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Alava et al. 1 evAP_2 Boletín SAO Vol. 20 Common Black in (No. 2) – evAP_2

Distributional records and potential threats to the Common () Black Hawk ( anthracinus subtilis) in southwestern Ecuador

REGISTROS DE DISTRIBUCION Y AMENAZAS POTENCIALES DEL GAVILÁN NEGRO DE MANGLAR EN EL SUROESTE DE ECUADOR

Juan José Alava1, 7, Miguel Saavedra2, Xavier Arosemena3, Madeleine Calle4, Carlos Vinueza5, Pedro J. Jiménez6, Raúl Carvajal7 & F. Hernán Vargas8

1School of Resource & Environmental Management, Faculty of Environment, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada. E-mail: [email protected]

2José de Antepara 4306 y Maracaibo , Ecuador.

3Consultora Amazilia S.A., Guayaquil, Ecuador.

4932 SW 8th lane Gainesville, FL 32601, USA.

5Tumbesian Birding, Sauces 2, Mz 52-F Villa 13, Guayaquil, Ecuador.

6Fundacion Ecuatoriana para el Estudio de Mamíferos Marinos (FEMM), Guayaquil, Ecuador.

7 Gobierno Provincial del Guayas, Dirección Coordinadora de Medio Ambiente y Agua, Jefatura de Biodiversidad y Áreas Protegidas, Illingworth 108 y Malecón, Guayaquil, Ecuador.

8The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID 83709, USA.

Abstract We studied the distribution of the Common (Mangrove) Black Hawk Buteogallus anthracinus subtilis in southwestern Ecuador in January 2002 and from 2005 to 2007. We recorded 10 adults and three juveniles in four coastal mangrove areas with different levels of habitat fragmentation, and where red mangrove (Rhyzophora spp.) was the dominant tree . One of the juveniles was approximately a 30 day old individual at one of the surveyed areas (Manglecito Island, the El Morro Wildlife Refuge). Shrimp farming and commercial banana cultivation were identified as the major conservation threats for this population in the long term. Between 1969 and 1999, mangrove deforestation due to shrimp aquaculture and other demographic activities (i.e. agriculture, urban sprawl, timber for coal production) reduced about 25% of the total potential mangrove habitat for this species. Pesticides used in banana plantations close to mangroves might be affecting this species and other raptors in southwestern Ecuador.

Keywords: anthropogenic impact, , mangrove forest, pollution, tropical raptors.

Resumen. En enero de 2002 y durante el período 2005-2007, estudiamos la distribución de Gavilán Negro de Manglar (Buteogallus anthracinus subtilis) en el suroeste del Ecuador. Registramos la presencia de 10 adultos y tres juveniles en cuatro lugares costeros con predominancia del manglar rojo (Rhyzophora spp.) y con diversos grados de fragmentación del hábitat. Solamente en uno (Isla Manglecito, Refugio de Vida Silvestre Manglares el Morro) de los cuatro lugares encontramos un juvenil de aproximadamente 30 días de edad. Identificamos a las camaroneras y bananeras como las potenciales causas principales de la declinación de esta población a largo plazo. Entre 1969 y 1999, la deforestación asociada a las camaroneras y a otras actividades antropogénicas redujeron en más del 25% el área de manglares disponible para la

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Alava et al. 2 evAP_2 Boletín SAO Vol. 20 in Ecuador (No. 2) – evAP_2 especie. Sugerimos que los pesticidas usados en las bananeras, contiguas a manglares, pueden estar afectando a ésta y otras especies de rapaces en el suroeste de Ecuador.

Palabras claves: bosque de manglar, impacto antropogénico, Golfo de Guayaquil, polución, rapaces tropicales.

Introduction (Arantinga erythrogenys), the vulnerable Grey-cheeked Parakeet (Brotogeris pyrrhopterus) and the endangered he Common (Mangrove) Black Hawk (Buteogallus Red-lored Amazon (Amazona autumnalis) (Delgado et T anthracinus subtilis) is distributed along the Pacific al. 2000, Jaramillo et al. 2002, Berg & Angel 2006, coast from Mexico to extreme northwestern Peru (Blake Carvajal et al. 2006). Mangroves are important foraging, 1977, Hilty & Brown 1986, Thiollay 1994, Clark 2007), roosting and breeding habitat for the Common however, it is probably one of the rarest tropical raptors (Mangrove) Black Hawk. Our study summarizes recent in Ecuador (Ridgely & Greenfield 2001). The species is observations and provides information on distribution mainly restricted to mangroves along the southwest coast and conservation status of this rare raptor inhabiting one of Ecuador in the estuary of the Guayaquil Gulf Basin, of the most threatened coastal ecosystems in Ecuador. including the Guayas and mangrove coastal areas of the southwards to the border of Peru Methods (Ridgely & Greenfield 2001). Definitive evidence about the species presence in northwestern Ecuador is still Surveys of mangrove were conducted at four sites in unclear, and it may occur in Manabí and Esmeraldas southwestern Ecuador during 2002 and 2005-2007 (Fig. provinces as well (Hilgert & Benavides 2002). For 1). Observations were opportunistically made on land instance, an individual was recently observed at Changal between 07:00 h am and 17:00 h, and each one lasted in the San Lorenzo mangrove forests, located northern from15-20 min using 7 x 50 mm and 10 x 42 mm Esmeraldas province, which might confirm the presence binoculars. We observed and other wildlife for a of this raptor in the area (Solano-Ugalde et al. 2009). total of 450 hours in 50 days during the surveyed years, Yet, pictures, video documentation or call recordings are and most (60%) of the observations took place during still required to further support the isolated finding in the wet season (December to April). We consider this Esmeraldas. taxa as a subspecies B. anthracinus subtilis, following Blake (1977), Ridgely & Greenfield (2001), and Clark The Guayaquil gulf estuary contains approximately (2007). We also reviewed the literature to identify 81% of the total area of Ecuadorian mangroves, potential threats to the . We used encompassing about 121,000 hectares (CLIRSEN 2007), mainly data from CLIRSEN (2007) to estimate and is suitable habitat for vast populations of different deforestation rates of mangroves and from INEC (2007, species of herons and egrets, and other species of birds 2009) to estimate areas of banana plantations at the El strongly associated with this type of habitat, including Oro Province. Here we describe the habitat features of the Red-lored Amazon Amazona autumnalis lilacina the four study areas where the accounts and distribution (Alava et al. 2005, Carvajal et al. 2005, Berg & Angel surveys were conducted (Fig. 1). 2006, Carvajal & Alava 2007). It has been suggested that deforestation and fragmentation in mangrove habitats Study areas have affected the local and nesting population of Roseate Spoonbills (Platalea ajaja) (Alava 2005), as well as the Reserva de Producción de Fauna Manglares el declining population of the Brown Wood- ( Salado-RPFMS. The RPFMS is a wildlife refuge wolfi), which is endangered and less tolerant to habitat confining 9,748 ha of remnant mangroves in southeast deterioration in Ecuador (Alava et al. 2007). Several Guayaquil City (2º10'S, 79º56'W), . species of parrots use these mangroves (i.e. Santay About 3% of the total area of this reserve is occupied by Island-National Recreation Area and Reserva de shrimp farms (<200 ha), of which 100 ha have been Producción de Fauna Manglares el Salado) for foraging abandoned. Three thermoelectric facilities, a water pump and resting, including endemic and threatened species at station and sewers also occur within its boundaries. the national level such as the Pacific Parrotlet (Forpus Small-scale clearing of mangrove trees (i.e. timber coelestis), the vulnerable Red-masked Parakeet extraction for coal production) occurs at specific

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Alava et al. 3 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 locations, while pollution from solid wastes and water including the Puerto Hondo Mangroves Sanctuary, are contamination are environmental issues of concern being roosting habitat for about 214 individuals of the Red- close to human urbanization and industrial parks lored Amazon (A. autumnalis lilacina) (Berg & Angel (Carvajal et al. 2006). Artisanal fisheries are subsistence 2006). Six species of mangrove trees recorded for activities practiced by communities residing within the Ecuador are found in this reserve: two species of Red RPFMS. Although the RPFMS has a moderate level of Mangrove (Rhizophora mangle; Rhizophora racemosa), fragmentation in some locations, and severe in others, hybrid Red Mangrove Rhizhopora harrisonii), Black some pristine mangroves in isolated patches are still well Mangrove (Avicennia germinans), White Mangrove conserved and act as biological corridors and provide (Laguncularia racemosa) and Button Mangrove suitable habitat for local populations of waterbirds (e.g., (Conocarpus erectus) (Carvajal et al. 2006, R. Carvajal heron nesting sites) and (e.g., South American pers. com.). raccoons and opossums). Mangroves around this area,

S Santay Island (Ramsar site) 2° Reserva de Produci ón Faunística Manglares El Salado (RPFMS) (El Salado Mangrove –Wildlife Production Reserve) Pacific Ocean Guayas Province

2.5° Refugio de Vida Silvestre Manglares El Morro (El Morro Mangroves –Wildlife Refuge) Puna Island

Manglecito Island Bajo Alto Mangroves Gulf of Guayaquil Gulf of Guayaquil 3°

N Santa Clara Island Wildlife Refuge - The El Oro Province Ramsar Site

25 km

81° 81.5 ° 80° W

Figure 1. Sightings and local distribution sites on mangrove-estuarine areas (as indicate by black rings) of the Guayaquil Gulf and Guayas River basin, where several individuals of the Common (Mangrove) Black–Hawk were observed. A juvenile hawk was recorded at a nest on Manglecito Island, El Morro Mangroves Wildlife Refuge, Ecuador.

Santay Island- National Recreation Area. Isla Santay Guayaquil City (Delgado et al. 2000, Jaramillo et al. is a Ramsar site (2º13'S, 79º51'W) with 4,700 ha located 2002, Santander & Muñoz 2004). Isla Santay includes in the inner estuary of the Guayaquil Gulf (Guayas River intertidal mud, sand or salt flats and intertidal forested Basin) and also close to the urban periphery of wetlands, encompassing mangrove swamps, nipah Boletín SAO | http://www.sao.org.co/boletinsao.html | Oct 2011| Protegido por – Protected by Creative commons Colombia|

Alava et al. 4 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 swamps and tidal freshwater swamp forests. The total Island, also known as the Frigatebirds’ Island is area of mangroves on Santay Island is 2224 ha. The inhabited by a large, breeding colony and year-round mangroves includes: R. mangle, R. harrisonii, A. population of about 2,000-6,000 Magnificent germinans, L. racemosa, C. erectus, Mangrove Golden Frigatebirds (Fregata magnificens), which is apparently Leatherfern (Acrostichum aureum), Salicornia fruticosa the largest seabird population on the Ecuadorian and Zizhypus thyrsiflora. During the rainy season (i.e. mainland coast (X. Arosemena pers. com.). Five species late December to May) 60% of the island is inundated. of mangrove trees occur in this island too, including red, The island is also inhabited by humans, and several hybrid red, black, white and button mangroves. Presence anthropogenic activities such as livestock farming of solid wastes (i.e. plastic bags and bottles) and illegal (goats, pigs, and chickens), coal production from camp fires are signs of human activity in this area. burning of trees and rice cultivation are conducted here (Delgado-Mendoza et al. 2000, Jaramillo et al. 2002). Bajo Alto Mangroves. The Bajo Alto Mangroves is Even though, it has a considerable degree of human located in the El Oro Province (3ºS, 79.5ºW), and has an perturbation, Isla Santay is still a refuge for numerous area of 555 ha, from which 357 ha are mangrove forests species of terrestrial birds and waterbirds. Two raptors, (Calle 2003). Bajo Alto Mangroves are not yet under any the (Buteogallus meridionalis) and protected area or reserve status; however, the Ecuadorian Harris’ Hawk ( unicinctus), have been also Mangrove Law protects the mangroves ecosystems. recorded on the island. Mangrove remnants are still semipristine, and seem suitable as habitat for birds. The El Oro Province is Isla Manglecito (Manglecito Island). This site is part of typically characterized by the vast amount of banana the Refugio de Vida Silvestre Manglares-El Morro plantations and shrimp farms. In this province, shrimp (2°39'S, 80°11'W), a recent protected area encompassing farm ponds are encroaching nearby mangrove habitat 10,130 ha of mangrove forests, intertidal mudflats, where mangrove were sighted. The predominant estuarine channels and creeks in El Morro Channel mangrove tree species in this area are the red mangroves, (Guayas Province), Gulf of Guayaquil. Manglecito followed by black and white mangroves (Calle 2003).

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Alava et al. 5 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2

Figure 2. A juvenile of Common (Mangrove) Black Hawk perched on branches of a Red Mangrove tree (Rhizophora sp.), exhibiting typical plumage features, observed in the Estero Salado Mangrove-Wildlife Production Reserve on March 2006, Guayas province, Gulf of Guayaquil (Photo: Miguel Saavedra).

Results island (Jaramillo et al. 2002). From 5!13 September 2005 (dry season), two individuals were observed in the Field observations. The sites for the new distributional Santay Island. These are the first records of the species records of the Mangrove Black Hawk in the Gulf of in this area. Interestingly, on both occasions these Guayaquil are depicted in Figure 1. Observation dates individuals were observed landing on piles of and the number of individuals observed in the study accumulated leaf litter (7–8 m in height) deposited over areas are shown in Table 1. Description on the accounts shrubs and vines, and we suspected the hawks were in surveyed mangrove sites is explained as follow: searching for small or other small .

Estero Salado Mangrove–Wildlife Production Manglecito Island. From December 2006 to July 2007, Reserve. Three Mangrove Black Hawks were recorded two juveniles and three adults were continually observed during 15!22 March 2006 and 21 April 2006. These at the entrance of Manglecito Island, at the El Morro were the first observations of this hawk for the area after Channel (the El Morro Mangroves Wildlife Refuge; Fig. Sheets (2005) reported this species in Puerto Hondo 1). A juvenile was observed in July 2007 (Table 1), and Mangroves Sanctuary, a remnant mangrove forest several adults and juveniles/inmmatures have been recently included within the boundaries of the reserve. A reported soaring and resting around the mangrove trees juvenile was also recorded in a site close to human (Figs. 3-4). In addition to the observations described residences (Fig. 2). These observations were made at above, a previous isolated sighting (by JJA) of a 12h00 and each hawk remained perched in red mangrove soaring over a marginal mangrove patch of tall trees next trees for 15–20 minutes. to a recent deforested mangrove site for shrimp aquaculture was made during early 2000 (no exact date Santay Island. During earlier avifaunal surveys, recorded) in the Guayaquil Gulf (Puna Island, Fig. 1) Mangrove Black Hawks have not been recorded on this during a mangrove survey and monitoring project.

Figure 3. Pictures of an adult individual soaring over mangrove trees in Isla Manglecito (El Morro Mangrove Wildlife Refuge), Guayas Province, Gulf of Guayaquil on December 2006 - July 2007 (Photo: Xavier Arosemena).

Bajo Alto mangroves. Two Mangrove Black Hawks are the first documented records for this species in the El were observed at this site, the first was recorded on Oro Province, Ecuador (Fig. 1). Other individuals have January 2002 and the second on 15 August 2005. These

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Alava et al. 6 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 previously been observed in this area (N. Hilgert pers. farms (aquaculture), but also for agriculture and urban com.). sprawl (Fig. 5, CLIRSEN 2007). Since this species is restricted to inhabit mangrove forests (Ridgely & Potential threats. It is estimated that about 54,400 Greenfield 2001), we believe the Mangrove Black Hawk hectares (27% of the original total area: 203,625 population could have suffered an ecologically similar hectares) of mangrove habitat has been lost in Ecuador rate of decline during the period (1969-1999), as the area from 1969 to 2006 due to uncontrolled clear-cutting of used by shrimp farms increased from 0 to 178,000 ha. mangroves, not only for construction of illegal shrimp

Figure 4. Immature-adult individual observed perched on a dry mangrove tree in Isla Manglecito (Photo: M. Saavedra).

Extensive banana plantations, using a broad spectrum organophosphates, carbamates and bipiridyls (e.g., of synthetic pesticides, are found in southwest Ecuador, Paraquat) to control and eliminate agriculture pests and and are primarily located in coastal provinces such as application of organochlorines (i.e. DDT) to overcome Los Rios-El Guayas and the El Oro (INEC 2007, INEC human diseases vectors (such as malaria mosquitoes) 2009). Although we were unable to collect historical represent a major threat to raptors in developing data to estimate trends in the area used by banana countries, jeopardizing their survival in the long term plantations, we were able to estimate a total average of (Thiollay 1989b). At present, the acute and chronic 232,235 ha of area dedicated to the production of impacts of persistent, toxic and bio-accumulative organic bananas at the national level (Fig. 6). About 79% of this pollutants potentially present in raptors are unknown in total was located on the costal zone, mainly in the El Ecuador. Guayas and El Oro provinces (an average of 51,183 and 44,607 ha, respectively, Fig. 3). Being relatively close to Discussion mangrove areas, there is a potential negative effect for the Mangrove Black Hawk via run-off and aerial In Ecuador, distribution, reproductive behavior and dispersion of pesticides used in agricultural lands close feeding are poorly known for Mangrove Black to the estuary and mangrove forests. It has been well Hawks. From multiple observations of an individual in documented that the use of pesticides such as the El Oro province, it appears that this hawk rests Boletín SAO | http://www.sao.org.co/boletinsao.html | Oct 2011| Protegido por – Protected by Creative commons Colombia|

Alava et al. 7 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 during noon and early afternoon hours in low and bulky & Brown 1986, Thiollay 1994), as well as different branches of Rhizophora spp. aside creeks in mangrove species of Ardeidae herons such as Great Egrets Ardea inlets. The Bajo Alto Mangroves have remnant stands of alba, Snowy Egrets Egretta thula, Little Blue Heron mangrove habitat in semi-pristine condition and are Egretta caerulea, Tricolored Heron E. tricolor, and believe to be suitable for this raptor. The hawk may Green-backed Heron Butorides striatus in mangroves, prefer protected habitat, not exposed to the waves or showing a strong preference for egrets (Caldwell 1986). high tide levels. On the other hand, Thiollay (1994) In Ecuadorian mangroves, have been reported that this raptor, in French Guiana, nests on the identified as the major prey item in the diet composition top of tall trees, which was not the case in the surveyed of this raptor (Hilgert & Benavides 2002), but no areas. stomach content studies are available to fully confirm this observation. The Common Black Hawk’s diet consist mostly of , fishes, shorebirds, small vertebrates and carcasses (Hilty

Figure 5. Temporal and spatial change of mangroves and shrimp farming areas on the continental coast of Ecuador from 1969 to 2006 (CLIRSEN 2007).

Conservation implications individuals, having an extent of occurrence no greater than 20,000 km2, taking into consideration both severe In Ecuador, the Mangrove Black Hawk is a vulnerable fragmentation and population fluctuations and declines species due to habitat fragmentation and likely declining (Ferguson-Lees & Christie 2001, BirdLife International population (Hilgert & Benavides 2002). Although the 2000, BirdLife International 2011). In Ecuador, this species is not globally threatened (Thiollay 1989, species is probably facing a dramatic decline caused by Bildstein et al. 1998, BirdLife International 2011), the the decimation of its fragile habitat, the mangrove forest, populations are also declining and included in the which is being drastically transformed for the Appendix II of CITES, with poorly documented status construction of shrimp ponds and by the urban sprawl and with taxonomic confusion of all populations within (Ridgely & Greenfield 2001, Hilgert & Benavides 2002). one or two species: Common Black Hawk B. anthracinus or Mangrove Black Hawk B subtilis This trend in habitat loss is critical and might be (Thiollay 1994, BirdLife International 2011). Its global affecting not only waterbirds, marine birds and population has been estimated to be about 10,000 shorebirds, but also Neotropical raptors and other birds

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Alava et al. 8 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 depending on mangroves forests. Thiollay (1989a) undertaken in the last decade (Carvajal & Alava 2007). pointed out that tropical raptors strongly depend on vast Fortunately, natural regeneration and rehabilitation of patches of forest, and habitat destruction is their major mangroves has taken place in several areas, where threat. This is more significant when taking into account shrimp ponds were abandoned or closed and when sedentary and forest restricted species, as well as gaps in hydrologic conditions were naturally recovered or the ecology of some raptors (Bildstein et al. 1998). The enhanced naturally by the El Niño event (Carvajal & potential reduction in foraging and nesting grounds for Alava 2007). For instance, the total mangrove area did this hawk can compromise its presence, and in particular not decrease significantly from 1995 to 2006 (Fig. 5). it may cause regional or local extirpation in some Similarly, all the observations, except for those made at locations of the Ecuadorian coast, as suggested by Bajo Alto mangroves, were conducted in areas already Ridgely & Greenfield (2001) in mangroves around Bahía categorized as reserves or wildlife refuges. These de Caráquez. Lately, regional environmental projects to protected areas benefit the local biodiversity, including protect the mangrove ecosystem and avoid its waterbirds, parakeets, parrots and raptors, by offering deforestation in the Gulf of Guayaquil have been renewed habitat.

Figure 6. Total national and coastal areas for banana production, including banana plantation areas for the El Guayas and El Oro coastal provinces, where more than 80% of the Ecuadorian mangrove wetlands are located. Data adapted from INEC (2009).

From the environmental pollution stand point, Guayas, Los Rios and the El Oro provinces, where organic chemicals contaminants are a major problem not pesticides are broadly used (Alava et al. 2007). Research only for raptors, but also for wildlife in general and on eco-toxicology is strongly encouraged in Ecuador to possibly humans too. It is likely that individuals of determine the levels and effect of insecticides and Mangrove Black Hawk inhabiting mangroves close to herbicides in top predator birds, including raptors and commercial banana cultivation (i.e. at El Oro Province) their food webs. might be facing exposures to chemicals and bio accumulative effects both in the long and short terms, as Ongoing national regulations for the protection and suggested for the Snail Kite (Rosthramus sociabilis) in conservation of mangroves are the only environmental Boletín SAO | http://www.sao.org.co/boletinsao.html | Oct 2011| Protegido por – Protected by Creative commons Colombia|

Alava et al. 9 evAP_2 Boletín SAO Vol. 20 Common Black Hawk in Ecuador (No. 2) – evAP_2 management strategies to conserve habitat in Ecuador, mangrove areas and the need of local environmental and we certainly encourage environmental compliance strategies to protect this species. In addition, field and enforcement. The observations reported here are research, monitoring and local training are urgently important because most of these findings are new required in this region to elucidate gaps in the natural sightings and contribute to our knowledge of the history of this vulnerable species and contribute to its distribution of this rare species in southwestern Ecuador, long-term conservation. confirming its presence in disturbed and pristine

Table 1. Number of observed Mangrove Black Hawks in 2002 and from 2005 to 2007 in different localities of the Guayaquil Gulf Estuary, Ecuador.

Position Date Observations Comments Bajo Alto Mangroves 3ºS, 79.5ºW January 2002 1 adult Perched on mangrove tree (Rhizophora spp.) Bajo Alto Mangroves 3ºS, 79.5ºW 15 August 2005 1 adult Perched on mangrove tree and landed on sand. Isla Santay 2º13'S, 79º51'W 05 September 2005 1 adult Observed on litterfall covering shrubs and vines Isla Santay 2º13'S, 79º51'W 13 September 2005 1 adult Same as above RPFMS (Estero Salado 2º11'S, 79º59'W 15 March 2006 1 adult Perched/resting on Red Mangrove–Wildlife 1 juvenile Mangrove (Rhizophora Production Reserve) spp.) RPFMS 2º11'S, 79º58'W 22 March 2006 1 adult Perched/resting on R. spp. RPFMS 2º12'S, 79º57'W 21 April 2006 1 adult Perched/resting on R. spp. Isla Manglecito 2°39'S, 80°11'W December 2006- 3 adults Two juveniles were July 2007 2 juveniles observed in this area

Acknowledgments Fundación Natura Capítulo Guayaquil and Fundación Pro Bosque for managing and conducting mangrove This research was possible thanks to the funding of conservation projects to protect wildlife. We specially different organizations sponsoring mangrove thank Russell Thorstrom, the editorial committee of conservation projects in the Gulf of Guayaquil, including Boletin SAO, and the reviewers for their insights and Compañía de Cervezas Nacionales and Energy comments to this manuscript, and all the volunteers Development Company. We express gratitude to participating during field work.

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