An Amphibian Adventure in Costa Rica

Group at the Santa Rosa Field Station.
(Photo: Robert Puschendorf)

By Alice Pawlik

In summer 2014 a group of students and lecturers from Plymouth University visited Costa Rica - an amazing country which supports wildlife ranging from frogs to fungi and everything in between!

The country's high diversity is due to Costa Rica's climate and geographic position. It is part of a land bridge which formed between North and South America around three million years ago, leading to a species interchange which caused the rich diversity seen today. Costa Rica now holds around 4% of all species in the world!


The trip was organised by Dr Robert Puschendorf who put together a team of “Tico” travellers to venture into the Central American forests. The team included Dr Sarah Collins, Dr Ben Brilot, Harriet Price, Roberta Spensley, Megan Wallace and me. The group arrived at San José international airport on 25th June and were met with a taste of what was to come, rain… lots of it! 2014 was an El Niño year, which caused unusual weather patterns.

The first week was spent at The Area de Conservacion Guanacaste (ACG). This organisation was set up in the 1970's by Dan Janzen who is the technical advisor, an evolutionary ecologist and biologist. Those studying ecology may recognise Janzen from his work on ant-acacia interactions (Janzen, D. H. 1966. Co-evolution of mutualism between ants and acacias in Central America. Evolution: 20(3) 249-275), amongst his other work. ACG is found in North-West Costa Rica and is one of the world’s oldest and most successful habitat restoration projects. It is split into sectors housing field stations and inventories run by parataxonomists, experts on local species. For more information about ACG, including its aims and achievements, please visit: http://www.acguanacaste.ac.cr/.

Fieldwork began at Maritza field station, set up by Janzen in 1988. Here creeks are sampled for Megaloptera which indicate water quality, and is the only place in Costa Rica with long term aquatic data (http://www.stroudcenter.org/research/projects/ltreb/costarica/index.shtm). We conducted our first amphibian sampling night here and it was quite the adventure as everyone got used to trekking in water filled wellies! Due to high winds there was little amphibian activity, but we did spot a Lesser Anteater, Tamanduate tradactyla, climbing in the trees above us.

Tamanduate tradactyla (Lesser Anteater)
at Maritza Field Station.
(Photo:Alice Pawlik)

River crossing at Maritza Field Station.
(Photo: Robert Puschendorf)

The unusually dry weather meant my original placement project of studying Lithobates warszewitschii could not go ahead. Instead, I helped the team to sample Craugastor ranoides instead. The group split into a night-sampling frog team (Rob, Ben, Megan and me) and a morning-sampling bird team (Sarah, Hattie and Roberta). A popular sampling site for the frog team was Playa del Blanca, Santa Elena peninsula. Here Ben and a crocodile managed to swim straight towards each other unnoticed! In the following week we all became prey items to hungry sand flies and the selfish herd strategy was employed as both teams swam in crocodile inhabited waters at the beach.

 

C. ranoides. (Photo: Alice Pawlik)

 

Santa Elena Bay (Photo: Alice Pawlik)

Crocodilus acutus near Murcielago field station, inland
from the beach, indicating over-crowding at the coast.(Photo: Robert Puschendorf)

Megan and I sampling a creek. (Photo: Robert Puschendorf)

Whilst at Santa Rosa field station I worked with Eliot Linton (http://eliotaway.tumblr.com/), a student from Princeton University working with Dan Janzen. Eliot, Memo (a Parataxonomist) and I ventured out to search for Udranomia kikkiwai larvae, to see which parasitoids affected them. A pupae I found in the forest will be entered onto ACG’s online database because a few days after collection Elliot informed me that the pupae split and 20-30 parasitic nympholid wasps emerged from it!

A new edition to the camp, Centruroides limbatus
which stung Sarah. (Photo: Alice Pawlik)

The infected pupa I collected.
(Photo: Alice Pawlik)

The group also visited San Gerardo, a butterfly rearing station and where parataxonomists Osualdo and his wife catalogue local caterpillars and parasitoids. This is part of a long term project to catalogue all species found in ACG. Here mature butterfly specimens are frozen and sent to the Bio-Lepidoptera lab at Santa Rosa field station, then on to Canada for genetic bar-coding.

Rearing bags for lepitoptera.
(Photo: Alice Pawlik)

Santa Rosa field station. (Photo: Rob Puschendorf)

At ACG, I kept a list of all the species we observed. A major addition to the list was an Ocelot, Leopardus pardalis, which Hattie recorded on her night vision camera trap.

 Video: Ocelot caught on the camera trap. (Hattie Price)

On the 2nd July 2014 the Tico group left Santa Rosa field station to explore the Caribbean side of the country. We travelled to Arenal, La Fortuna, where we stayed overnight at Montanade Fuego under the Arenal volcano. Taking full advantage of the hotel's wildlife trails, I spotted the first toucan of the trip, Ramphastos ambiguous, after which we headed to Siquirres and into the hills to The Costa Rican Amphibian Research Centre (CRARC), where we stayed until the 8th July. On arrival we met Angus McNabb, a Master’s student and wildlife consultant from Australia. We also met Brian Kubicki, the owner of the site, set up in 2002 when he bought the 121 acre piece of land (http://cramphibian.com). The centre was created to aid the conservation and research of Costa Rican amphibians. Brian’s focus is on glass frogs (Cetrolenidae family), and since 1998 he has managed to rediscover four of Costa Rica’s 13 glass-frog species.

A few days into the stay, the group headed out on a night trek where we learnt that some frogs secrete fragrant peptides to deter predators, just like some trees possess allelopathic chemicals. To me Diasporus diastema's smelled of mixed herbs, while Agalychnis callidayas, the red-eyed tree frog, smelled sweet. The trip highlight was spotting a Kinkajou, Potus flavus, high in the trees. This, and the following night trails, were really exciting with surprises such as fallen trees blocking paths, more challenging routes, and added bonuses such as bullet ants (Paraponera clavata), inquisitive snakes, and numerous eight legged friends.

Agalychnis callidryas. (Photo: Alice Pawlik)

Brian was the tour guide for one of the last forest treks. Before this he had been understandably busy with his daughter, born shortly after we arrived! During the tour, a Sachatamia ilex jumped on me and we found Bolitoglossa striatula, a salamander which I had waited all trip to see! The next day fulfilled all my species spotting dreams when we watched a three toed Sloth, Bradypus variegates in a Cecropia tree. I battled through tall vegetation, sustaining painful ant bites to get a better look, but I was rewarded with the experience of leaves falling on me from the shuffling sloth above my head.

 

Bolitoglossa striatula. (Photo: Alice Pawlik)

The Sloth sighting was a brilliant departing gift, because the next day the group headed their separate ways. Hattie, Roberta and I carried on the adventure by travelling to Cahuita where we visited the national park, animal rescue centre and botanical gardens. The best bit was visiting the Sloth sanctuary, but we also experienced some building-shaking thunderstorms and managed to see some wild sloth’s too, both in the national park, climbing around the power lines and on the Costa Rican currency!

Juvenile sloth. (Photo: Alice Pawlik)

On the last day and with a total of 101 visible insect bites, I was ready to come home and two days later we made it. The material I studied whilst studying Conservation Biology at Plymouth and previous fieldwork really helped me in Costa Rica, it allowed me to identify species and feel comfortable working in the field and handling amphibians. I learnt so much in Costa Rica, from measuring and handling frogs to collecting parasitoids in the jungle, I feel much more confident conducting field work now and would definitely recommend carrying out fieldwork in Costa Rica. We had so many wonderful experiences, I couldn’t possibly fit them all in here!

Handling Hyloscirtus palmeri. (Photo: Robert Puschendorf)

The sunset at Playa Del Blanca. (Photo: Alice Pawlik)