Dab solver - Foothill Yellow-legged Frog

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A triangular, buff-colored patch occurs on the snout, and, unlike other frogs in the genus, there is no eye stripe. The throat and chest are often boldly mottled; and the species has indistinct [[dorsolateral]] skin folds and [[granular]] skin.  Males of this species develop [[nuptial pad]]s on their thumb bases during the breeding season. These frogs can be identified by their rough skin, horizontal pupils, fully webbed hind feet, and their habit of jumping into moving water.^ref  

Tadpoles of this species, though, resemble those of the western toad, [[Bufo boreas]]. R. boylii as tadpoles have fairly flattened tails that lack color at the end and are the tallest in the midsection. The mouths of the tadpoles are made for suction to rocks, with  teeth rows used for scraping algae and diatoms, unicellular algae with cells walls that contain [[silica]], off of the rocks to which they are clinging. The mouth of the young R. boylii is also helpful in identifying it from B. boreas because the young foothill yellow-legged frogs develop more defined teeth rows after three weeks, while their counterparts do not.^ref

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{{Taxobox|name=Foothill yellow-legged frog|status=NT|status_system=IUCN3.1|status_ref=<ref>Georgina Santos-Barrera, Geoffrey Hammerson and Gary Fellers, 2004</ref>
|trend=down
|image=Rana boylii.jpg|image_width=240px
|regnum=[[Animal]]ia
|phylum=[[Chordate|Chordata]]
|classis=[[Amphibian|Amphibia]]
|ordo=[[Frog|Anura]]
|familia=[[True frog|Ranidae]]
|genus=''[[Rana (genus)|Rana]]''
|species='''''R. boylii'''''
|binomial=''Rana boylii''|binomial_authority=[[Spencer Fullerton Baird|Baird]], 1854}}
The '''foothill yellow-legged frog''' ('''''Rana boylii''''') is a small-sized {{convert|3.72|-|8.2|cm|abbr=on}} [[frog]]<ref>Robert N. Fisher and Ted J. Case, 2003</ref> from the [[Rana (genus)|''Rana'']] genus in the [[Ranidae]] family. This species can be found from northern [[Oregon]], down [[California|California’s]] west coast, and into [[Baja California]], [[Mexico]]. Both the [[Columbia spotted frog]] and the [[Cascades frog]], also part of the ''Rana'' genus, live in the northern regions of this frog's territory.  They prefer to live in streams and rivers, and lay their eggs in masses attached to rocks underwater.
==Appearance==
[[Image:Rana boylii02.jpg|thumb|left|down|The frog is part of the olive variety with the yellowish legs.]]
[[Image:Rana boylii16.jpg|thumb|right|down| This frog displays the reddish dorsum.]]

The foothill yellow-legged frog has a grey, brown, or reddish [[dorsum (biology)|dorsum]], or the back of the frog. It is commonly spotted or [[mottle]]d, but occasionally is plainly colored. Adults have yellow coloration under their legs, which may extend to their abdomens, but this characteristic is faint or absent in young frogs.

A triangular, buff-colored patch occurs on the snout, and, unlike other frogs in the genus, there is no eye stripe. The throat and chest are often boldly mottled; and the species has indistinct [[dorsolateral]] skin folds and [[granular]] skin.  Males of this species develop [[nuptial pad]]s on their thumb bases during the breeding season. These frogs can be identified by their rough skin, horizontal pupils, fully webbed hind feet, and their habit of jumping into moving water.<ref name="history">Ashton, Don T., Amy J. Lind, and Kary E. Schlick. "Foothill Yellow-Legged Frog (''Rana boylii'') Natural History." USDA Forest Service (1998).</ref>

Tadpoles of this species, though, resemble those of the western toad, ''[[Bufo boreas]]''. ''R. boylii'' as tadpoles have fairly flattened tails that lack color at the end and are the tallest in the midsection. The mouths of the tadpoles are made for suction to rocks, with <<link:0>> teeth rows used for scraping algae and diatoms, unicellular algae with cells walls that contain [[silica]], off of the rocks to which they are clinging. The mouth of the young ''R. boylii'' is also helpful in identifying it from ''B. boreas'' because the young foothill yellow-legged frogs develop more defined teeth rows after three weeks, while their counterparts do not.<ref name="history"/>
==Food sources==
Food supplies, such as algae the tadpoles eat, also affect the sexual maturity of the species. Reportedly, the “amount of protein in different algae, can affect size at and time to [[metamorphosis]]” and  “these food effects may be mediated through diet-induced changes in [[thyroid]] function”, which means the food the tadpoles ingest dictates the changes in the thyroid gland's production of certain proteins.<ref>Kupferberg, Sarah J. "The Role of Larval Diet in Anuran Metamorphosis." American Zoologist 37 (1997): 146-59.</ref> Tadpoles most commonly feed on algae, [[diatom]]s, and [[detritus]].  As the species grows older, it changes its diet to animal tissue which must be swallowed whole because the frog's jaw is structured on a hinge joint that does not allow for sideways movement as in humans. Adult frogs eat a range of foods such as [[moth]]s, [[ant]]s, [[grasshopper]]s, [[hornet]]s, beetles, flies, [[water strider]]s, and snails.<ref name="amphibia">"Rana boylii." AmphibiaWeb. 21 Apr. 2009<http://amphibiaweb.org/cgi-bin/amphib_query?where-genus=Rana&where-species=boylii>.</ref>
==Mating habits==
[[Image:Rana boylii22.jpg|thumb|right|up|This egg mass is placed between two large rocks.]]
The mating “ceremonies” begin in spring, when adult frogs congregate on sandy and/or rocky bars to mate.  Previously believed to mate from March to May, recent experiments have shown the time to be closer to April to late June.<ref name="history"/> High stream velocities, however, may dislodge ''R. boylii'' [[egg (biology)|egg]] masses from [[oviposition]] substrates.<ref name="mating">Welsh, Jr., Hartwell H., and Clara A. Wheeler. "Mating Strategy and Breeding Patterns of the 
Foothill Yellow-Legged Frog (Rana Boylii)." Herpetological Conservation and Biology 3(2008): 128-42.</ref> Thus, ''R. boylii'' avoids rapid waters to protect the egg masses from being swept away.  This technique is why the species has a long breeding season.  If the conditions do not meet their standards, they refuse to mate and wait until the water velocities go back down to ideal.

For the foothill yellow-legged frog, oviposition, or the depositing of eggs, is somewhat sporadic because delays such as rains could cause problems such as unwanted removal of eggs.<ref name="history"/> The males also perform mating calls mostly underwater, and those above the water are faint and hard to hear over 50 m.  After the frogs have successfully mated, the egg masses are laid about 0.5 mr down in the river and with flow velocities ranging from 0.1 to 0.6 m<sup>3</sup>/second.<ref name="mating"/>

These egg masses can contain 100 to 1000 eggs in one batch,  contained in a bluish gel that disappears once the eggs take on water, and the dark [[ovum]], the center of egg, is covered by three jelly envelopes about 5.4&nbsp;mm in diameter. Eggs hatch in about five to over thirty days depending on the temperature that the mass is at and the surrounding water.<ref name="history"/> The tadpoles continue to stay associated with the egg mass for several days, and continue to need higher temperatures to grow quickly.  By the time the tadpoles reach about 40 mm, roughly 1.5 in, they are adults and their reproductive organs are mostly functional.  The frogs are usually fully developed by the summer after their first [[metamorphosis]], though some begin breeding after six months.
==Habitat==
The foothill yellow-legged frog's territory spans from northern [[Oregon]], to [[California|California's]] coast where it most commonly found, and into [[Baja California]], [[Mexico]]. They are found in flowing streams and rivers with either rocky substrate or sunny banks.<ref name="amphibia"/>
==Chemical defense==
''R. boylii'' uses a chemical defense to protect itself from [[fungal]] infections, such as the ''[[Batrachochytrium dendrobatidis]]''.<ref name="defense">Benard, Michael F., and Et al. "Effects of Chytrid and Carbaryl Exposure on Survival, Growth and Skin Peptide Defenses in Foothill Yellow-legged Frogs." Environmental Science and Technology 41 (2007): 1771-776.</ref>  The frog secretes a [[peptide]] through the skin and the [[hydrophobic]] (water repellent) sections of the peptide access to [[fungus|fungi]] that want to attach to the amphibian.<ref name="pmid14531844">{{cite journal|author=Conlon JM, Sonnevend A, Patel M, ''et al''|title=Isolation of peptides of the brevinin-1 family with potent candidacidal activity from the skin secretions of the frog Rana boylii|journal=The Journal of Peptide Research: Official Journal of the American Peptide Society|volume=62|issue=5|pages=207–13|year=2003|month=November|pmid=14531844|doi=|url=http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=1397-002X&date=2003&volume=62&issue=5&spage=207|issn=|accessdate=2009-04-26}}</ref> This ability can also be found in other ''[[Rana (genus)|Rana]]'' species, including the Cascades frog and the moor frog.  The former secretes a milky substance that fights against fungal infections and the latter uses its capability to have males turn blue during mating season.  Still, the foothill yellow-legged frog's chemical defense has not been fully examined.  Although not much is known about it, this ability of the species has been of interest to many companies because of its overall [[Antifungal medication|antifungal]] effectiveness.  However, current pesticide use has caused problems for the frog.  So far, exposure to [[carbaryl]], a substance found in common pesticides, has been shown to not kill the frogs, it does lower the peptides’ abilities to defend the species against invaders like the chytrid, ''B. dendrobatidis''.<ref name="defense"/>  More research is being done to see the full effects pesticides may have on ''R. boylii''.

== Environmental issues ==
Along with the problems associated with pesticides being washed into this frog's habitat, in [[Trinity County, California|Trinity County]], [[California]], a dam on the major river of the frog's home has affected about 94% of the possible [[procreation]] areas for the frogs, which has endangered the population.<ref name="history"/> One study suggests the “data from a comparably sized undammed river fork in the same system…demonstrated that both the number of potential sites and the total number of egg masses were…higher on this fork than in our main stem”, so the unseasonal flooding required by the dam was negatively affecting the mating behavior of the frog.<ref name="dam">Lind, Amy J., Hartwell H. Welsh, Jr., and Randolph A. Wilson. "The Effects of a Dam on Breeding Habitat and Egg Survival of the Foothill Yellow-legged Frog (''Rana boylii'') in Northwestern California." Herpetological Review 27 (1996): 62-67.</ref>

The temperature of the water in Trinity County is also lower than it was before the dam was put into place.  To keep up with demands of fisheries, the water’s temperature is kept artificially lower than normal, which consequently slows the development of ''R. boylii''.<ref name="dam"/> Therefore, the colder temperatures are making it more difficult for the frogs to grow quickly, which sometimes leaves the species prey to many other animals that feed on their young.  The problems occurring between the foothill yellow-legged frog and the dam are being handled by several [[herpetological]] organizations, along with the Forest Service, to find ways to alter the effects in a beneficial way for the frog. This species is also estimated to be gone from most of its range in the Sierra Nevadas, especially south of Highway 80, where pesticides often contaminate rivers, and dams block the essential stream flows.<ref name="frogs">"R boylii." californiaherps 07 Sept 2011<http://www.californiaherps.com/frogs/pages/r.boylii.html#status</ref>

==Predators==
The foothill yellow-legged frog is a natural prey of diving beetles, water bugs, garter snakes, rough-skinned newts, bullfrogs, and western toads.<ref name="history"/>
==References==
{{Commons|Rana boylii}}
{{reflist}}
*{{aut|Hillis, D.M. & Wilcox, T.P.}} (2005): Phylogeny of the New World true frogs (''Rana''). ''[[Molecular Phylogenetics and Evolution|Mol. Phylogenet. Evol.]]'' '''34'''(2): 299–314. <small>{{doi|10.1016/j.ympev.2004.10.007}}</small> [http://www.cnah.org/pdf_files/215.pdf PDF fulltext].
*{{aut|Hillis, D. M.}} (2007) Constraints in naming parts of the Tree of Life. ''[[Molecular Phylogenetics and Evolution|Mol. Phylogenet. Evol.]]'' '''42''': 331–338.
*{{IUCN2006|assessors=Georgina Santos-Barrera, Geoffrey Hammerson, Gary Fellers|year=2004|id=19175|title=Rana boylii|downloaded=11 May 2006}} Database entry includes a range map and justification for why this species is near threatened
*"Rana boylii." AmphibiaWeb. 21 Apr. 2009 <http://amphibiaweb.org/cgi-bin/amphib_query?where-genus=Rana&where-species=boylii>
*Ashton, Don T., Amy J. Lind, and Kary E. Schlick. "Foothill Yellow-Legged Frog (Rana boylii) Natural History." USDA Forest Service (1998). <http://www.krisweb.com/biblio/gen_usfs_ashtonetal_1997_frog.pdf>.
*Benard, Michael F., and Et al. "Effects of Chytrid and Carbaryl Exposure on Survival, Growth and Skin Peptide Defenses in Foothill Yellow-legged Frogs." Environmental Science and Technology 41 (2007): 1771-776. <http://www.jcu.edu.au/school/phtm/PHTM/frogs/papers/davidson-2007.pdf>.
*C. Michael Hogan (2008) [http://www.globaltwitcher.com/artspec_information.asp?thingid=43182''Rough-skinned Newt (Taricha granulosa)'', Globaltwitcher, ed. Nicklas Stromberg]
*Conlon, J.M., C. Davidson, P.F. Nielson, T. Pal, M. Patel, and L.A. Rollins-Smith. "Isolation of peptides of the brevinin-1 family with potent candidacidal activity from the skin secretions of the frog Rana boylii." Journal of Peptide Research 62 (2003): 207-13.
*Kupferberg, Sarah J. "The Role of Larval Diet in Anuran Metamorphosis." American Zoologist 37 (1997): 146-59. <http://icb.oxfordjournals.org/cgi/content/abstract/37/2/146>.
*Lind, Amy J., Hartwell H. Welsh, Jr., and Randolph A. Wilson. "The Effects of a Dam on Breeding Habitat and Egg Survival of the Foothill Yellow-legged Frog (Rana boylii) in Northwestern California." Herpetological Review 27 (1996): 62-67. <http://www.fs.fed.us/psw/programs/snrc/bio_diversity/aquatic_lessdistrubed_sub2/lind%20et%20al%201996.pdf>.
*Robert N. Fisher and Ted J. Case (2003) [http://www.werc.usgs.gov/fieldguide/rabo.htm ''A Field Guide to the Reptiles and Amphibians of Coastal Southern California'', U.S. Geological Survey, Western Ecological Research Center]
*Welsh, Jr., Hartwell H., and Clara A. Wheeler. "Mating Strategy and Breeding Patterns of the Foothill Yellow-Legged Frog (Rana Boylii)." Herpetological Conservation and Biology 3 (2008): 128-42. <http://www.fs.fed.us/psw/publications/welsh/psw_2008_welsh(wheeler)002.pdf>.

[[Category:Rana]]
[[Category:Animals described in 1854]]
[[Category:Amphibians of North America]]

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Dab solver - Foothill Yellow-legged Frog

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