Author: Jhan Salazar

Observaciones de una Salida de Campo para Estudiar Anoles en Puerto Rico

Anolis occultus durmiendo en una rama, por Jhan C. Salazar

He tenido la oportunidad de buscar Anolis en tres países diferentes, dos en el Caribe (Puerto Rico y República Dominicana; escribiré sobre mi experiencia en República Dominicana también) y uno en el continente (Colombia), y siempre me sorprende lo diverso que es este grupo de lagartijas. Este año, finalmente fui a una salida de campo luego de la locura de la pandemia, o debería decir durante la locura de la pandemia. Fui por tres semanas a Puerto Rico junto con el increíble grupo de colegas del Laboratorio de Losos (los de Washington University) – Dr. Kristin Winchell (la líder del equipo), Dr. Elizabeth Carlen (la nueva postdoctorado del laboratorio), Ari Miller, Ansley Petherick y yo, y otras tres personas increíbles: Sarah Swiston (estudiante de doctorado en Landis Lab de Washington University), Albert Chung (estudiante de doctorado en Campbell-Staton Lab de Princeton University) y Armando Vera (un microbiólogo de la Universidad de Puerto Rico son que nos estaba ayudando).

He estado en varias salidas de campo en el pasado trabajando con diferentes tipos de organismos, pero este viaje de campo tuvo algo especial; fue el más concurrido que he tenido. No me malinterpreten aquí, realmente disfruté mi tiempo allí. Estábamos haciendo varios experimentos (de los que oirán hablar en el futuro) centrados en las diferencias entre los Anolis urbanos y de bosque.

Ahora, hablemos del por qué estoy escribiendo esta publicación. Llegamos a Puerto Rico en agosto y nos quedamos la mayor parte del mes, alojándonos en la Reserva Natural y Estación de Campo Mata de Plátano. Desde el momento en que aterricé, sentí lo cálida y agradable que es la gente de Puerto Rico, no hay nada mejor que sentirse bienvenido. Una vez que llegamos a la estación de campo, también me di cuenta de lo mucho que me encanta estar rodeado de naturaleza y desconectado del mundo; no tenía recepción telefónica en la estación de campo.

No voy a mentir, una de las razones por las que quería ir a Puerto Rico era para ver algunas o todas las especies de aves endémicas que tiene esta hermosa isla. Vi algunos de ellos, solo para nombrar un par, vi el búho puertorriqueño o múcaro y el cuco lagartijero. Lamentablemente, no vi especies como el san pedrito o tody puertorriqueño o la cotorra puertorriqueña. Sin embargo, esta vez optamos por un tipo diferente de grupo: los Anolis, en particular Anolis cristatellus.

Aunque estábamos buscando Anolis cristatellus, este no era el único Anolis que quería ver. Había otras 9 especies que estaba buscando; lamentablemente, no fuimos a Culebras, Vieques o Mona, supongo que tendré que volver para ver los que me faltan.

En nuestro primer día de muestreo, fuimos a la ciudad de Arecibo para buscar A. cristatellus, y mientras buscábamos esta especie, vi un lagartijo de aspecto extraño con algunas manchas negras en la espalda. Fue entonces cuando me di cuenta de que acababa de divisar mi segunda especie de anole, Anolis stratulus. En la tarde de ese día, estábamos trabajando en Mata de Plátano cuando Ari dijo “Hola Jhan, hay un gigante de corona”, y yo pensé, “no hay forma de que esto suceda tan temprano en nuestro viaje de campo”; eso era cierto. Vimos un hermoso anole de color esmeralda, Anolis cuvieri. Más tarde ese día, vi mi cuarta especie, una pequeña con líneas blancas a cada lado del cuerpo, Anolis pulchellus. ¡Cuatro especies diferentes en un día! ¿Qué tan loco es eso?

No fue hasta nuestra segunda semana que encontré mi quinta especie. Esta vez estábamos en un pequeño bosque en Mayagüez. Caminábamos por el bosque y vi un lagartijo de aspecto familiar, pero no estaba seguro de qué era. Le pregunté a Ari de qué especie era y me dijo: “Ese es Anolis krugi“. En nuestros últimos días en Puerto Rico, fuimos a un par de lugares donde encontramos los anoles que me faltaban por. Nuestra primera parada fue en el Parque Nacional El Yunque; si vas a Puerto Rico, debes ir aquí, totalmente recomendado. Me impresionó lo diferente que son las montañas colombianas de las puertorriqueñas. Incluso antes de que empezáramos a caminar, alguien señaló un anole en una palmera (lamentablemente, no recuerdo quién fue), ¡y era otro anole verde! Pero esta vez fue Anolis evermanni, y una vez más me sorprendió lo fácil que es ver algunas especies cuando solían pasar semanas buscando un individuo de una especie en los Andes.

Macho adulto de Anolis cooki tomando el sol en un tronco, por Jhan C. Salazar

Cuando estábamos a punto de comenzar a caminar, escuché decir a Kristin en el fondo, “ese es Anolis gundlachi, ¡mira esos ojos azules!”. Una vez escuché esto, corrí a ver a este lagartijo; cuando lo vi, me di cuenta de que los anoles son un grupo extraordinario de lagartijas. No sabía que podían tener ojos azules, o tal vez nunca lo noté hasta ese momento. Al día siguiente fuimos a Cabo Rojo, y allí encontramos dos especies: Anolis cooki y Anolis poncensis. En este lugar, Sarah, Armando, Kristin y yo estábamos caminando por un pequeño bosque y encontramos un lagartijo gris, A. cooki, y nuevamente, me sorprendí. ¡Nunca pensé que los anoles pudieran ser grises también! ¿Qué puedo decir sobre A. poncensis? Bueno, lo vi por un breve período, es una especie rápida; cuando caminábamos, Armando gritó “¡Anolis poncensis! ¡Te dije que estaba aquí!”. Armando me señaló, pero no lo vi sino hasta que empezó a correr; luego, se detuvo por un segundo, y en ese segundo, vi lo hermosa que es esa especie, tan pequeña, pero tan rápida.

Solo me faltaba una especie, pero esta historia es única. Al comienzo de la salida de campo, estaba hablando con Armando sobre los anoles que vio cuando estaba trabajando con Anna Thonis (una estudiante de posgrado en Akçakaya Lab en Stony Brook University) solo unas semanas antes, y dijo que le faltaba por ver solo una especie, Anolis occultus – esa fue la primera vez que escuché sobre esa especie; Ni siquiera sabía cómo se veía. El día que Armando me contó esa historia, comenzamos a planear la búsqueda para encontrar esa especie. Mientras estábamos en Mata de Plátano, había otro equipo trabajando también en Anolis, y uno de ellos, Alejandro, nos dijo dónde podíamos encontrar esta especie. Esa noche Armando y yo fuimos al bosque a buscar A. occultus; comenzamos a buscarla a las 9:00 pm y regresamos a las 12:30 am con las manos vacías; no lo vimos. Unos días después, Armando fue por su cuenta a buscar esta especie ootra vez, y nuevamente, no lo encontró. Otra noche, Albert y el otro equipo fueron a buscar A. occultus y nos preguntaron a Armando y a mí si queríamos unirnos a ellos, pero estábamos cansados; Al día siguiente, Albert nos mostró una foto de A. occultus; sí, la encontraron. Le pedí a Albert que se uniera a Armando y a mí para buscar esta especie tan misteriosa; esa noche fuimos a buscarla, desde las 10:00 pm hasta casi la 1:00 am, y una vez más fuimos derrotados.

En nuestra última noche, un sábado por la noche, Armando, Ansley, Ari, Sarah y yo estábamos decididos a encontrar A. occultus. Empezamos a mirar a las 8:00 pm más o menos. Caminamos y caminamos, mirando aquí y allá, pasaron minutos y nada. Pensé que íbamos a irnos de Puerto Rico sin ver esta especie, ya las 9:25 pm – sí, registré la hora – miré una rama con algo en ella, y me di cuenta de que lo habíamos encontrado, después de todos estos intentos allí estaba, Anolis occultus. Dije “lo encontré, finalmente lo encontramos”; todos estaban emocionados, especialmente Armando. Ari dijo entonces, “debe haber más individuos alrededor”, y efectivamente, ¡Ari encontró otro! Tomamos cientos de fotos de esos dos Anolis, y fue entonces cuando me di cuenta de que en tres semanas, ¡vi las 10 especies de Anolis que tiene Puerto Rico!

Me siento agradecido de visitar y trabajar en un lugar tan impresionante como Puerto Rico, con gente cálida, y playas y comida increíbles, en particular el mofongo y Church’s Chicken (nunca hicieron bien mi pedido, pero todavía me gusta). Ojalá pueda volver a trabajar en tan hermoso lugar, pero por ahora: “Con un cariño profundo en ti la mirada fija” – poema a Puerto Rico de José Gautier Benítez.

Macho adulto Anolis gundlachi tomando el sol en un tronco, por Jhan C. Salazar

Observations from a Field Trip to Study Anoles in Puerto Rico

Anolis occultus sleeping on a branch. Photo by Jhan C. Salazar

I have had the opportunity to search for anoles in three different countries— two in the Caribbean (Puerto Rico and the Dominican Republic; I will write about my experience in the Dominican Republic, too) and one on the mainland (Colombia)— and it always surprises me how diverse this group of lizards is. This year, I finally went on a field trip after the craziness of the pandemic—or should I say, during the craziness of the pandemic? I went for three weeks to Puerto Rico along with the incredible Losos Lab combo (the ones at Washington University): Dr. Kristin Winchell (the leader of the team), Dr. Elizabeth Carlen (the new postdoc of the lab), Ari Miller, Ansley Petherick and me—and three other incredible people: Sarah Swiston (a grad student in the Landis Lab at Washington University), Albert Chung (a grad student in the Campbell-Staton Lab at Princeton University) and Armando Vera (a microbiologist from Universidad de Puerto Rico).

I have been on several field trips in the past working with different kind of organisms, but this field trip had something special; it was the busiest one I have ever participated in. Do not get me wrong here: I really enjoyed my time there. We were doing several experiments (that you will hear about in the future) focused on differences between urban and forest anoles.

Now, let’s talk about why I am writing this post. We arrived in Puerto Rico in August and stayed for most of the month, staying at Mata de Plátano Field Station and Nature Reserve. Since the moment I landed, I felt how warm and nice people from Puerto Rico are—there is nothing better than feeling welcome.  Once we got to the field station, I also realized how much I love to be surrounded by nature and disconnected from the world—I did not have phone reception in the field station.

I am not going to lie: one of the reasons I wanted to go to Puerto Rico was to see some or all the endemic bird species this beautiful island has. I saw a few of them—the Puerto Rican owl or múcaro and the Puerto Rican lizard cuckoo or cuco lagartijero, just to name a couple. Sadly, I did not see species such as the Puerto Rican tody or the Puerto Rican parrot. However, this time we went for a different kind of group: anoles, particularly Anolis cristatellus.

Even though we were looking for Anolis cristatellus, this one was not the only anole that I wanted to see. There were another nie species that I was looking for—sadly, we did not go to Culebras, Vieques, or Mona, so I guess I’ll have to go back to see the ones I’m missing!

On our first day of sampling, we went to the city of Arecibo to look for A. cristatellus, and while we were looking for this species, I saw a weird-looking anole with some black spots in the back. This was when I realized that I had just spotted my second anole species, Anolis stratulus. In the afternoon of that day, we were working in Mata de Plátano when Ari said “Hey Jhan, there’s a crown giant,” and I thought, “there’s no way this is happening so early on our field trip”; but it was true! We saw a beautiful emerald-colored anole, Anolis cuvieri. Later that day, I spotted my fourth species, one small with white lines on each side of the body, Anolis pulchellus. Four anoles in one day! How crazy is that?

Adult male Anolis cooki basking on a tree trunk. Photo by Jhan C. Salazar.

It was not until our second week that I found my fifth species. This time we were in a small forest patch in Mayagüez. We were walking in the forest, and I saw a familiar-looking anole, but I was not sure what it was. I asked Ari which species it was, and he said “that’s Anolis krugi.” On our last days in Puerto Rico, we went to a couple of places where we found the anoles that were missing from my checklist. Our first stop was El Yunque National Park—if you go to Puerto Rico, you should go there. I was impressed by how different the Colombian mountains are from the Puerto Rican ones. Before we even started to hike, someone pointed out an anole on a palm tree (sadly, I do not remember who it was), and it was another green anole! But this time, it was Anolis evermanni, and once again I was amazed by how easy it is to see some species when I used to spend weeks looking for even one individual of one species in the Andes.

When we were about to start hiking, Kristin said, “that’s Anolis gundlachi, look at those blue eyes!”. Once I heard that, I ran to see this anole; when I saw it, I realized that anoles are a crazy group. I did not know they could have blue eyes, or maybe I never noticed it until that moment. The next day, we went to Cabo Rojo, and there we found two species: Anolis cooki and Anolis poncensis. In this place, Sarah, Armando, Kristin, and I were walking on a small forest patch, and we found a grey anole, A. cooki—and again, I was surprised. I never thought anoles could be grey too! What can I say about A. poncensis? Well, I saw it for a brief period—it is a fast species. When we were walking, Armando yelled “Anolis poncensis! I told you it was here!”. Armando pointed the lizard out to me, but I did not see it until it started running; then, it stopped for one second, and in that second, I saw how beautiful that species is—so small, yet so fast.

I had just one species missing, but this story is unique. At the beginning of the field trip, I was talking with Armando about the anoles he saw when he was working with Anna Thonis (a grad student at Akçakaya Lab at Stony Brook University) just a few weeks before, and he said he was missing Anolis occultus—that was the first time I heard about that species. I did not even know how it looked. We made our quest to find that species. While we were in Mata de Plátano, there was another team working on anoles too, and one of them, Alejandro, told us where we could find this anole. That night, Armando and I went to the forest to look for A. occultus; we went at 9:00 pm and returned at 12:30 am empty-handed; we did not see it. A few days later, Armando went on his own to look for A. occultus, and again, he did not find it. Another night, Albert and the other team went looking for A. occultus, and they asked Armando and I if we wanted to join them, but we were tired; the next day, Albert showed us a picture of A. occultus—yes, they found it. I asked Albert to join Armando and I to look for this occult species; that night, we went to look for A. occultus from 10:00 pm to almost 1:00 am, and once again, we were defeated, with no clue where this species was.

On our last night, a Saturday night, Armando, Ansley, Ari, Sarah, and I were determined to find A. occultus. We started looking at 8:00 pm or so. We walked and walked, looking here and there, minutes passed and nothing. I thought we were going to leave Puerto Rico without seeing this species, and at 9:25 pm—yes, I recorded the time—I looked at a branch with something in it, and there it was. I realized that we had found it; after all these attempts, there it was, Anolis occultus. I said “found it, we finally found it”; everyone was excited, especially Armando. Ari then said, “there must be more individuals here,” and sure enough, Ari found another one! We took hundreds of pictures of those two anoles, and that was when I realized that in three weeks, I saw all ten anoles species that Puerto Rico has!

I feel thankful to visit and work in such an amazing place like Puerto Rico, with amazing people, amazing beaches, and food—particularly, mofongo and Church’s Chicken (they never got my order right, but I still like it). Hopefully, I will be back to work a little bit more, but for now: “Con un cariño profundo en ti la mirada fijo”—“With deep affection fixed gaze on you”—poem to Puerto Rico by José Gautier Benítez

Adult male Anolis gundlachi basking on a tree trunk, by Jhan C. Salazar.

 

Thermal Ecology and Activity Pattern of the Lizard Anolis onca (Squamata: Polychrotidae) in Araya Peninsula, Venezuela

Adult male Anolis onca from Isla de Margarita basking, by Gabriel N. Ugueto

We all know that anoles have subdigital lamellae; however, there is one species in which these lamellae are lacking: Anolis onca, which is known for being a sand-dwelling anole. In 2011, Dr. Jennifer Velásquez and colleagues published a paper in SABER, in which they studied the differences in thermal ecology and the activity pattern of male and female Anolis onca in Araya Peninsula, Venezuela, during the dry and wet season in a dry forest (10 m a.s.l). This study was conducted from September 2004 to April 2005, during which time 56 individuals were captured (15 females and 41 males). Dr. Velásquez and colleagues measured body temperature (Tb), substrate temperature (Ts) on the capture site, and air temperature (Ta).

Dr. Velásquez and colleagues found that in males and females, the Tb was higher during the dry season compared to the wet season: 33.6 ºC (30.0 – 37.2; n = 23) and 33.6 ºC (30.0 – 35.5; n = 7) for males and females, respectively, during the rainy season, and 34.4 ºC (33.0 – 35.8; n = 18) and 34.3 ºC (34.0 – 35.7; n = 8) during the dry season. Mean Ta and Ts were also higher during the dry season compared to the rainy season; during the dry season, Ta was 37.4 ± 0.69 ºC (n = 30) and Ts was 38.4 ± 0.69 ºC (n = 30), while during the rainy season, Ta was 33.9 ± 0.82 ºC (n = 26) and Ts was 34.9 ± 1.58 ºC (n = 26). In addition, Dr. Velásquez and colleagues found that A. onca changes its timing of activity depending on the season. During the rainy season, A. onca is more active from 9:00 am to 10:00 am, and during the dry season from 12:00 am to 1:00 pm; during both seasons, there is low activity from 3:00 pm to 5:00 pm.

The authors argued that there is a relationship between Tb, Ta and Ts during the rainy and the dry season, in which the thermophysiology of A. onca is influenced by the climate variability of the microhabitat it occupies, suggesting that this species is a thermoconformer. In conclusion, the body temperature of this species varies during the day and across seasons, and it also varies as air and substrate temperature vary.

Abstract:

Aspects of the thermal ecology and activity pattern of the lizard, Anolis onca, during the dry and rainy season, and both periods in a belt of xerophytic forest located in the Araya Peninsula, Sucre state, Venezuela. The mean body temperature of A. onca was 33.9 ± 1.50 ºC in both periods to A. onca, while it reached 34.4 ± 0.75 ºC during the drought period and 33.6 ± 1.87 °C during the rainy period. In both climate periods, we found positive and significant correlations between body temperature with air and substrate temperature. The results suggest that thermoregulation is done passively, influenced by microhabitat temperature (air and substrate). There was a unimodal daily activity pattern during both periods. The thermal niche breadth was greater in males, while niche overlap between sexes was higher during the rainy period.

Read the full paper here!

What Are the Ecophysiological Implications of Nocturnal Activity in “Diurnal” Reptiles? A Review

Anolis marmoratus, by Kristin Winchell. This photo is featured in the Anole Annals 2021 calendar!

Last year, Rafael Alejandro Lara Resendiz (Centro de Investigaciones Biológicas del Noroeste and Instituto de Diversidad y Ecología Animal) published a paper in Acta Biológica Colombiana, in which he summarizes nocturnal activities in exclusively diurnal reptiles and addresses the question of how this behavior affects their ecophysiology.

Ectotherms – reptiles, amphibians, fish, and most invertebrates – need environmental temperature to produce heat internally, meaning that these organisms depend upon an external source of heat to regulate their internal functions. Thermoregulation is a complex physiological process that is involved in every activity that allows ectotherms to survive in nature (e.g., feeding and reproductive behavior, growth patterns, locomotion, digestion). In this regard, ectotherm species differ in their thermoregulation behaviors; some species are more active during the day while others are active during the twilight. However, some species that are known to be diurnal have been found active during the twilight. Lara-Resendiz (2020) address four-point in his work. Specifically, he 1) reviews nocturnal activity events in reptiles considered exclusively diurnal; 2) discusses the ecophysiological implications on this topic; 3) identifies the aspects that have not yet been approached in-depth; and 4) proposes possible directions for future lines of research.

Several species that are known to be exclusively diurnal have been observed carrying out nighttime activities, including lizards (e.g., Agama, Anolis, Callisaurus, Dipsosaurus, Gerrhonotus, Liolaemus, Ophisaurus, Phrynosoma), snakes (e.g., Charina, Contia, Masticophis), tortoises (e.g., Gopherus, Geochelone), marine turtles (e.g., Chelonia). Particularly, reptiles inhabit a wide variety of habitats including tropical and cold areas, desserts, high and low elevation areas, and the sea. Living in this different environment may cause lizards to have different patterns of activities throughout the daytime or nighttime: geographical location and thermal environmental variability have a tight relationship with the period of activities of all ectotherms.

One hypothesis has been proposed to explain the nocturnal behavior in diurnal species, in which ectotherm species have different optimal temperatures in the photophase (daytime) and scotophase (nighttime). In this regard, by selecting different environmental temperatures during each phase species that are active during the day can also be active during the night. In some other cases, species that are known to be strictly diurnal can behave opportunistically during the night due to ecological or physiological conditions – high levels of humidity and/or low predation rate, and prey can be easily spotted. Another possible explanation of this change in the time of activity in lizards and snakes is the heterogeneity or homogeneity in the temperature variation in the environment, where species that inhabit stable habitats cannot increase the length of their foraging time, while those species in more heterogenous habitats have more opportunities to extend their activity period due to their wide-body temperature range; this hypothesis has not been tested yet.

Currently, ectotherm species are facing the consequences of the change in the global temperature because they depend on the temperature of their habitat. Climate change is causing species to overheat, therefore, changing their diurnal activity and increasing vulnerability in their population structure. Particularly, these effects have been stronger in the atropical ectotherms which are inhabiting places where the temperature is near their optimal temperature. This suggests that the nocturnal opportunistic behavior of some ectotherm species could be a response to the increasing temperatures.

In conclusion, we need to address questions regarding why these changes in the foraging activity of ectotherm is occurring, and how their ecology and physiology is or could be affected by foraging during the nighttime.

Abstract:

This review is the first to summarize published studies that document nocturnal activity events in reptiles previously considered exclusively diurnal. The ecophysiological implications of this nocturnal activity in tropical and high-latitude environments are described and discussed from the perspective of optimal activity temperature ranges, tolerance thresholds, activity periods, cathemerality, voluntary hypothermia, and its importance in the face of global climate change. Gaps in the research field are finally identified, and new lines of study are proposed.

Read the full paper here!

Interview on Lizard Science and Racism

Carlos Guarnizo along with several other scientists created Ciencia Café, pa’ Sumercé, which is a space where citizens can access first-hand (directly from researchers) excellent research in science and technology that Colombians are doing inside and outside the country. At the same time, this space offers scientists and researchers the opportunity to meet citizens and understand the concerns and interests of the public; all of this through respectful dialogue, promoting an appreciation for science and technology by encouraging everyone to participate.

Two weeks ago, I was invited to one of the interviews from Ciencia Café, pa’ Sumercé, in which I talk about two different things that are not necessarily exclusive: science and racism. During the interview, Carlos asked me about why I decided to study biology and lizards, especially, he was interested in knowing how I ended up doing a Ph.D. with Jonathan Losos. After I talked about that part of my professional life, Carlos asked me about the BLM movement and its consequences in Colombia. I told him that despite the miles apart that Colombia is from the USA, we – the black community – suffer from the same kind of discrimination (punctual and systemic racism) in our daily bases, and I also told him that it is important to talk about racism in our families and in our work areas. At the end of the interview, I told a short story about how the Anolis chloris photo I took in 2016 ended up as the cover image in Evolution in 2019.

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