Geneva, Anthony J.

Glor, Richard E.

Landestoy, Miguel

Ng, Julienne

Scantlebury, Daniel P.

English

The University of Kansas: Journals@KU

	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011	 13Dwarf	geckos	of	the	genus	Sphaerodactylus	(“sphaeros”)	are	one	of	the	dominant	components	of	the	West	Indian	herpetofauna	in	terms	of	species	richness	and	sheer	local	abundance	—	88	West	Indian	species	and	numerous	subspecies	are	presently	recognized	(henderson	and	powell	2009)	and	some	populations	approach	densities	of	60,000/ha	(Rodda	et	al.	2001).	Indeed,	they	are	such	a	ubiquitous	feature	of	Caribbean	herpetology	that	sphaeros	and	rum	might	well	be	staples	of	Caribbean	islands.	these	geckos	occupy	the	full	scope	of	available	habitats	in	the	West	Indies	—	coastal	regions	including	mangrove	thickets,	cactus-covered	xeric	badlands,	and	montane	cloud	forests.	 sphaeros	are	tiny	geckos,	and	include	the	smallest	amniote	species	(hedges	and	thomas	2001).	overall,	the	genus	is	considered	to	be	diur-nally	active,	although	nocturnal	activity	is	reported	for	a	few	species.	most	species	live	a	secretive,	semi-fossorial	lifestyle	that,	coupled	with	their	min-iscule	size,	renders	observation	challenging	(e.g.,	henderson	and	powell	2009).	this	difficulty	has	no	doubt	contributed	to	the	fact	that	we	cur-rently	know	next	to	nothing	about	their	behavior,	ecology,	distributions,	and	functional	morphology.	this	dearth	of	knowledge,	however,	makes	sphaeros	very	rewarding	animals	to	study.	Almost	every	day	of	fieldwork	spent	on	these	geckos	generates	new	discoveries.	In	this	paper,	we	discuss	notes on activity Patterns of five species of Sphaerodactylus (squamata: sphaerodactylidae) from the Dominican RepublicDaniel	p.	scantlebury1,	Julienne	ng1,	miguel	landestoy2,	Anthony	J.	Geneva1,	and	Richard	e.	Glor11Department	of	biology,	University	of	Rochester,	Rochester,	new	York	14627-0211,	UsA	(dscantle@mail.rochester.edu)2ministerio	de	medio	Ambiente	y	Recursos	naturales,	santo	Domingo,	Dominican	Republic;	sociedad	ornitologica	de	la	hispaniola,	santo	Domingo,	Dominican	Republic	(hispanioland@gmail.com)photographs	by	the	senior	author	except	where	noted.SPhaerodaCtyluS	In	the	DomInICAn	RepUblICmale	Sphaerodactylus ladae	from	parque	nacional	Francis	Caamaño.	MiGueL Landestoy14	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011some	recent	observations	of	nocturnal	or	crepuscular	activity	patterns	in	five	poorly	known	species	from	the	Dominican	Republic.	 nocturnality	is	the	ancestral	lifestyle	for	geckos,	although	diurnal-ity	has	evolved	multiple	times.	In	fact,	the	family	sphaerodactylidae	con-tains	a	mixture	of	diurnal	and	nocturnal	species.	the	genera	Aristelliger,	Saurodactylus,	Euleptes,	 and	Teratoscincus	 are	predominately	nocturnal	(although	some	species	of	Aristelliger	are	known	to	bask	on	exposed	sur-faces	during	the	day;	henderson	and	powell	2009).	every	other	genus	in	the	family	is	largely	diurnal,	although	nocturnal	or	crepuscular	species	are	known	from	Gonatodes,	Pristurus,	and	Sphaerodactylus.	sphaeros	with	recorded	nocturnal	activity	patterns	include	S. inaguae,	from	xeric	coastal	areas	 in	 the	bahamas,	S. roosevelti,	 from	xeric	 forests	of	 southwestern	puerto	Rico,	S. savagei	from	the	xeric	southeastern	coast	of	the	Dominican	Republic,	and	S. sputator	from	the	northern	lesser	Antilles	(references	in	schwartz	and	henderson	1991,	henderson	and	powell	2009).	 Inspection	of	where	these	species	fall	within	published	phylogenies	(hass	1991,	Gamble	et	al.	2008)	suggests	that	nocturnality	has	evolved	multiple	times	within	Sphaerodactylus.	however,	the	differences	between	diurnal	and	nocturnal	lifestyles	may	be	exaggerated	by	human	perception.	because	sphaeros	are	largely	semi-fossorial,	they	may	be	“active	in	a	per-petual	twilight”	(henderson	and	powell	2009)	regardless	of	the	time	of	day.	therefore,	even	diurnally	active	sphaeros	might	possess	the	ocular	morphol-ogy	more	typical	of	nocturnal	lizards.	In	any	case,	so	little	is	known	about	these	geckos	that	a	basic	understanding	of	activity	patterns	is	critical	for	accurate	survey	work.	Indeed,	for	most	species,	no	published	data	address	activity	patterns.Sphaerodactylus leucaster and S. thompsoniSphaerodactylus leucaster and	S. thompsoni	are	poorly	known	xerophilic	geckos	from	hispaniola.	During	recent	research	trips	to	the	Dominican	Republic,	we	collected	individuals	of	these	species	under	dead	Agave	plants	and	rocks,	respectively,	during	the	day.	shortly	after	collecting	these	ani-mals,	we	noted	the	presence	of	vertically	elliptical	pupils,	which	stands	in	contrast	to	the	round	pupil	characteristic	of	most	species	in	the	genus,	and	is	more	typical	of	nocturnal	geckos.	Considering	the	oppressive	heat	of	the	habitat	(exposed	surface	temperatures	often	surpass	60	°C	during	the	heat	of	the	day),	we	decided	to	survey	habitats	at	night	to	see	if	these	geckos	were	active,	and	perhaps	more	abundant	than	daytime	surveys	implied.	 on	successive	nights,	we	observed	multiple	animals	of	both	species	moving	around	on	exposed	surfaces.	For	S. leucaster,	we	observed	a	total	of	20	individuals	(all	adults	or	sub-adults)	over	the	course	of	two	separate	nights	(21	August	2009,	14	January	2010)	on	a	karst-strewn	hillside	south	of	monte	Río,	Azua	province.	We	found	individuals	of	both	sexes	on	the	ground	or	on	the	sides	of	rocks	revealed	by	direct	encounters	or	reflective	eye-shines.	once	disturbed,	geckos	would	run	for	the	nearest	cover,	which	was	either	dead	Agave	or	karst	talus.	For	S. thompsoni,	we	observed	>30	ani-mals	during	multiple	nights	of	searching	(August	2009	and	January	2010)	and	at	multiple	localities	along	the	Alcoa	Road	between	Cabo	Rojo	and	las	mercedes.	the	geckos	were	on	karst	rocks	at	2000–2300	h,	and	included	both	sexes	and	all	age	classes.	Animals	were	frequently	found	on	vertical	rock	faces,	and	were	rarely	far	from	crevices.	A	number	of	animals	also	were	found	by	flipping	small	talus	piles.	In	such	instances,	geckos	were	often	on	the	undersides	of	the	rocks.	We	found	more	animals	in	these	piles	at	night	than	we	did	with	similar	effort	during	the	day.	our	field	observations	are	recapitulated	for	both	species	by	captive	specimens;	animals	emerge	after	the	lights	are	turned	off	and	remain	active	for	several	hours.	 We	collected	microhabitat	temperature	data	for	some	individuals	of	S. thompsoni	by	using	an	infrared	temperature	gun	to	record	the	surface	temperature	at	the	site	of	encounter.	the	average	surface	temperature	was	31.9	±	1.5	°C	(n	=	6).	We	also	recorded	the	temperature	of	active,	but	undisturbed,	tarantulas	(Phormictopus cancerides),	which	we	have	witnessed	killing	Sphaerodactylus	ladae.	the	average	tarantula	temperature	was	29.1	±	0.8	°C	(n	=	3).	Although	the	sample	size	is	small,	a	student’s	t	test	indicated	that	the	difference	in	average	temperatures	of	these	species	was	significant	(t =	2.97,	df	=	7,	p	=	0.02).	these	limited	and	admittedly	very	preliminary	data	suggest	that	interactions	between	tarantulas	and	geckos	might	be	minimized	by	different	thermal	preferences.sCAntlebURY	et	Al.male	Sphaerodactylus leucaster	from	the	karst	hills	of	monte	Río,	south	of	Azua.	this	lizard	was	active	at	night.Juvenile	 female	Sphaerodactylus ladae	collected	at	night	 from	parque	nacional	Francis	Caamaño.Female	Sphaerodactylus cryphius	from	an	old	rock	quarry	between	Duvergé	and	Jimaní.	the	scale	is	in	mm.	this	gecko	was	collected	as	an	adult	underneath	a	dead	Agave	during	the	afternoon	in	August	2008;	she	is	still	alive	as	of	27	January	2011.	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011	 15Sphaerodactylus ladaeSphaerodactylus ladae	is	known	only	from	the	Dominican	Republic,	where	it	inhabits	the	scrubby	foothills	of	the	sierra	de	martín	García	and	the	sur-rounding	lowlands	toward	the	city	of	Azua.	We	have	collected	this	species	from	near	Ranchería	and	at	parque	nacional	Francis	Caamaño.	to	our	knowledge,	the	latter	site	represents	the	most	northern	and	eastern	records	for	this	species.	Geckos	were	abundant	at	both	sites.	At	Ranchería,	we	col-lected	animals	during	the	day	from	beneath	dead	and	rotting	Agave	plants,	completely	oblivious	to	what	we	would	discover	later	at	parque	nacional	Francis	Caamaño.	In	January	2010,	one	of	us	(ml)	visited	the	park	to	pho-tograph	the	area	at	sunset	and	conduct	a	preliminary	survey	of	the	area	at	night.	this	trip	resulted	in	the	collection	of	three	adult	S. ladae,	which	were	moving	around,	fully	exposed,	just	after	sunset.	We	revisited	the	site	one	year	later	in	January	2011	at	2200–2300	h	and	found	five	animals	actively	moving	around	in	shallow	leaf	litter	collected	on	a	boulder-strewn	hillside.	All	were	female	and	included	two	adults	and	three	juveniles	(Dps	sexed	them	based	on	pattern	and	the	absence	of	an	enlarged	escutcheon	patch).	We	observed	but	failed	to	secure	an	additional	three	animals.	the	habitat	at	this	site	consists	of	karst	limestone	boulders	with	a	short	scrub	canopy.	the	exposed	ground	between	large	rocks	consists	of	shallow	leaf	litter	atop	gravel.	We	observed	all	of	the	geckos	completely	exposed	on	these	patches	of	leaf	litter.	 We	 also	 collected	 three	 S. leucaster	 at	 parque	 nacional	 Francis	Caamaño,	where	they	occur	sympatrically	with	S. ladae.	one	adult	female	and	two	juveniles	were	active	at	2200–2300	h	in	exposed	patches	of	leaf	litter	adjacent	to	large	limestone	rocks.	sympatry	between	S. ladae	and	S. leucaster	is	noteworthy	because	these	species	are	similar	in	size,	activity	pat-tern,	and	appearance	(males	have	a	pale	gray	body	with	a	streaked,	bright	yellow	head;	females	are	a	dull	purple-gray,	with	bold	dorsolateral	lines).Sphaerodactylus cryphiusA	final	xerophilic	species	we	have	observed	while	active	at	night	is	S. cry-phius.	this	observation,	however,	is	limited	to	a	single	individual	observed	after	2200	h	crawling	in	leaf	litter	near	the	base	of	a	limestone	cliff	at	an	old	rock	quarry	between	Duvergé	and	Jimaní.	Additional	work	is	necessary	to	clarify	if	this	is	an	isolated	incident	or	typical	of	this	species.Sphaerodactylus cochranaeSphaerodactylus cochranae	is	known	only	from	the	southern	shore	of	the	bahía	de	samaná.	this	beautiful	and	rarely	seen	species	has	been	col-lected	by	only	a	small	handful	of	herpetologists.	on	11	september	2009	at	1800–1845	h	(just	around	dusk),	we	observed	four	geckos	within	a	50-m	radius	on	leaf	litter	near	the	coast	in	parque	nacional	los	haitises.	three	of	the	sightings	were	between	1830	and	1845	h,	suggesting	that	they	were	just	becoming	active.	Alternatively,	the	animals	were	ending	activity	and	seeking	roosting	spots;	however,	this	seems	unlikely,	considering	that	we	spent	much	of	the	day	in	suitable	habitat	and	did	not	collect	any	indi-viduals.	Additionally,	previous	informal	nighttime	surveys	in	los	haitises	conducted	in	1996–1998	by	one	of	us	(ReG)	recovered	active	S. cochranae	in	and	around	bromeliads.Discussionour	success	in	finding	and	collecting	S. ladae, S. leucaster, and	S. thompsoni increased	at	night.	Furthermore,	we	substantially	reduced	our	impact	on	the	habitat	during	nocturnal	searches	because	we	did	not	have	to	disturb	dead	Agaves	and	rock	piles.	Considering	the	close	phylogenetic	relationship	of	S. leucaster	and	S. thompsoni,	we	hypothesize	that	the	related	species	S. asterulus, S. rhabdotus,	and	S. shrevei,	which	also	inhabit	xeric	habitats,	are	SPhaerodaCtyluS	In	the	DomInICAn	RepUblICFemale	Sphaerodactylus cochranae	perched	on	the	top	leaf	of	a	bromeliad	that	is	common	at	localities	where	this	species	lives.	these	geckos	have	been	seen	crawling	in	the	axils	of	this	plant	at	night.	riChard e. GLor16	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011 sCAntlebURY	et	Al.also	nocturnal	and	might	occur	in	greater	abundance	than	daytime	surveys	imply.	similarly,	S. schuberti,	the	presumed	relative	of	S. ladae	from	the	sierra	de	neiba	(thomas	and	hedges	1998),	might	be	nocturnal	as	well.	Sphaerodactylus schuberti	is	only	known	from	the	type	locality,	but	this	area	is	very	similar	to	habitats	in	which	we	have	collected	S. ladae.	similarly,	the	ranges	of	these	species	might	well	have	been	underestimated.	 Imagining	a	gecko	as	small	as	S. cryphius	surviving	in	brutally	hot	and	dry	habitats	is	difficult.	nocturnal	behavior	could	conceivably	allow	this	species	to	forage	when	surface	temperatures	have	cooled	substantially	from	daytime	highs.	however,	we	must	note	that	we	never	observed	S. plummeri	active	at	night	during	surveys	for	S. thompsoni.	Sphaerodactylus plummeri	is	approximately	the	same	size	as	S. cryphius	and	lives	in	similar	habitats	on	the	southern	part	of	the	barahona	peninsula.	however,	we	readily	col-lected	S. plummeri	during	the	day	at	the	same	sites	at	which	we	collected	S. thompsoni	the	night	before.	Although	more	research	is	necessary,	this	is	highly	suggestive	of	temporal	niche	partitioning.A	fisheye	view	of	typical	habitat	of	Sphaerodactylus thompsoni	and	S. plummeri.	note	the	high	percentage	of	exposed	surfaces	and	xerophytic	vegetation.Coastal	leaf	litter	in	parque	nacional	los	haitises	where	we	collected	Sphaerodactylus cochranae.	the	orange	flag	in	the	center	of	the	image	denotes	the	exact	place	where	a	gecko	was	first	seen.A	fisheye	view	of	the	habitat	where	we	collected	Sphaerodactylus cryphius	and	S. rhab-dotus	during	the	day.	this	habitat,	with	a	mixture	of	scrub	vegetation,	dead	Agave,	and	limestone	rocks	is	typical	of	localities	where	we	have	collected	S. ladae	and	S. leucaster.	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011	 17SPhaerodaCtyluS	In	the	DomInICAn	RepUblIC	 nocturnality	has	evolved	multiple	times	within	Sphaerodactylus,	and	noc-turnal	sphaeros	are	largely	restricted	to	hot	and	dry	habitats.	Although	a	more	rigorous	comparative	analysis	is	necessary	(and	forthcoming),	we	hypothesize	that	nocturnality	is	an	adaptation	to	xeric	conditions	as	it	would	almost	cer-tainly	reduce	evaporative	water	loss	by	restricting	activity	to	cooler	periods.	such	transitions	between	activity	patterns	may	be	facilitated	if	sphaeros	are	already	pre-adapted	to	low-light	conditions	because	of	their	semi-fossorial	nature.	Future	work	should	investigate	the	ocular	morphology	of	species	in	a	comparative	framework,	as	well	as	quantify	activity	across	species	in	terms	of	ambient	light	conditions	—	instead	of	emphasizing	time	of	day.	the	observa-tion	that	S. leucaster	and	S. thompsoni	possess	vertically	elliptical	pupils,	typical	of	most	nocturnal	geckos,	whereas	S. ladae	has	round	pupils,	suggests	that	multiple	paths	could	facilitate	seeing	in	the	night.AcknowledgmentsWe	humbly	thank	the	sociedad	ornitologica	de	la	hispaniola,	and	in	par-ticular	Jorge	brocca	for	assisting	us	with	securing	permits	and	field	arrange-ments	while	traveling	in	the	Dominican	Republic.	J.	Yoel	hernández	pro-vided	invaluable	assistance	at	parque	nacional	Francis	Caamaño.	Gabriel	de	 los	santos	santana	confirmed	 the	 identity	of	 the	 tarantulas	 found	alongside	S. thompsoni.	We	also	thank	the	ministerio	de	medio	Ambiente	y	Recursos	naturales	in	santo	Domingo	for	providing	us	with	permits	and	assistance	in	the	field.	the	quality	of	this	manuscript	benefited	from	the	insightful	comments	of	two	reviewers.Literature CitedGamble,	t.,	A.m.	bauer,	e.	Greenbaum,	and	t.R.	Jackman.	2008.	evidence	for	Gondwanan	vicariance	in	an	ancient	clade	of	gecko	lizards.	Journal of Biogeography	35:88–104.hass,	C.A.	1991.	evolution	and	biogeography	of	West	Indian	Sphaerodactylus	(sauria,	Gekkonidae)	–	a	molecular	approach.	Journal of Zoology	225:525–561.hedges,	s.b.	and	R.	thomas.	2001.	At	the	lower	size	limit	in	amniote	vertebrates:	A	new	diminutive	lizard	from	the	West	Indies.	Caribbean Journal of Science	37:168–173.henderson,	R.W.	and	R.	powell.	2009.	Natural History of West Indian Reptiles and Amphibians.	University	press	of	Florida,	Gainesville.Rodda,	G.h.,	G.	perry,	R.J.	Rondeau,	and	J.	lazell.	2001.	the	densest	terrestrial	vertebrate.	Journal of Tropical Ecology	17:331–338.schwartz,	A.	and	R.W.	henderson.	1991.	Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History.	University	of	Florida	press,	Gainesville.thomas,	R.	 and	s.b.	hedges.	1998.	A	new	gecko	 from	 the	sierra	de	neiba	of	hispaniola	(squamata:	Gekkonidae:	Sphaerodactylus).	Herpetologica	54:333–336.Juvenile	Sphaerodactylus schuberti	collected	at	the	type	locality	near	la	Descubierta	in	August	2009.male	Sphaerodactylus plummeri	collected	at	the	type	locality	along	the	Alcoa	Road	in	August	2009.18	 IRCF	ReptIles	&	AmphIbIAns		•		Vol	18,	no	1		•		mAR	2011 mCGAUGheY,	WAllACe,	AnD	peRRYUrban	box	turtles,	such	as	this	ornate	box	turtle	(Terrapene ornata ornata)	in	lubbock,	frequently	cross	roads	and	sometimes	get	hit	by	cars.

Notes on Activity Patterns of Five Species of Sphaerodactylus (Squamata: Sphaerodactylidae) from the Dominican Republic

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Notes on Activity Patterns of Five Species of Sphaerodactylus (Squamata: Sphaerodactylidae) from the Dominican Republic

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