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Drones are important tools for a wide array of applications in scientific research and monitoring with marine mammals. Few studies have examined if different crafts and systems affect the behavior of animals, or attempted to identify factors influencing the probability of these responses or their subsequent effects. Some published studies on effects of drones demonstrate low levels of reaction in some focal species (e.g., baleen whales) but higher likelihood in others (e.g., pinnipeds). More data are needed across species types and context to determine variables influencing these responses across taxa and species. In this study, we examine marine mammal responses to drone flights collected from a combination of opportunistic and experimental drone flights (n = 658) flown for collection of respiratory samples of whale blow and behavioral observations of dolphins and manatees. We described and compare behavioral responses in Southern right whales, humpback whales, bottlenose dolphins, rough toothed-dolphins, and Antillean manatees. We examined a variety of metrics (e.g., behavior state, altitude, animal orientation relative to craft) to characterize behavioral reactions across species and minimize unintended effects on focal species. We discuss these findings within established theoretical and experimental framework on disturbances to marine mammals and provide practical recommendations for best practices for research flights with marine mammals across different taxa.
Food sharing is common in the animal kingdom, but rarely reported in marine mammals since it is challenging to observe their feeding behaviors in the wild. Here, we describe food sharing by rough-toothed dolphins, an open ocean dolphin species, off the southwestern coast of Mexico. We observed two dolphins exchanging a fish back and forth during a complex series of exchanges from the perspective of a drone. This is the second time this behavior has been documented in this species and our findings highlight the need for further study of the importance of food sharing in dolphin societies.
This presentation documents the presence/absence of marine mammals, establishes patterns of spatio-temporal habitat use and identifies sensitive marine mammal areas in the interest of improved ecosystem management in the state of Guerrero, SW Pacific Mexico. Between January-March 2014-2017, we conducted 200 boat surveys (1303 hours), covering 50 coastal miles surrounding Ixtapa-Zihuatanejo and extending 10 NM to sea. Our focal species were humpback whales; we collected data on other marine mammals and large marine fauna opportunistically. Final results, along with our concurrent outreach and educational programs are in this presentation, to help guide monitoring, protection recommendations and support improved marine resource management in this unregulated region.
Between 2014-2018, we collaborated with Guerrero communities to cultivate a shift toward marine conservation through: capacity building (wildlife guide and artist training programs); compensation via participatory research; education (2500+ youth, ages 8-12 at 12 schools); 125 outreach events (200,000+ audience reached); ecotourism market development; and a 1600-hour participatory marine mammal survey. We lived with host families, and locals comprised half of our team. Program activities beyond the survey were determined by consensus. We documented changes in perceptions regarding marine mammals and the environment and identified productive pathways and underlying concerns via interviews, surveys and rates of activity involvement and participant retention. Advances included: a 75% increase in awareness and investment in marine mammals; a community-supported safe whale watch program (75 guides trained); development of ecotourism market and activities to alleviate pressure on the fishery and motivate environmental stewardship; a voluntary 30-member stranding network; a 100+ fishermen marine mammal spotting network; and results from a 5-year humpback whale survey.
Data is deficient regarding humpback whales in south Pacific Mexico. The distinct population segments (DPS) of whales off of Mexico and Central America are listed as threatened (3,264 individuals) and endangered (411 individuals). We conducted 1,303 survey hours off Petatlán and Zihuatanejo, Guerrero between 2014-2017 and determined migratory patterns, site fidelity and habitat use by means of photo-identification, acoustic and genetic analysis in order to contribute to the characterization of the North Pacific humpback whale population and generate local conservation strategies. This presentation details our findings
Lobomycosis and lobomycosis-like diseases (LLD) (also: paracoccidioidomycosis) are chronic cutaneous infections that affect Delphinidae in tropical and subtropical regions worldwide. In the Americas, these diseases have been relatively well-described, but gaps still exist in our understanding of their distribution across the continent. Here we report on LLD affecting inshore bottlenose dolphins Tursiops truncatus from the Caribbean waters of Belize and from the eastern tropical Pacific Ocean off the southwestern coast of Mexico. Photo-identification and catalog data gathered between 1992 and 2017 for 371 and 41 individuals, respectively from Belize and Mexico, were examined for the presence of LLD. In Belize, 5 free-ranging and 1 stranded dolphin were found positive in at least 3 communities with the highest prevalence in the south. In Guerrero, Mexico, 4 inshore bottlenose dolphins sighted in 2014−2017 were affected by LLD. These data highlight the need for histological and molecular studies to confirm the etiological agent. Additionally, we document a single case of LLD in an adult Atlantic spotted dolphin Stenella frontalis in southern Belize, the first report in this species. The role of environmental and anthropogenic factors in the occurrence, severity, and epidemiology of LLD in South and Central America requires further investigation.
The status of humpback whale populations under the Endangered Species Act (ESA) was changed recently to remove the species level-listing of endangered and, instead, recognize 14 Distinct Populations Segments (DPS) with their own ESA status, including three in the central and eastern North Pacific with Hawaii delisted, Mexico threatened, and Central America endangered . Although DPSs are based on their breeding population regions, humpbacks spend most of their time on feeding areas where they show strong site fidelity and where most human impacts occur. Therefore, management actions are critical on feeding areas. This is important for the whales in the US West Coast feeding area which include animals coming from the delisted Hawaiian, threatened Mexican and endangered Central American DPSs and where fisheries have entanglements increased dramatically since 2015. Here we examine interchange rates on a finer geographic than those defined in previous studies.
Association patterns have been studied in several cetacean species such as killer whales, bottlenose and humpback dolphins. However, rough toothed dolphin populations are rarely described due to their preference for deep water and pelagic areas. Based on other studies (Ritter 2002, Baird 2008) we hypothesized that rough toothed dolphins form a fission-fusion society where animals associate with each other to form groups of varying size and composition over time. Associations between individuals are organized according to preferential relations and may be influenced by environmental changes. In Southwest Pacific Mexico, coastal rough toothed dolphins have been identified in a 300 km² study area near Ixtapa/Zihuatanejo during 960 hours of small powered vessel surveys following general and line transect search patterns. Group size, composition, location, behavior state, environmental parameters and photographs were recorded. Individual rough toothed dolphins were seen regularly in the study region and 53 of 151 identified dolphins were resighted (73.6% seen twice, 15.1% three times and 11.3% four times) during the 3-years study (January-March 2014-2016). The HWI association index was used to calculate the strength of associations between individuals, as well as the social differentiation index to show how the society varies (from homogeneous to extremely differentiated). Preliminary results indicate that rough toothed dolphins in Guerrero exhibit a fission-fusion society in a well-differentiated society (S=0.65). Indeed, the mean HWI for the whole set of individuals is low (0.11), while the maximum HWI is high (1.00). This difference suggest an important variation in the associations, confirming that animals associate preferably with one or another. Moreover, the use of space seems to differ depending on group composition.
Marine mammal diversity, abundance and habitat use data are lacking in the southwestern Pacific state of Guerrero, Mexico. Aggressive behavior from fishing and tourist boats toward marine mammals, exacerbated by the absence of monitoring and enforcement underlies the need for a better understanding of species present. Our intended five-year study aims to document presence/absence of marine mammals, to establish patterns of spatio-temporal habitat use and to identify sensitive marine mammal areas in the interest of improved ecosystem management.
This talk was presented to the US FWS to share information about the Whales of Guerrero Research Project, a 5-year citizen science project supported by the U.S. Fish and Wildlife Service Mexico Program, National Geographic, and others that aims to survey humpback whales in a little explored area of Mexico, provide local fishermen and boat operators with a means to survive without further depleting natural resources, and promote a unique region as worth visiting and protecting.
Knowledge regarding odontocete species occurrence and distribution off the southwestern state of Guerrero, Mexico is extremely limited. Our study goal was to describe and quantify winter occurrence and habitat-use patterns of delphinids in 300 km2 of undescribed coastal waters near Barra de Potosi (20 km south of Zihuatanejo), Guerrero. We hypothesized delphinids would exhibit habitat partitioning based on studies in other regions, resulting in different distribution, group size and behavioral states. We conducted 636 hr of small-vessel surveys following general and line-transect search patterns during January-March 2014 and 2015. Species, group size/composition, location, behavior state, environmental parameters, and photographs were recorded. We observed 85 pantropical spotted dolphin (Stenella attenuata), 48 rough-toothed dolphin (Steno bredanensis) and 20 bottlenose dolphin groups (Tursiops truncatus). As hypothesized, distributional differences occurred among species; however, group size and behavior states did not differ significantly by species. Bottlenose dolphins were found nearly exclusively <1 km from shore, rough-toothed dolphins were farther offshore in deeper northern waters, while pantropical spotted dolphins were seen throughout the study area. Although mean group size was largest among pantropical spotted dolphins (mean=7.5, SD=6.33) followed by rough-toothed (mean=5.1, SD=5.03) and bottlenose dolphins (mean=4.3, SD=4.03), differences were insignificant (p=0.11). Foraging, travelling and resting behavior states were observed for all three species. Rough-toothed dolphins were most frequently (3.4% of 48 groups) with other cetacean species (humpback whales, pantropical spotted dolphins), compared to pantropical (1.7% of 85; humpback whales, rough-toothed dolphins) and bottlenose dolphins (0% of 20). Observed habitat-use differences are likely related to differences in preferred prey distribution, predator avoidance and possibly inter-specific social avoidance, based on comparisons with other studies. Within the next three winter seasons, the Whales of Guerrero Research Project will provide scientific data supporting regional designation as a marine preserve and promoting sustainable ecotourism for the overfished impoverished local community.