Search

Human-wildlife cooperation occurs when humans and free-living wild animals actively coordinate their behavior to achieve a mutually beneficial outcome. These interactions provide important benefits to both the human and wildlife communities involved, have wider impacts on the local ecosystem, and represent a unique intersection of human and animal cultures. The remaining active forms are human-honeyguide and human-dolphin cooperation, but these are at risk of joining several inactive forms (including human-wolf and human-orca cooperation). Human-wildlife cooperation faces a unique set of conservation challenges, as it requires multiple components-a motivated human and wildlife partner, a suitable environment, and compatible interspecies knowledge-which face threats from ecological and cultural changes. To safeguard human-wildlife cooperation, we recommend: (i) establishing ethically sound conservation strategies together with the participating human communities; (ii) conserving opportunities for human and wildlife participation; (iii) protecting suitable environments; (iv) facilitating cultural transmission of traditional knowledge; (v) accessibly archiving Indigenous and scientific knowledge; and (vi) conducting long-term empirical studies to better understand these interactions and identify threats. Tailored safeguarding plans are therefore necessary to protect these diverse and irreplaceable interactions. Broadly, our review highlights that efforts to conserve biological and cultural diversity should carefully consider interactions between human and animal cultures. Please see AfricanHoneyguides.com/abstract-translations for Kiswahili and Portuguese translations of the abstract.

Some dolphin species produce signature whistles, which may allow the identification of individual dolphins using passive acoustic monitoring (PAM). Identifying individuals by their sounds may enhance the opportunities for monitoring and addressing biological and ecological questions about these species. Here, we explored the potential of signature whistles to investigate ecological aspects of a resident bottlenose dolphin population. Using a limited data set, with few individuals recognized by signature whistles, combined with spatial capture‐recapture (SCR) methods, we investigated how effective such approach is describing spatial use patterns and estimating density for this population. The data were collected using 4–6 stationary bottom‐moored recorders. Since only eight signature whistles were identified, our density estimate may represent a subset of the entire population. However, even with only a few signature whistles identified, our results confirmed the center of the core area used by these dolphins as the area with the highest encounter probability. In addition, our results provided evidence that these dolphins have the same spatial use pattern at night as during the day. This study shows that SCR analysis of signature whistle data can improve our ecological knowledge and understanding of dolphin populations. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of small-scale fisheries requires considering the diversity of behaviours and skills of fishers. Fishers may have different abilities and tactics that can translate into different fishing outcomes. Here, we investigate variation in fishing behaviours among traditional net-casting fishers that are assisted by wild dolphins, and how this variation interacts with environmental conditions and influences fishing success. By combining in situ environmental sampling with fine-scale behavioural tracking from overhead videos, we found a higher probability of catching fish among fishers well-positioned in the water and that cast their nets wide-open and closer to dolphins. These differences in net-casting performance affect their chance of catching any fish over and above environmental conditions related to fish availability. This finding suggests that fishers' success may not be simply an outcome of variations in resource availability, but also result from subtle variations in fishing behaviours. We discuss how such behavioural variations can represent skills acquired over the years, and how such skills can be crucial for fishers to benefit and keep interacting with dolphins. Our study demonstrates the role of behavioural variation in the dynamics of a century-old fishery and highlights the need to consider fishers' behaviours in co-management of small-scale fisheries. [ABSTRACT FROM AUTHOR]

Coastal and offshore ecotypes of common bottlenose dolphins have been recognized in the western South Atlantic, and it is possible that trophic niche divergence associated with social interactions is leading them to genetic and phenotypic differentiation. The significant morphological differentiation observed between these ecotypes suggests they represent two different subspecies. However, there is still a need to investigate whether there is congruence between morphological and genetic data to rule out the possibility of ecophenotypic variation accompanied by gene flow. Mitochondrial DNA (mtDNA) control region sequence data and 10 microsatellite loci collected from stranded and biopsied dolphins sampled in coastal and offshore waters of Brazil as well as 106 skulls for morphological analyses were used to determine whether the morphological differentiation was supported by genetic differentiation. There was congruence among the data sets, reinforcing the presence of two distinct ecotypes. The divergence may be relatively recent, however, given the moderate values of mtDNA nucleotide divergence (dA = 0.008), presence of one shared mtDNA haplotype and possibly low levels of gene flow (around 1% of migrants per generation). Results suggest the ecotypes may be in the process of speciation and reinforce they are best described as two different subspecies until the degree of nuclear genetic divergence is thoroughly evaluated: Tursiops truncatus gephyreus (coastal ecotype) and T. t. truncatus (offshore ecotype). The endemic distribution of T. t. gephyreus in the western South Atlantic and number of anthropogenic threats in the area reinforces the importance of protecting this ecotype and its habitat. [ABSTRACT FROM AUTHOR]

Sympatric species are expected to differ in ecological requirements to minimize niche overlap and avoid competition. Here we assess the trophic interactions among three coexisting dolphin species from southern Brazil: the franciscana dolphin (Pontoporia blainvillei), the Guiana dolphin (Sotalia guianensis), and the Lahille's bottlenose dolphin (Tursiops truncatus gephyreus). We evaluated temporal variation in carbon (δ13C) and nitrogen (δ15N) isotope values of bone collagen to examine potential dietary shifts resulting from increased fishing activity over the past three decades. We estimated the degree of niche overlap among these species and the contribution of potential prey sources to their diet. δ15N values were consistent among species and across years, while δ13C values increased for Guiana dolphins and decreased for bottlenose dolphins, suggesting changes in diet and/or foraging habitats through time. The similar δ13C and δ15N values and the high niche overlap between Guiana and bottlenose dolphins indicate that these species are primarily feeding on demersal prey. The franciscana diet is primarily composed of pelagic prey, resulting in a lower niche overlap in comparison with the other dolphin species. Our study provides further information about the foraging ecology of this unique dolphin community in southern Brazil with implications for its management and conservation. [ABSTRACT FROM AUTHOR]

A subset of the bottlenose dolphin Tursiops truncatus gephyreus population in Laguna, southern Brazil, specialize in foraging cooperatively with fishermen. In this study, we describe reproductive parameters for these dolphins and investigate whether this specialized tactic generates reproductive advantages for females that frequently engage in this unusual behavior. We analyzed photo-identification data collected during 233 boat-based surveys during 2007–2009 and 2013–2017. From 27,808 high-quality photographs, we identified and tracked the fate of 24 reproductive females and 45 of their calves. Calving was found to be seasonal, with most births occurring in late spring/summer. The average crude birth rate was 0.09, and estimated fecundity was 0.17. The mean inter-birth interval was 2.09 (for all calves) or 2.43 years (for surviving calves only). Survival to 1 and 2 years estimated by the Kaplan–Meier method was 0.78 (95% CI 0.65–0.92) and 0.65 (95% CI 0.51–0.83), respectively—which represents a survival rate in the second year of 0.83. We investigated the potential influence of birth timing, resource availability, and maternal foraging tactic, home range size and frequency of interaction with fishermen on calf survival. Timing of birth was a significant predictor of calf survival. Giving birth close to the local mullet season would provide lactating females with increased seasonal prey resources, leading to increased calf survival. Due to our sample size (n = 9 cooperative and 15 non-cooperative females), we could not conclude whether or not the cooperative foraging tactic influences calf survival and female reproductive success. We emphasize the importance of long-term monitoring of populations to understand regional life history characteristics and provide accurate information for viability analyses. [ABSTRACT FROM AUTHOR]

Recent years have seen an increasing interest in individual behavioral variation. However, the implications of such variation for population dynamics are often unknown. We studied the dynamics of a bottlenose dolphin (Tursiops truncatus gephyreus) population from southern Brazil, where some individuals forage cooperatively with artisanal fishermen. We fitted mark‐recapture models to 10 yr of photo‐identification data to investigate the influence of this foraging specialization on dolphins' population parameters, controlling for sex and ranging behavior. We estimated adult survival to be high (0.949 ± 0.015 SE), weakly influenced by home range size, sex or the frequency of interaction with fishermen. The slightly higher survival probability for individuals with smaller home ranges could stem from the benefits of reduced spatial requirements implied by the specialized foraging. Foraging also influenced the probability of resighting individuals, and there was no temporary or permanent emigration. Abundance fluctuated slightly over the years from 54 (95% CI = 49–59) to 60 (95% CI = 52–69) individuals, with no evident population trend. Despite such apparent population stability, we confirm this population remains small and geographically isolated which may threaten its viability and the viability of its unusual, localized foraging specialization. Our study also illustrates how accounting for individual variation can portray animal population dynamics more realistically. [ABSTRACT FROM AUTHOR]