Dalia C. Barragán Barrera

Con de propósito de aunar esfuerzos técnicos, administrativos y financieros entre el Instituto Alexander von Humboldt y la Asociación Colombiana de Zoología (ACZ), para identificar, gestionar y consolidar los registros biológicos e información sobre ecología, uso y amenazas de un grupo determinado de especies de mamíferos de Colombia, de acuerdo con las necesidades de información del sistema de categorización y criterios de la UICN, se generó una base de datos de registros a partir de información de fototrampeo de diferentes investigadores y instituciones interesadas. Con base a ello, se obtuvieron un total de 19.999 registros, que permitieron obtener información para 10 órdenes, 26 familias, 50 géneros y 66 especies. Los órdenes con mayor representatividad fueron Carnívora (35.97%), Rodentia (28.56%) y Artiodactyla (16.55%). Esto registros provienen de 56 organizaciones y 121 autores que compartieron sus datos para la publicación. Todos los datos recibidos fueron organizados en los...

The southern elephant seal (SES; Mirounga leonina) has a circumpolar distribution, breeding mainly on sub‐Antarctic islands and making long trips between breeding or molting and foraging areas. Most individuals from colonies in the South Shetland Islands (western Antarctic Peninsula; WAP) are distributed in Antarctic Specially Protected Areas (ASPA). Despite these protected habitats, pollutants can reach such remote areas far away from emission sources, affecting local fauna. To assess possible mercury (Hg) contamination in SES, we analyzed skin samples collected from free‐ranging molting individuals using the remote biopsy PAXARMS system in Isla 25 de Mayo/King George Island (62°15′S, 58°39′W; ASPA 132). Hairless skin samples were analyzed to determine total‐Hg (THg) concentrations, which ranged between 145 ng/g and 1,915 ng/g (M = 730, SD = 388 ng/g), showing significant differences between sexes, with adult‐females having higher concentrations (range = 306–1,915, M = 859, SD = 42...

The Agoa protected marine area, located in the French West Indies, eastern Caribbean, holds several cetacean species, of which the pantropical spotted dolphinStenella attenuatais the most commonly observed. This species is the focus of whale-watching activities off the leeward coasts of Guadeloupe and Martinique, which has allowed the development of a citizen science program to characterize individuals through the collection of photographic data. Here, we conducted a photo-identification study with a sample of 115,705 photos collected between 2014 and 2019, in which 290 marked individuals (179 in Guadeloupe and 111 in Martinique) were identified. Based on an Agglomerative Hierarchical Classification (AHC) analysis, dolphins from each island were separated into two residency clusters. The Catch–Mark–Release (CMR) POPAN statistical model for open populations estimated the pantropical spotted dolphin populations in Guadeloupe and Martinique at 657 (95% CI: 525–821) and 336 (95% CI: 253...

We studied the sperm whale Physeter macrocephalus in the Colombian Caribbean by combining data from our offshore surveys of behaviour, encounter rate, group structure and density with data from the literature. We describe for the first time the potential distribution of sperm whales in the Colombian Caribbean, using sighting and acoustic data obtained during our surveys, published information, and opportunistic encounters during 1988–2020. We conducted surveys on seismic vessels over 703 days during 2011–2016, covering an area of 68,904 km2. We recorded 98 individuals in a total of 50 groups, a density of 1.42 individuals per 1,000 km2. To determine the potential distribution of the species, we built Maxent models with uncorrelated environmental variables at five depths (from the surface to c. 2,000 m). The model for 1,000 m depth had the best performance, with areas of high probability of occurrence of sperm whales in the south and north-east Colombian Caribbean over the shelf brea...

En Colombia existen actualmente 1.391 áreas protegidas y tanto en su interior como en sus fronteras (zonas de amortiguación) se desarrollan muchas actividades humanas. El estudiante doctoral de la Facultad de Ciencias Naturales Kristian Rubiano mapeó 51 áreas protegidas para determinar las trayectorias de cambio en el uso de la tierra. Los resultados, que fueron presentados en la 58a Reunión Anual de la Asociación para la Biología Tropical y Conservación (ATBC), mostraron que las áreas protegidas están cumpliendo parcialmente su rol de conservar los ecosistemas.

The Agoa protected marine area, located in the French West Indies, eastern Caribbean, holds several cetacean species, of which the pantropical spotted dolphin Stenella attenuata is the most commonly observed. This species is the focus of whale-watching activities off the leeward coasts of Guadeloupe and Martinique, which has allowed the development of a citizen science program to characterize individuals through the collection of photographic data. Here, we conducted a photo-identification study with a sample of 115,705 photos collected between 2014 and 2019, in which 290 marked individuals (179 in Guadeloupe and 111 in Martinique) were identified. Based on an Agglomerative Hierarchical Classification (AHC) analysis, dolphins from each island were separated into two residency clusters. The Catch–Mark–Release (CMR) POPAN statistical model for open populations estimated the pantropical spotted dolphin populations in Guadeloupe and Martinique at 657 (95% CI: 525–821) and 336 (95% CI: 253–446) individuals for frequent users, respectively, while occasional visitors were estimated at 3,063 (95% CI: 2,133–4,398) and 1,443 (95% CI: 1,024–2,033), respectively. The Martinique population tended to use a reduced coastal area and appeared to be smaller and stable, while the Guadeloupe population showed a slight decline in abundance throughout the study period. These results showed that the leeward coasts of Guadeloupe and Martinique are of particular importance for pantropical spotted dolphin populations, highlighting the need for continued monitoring through both scientific and citizen science programs to fill information gaps on this species in the eastern Caribbean.

This research note was accepted to be part of the Aquatic Mammals Journal Special Issue to celebrate its 50 years. Here we report the first record of a Bryde’s whale (Balaenoptera edeni) in the Gulf of Tribugá, Chocó, as well as its interaction with a group of mother, calf and escort of humpback whales (Megaptera novaeangliae) in the Gulf of Tribugá, Chocó, northern Colombian Pacific. This record was possible through a citizen science program established by the R&E Ocean Community Conservation NGO during the covid-19 lockdown, in which three fishermen were trained to conduct marine mammals monitoring within the Gulf.

This research note was accepted to be part of the Aquatic Mammals Journal Special Issue to celebrate its 50 years. Here we describe a play behavior by a juvenile humpback whale (Megaptera novaeangliae) with an inanimate object (driftwood) in the Gulf of Tribugá, nothern Colombian Pacific. This observation was possible through a citizen science program established by the R&E Ocean Community Conservation NGO during the covid-19 lockdown, in which three fishermen were trained to conduct marine mammals monitoring within the Gulf.

To test this hypothesis a photo-ID survey in 2018 and 2019 was conducted, resulting in 54,298 photographs. With no matches of individuals between islands, our findings do not support regular exchange of PSD individuals between Martinique and Guadeloupe. However, given previous re-sighting data, it is possible that movement of individuals between islands exists but at lower frequencies than expected, which can only be detected through long-term surveys. Additionally, populations from both islands showed relatively high site fidelity. We found that in Guadeloupe the PSD population is homogeneously distributed along the coast. In contrast, in Martinique the PSD population was composed of two resident groups concentrated in one area. Moreover, 70 new individuals were identified in Guadeloupe and 54 in Martinique while POPAN modelling estimated the number of marked individuals in the study area during 2018 and 2019 at 89 in Guadeloupe and 90 in Martinique. This research provides the first insights on the residency and movement patterns of S. attenuata in the Agoa Sanctuary and can inform future efforts in management and conservation.

Baseline data on the distribution and occurrence of marine mammals are needed to better understand their role in marine ecosystems and to protect them from the negative impacts of climate change and human activity. Here, we report the results of vessel-based surveys to document marine mammals throughout the territorial waters of Belize in the Western Caribbean Sea. In 2016 and 2017, 543 km of transects (85 h of survey effort) aboard a 14-m catamaran resulted in 17 sightings of four species of marine mammal: inshore and offshore bottlenose dolphins Tursiops truncatus, Atlantic spotted dolphins Stenella frontalis, pantropical spotted dolphins Stenella attenuata, and Antillean manatees Trichechus manatus manatus. Coastal manatees and bottlenose dolphins were found in shallow waters and all other species exclusively in deep waters east of the Mesoamerican Barrier Reef System. These preliminary findings suggest there is a low density of marine mammals in the offshore habitats of Belize. Future studies should employ vessel-based distance sampling techniques and passive acoustic monitoring to reliably track the occurrence of marine mammals in this region and assess their distribution and abundance.

Sharks are fished for human consumption in Colombia, and fins are exported illegally to international markets. The goal was to identify differences in total mercury (THg) concentrations in fins and muscles of shark species seized in the Buenaventura port (Colombian Pacific), and to assess potential human health risks related to shark consumption. Seven species were considered in this study: Pelagic Thresher (Alopias pelagicus), Pacific Smalltail Shark (Carcharhinus cerdale), Brown Smoothhound (Mustelus henlei), Sicklefin Smoothhound (Mustelus lunulatus), Scalloped Bonnethead (Sphyrna corona), Scalloped Hammerhead (Sphyrna lewini), and Bonnethead Shark
(Sphyrna tiburo), and THg was analyzed in shark tissues. 24% muscle samples concentrations were above international recommended limits for human consumption, especially for A. pelagicus and S. lewini. Stable isotopes (δ13C and δ15N) analysis showed a foraging overlapping in coastal habitats, where overfishing usually occurs. This study provides useful scientific information to develop management plans for sharks in Colombia and neighboring countries.

The Atlantic spotted dolphin (Stenella frontalis) is endemic to tropical, subtropical, and warm temperate waters of the Atlantic Ocean. Throughout its distribution, both geographic distance and environmental variation may contribute to population structure of the species. In this study, we follow a seascape genetics approach to investigate population differentiation of Atlantic spotted dolphins based on a large worldwide dataset and the relationship with marine environmental variables. The results revealed that the Atlantic spotted dolphin exhibits population genetic structure across its distribution based on mitochondrial DNA control region (mtDNA-CR) data. Analyses based on the contemporary landscape suggested, at both the individual and population level, that the population genetic structure is consistent with the isolation-by-distance model. However, because geography and environmental matrices were correlated, and because in some, but not all analyses, we found a significant effect for the environment, we cannot rule out the addition contribution of environmental factors in structuring genetic variation. Future analyses based on nuclear data are needed to evaluate whether local processes, such as social structure and some level of philopatry within populations, may be contributing to the associations among genetic structure, geographic, and environmental distance.

A small and genetically isolated bottlenose dolphin (Tursiops truncatus) population resides year-round in the Bocas del Toro Archipelago-Panama (BDT). Photo-identification and genetic data showed that this dolphin population is highly phylopatric and is formed exclusively by individuals of the “inshore form”. This study aimed to investigate the trophic ecology and mercury concentrations of bottlenose dolphins in BDT to assess their coastal habits. We collected muscle samples (n = 175) of 11 potential fish prey species, and skin samples from free-ranging dolphins in BDT (n = 37) and La Guajira-Colombia (n = 7) to compare isotopic niche width. Results showed that BDT dolphins have a coastal feeding habit, belong to the “inshore form” (δ13C = −13.05 ± 1.89‰), and have low mercury concentrations (mean = 1637 ± 1387 ng g−1dw). However, this element is biomagnified in the BDT food chain, showing a marginal dolphins health risk (RQ = 1.00). We call for a monitoring pollutant program and conservation strategies aimed to protect the dolphin population at BDT.

The current conservation status of the bottlenose dolphin (Tursiops truncatus) under the IUCN is ‘least concern’. However, in the Caribbean, small and localized populations of the ‘inshore form’ may be at higher risk of extinction than the ‘worldwide distributed form’ due to a combination of factors including small population size, high site fidelity, genetic isolation, and range overlap with human activities. Here, we study the population genetic structure of bottlenose dolphins from the Archipelago of Bocas del Toro in Panama. This is a small population characterized by high site fidelity and is currently heavily-impacted by the local dolphin-watching industry. We collected skin tissue samples from 25 dolphins to study the genetic diversity and structure of this population. We amplified a portion of the mitochondrial Control Region (mtDNA-CR) and nine microsatellite loci. The mtDNA-CR analyses revealed that dolphins in Bocas del Toro belong to the ‘inshore form’, grouped with the Bahamas-Colombia-Cuba-Mexico population unit. They also possess a unique haplotype new for the Caribbean. The microsatellite data indicated that the Bocas del Toro dolphin population is highly structured, likely due to restricted movement patterns. Previous abundance estimates obtained with mark-recapture methods reported a small population of 80 dolphins (95% CI = 72–87), which is similar to the contemporary effective population size estimated in this study (Ne = 73 individuals; CI = 18.0 - ∞; 0.05). The combination of small population size, high degree of genetic isolation, and intense daily interactions with dolphin-watching boats puts the Bocas del Toro dolphin to at high risk of extinction. Despite national guidelines to regulate the dolphin-watching industry in Bocas del Toro and ongoing educational programs for tour operators, only in 2012 seven animals have died due to boat collisions. Our results suggest that the conservation status of bottlenose dolphins in Bocas del Toro should be elevated to ‘endangered’ at the national level, as a precautionary measure while population and viability estimates are conducted.

The nearest known population of common dolphins (Delphinus sp.) to the Colombian Caribbean occurs in a fairly restricted range in eastern Venezuela. These dolphins have not been previously reported in the Colombian Caribbean, likely because of a lack of study of the local cetacean fauna. We collected cetacean observations in waters of the Guajira Department, northern Colombia (~11°N, 73°W) during two separate efforts: (a) a seismic vessel survey (December 2009—March 2010), and (b) three coastal surveys from small boats (May—July 2012, May 2013, and May 2014). Here we document ten sightings of common dolphins collected during these surveys, which extend the known range of the species by ~1000 km into the southwestern Caribbean. We also collected nine skin biopsies in 2013 and 2014. In order to determine the taxonomic identity of the specimens, we conducted genetic barcoding and phylogenetic analyses using two mitochondrial markers, the Control Region (mtDNA) and Cytochrome b (Cytb). Results indicate that these specimens are genetically closer to the short-beaked common dolphin (Delphinus delphis) even though morphologically they resemble a long-beaked form (Delphinus sp.). However, the specific taxonomic status of common dolphins in the Caribbean and in the Western Atlantic remains unresolved. It is also unclear whether the distribution of the species between northern Colombia and eastern Venezuela is continuous or disjoined, or whether they can be considered part of the same stock.

Population structure studies play an increasingly integral role in conservation and management of marine mammal species. Genetic markers are commonly used; however, ecological markers (i.e. chemical compounds) are a fairly recent and useful tool to investigate ecological management units. The objective of this study is to investigate the population structure of the Atlantic spotted dolphin (Stenella frontalis) within its distribution in the Atlantic Ocean using data from stable isotopes of δ13C and δ15N and persistent organic pollutants as ecological markers. Based on previous studies that addressed distribution, morphometric analyses and molecular and ecological markers, we hypothesize that there are several ecological management units within the Atlantic Ocean. Our results confirmed population differentiation previously detected using genetic markers. Additionally, dolphins from the south-eastern coast of Brazil do not show complete ecological segregation from the Caribbean ones, while molecular analyses suggested genetic differentiation between the two regions. In the light of these results, we propose that at least two ecological management units should be considered, east and west of the Atlantic Ocean; however, the presence of one or two management units along the Atlantic coast of Central and South America needs further investigation.

Coastal bottlenose dolphin populations are frequently in contact with humans and are targeted by dolphin-watching boats. In the past 10 years dolphin watching has become a popular and profitable tourist attraction in Panama. Profitable wildlife observation can mutually benefit humans and wild animal populations, resulting in successful conservation. However, high observation intensities may nevertheless negatively affect animals. Dolphin watching is largely boat-based, and engine noise
potentially elicits avoidance behaviors in dolphins and can interfere with important communicative and foraging acoustic signals. We studied the effect of engine noise on the occurrence, and behavior of bottlenose dolphins of Bocas del Toro, Panama. The study area was surveyed using predetermined strip transects that maximized the coverage of the Archipelago. Surveys ran from 7 a.m. to 5 p.m. and observations were made from a 10 m boat with a double 4-stroke 150hp engine. For each group sighted we estimated group size, predominant behavior, noted number of dolphin-watching boats interacting with the group, and recorded communicative signals (whistles) using a broadband recording system. Preliminary analysis suggest that the Bocas del Toro local dolphin population is small, probably with less than 150 individuals, half of which appear to be year-round residents. A yearly decrease in group size and number of groups sighted correlates with an increase in the number of boats interacting with the animals. The behavioral data indicates that dolphins tend to show more avoiding behaviors in the presence of dolphin-watching boats when compared to the research boat. Groups show increase in whistle emission and increased whistle modulation, frequency, and duration in the presence of dolphin-watching boats. Our results suggest that dolphin watching can negatively affect the bottlenose dolphins of Bocas del Toro, when numerous boats are involved. Although Bocas del Toro bottlenose dolphins are notably plastic in their behavior and acoustic communication the growing tourism development and associated increase in boats transiting the Archipelago may
challenge their survival by increasing engine noise to levels that may render their habitat less habitable. Also, boat maneuvering may directly impact the dolphins. We have observed up to 25 boats following the same group and with most of the boats involved circling the animals and disrupting the activities as well as separating group members including calves from mothers. The Panamanian Government Conduct guidelines are appropriate to conserve the dolphin’s acoustic environment, but few operators are well informed about these guidelines and their importance. Rapid action is urgently needed to ensure adherence to conduct guidelines, promoting less aggressive dolphin watching and thus help protecting the dolphin population, and simultaneously the operator’s income.