{{Short description|Species of lizard}}
{{Refimprove|date=June 2025}} {{Speciesbox | name = Boyd's forest dragon | image = Boyd's forest dragon (Lophosaurus boydii) Daintree.jpg | image_caption = Daintree National Park, Queensland, Australia | status = LC | status_system = IUCN3.1 | status_ref =<ref name="iucn status 20 November 2021">{{cite iucn |author=Hoskin, C. |author-link=species:Conrad J. Hoskin|author2=Couper, P. |author2-link=species:Patrick J. Couper|author3=Vanderduys, E. |author3-link=species:Eric P. Vanderduys|author4=Amey, A. |author4-link=species:Andrew P. Amey|date=2018 |title=''Lophosaurus boydii '' |volume=2018 |article-number=e.T22528830A22528836 |doi=10.2305/IUCN.UK.2018-1.RLTS.T22528830A22528836.en |access-date=20 November 2021}}</ref> | genus = Lophosaurus | species = boydii | authority = (Macleay, 1884) | synonyms = * ''Tiaris boydii'' <br />{{small|Macleay, 1884}} * ''Gonyocephalus boydii'' <br />{{small|— Boulenger, 1885}} * ''Hypsilurus boydii'' <br />{{small|— Cogger, 1983}} * ''Lophosaurus boydii'' <br />{{small|— Denzer & Manthey, 2016}} | synonyms_ref =<ref>{{EMBL species|genus=Hypsilurus|species=boydii}}</ref> }} thumb
'''Boyd's forest dragon''' ('''''Lophosaurus boydii''')'' is a species of arboreal lizard in the family Agamidae. The species is native to rainforests and their margins in the Wet Tropics region of northern Queensland, Australia.<ref>{{Cite journal|last1=Denzer|first1=Wolfgang|author1-link=species:Wolfgang Denzer|last2=Manthey|first2=Ulrich|author2-link=species:Ulrich Manthey|title=Remarks on the taxonomy and nomenclature of the genus ''Hypsilurus'' Peters, 1867 (Reptilia, Agamidae, Amphibolurinae) |url=https://zse.pensoft.net/articles.php?id=7469|journal=Zoosystematics and Evolution|year=2016|language=en|volume=92|issue=1|pages=103–110|doi=10.3897/zse.92.7469 |doi-access=free}}</ref> It is the larger of the two species of ''Lophosaurus'' found in Australia. Another species, the southern angle-headed dragon, ''L. spinipes'', is found in southern Queensland and northern New South Wales.
==Etymology== The generic name ''Lophosaurus'' stands for "crested lizard", from the Greek ''lophos'' for "crest", and ''saurus'' for "lizard".{{source needed|reason=Saurus isn't the Greek form. So, what source was used? I've removed the Wiktionary as source, as Wiktionary is not permitted as source.|date=July 2025}} The specific name, ''boydii'', is a reference to English-born John Archibald Boyd (1846–1926), who lived in Fiji from 1865 to 1882 and then on a sugar plantation at Ingham, Queensland, and collected specimens for the Australian Museum. The binomial authority is William John Macleay, who provided the original description of the species in 1884.<ref>{{cite book|last=Ehmann|first=Harald|author-link=species:Harald Ehmann|title=Encyclopedia of Australian Animals: Reptiles|year=1992|publisher=Angus and Robertson}}</ref><ref>Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. (''Hypsilurus boydii'', p. 36).</ref> Additionally, the Kuku Yalanji people of North Queensland named this lizard "Jalbil" which refers not only to this species, but also to the mythological creature who split Snapper Island away from the mainland.<ref>{{Cite journal |last=Muir |first=D.M. |date=March 1983 |title=Work Papers of SIL-AAB. Series B Volume 8Language and Culture. Editor S. Hargrave. Summer Institute of Linguistics, Australian Aborigines Branch, Darwin, December 1982. |journal=The Aboriginal Child at School |volume=11 |issue=1 |pages=57–59 |doi=10.1017/s031058220001258x |issn=0310-5822}}</ref>
==Geographic range and habitat== The species ''Lophosaurus boydii'' is restricted to rainforests and their margins in northern Queensland, Australia, from just north of Townsville to near Cooktown.<ref>{{cite book|title=Rainforest Animals: Atlas of the Vertebrates Endemic to Australia's Wet Tropics|year=1991|publisher=Kowari|location=Canberra|author=Nix, H.A. |author2=Switzer, Margaret Ann}}</ref> It is found in both upland and lowland rainforest, and is often seen around Lake Eacham (Yidyam) and Lake Barrine, and in parts of Malanda Falls Conservation Park and at Mossman Gorge.{{citation needed|date=March 2024}}
It is recorded using tree-hollows.<ref name="Gibbons">{{cite book|url=https://books.google.com/books?id=6Q28RIlsW_IC&q=Hypsilurus+boydii&pg=PA9|title=Tree Hollows and Wildlife Conservation in Australia|publisher=CSIRO Publishing|author=Gibbons, Philip|author2=Lindenmayer, David|author2-link=David Lindenmayer|year=2002|page=9|isbn=978-0-643-06705-9}}</ref>
==Description== thumb|left|Boyd's forest dragon (''Lophosaurus boydii'')
Boyd's forest dragon is generally brown or grey above, with some individuals having a green flush. The body is laterally compressed. It has very enlarged cheek scales, a prominent nuchal crest, and a yellow dewlap under the chin that is edged with enlarged spines. The tympanum is large and superficial. A dorsal crest, discontinuous with the nuchal crest, consisting of enlarged, hardened and pointed scales, runs down to the base of the tail.{{citation needed|date=March 2024}}
Adults are sexually dimorphic, with males larger than females and having larger, blockier heads. Adult males grow to an average body length (snout-vent length) of about {{convert|160|mm|in|abbr=on}}, with the tail adding another {{convert|325|mm|in|abbr=on}}; average body length for adult females is about {{convert|140|mm|in|abbr=on}} and tail length is about {{convert|280|mm|in|abbr=on}}. Average body mass for adult males is about {{convert|150|g|oz|abbr=on}}, and for females is about {{convert|100|g|oz|abbr=on}}.{{citation needed|date=March 2024}}
==Behavior== Boyd's forest dragon spends the majority of its time perched on the trunks of trees, usually at around head height, although daily movements can exceed {{convert|100|m|ft|abbr=on}} on the ground. When approached, it will usually move around to the opposite side of the tree, keeping the trunk between it and its harasser.<ref>{{cite journal|last=Torr|first=Geordie|title=Forest dragons|journal=Nature Australia|year=1997|volume=25|pages=32–39}}</ref>
Unlike most other lizards, Boyd's forest dragon does not bask in the sun, instead letting its body temperature fluctuate with air temperature (thermoconforming rather than thermoregulating). The one possible exception to this general rule is gravid (pregnant) females, which are often observed sitting on or beside forest roads and exhibit elevated body temperatures.{{citation needed|date=March 2024}}
Boyd's forest dragon typically commences activity at dawn and ceases activity at dusk, remaining active even when it rains. Activity is highly seasonal, all but ceasing during the cooler months, when lizards typically move into the rainforest canopy.{{citation needed|date=March 2024}}
Both males and females appear to be territorial, with males defending an area of around 1,000 square metres (0.247 acres). Female territories are smaller, with male territories often containing the territories of more than one female.{{citation needed|date=March 2024}}
Hatchlings, juveniles and smaller adults can often be found "sleeping" at night at the ends of tree branches with the head pointing back towards the trunk.{{citation needed|date=March 2024}}
==Diet== Boyd's forest dragon is a sit-and-wait predator, catching prey that it spies from its perch, although once on the ground, it will frequently move over a wider area, catching prey as it goes. Its diet consists primarily of invertebrates, with earthworms making up a relatively high proportion. Small fruits and vertebrates are also occasionally consumed.<ref>{{cite journal|last=Torr|first=Geordie|title=Here be dragons|journal=Australian Geographic|year=2003|volume=69|pages=68–77}}</ref>
==Reproduction== Reproduction in ''Lophosaurus boydii'' is via eggs, with clutch sizes varying from one to six eggs. Eggs are about {{convert|30|mm|in|abbr=on}} long and {{convert|15|mm|in|abbr=on}} wide, and weigh about {{convert|3|-|4.5|g|oz|abbr=on}}. Egg size and weight are both higher in upland populations. Females in lowland populations may lay more than one clutch in a season, but clutch sizes are typically smaller than those laid by upland females. The eggs are laid in shallow nests, often in rainforest clearings—both natural and man-made (the verges of roads are particularly popular). The eggs take about 100 days to incubate.{{citation needed|date=March 2024}}
Sexual maturity is achieved in around one to two years in lowland populations but probably takes at least a year longer in upland populations.{{citation needed|date=March 2024}}
==Predators== Known predators of juvenile and adult Boyd's forest dragon include grey goshawks and feral pigs. Slaty-grey snakes (''Stegonotus cucullatus'') have also been known to eat forest dragon eggs.<ref>{{cite journal|last1=Trembath |first1=Dane Simon |last2=Fearn |first2=Simon |last3=Undheim |first3=Eivind Andreas Baste|title=Natural history of the slaty grey snake (''Stegonotus cucullatus'') (Serpentes: Colubridae) from tropical north Queensland, Australia|journal=Australian Journal of Zoology|year=2009|volume=57|issue=2|pages=119–124|doi=10.1071/zo08091|url=https://www.researchgate.net/publication/258341509_Natural_history_of_the_slaty_grey_snake_Stegonotus_cucullatus_Serpentes_Colubridae_from_tropical_north_Queensland_Australia|publisher=CSIRO Publishing |access-date=2025-07-02}}</ref>
==Parasites== Small orange mites are commonly found on the dewlap and in the groin areas of the legs of Boyd's forest dragon.{{Citation needed|date=March 2024}}
==References== {{Reflist}}
==Further reading== * Boulenger GA (1885). ''Catalogue of the Lizards in the British Museum (Natural History)''. Second Edition. [https://archive.org/details/cu31924024782124/mode/2up Volume I: ''Geckonidæ, Eublepharidæ, Uroplatidæ, Pygopodidæ, Agamidæ'']. London: Trustees of the British Museum (Natural History); Taylor and Francis, printers. xii + 436 pp. + Plates I–XXXII. (''Gonyocephalus boydii'', [https://archive.org/details/cu31924024782124/page/296/mode/2up pp. 297–298]). * Macleay W (1884). "Notes on Some Reptiles from the Herbert River, Queensland". ''Proceedings of the Linnean Society of New South Wales'' '''8''': 432–436. (''Tiaris boydii'', new species, pp. 432–433).
==External links== {{Commons}} * [http://rainforest-australia.com/Boyd's_Forest_Dragon.html Boyd's Forest Dragon] * [https://www.wettropics.gov.au/site/user-assets/docs/33%20Lizards.pdf Tropical Topics]
{{Taxonbar|from=Q2711409}}
Category:Agamid lizards of Australia Category:Endemic fauna of Australia Category:Lophosaurus Category:Reptiles described in 1884 Category:Reptiles of Queensland Category:Taxa named by William John Macleay