Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Dedicated exclusively to field herping.

Moderator: Scott Waters

Post Reply
User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 10:14 pm
Location: San Antonio, TX
Contact:

Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by chrish »

Just a quick report about my trip to Costa Rica from August. I was looking for a summer herping trip somewhere in the neotropics. As it turned out, I had the option of a free place to stay for 10 nights near Aguas Zarcas, Alajuela, Costa Rica and a flight voucher that would cover most of my airfare so Costa Rica seemed like an obvious choice. I had decided before I left that this was not going to be a "herp-til-you-drop" type trip but just a relaxing stay in a nice place with the option of doing some birding, herping and frog recording along the way.

I know some of us get tired of trying to get through a 200 photo mega post, so I will break this trip up into
Aguas Zarcas Area - Frogs
Aguas Zarcas Area - Reptiles
Caño Negro Area (maybe separate frogs and reptiles again?)
Sarapiqui Area
Stay tuned for those.

The grounds of our hotel included a short trail into an area of rainforest. This was a productive place for walking, particularly at night. I walked the trail half a dozen times or so, both in the day and at night. The most commonly observed/heard herp was the Common Tink Frog (Diasporus diastema). These frogs were absolutely abundant in the grounds of the hotel and at night you heard them everywhere. They were surprisingly hard to find, however, because they tended to call while sitting on a leaf in a tree or bush that was partially covered by another leaf. We did see a bunch of them though -

(NB - this individual may be a species of Craugastor, rather than Diasporus)

Image

Here's what their choruses sounded like as you walked the forest at night -



Even though the sound is sort of pleasant, when you are close to one of these frogs these little "tinks" can be painfully loud!

One evening, I was trying to photograph a calling male who wasn't being very cooperative. But as I was waiting for him to call from a good pose, he suddenly turned and looked up and began calling repeatedly -

Image

When I took my eye off the camera for a second, I saw the cause of his sudden increase in activity. There was another Tink Frog just above him -

Image

He called and called and the other frog gradually climbed down towards him -

Image

He decided to climb up and meet her halfway -

Image

They met nose to nose on the leaf (this picture is rotated 90°) and he kept calling -

Image

I didn't capture the behavior, but she would sit there with there noses touching and periodically raise her arm almost reaching towards his snout then put it back down. I was fascinated by their little interaction and was thinking about watching through the whole "consummation" of their relationship when I noticed that my light was disturbing her and she was backing off. So I shut off my light and left the young couple to their business. I would love to have witnessed the whole event, but sometimes the frogs come first!

Anyone who has been around the lowlands of southern Central America knows that there are actually a few species of these little "tink" frogs and they can be difficult to tell apart. They are differentiated by the shapes of their toes and the relative distribution of the tubercules on their bodies. I believe this is a different species that we found along the same area, Diasporus hylaeformis -

Image

Another amphibian that we encounted quite often in this area was the very beautiful Brilliant Forest Frog (Lithobates warszewitschii). These frogs were commonly seen on the forest floor at night -

Image

Although at first appearance this appears to be a somewhat drab forest frog, their colors of their hindlimbs are quite striking -

Image

The other widespread Ranid was the large Vaillant's Frog (Lithobates vaillanti). There were common on the lawns near artificial ponds, rather than the forest itself -

Image

We saw quite a few toad species. The abundant toad on the forest floor was the handsome Truando Toad (Rhaebo haematiticus)

Image
Image

Another toad we found in lesser numbers around this area, mostly in cleared land was the Dark Green Toad (Incilius melanochorus) -

Image

This relative of the northern "Gulf Coast" Toads (I. nebulifer and valliceps) has a very similar long trilled call (heard here with Leptodactylus melanonotus) -



Of course, the other common toad we saw was the ubiquitous Cane/Marine Toad (Rhinella marina). They were abundant on the grounds of our hotel in all the ponds -

Image

We heard a few calling in local fields



We saw a lot of smaller toads which can be tough to separate from young Cane Toads sometimes.
I believe this is the Dry Forest Toad (Incilius coccifer)

Image

We saw surprisingly few hylids over all, but every night we could count on seeing and hearing Masked Treefrogs (Smilisca phaeota) calling from flooded areas under the plants in the garden -

Image

Their calls were very loud and could be heard from a long way within the grounds:



Apparently their romantic calls were being heard because I found a few of these tiny metamorphs around the puddles -

Image

One of my favorite finds on this trip was a frog that had evaded me on my previous trips to the neoptropics, the Smoky Jungle Frog (Leptodactylus pentadactylus), although these Costa Rican forms are actually the "Northern Smoky Jungle Frog" (L. savagei). I only saw one, sitting in a roadside ditch. I heard it call out the car window as I drove by, stopped and ran over and grabbed this quick photo. But when I tried to climb down to get it and it rocketed away through a road culvert and down a creek on the other side never to be seen or heard from again.

Image

But closer to town, we heard a big chorus in a flooded field. Their calls are simply amazing!



Another frog we had hoped to see was the "blue jeans" version of the Strawberry Poison-dart Frog (Oophaga pumilio). In this particular area, I only spotted one and it quickly hopped back into the "protection" under an overhanging rock out of reach -

Image

I was happy to see this species but in the next days we hit another slightly lower spot area where they were ridiculously abundant.

I did record a few other species in the area that I didn't actually see. One of the most depressing was captured one night while I had my recorder running to capture some ambient sound while I was looking around. The reason this is depressing to me is that I have never seen any species of Centrolenid (Glass) Frog even though I have been in their range many times. They aren't rare, I just haven't ever found one for some reason. So I was bummed when I listened to this recording and picked out the high whistling of Fleischmann's Glass Frog (Hyalinobatrachium fleischmanni) above the Tink Frogs (Diasporus) calls -



A little north of Aguas Zarcas I recorded a pair of White-lipped Frogs (Leptodactylus fragilis) in a flooded pasture -



and most flooded fields all around had a few Sabinal Frogs (Leptodactylus melanonotus) doing their strange "pok, pok" calls -



I will follow this up with a report of the reptiles from this area before moving on to other areas of CR.

Chris

NACairns
Posts: 372
Joined: December 30th, 2013, 7:27 am

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by NACairns »

Great stuff, thanks for including all the calls.

User avatar
Brian Folt
Posts: 79
Joined: June 10th, 2010, 9:20 am

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by Brian Folt »

Cool post! You images are nice, but your audio recordings are terrific! What sort of set-up do you use to collect the audio? I've had a long-time goal of collecting the calls for all the frogs of my study site in the Caribbean lowlands of Costa Rica, and I would be curious to know what goes into collecting audio files of that quality.

While living in Costa Rica, I walked a bridge over water at night probably close to 100 times before I ever noticed the Hyalinobatrachium fleischmanni that live within an arms reach to either side. After learning the call and the search image required to spot those animals, I noticed them calling almost every night, rain or not, during the wet season. So, I feel your pain there!

Also, I believe the first image is not Diasporus diastema, but rather a Craugastor - likely either fitzingeri or crassidigitus. I believe the other Diasporus were all correctly identified, though.

John Williams
Posts: 104
Joined: June 16th, 2010, 4:50 pm

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by John Williams »

Fantastic post Chris. Love the calls.

User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 10:14 pm
Location: San Antonio, TX
Contact:

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by chrish »

Brian Folt wrote:Cool post! You images are nice, but your audio recordings are terrific! What sort of set-up do you use to collect the audio? I've had a long-time goal of collecting the calls for all the frogs of my study site in the Caribbean lowlands of Costa Rica, and I would be curious to know what goes into collecting audio files of that quality.

While living in Costa Rica, I walked a bridge over water at night probably close to 100 times before I ever noticed the Hyalinobatrachium fleischmanni that live within an arms reach to either side. After learning the call and the search image required to spot those animals, I noticed them calling almost every night, rain or not, during the wet season. So, I feel your pain there!

Also, I believe the first image is not Diasporus diastema, but rather a Craugastor - likely either fitzingeri or crassidigitus. I believe the other Diasporus were all correctly identified, though.
Thanks for the ID hints on the Craugastor. I will have to look in Savage and see if I can figure it out.
And the frustrating thing about the fleischmanni was that had I heard them, I could have at least looked for them. I didn't know what that call was until after I got back to the US.

I have a few links/tips about getting frog recordings here - viewtopic.php?f=15&t=14879

In CR, I got most of my recordings using an Olympus LS-11 recorder with its inboard microphones or a Tascam DR-100 mk-II recorder with a Sennheiser K6/ME66 shotgun microphone. PM me if you want some specific recommendations on what gear you might consider starting with. I just got back from Australia and recorded a bunch of frogs with the same gear. Good, field hardy equipment.
For cleaning up the recordings, there is no reason to use anything other than the open source program Audacity.

Chris

User avatar
Phil
Posts: 65
Joined: June 7th, 2010, 7:11 am
Location: Lafayette, LA

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by Phil »

Thank you so much for this post, Chris. I visited Costa Rica for the first time last May, and I heard and saw many of the same things you did. The audio recordings are awesome; it's incredible how similar the Incilius calls are to that of the ones here in the states. I have been diligently searching for recordings of Costa Rican Incilius without luck, so thank you very much for including that in this post.

Cheers!

-Phil

User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 10:14 pm
Location: San Antonio, TX
Contact:

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by chrish »

Phil wrote:Thank you so much for this post, Chris. I visited Costa Rica for the first time last May, and I heard and saw many of the same things you did. The audio recordings are awesome; it's incredible how similar the Incilius calls are to that of the ones here in the states. I have been diligently searching for recordings of Costa Rican Incilius without luck, so thank you very much for including that in this post.

Cheers!

-Phil
I have an I. valliceps recording as well coming in the next installment of the trip from Cano Negro. You can hear/download my CR recordings on my blog if you want - frogcalls.blogspot.com

User avatar
Phil
Posts: 65
Joined: June 7th, 2010, 7:11 am
Location: Lafayette, LA

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by Phil »

chrish wrote: I have an I. valliceps recording as well coming in the next installment of the trip from Cano Negro. You can hear/download my CR recordings on my blog if you want - frogcalls.blogspot.com
Awesome! I'm kind of obsessed with frog calls, so I will enjoy it very much. Thanks! I'm looking forward to the future posts!

-Phil

User avatar
Roki
Posts: 199
Joined: January 23rd, 2012, 10:08 am
Location: Salt Lake City, Utah

Re: Costa Rica - August 2014 - Aguas Zarcas - Amphibians

Post by Roki »

Fun post. I really enjoyed all the recordings.

Post Reply