat, the two species generally do not interbreed.

D. chrysoscelis is known to be largely intersterile with D. versicolor but there may be a limited amount of interfertility in sympatry. To enforce speciation there may be unknown mechanisms of reinforcement deployed between these species and further research may be fruitful.{{cite journal | last1=Noor | first1=Mohamed A F | author1-link=Mohamed Noor | title=Reinforcement and other consequences of sympatry | journal=Heredity | publisher=The Genetics Society (Nature) | volume=83 | issue=5 | year=1999 | issn=0018-067X | doi=10.1038/sj.hdy.6886320 | pages=503–508| pmid=10620021 | doi-access=free }}

File:Hyla chrysoscelisPCCA20060401-2867B.jpg

Both D. chrysoscelis and D. versicolor have black-marked bright orange to yellow patches on their hind legs, which distinguishes them from other treefrogs, such as D. avivoca. The bright-yellow pattern is normally hidden, but exposed when the frog leaps. This "flash pattern" likely serves to startle a predator as the frog makes its escape.Tesler, P. [http://www.exploratorium.edu/frogs/mainstory/frogstory3.html Exploratorium The Amazing, Adaptable Frog.] The Exploratorium. San Francisco. The pattern and color variations of skin for this species will change depending on the environment they are found in.{{Cite book |last1=Bogart |first1=James P. |url=http://dx.doi.org/10.5962/bhl.title.52057 |title=Distribution and call parameters of Hyla chrysoscelis and Hyla versicolor in Michigan |last2=Jaslow |first2=Alan P. |date=1979 |publisher=Royal Ontario Museum |isbn=0-88854-229-1 |location=Toronto|doi=10.5962/bhl.title.52057 }} Similar hidden bright patterns are common in various Lepidoptera, for instance moths of the genus Catocala.Sargent. (1969). [http://research.yale.edu/peabody/jls/htms/1960s/1969-23(4)261-Sargent.htm A suggestion regarding hindwing diversity among moths of the genus Catocala OF (Noctuidae).] {{webarchive|url=https://web.archive.org/web/20070313073736/http://research.yale.edu/peabody/jls/htms/1960s/1969-23%284%29261-Sargent.htm |date=2007-03-13 }} Journal of the Lepidopterists' Society 23: 261-264. Both species of gray treefrogs are slightly sexually dimorphic. Males have black or gray throats in the breeding season, while the throats of the females are lighter.Tyning, T. F. (1990). A Guide to Amphibians and Reptiles. Boston: Little, Brown and Company. {{ISBN|0-316-81719-8}}. Usually, the younger frogs in this species will often be seen more with the greenish color throughout the breeding seasons. As they age they will lose the greenish color and move towards the distinct gray color. {{Cite journal |last=Roseman |first=Kimberly |date=2017 |title=The Utility of Hyla squirrella Microsatellite DNA Markers for Population Genetic Studies of Hyla versicolor and Hyla chrysoscelis |url=https://www.proquest.com/docview/1933027058 |journal=Western Illinois University ProQuest Dissertations|id={{ProQuest|1933027058}} }}

File:H chrysoscelis male.JPG

Skin secretions from this species may be irritating or toxic to mouth, eyes, other mucous membranes.{{cite web|title=Species profile: Cope's Gray Treefrog (Hyla chrysoscelis)|url=http://srelherp.uga.edu/anurans/hylchr.htm|website=Savannah River Ecology Laboratory - University of Georgia}}

The range of D. chrysoscelis is more southerly; it is apparently the species found in the lower elevation Piedmont and Coastal Plain of Virginia and the Carolinas. In those areas, D. versicolor may be present only in the Appalachians. While this species is most abundant in the southeast, it can be found as far north as Manitoba. D. chrysoscelis has also been observed to practice freeze tolerance in a lab setting, which could help it survive in cold climates.{{cite journal |last1=Costanzo |first1=Jon |title=Freeze Tolerance as an Overwintering Adaptation in Cope's Grey Treefrog (Hyla chrysoscelis) |journal=Copeia |date=May 1, 1992 |volume=1992 |issue=2|pages=565–569 |doi=10.2307/1446222 |jstor=1446222 }} These frogs are one of the very few that can mobilize glycerol as a cryoprotectant. Glycerol production is low when the temperature is warmer, but when it gets colder, the glycerol in the body is rapidly produced.Amarl M. C. F. 2018 When studying ice concentration of overwintering frogs, 40-50% of total body water was frozen.{{Cite journal |last1=Costanzo |first1=Jon P. |last2=Wright |first2=Michael F. |last3=Lee |first3=Richard E. |date=1992 |title=Freeze Tolerance as an Overwintering Adaptation in Cope's Grey Treefrog (Hyla chrysoscelis) |url=https://www.jstor.org/stable/1446222 |journal=Copeia |volume=1992 |issue=2 |pages=565–569 |doi=10.2307/1446222 |jstor=1446222 |issn=0045-8511}} Studies have revealed that Cope's gray treefrog could be more resilient to climate change in the long-term, though populations may suffer short-term drawbacks.{{cite journal |last1=Litmer |first1=Allison |last2=Murray |first2=Christopher |title=Critical Thermal Capacities of Hyla chrysoscelis in Relation to Season |journal=Journal of Herpetology |date=2020 |volume=54 |issue=4 |pages=413–417 |doi=10.1670/19-124 }} Either way, distribution will hopefully change little in the long-term because of this. They prefer to perch on pipes located along the edges of wetlands and close to trees, which suggests that the terrestrial habitat surrounding wetlands is an important component of the species habitat.{{cite journal |last1=Pittman |last2=Jendrek |first2=A.L |last3=Price |first3=S. |last4=Dorcas |first4=M.E |title=Habitat Selection and Site Fidelity of Cope's Gray Treefrog (Hyla chrysoscelis) at the Aquatic-Terrestrial Ecotone. |journal=Journal of Herpetology |date=2008 |volume=42 |issue=2 |pages=378–385 |doi=10.1670/07-1702.1|s2cid=86035585 }} The bird-voiced treefrog, D. avivoca, is similar to D. chrysoscelis and D. versicolor, but is smaller (25–50 mm in length vs 32–62 mm for the gray treefrog).

File:Hyla chrysoscelis metamorph 2.jpg

File:Hyla chrysoscelis call video.webm.]]

In the Southeastern United States, Cope's gray treefrog breeds and calls from May to August. Isolated males start calling from woodland areas during warm weather a week or more before migrating to temporary ponds to breed. There they form aggregations (choruses) and call together. Chorusing is most frequent at night, but individuals often call during daytime in response to thunder or other loud noises. These individual calls are produced at high sound pressure levels (SPLs) reaching 85 to 90 dB and sustained noise levels in choruses commonly range between 70 and 80 dB SPL.{{cite journal |last1=Lee |first1=N. |last2=Ward |first2=J. L. |last3=Vélez |first3=A. |last4=Micheyl |first4=C. |last5=Bee |first5=M. A. |year=2017 |title=Frogs exploit statistical regularities in noisy acoustic scenes to solve cocktail-party-like problems |journal=Current Biology |volume=27 |issue=5 |pages=743–750 |doi=10.1016/j.cub.2017.01.031|pmid=28238657 |pmc=5340627 |bibcode=2017CBio...27..743L }} Female treefrogs have been found to be able to differentiate calls at scales of up to a few decibels.{{Cite journal |last1=Bee |first1=Mark A. |last2=Vélez |first2=Alejandro |last3=Forester |first3=James D. |date=2012-05-01 |title=Sound level discrimination by gray treefrogs in the presence and absence of chorus-shaped noise |journal=The Journal of the Acoustical Society of America |volume=131 |issue=5 |pages=4188–4195 |doi=10.1121/1.3699271 |issn=0001-4966 |pmc=3356323 |pmid=22559390|bibcode=2012ASAJ..131.4188B }} Females prefer calls with average frequencies over calls with frequencies that were 2 or 3 semitones lower than the population mean.{{cite journal |last1=Schrode |first1=K. M. |last2=Ward |first2=J. L. |last3=Vélez |first3=A. |last4=Bee |first4=M. A. |year=2012 |title=Female preferences for spectral call properties in the western genetic lineage of Cope's gray treefrog (Hyla chrysoscelis) |journal=Behavioral Ecology and Sociobiology |volume=66 |issue=12 |pages=1595–1606 |doi=10.1007/s00265-012-1413-5|pmid=24496093 |pmc=3564599 }} Calls higher than the average semitones do not face behavioral discrimination like the lower calls do. Eggs are laid in batches of 10 to 40 on the surfaces of shallow ponds and other small bodies of water. These temporary bodies of water usually lack fish, and females preferentially lay their eggs in water bodies that lack fish or other predatory vertebrates and have lower desiccation risk.{{cite journal |first1=William J. |last1=Resetarits, Jr. |title=Choice of oviposition site by Hyla chrysoscelis: role of predators and competitors |journal=Ecology |volume=70 |issue=1 |pages=220–228 |year=1989 |url=https://www.researchgate.net/publication/245657502 |doi=10.2307/1938428|jstor=1938428 |bibcode=1989Ecol...70..220R }}{{cite journal |first1=Matthew R. |last1=Pintar |first2=William J. |last2=Resetarits, Jr. |title=Out with the old, in with the new: oviposition preference matches larval success in Cope's gray treefrog, Hyla chrysoscelis |journal=Journal of Herpetology |volume=51 |issue=2 |pages=186–189 |year=2017 |url=http://www.matthewpintar.net/uploads/2/9/8/5/29857083/pintar___resetarits_2017_jherp.pdf |doi=10.1670/16-019|s2cid=53633353 }}{{cite journal |first1=Matthew R. |last1=Pintar |first2=William J. |last2=Resetarits, Jr. |title=Relative predation risk and risk of desiccation co-determine oviposition preferences in Cope's gray treefrog, Hyla chrysoscelis |journal=Oecologia |volume=184 |issue=2 |pages=423–430 |year=2017 |url=https://www.researchgate.net/publication/316689673 |doi=10.1007/s00442-017-3875-7 |pmid=28470466 |bibcode=2017Oecol.184..423P |s2cid=2743867 }} Eggs hatch in about five days and metamorphosis takes place at about 45–65 days.Rubio, M. [http://sherpaguides.com/georgia/atlanta_urban_wildlife/backyard_herps/index.html Atlanta's Backyard Herps.] Accessed 2 June 2013.

The diet of Cope's gray treefrog primarily consists of insects such as moths, mites, spiders, plant lice, and harvestmen. Snails have also been observed as a food source. Like most frogs, Dryophytes chrysocelis is an opportunistic feeder and may also eat smaller frogs, including other treefrogs.{{Cite book |last=Conant |first=Roger |url=https://www.worldcat.org/oclc/1423604 |title=A field guide to reptiles and amphibians of Eastern and Central North America |date=1975 |publisher=Houghton Mifflin |others=Isabelle Hunt Conant |isbn=0-395-19979-4 |edition=[2d ed.] |location=Boston |oclc=1423604}} Once the breeding season is over, Cope's gray treefrogs will forage continuously until winter.{{cite journal |last1=Ritke |first1=M. E. |last2=Babb |first2=J. G. |last3=Ritke |first3=M. K. |year=1992 |title=Temporal patterns of reproductive activity in the gray treefrog (Hyla chrysoscelis) |journal=Journal of Herpetology |volume=26 |issue=1 |pages=107–111|doi=10.2307/1565039 |jstor=1565039 }}

Cope's gray treefrog exhibits freeze tolerance.{{cite journal |last1=Ward |first1=J. L. |last2=Love |first2=E. K. |last3=Vélez |first3=A. |last4=Buerkle |first4=N. P. |last5=O'Bryan |first5=L. R. |last6=Bee |first6=M. A. |year=2013 |title=Multitasking males and multiplicative females: dynamic signalling and receiver preferences in Cope's grey treefrog |journal=Animal Behaviour |volume=86 |issue=2 |pages=231–243|doi=10.1016/j.anbehav.2013.05.016 }} Dryophytes chrysoscelis is capable of surviving temperatures as low as {{cvt|-8|C}}.[https://www.int-res.com/articles/cr/5/c005p053.pdf Adaptations of Frogs to Survive Freezing] They can withstand the physiological challenges of corporeal freezing, by accumulating cryoprotective compounds of hepatic origin, including glycerol, urea, and glucose.{{cite journal |last1=do Amaral |first1=M. C. F. |last2=Frisbie |first2=J. |last3=Crum |first3=R. J. |last4=Goldstein |first4=D. L. |last5=Krane |first5=C. M. |year=2020 |title=Hepatic transcriptome of the freeze-tolerant Cope's gray treefrog, Dryophytes chrysoscelis: responses to cold acclimation and freezing |journal=BMC Genomics |volume=21 |issue=1 |pages=226 |doi=10.1186/s12864-020-6602-4|doi-access=free |pmid=32164545 |pmc=7069055 }} It is one of a few freeze tolerant frogs that use glycerol as a cryoprotectant.{{Cite journal |last=do Amaral |first=M. Clara F. |last2=Frisbie |first2=James |last3=Goldstein |first3=David L. |last4=Krane |first4=Carissa M. |date=2018-07-01 |title=The cryoprotectant system of Cope’s gray treefrog, Dryophytes chrysoscelis: responses to cold acclimation, freezing, and thawing |url=https://link.springer.com/article/10.1007/s00360-018-1153-6 |journal=Journal of Comparative Physiology B |language=en |volume=188 |issue=4 |pages=611–621 |doi=10.1007/s00360-018-1153-6 |issn=1432-136X |pmc=6006228 |pmid=29550887}}

{{Reflist}}

do Amaral, M. C. F., Frisbie, J., Goldstein, D. L., & Krane, C. M. (2018). The cryoprotectant system of Cope’s gray treefrog, Dryophytes chrysoscelis: responses to cold acclimation, freezing, and thawing. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, 188(4), 611–621. https://doi.org/10.1007/s00360-018-1153-6

• {{cite journal|author=Mary Hoff|title=Chirp, Croak, Snore|publisher=Minnesota Conservation Volunteer|journal=DNR|date=March–April 2014|page=32}}

{{Commons}}

• [https://web.archive.org/web/20070313052816/http://www.amphibiaweb.org/cgi/amphib_query?query_src=aw_lists_genera_&where-genus=Hyla&where-species=chrysoscelis Hyla chrysoscelis.] Amphibiaweb. Accessed 2 June 2013.
• [http://www.natureserve.org/explorer/servlet/NatureServe?searchName=hyla+chrysoscelis Hyla chrysoscelis.] NatureServe. Accessed 2 June 2013.

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Category:Dryophytes

Category:Cryozoa

Tree Frog, Grey

Category:Articles containing video clips

Category:Extant Pleistocene first appearances

Category:Amphibians described in 1880

Category:Taxa named by Edward Drinker Cope