Genets and 'genet-like' taxa (Carnivora, Viverrinae): phylogenetic analysis, systematics and biogeographic implications

The subfamily Viverrinae is a taxon of uncertain systematic status. This study consists of cladistic analyses based on morphological characters of specimens belonging to the genera Genetta , Osbornictis , Poiana and Prionodon . Two levels of analysis are carried out, one concerning generic relationships (intergeneric analysis) and one dealing with the interrelationships of species within the genus Genetta (intrageneric analysis). In the first analysis, different outgroups were used in order to test the ingroup topology.
With regard to the intergeneric analysis, Osbornictis , Poiana and Prionodon , together with Genetta johnstoni , constitute a monophyletic group (including Nandinia ), which is the sister-group of a clade formed by the other species of genets. Thus, the genus Genetta is regarded as paraphyletic. Prionodon appears to be a derived taxon. The Poiana – Prionodon clade is well supported, especially by ultrastructural hair characters. The cladogram topology in the intrageneric analysis indicates an ecological transition from the rain forest genets to the savanna genets. This supports a rain forest origin of the genus Genetta , a conclusion which may be generalized to the entire study group. © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society , 2002, 134 , 317–334.     

Comparative phylogeography of two African carnivorans presumably introduced into Europe: disentangling natural versus human‐mediated dispersal across the Strait of Gibraltar

Aim Natural processes of colonization and human‐mediated introductions have shaped current patterns of biodiversity in the Mediterranean Basin. We use a comparative phylogeographic approach to investigate the genetic structure of Herpestes ichneumon and Genetta genetta (Carnivora) across the Strait of Gibraltar, and test for their supposedly contemporaneous introduction into Iberia. Location Mediterranean Basin and Africa. Methods We sequenced two mitochondrial fragments (cytochrome b and control region) of 91 (H. ichneumon) and 185 (G. genetta) individuals, including the sole archaeological record of G. genetta in Iberia, dating from the Muslim occupation. We used phylogenetic and tokogenetic methods, summary statistics, neutrality tests, geographic–genetic pairwise comparisons and coalescent estimates to explore the history of the two species in the Mediterranean Basin. Results In North Africa, an autochthonous (Clade I) and a western African mtDNA clade, coalescing in the Middle to Late Pleistocene, co‐occurred in both species. Only Clade I was present in Europe. In H. ichneumon, the European pool showed deep coalescence (median = 335 kyr) and high genetic differentiation and diversity compared with its North African counterpart, suggesting long‐term stability of female effective population size. In sharp contrast, G. genetta in Europe exhibited lower genetic diversity, weak differentiation with North Africa and recent demographic expansion; however, Andalusia and Catalonia (Spain) showed distinctly higher genetic diversity, and the archaeological specimen had the predominant European haplotype. Main conclusions The co‐occurrence of autochthonous and sub‐Saharan lineages in North Africa (1) supports a new, emerging biogeographic scenario in North Africa, and (2) suggests a connection through the Sahara, possibly from the Middle Pleistocene onwards. Our results refute the idea that H. ichneumon was introduced into Europe contemporaneously with G. genetta. Instead, they support a scenario of sweepstake dispersal during Late Pleistocene sea‐level fluctuations, followed by long‐term in situ evolution throughout the last glaciation cycles. Genetta genetta appears to have undergone a recent spread from at least two independent introduction ‘hotspots’ in Catalonia and Andalusia, possibly following antique trade routes and/or Muslim invasions. Despite their contrasting histories, the European gene pools of both species represent unusual cases leading to the preservation of autochthonous, North African lineages.     

Correcting observer effect bias in estimates of nesting success of a coastal bird,the White-fronted Plover Charadrius marginatus

Capsule A recently developed observer-effects model gives better estimates than the survival model.

Aims To compare the performance of the traditional survival model with that of an observer-effects model in estimating nesting success.

Methods We used survival data from 654 nests in a covariate-dependent extension of a maximum-likelihood estimator model to simultaneously estimate daily survival rate and observer effect on nesting success in four different sectors of a study site. Standard likelihood-ratio tests and Akaike's information criterion differences were used to compare model performances.

Results A significant (negative) observer effect was detected in one of four sectors of the study area, and was probably attributable to small mammal predators. Despite significantly higher predation risk during the laying period, there was a significant positive observer effect during the laying period, contrasting with a weak negative effect during the incubation period, suggesting that an observer's tracks around unattended nests reduced predation risk. Likelihood-ratio tests indicated a significantly better fit using the observer effects model versus the Mayfield survival model in four of six scenarios.

Conclusion The observer-effects model accounts for bias in estimates of nest survival rates, and is preferred over the survival model because the inclusion of observer effect as a variable does not over-parameterize the model.     

Niche dynamics in the European ranges of two African carnivores reflect their dispersal and demographic histories

According to recent phylogeographical evidence, the common genet (Genetta genetta) and the Egyptian mongoose (Herpestes ichneumon) have dissimilar dispersal histories from Maghreb to south‐western Europe. Through comparative ecological niche modelling based on >1100 occurrences, we assessed whether the niche dynamics (i.e. niche shift versus conservatism) of the two species in their European ranges reflected DNA‐based demographic scenarios. Sensitivity analyses and projections of climatic niche models from the species' native ranges (Africa and Middle East) to Europe yielded support for (1) partial climatic niche shift in the northern European range of the common genet and (2) climatic niche conservatism in the Egyptian mongoose. Our results were consistent with demographic scenarios that predicted multiple introductions and demographic expansion in the common genet and long‐term, stable historical demography in the Egyptian mongoose. Our models further predicted a range expansion of the common genet in north‐western France and Italy, and progression of the Egyptian mongoose into Europe from the Near East. Overall, our study suggested a scenario of different niche dynamics in Europe for these two species of African carnivores, supporting the view that historical factors such as dispersal and demographic history may shape niche dynamics and thus distribution potential in colonized ranges. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 737–751.     

Development and characterization of 11 microsatellite loci in a historically introduced carnivoran, the common genet (Genetta genetta)

Microsatellite markers were developed to assess population structure and patterns of translocation in the introduced European common genet (Genetta genetta). Primer pairs were designed for 60 microsatellite sequences enriched for CA, GA, CATC and TAGA repeat motifs. Eleven loci that proved to be polymorphic were genotyped in 33 individuals from southwestern France. The number of alleles per locus and observed heterozygosities varied from three to seven and from 0.2121 to 0.7576, respectively. One locus (B103) showed significant departure from Hardy-Weinberg equilibrium, probably due to the presence of null alleles. Tests of linkage disequilibrium did not detect significant associations among loci.     

A reassessment of the distribution of the rare Genetta johnstoni (Viverridae, Carnivora) with some newly discovered specimens

The rare Johnston’s Genet (Genetta johnstoni) is one of the least known small carnivores inhabiting the West African rain forest. Some newly discovered specimens collected from the field (Guinea and Ivory Coast) and several rediscovered specimens resulting from reinvestigating collections, have permitted us to reconsider the distribution of the species. Coupled with a bibliographic review and a census of specimens kept in public collections, a reassessed distribution map is proposed, extending the previous estimated range 400 km to the West (Kolenté Plates, Guinea) and more than 600 km to the East (Tarkwa, Ghana). The majority of collected specimens have come from the inland forests of northern Liberia and south‐eastern Guinea, while the surroundings of Mt. Nimba also support numbers of this species. We suggest that the supposed restriction of G. johnstoni to rain forest be re‐evaluated because a specimen was collected in a region of moist woodlands and savannah (Kolenté Plateau). With regard to these new distributional data, conservation implications for the whole Upper Guinean block population are discussed.     

Nestbox provisioning in a rural population of Eurasian Kestrels: breeding performance,nest predation and parasitism

The breeding biology of the Eurasian Kestrel Falco tinnunculusin nestboxes in farmland was studied to test for differences between artificial and natural sites. We report on the direct effect of nestbox provisioning on some life-history traits and how nestbox use affects nest predation and parasitism. Five types of nest-sites were available: nestboxes on poles and trees (artificial sites), stick nests on trees, stick nests on pylons and holes in buildings (‘natural’ sites). The Kestrel population increased from 23 pairs in 1993 (prior to nestbox installation) to 55 in 1998 as nestboxes were provided. In general, pairs breeding in trees started to lay later than those nesting in nestboxes on poles or in building holes, but this difference was probably associated with habitat quality rather than nest type. Differences in clutch size were found between nest-sites in some years, and were associated with laying date and, probably, with variation in territory quality. Using only data from successful nests, pairs breeding in nestboxes produce more fledglings than those in building holes or pylons. The frequency of nest predation was higher in natural sites than in nestboxes. The number of fledglings from pairs breeding in nestboxes was higher than from those breeding in old stick nests in trees when all nests were considered. Nestbox provisioning had no effect on the occurrence of the ectoparasite Carnus hemapterus, but chicks from nestboxes showed higher intensity of infection. Our results suggest that nestbox provisioning increases reproductive success and the frequency of nest predation or intensity of parasite infestation in Kestrels.     

Fine‐scale coexistence between Mediterranean mesocarnivores is mediated by spatial,temporal, and trophic resource partitioning

1. The partition of the ecological niche can enhance the coexistence of predators due to differences in how they exploit three main resources: food, space, and time, the latter being an axis that often remains unexplored.
2. We studied niche segregation in a Mediterranean mesocarnivore community composed by Vulpes vulpes, Genetta genetta, Meles meles, and Herpestes ichneumon, addressing simultaneously different niche axes: the temporal, trophic, and spatial axes.
3. We assessed temporal segregation between mesopredators and prey and between potential competitors, using camera trap data between 2018 and 2020 in a Mediterranean landscape in Southern Spain. We deployed camera traps in 35 stations in three sites with varying vegetation cover within Doñana National Park. We further examined the spatial overlap in activity centers and trophic preferences between potential competitors using diet information from studies performed in the study area.
4. We found an overall temporal segregation between trophic generalist species, with species showing higher temporal overlap differing in their trophic preferences and/or showing limited spatial overlap. Furthermore, we observed an overall high overlap between the activity patterns of predators and their major prey in the area (the common genet vs. small mammals and the red fox vs. European rabbit).
5. Our study suggests that coexistence of the different species that compose the mesocarnivore assemblage in Mediterranean landscapes can be facilitated by subtle differences along the three main niche axes, with temporal segregation being a most pronounced mechanism. Our findings reinforce the idea that the coexistence mechanisms underlying community structure are multidimensional.

     

Genets (Carnivora, Viverridae) in Africa: an evolutionary synthesis based on cytochrome b sequences and morphological characters

The taxonomy of the genets (genus Genetta) has long been discussed, thus hampering endeavours towards evolutionary reconstruction. Sequence data from the complete cytochrome b gene (cyt b) were generated for 50 specimens representing 15 morphological species in order to allow the production of the first exhaustive molecular phylogeny of the genets. Second, a revised morphological matrix comprising 50 characters was combined with the cyt b data to estimate the level of morphological homoplasy. Phylogenetic analyses were conducted using parsimony, maximum likelihood and Bayesian procedures. Our results based on cyt b contradict a part of the traditional taxonomy of genus Genetta, the servaline and small‐spotted genets being paraphyletic, but confirmed the species status recently re‐investigated for three genets belonging to the large‐spotted complex, including the newly described G. bourloni. The combined analysis yielded similar results although morphological characters were clearly homoplasic. Partitioned Bremer supports indicated conflicting signals between the two data sets throughout the tree, and species‐diagnostic characters, useful for delimiting species boundaries, were significantly correlated to habitat. However, morphological data supported the monophyly of clades (G. victoriae, other genets) (G. servalina, G. cristata), large‐spotted genet complex and forest forms. Our results suggest a complex evolutionary history of the genets in Africa, with a Poiana‐like ancestor inhabiting rain forest, and then a diversification involving two independent invasions of open habitats and one reversion to rain forest. Divergence estimates based on cyt b revealed that splitting events within genets partly follow a climatic speciation model during the cyclical periods of the Quaternary, although ‘primitive’ rain forest lineages diverged earlier, during the Late Miocene and Early Pliocene. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81 , 589–610.