Assessing occupancy and habitat connectivity for Baird’s tapir to establish conservation priorities in the Sierra Madre de Chiapas,Mexico

Baird’s tapir (Tapirus bairdii) is the largest native mammal that inhabits the Neotropics, and it is enlisted as Endangered by the IUCN Red List. The historic distribution of this species included the area from southern Mexico to northern Colombia. However, its distribution and populations have been reduced drastically during the past 30 years. The main threats for Baird’s tapir are the direct persecution for subsistence hunting, habitat destruction, and habitat fragmentation. In this study, we used camera traps and occupancy models to identify the landscape characteristics that were associated with the occurrence of tapirs in the Sierra Madre de Chiapas, which is one of the most important populations of the species in Mexico, with the aim to identify areas with habitat suitability for the species. We used our best occupancy model to generate a resistance matrix to develop a model of habitat connectivity using Circuit Theory. According to the best occupancy model, the most suitable areas for this species were the forested areas located at the highest elevations of the mountain ranges that provided rugged terrain. We identified three critical corridors to allow for the connectivity of tapir populations in the Sierra Madre de Chiapas, and one of these corridors provides connectivity between this population and the population in the Ocote Biosphere Reserve. With this approach, we propose a conservation strategy for the species that incorporates a more realistic and detailed scheme of Baird’s tapir occurrence in the Sierra Madre de Chiapas region. Priority actions to conserve tapirs in the Sierra Madre de Chiapas over the long term include ensuring the complete protection of prime habitat for the species, improved connectivity by protecting forest cover, implementation mitigation measures in areas where paved roads interrupt connectivity of populations, and eradicating poaching of the species in the region completely.     

Tree species identity and forest composition affect the number of oak processionary moth captured in pheromone traps and the intensity of larval defoliation

1. Pure forests are often seen as being more prone to damage by specialist pest insects than mixed forests, and particularly mixed forests associating host and nonhost species. We addressed the effect of tree diversity on oak colonization and defoliation by a major specialist pest, the oak processionary moth (OPM)
2. We quantified the number of male OPM moths captured and larval defoliation in pure stands of two oak host species (Quercus robur and Quercus petraea) and in mixed stands associating the two oak species or each oak species with another nonhost broadleaved species. We conducted two complementary studies to test the effect of host species and stand composition: (i) we used pheromone trapping to compare the number of males OPM captured throughout the distribution of oak hosts in France and (ii) we noted the presence of OPM nests and estimated defoliation in mature forests of north‐eastern France.
3. Oak species and stand composition significantly influenced the number of male OPM captured and defoliation by OPM larvae. Quercus petraea was consistently more attractive to and more defoliated by OPM than Q. robur. Both oak trees were attacked more in pure stands than in mixed stands, in particular mixed stands associating oaks with another (nonhost) broadleaved species.
4. The results of the present study support the view that mixed forests are more resistant to specialist pest insects than pure stands, and also indicate that this trend depends on forest composition. Our study provides new insights into OPM ecology and has potential implications for forest management, including the management of urban forests where OPM causes serious human health issues.

     

Culicoides biting midges and mosquito fauna at three dog and cat shelters in rural and periurban areas in Northern Spain

The diversity and abundance of Culicoides (Diptera: Ceratopogonidae) and mosquitoes (Diptera: Culicidae) were studied in three animal protection centres (APCs) in Northern Spain between 1 July and 31 October 2018. Four miniature suction CDC light traps (two UV and two standard incandescent bulb traps, both types baited and non‐baited with CO₂) were placed in each APC to compare their efficiency in the collection of these Diptera groups. A total of 1176 biting midges (14 species), 224 mosquitoes (8 species) and 1 black fly were collected and identified by both morphological and molecular approaches. The Culicoides obsoletus complex (C. obsoletus/C. scoticus) accounted for 58.2% of the total collection within the Ceratopogonidae family, whereas Culex pipiens/Cx. torrentium comprised 76.8% of the Culicidae. The input of CO₂ in light traps proved largely ineffective in improving the collections of both Diptera groups. UV‐light traps were 7.8 and 2.2 times more effective than incandescent light traps in trapping Culicoides and mosquitoes, respectively. Seasonal dynamics differed between both Diptera taxa but captures of both taxa were significantly larger at the beginning of the summer. The epidemiological relevance of the most prevalent species is also discussed.     

Comparative field studies of various traps and attractants of the olive fruit fly,Bactrocera oleae

In the framework of an ongoing testing and refining process of a mass trapping method, using a combination of semiochemicals, for the control of the olive fruit fly,Bactrocera (Dacus) oleae, four trap designs, three trap colors, six different food attractants, and two pheromone formulations were compared under field conditions. No differences were observed between the trap designs and the food attractants tested. Trap color had a significant effect in preference tests only. Traps combining food attractants and pheromones attracted higher numbers of both male and female flies but the differences became statistically significant only in cases of low trap densities. Pheromones enclosed in cyclodextrenes were not as attractive as standard pheromone formulations. The findings of these tests allow a choice among trap types and semiochemicals for cost reduction and convenience, but not for enhancement of the efficacy of the method.     

Tick-tock… says the moon and the sun: Daily activity patterns of mid-large-sized mammals in grassland-dominated landscapes afforested with Eucalyptus

Species can change their activity patterns in response to biotic and abiotic factors, such as sunlight and moonlight. The influence of these variables is a key question for ecological research and biodiversity conservation. The conversion of natural grasslands into tree plantations has reached high levels in temperate South America. These novel ecosystems elicit behavioural changes that can be detrimental or beneficial to wildlife. In this research, we describe the activity patterns of mammals (mid and large-sized) during sun and lunar phases using camera trap data (2015–2021; 22 926 camera/nights) to assess the effects of the season (warm and cold), habitat type (native forests, grasslands, Eucalyptus plantations) and landscape afforestation degree (10%–90%) in eight landscape samples (5 km radius) at Uruguayan grasslands. This represents the first study of temporal patterns in grassland afforestation worldwide, and concerning solar time and lunar patterns in Uruguay. Across 257 camera trap stations, 5297 independent detections of 13 species were recorded. While there were no significant differences among seasons nor through a landscape gradient of afforestation cover, the local habitat type affected most species temporal niches, finding significant differences between native ecosystems and Eucalyptus plantations, despite their close spatial proximity. Cathemeral and nocturnal activity patterns were seen for 12 species, and nine showed lunarphobic or lunarphilic trends according to habitat cover. In tree plantations, five of seven species narrowed their temporal activity compared to native habitats, and four changed their nocturnal activity. These alterations showed that several species adjust their daily activity patterns according to sun and moon phases under Eucalyptus plantations, probably reacting to changes in predation risk, hunting pressure, or foraging opportunities. Given that afforestation is projected to grow in southern South America, we must improve our understanding of how species adjust their activities in such novel ecosystems to identify measures needed to increase their conservation opportunities.     

A quantitative study of tissue dynamics in Venus's flytrap Dionaea muscipula (Droseraceae). II. Trap reopening

Changes in normalized cell length (NCL) and tissue volume densities (V_v) of five trap tissues were studied during reopening of fully closed traps of Venus's flytrap (Dionaea muscipula Ellis). Four trap-reopening stages were identified based on morphological changes observed in time-lapse video: (1) Sealed—the last stage of trap closure before the trap began to reopen; (2) Deappressed—characterized by a convex bulge in the upper region of the trap; (3) Release—in which the bulge region moved closer to the trap margins initiating lobe separation while the marginal tynes remained interdigitated; (4) Fully opened—the trap lobes assumed a morphology similar to that of a nonstimulated trap. Morphological changes associated with trap reopening occurred as a series of relatively fast (l-5h) and slow (10-15 h) movements and appeared to be a reversal of the morphologies observed during trap closure. However, comparison of changes in NCL of trap tissues during closure and reopening showed very little statistical correlation indicating that the tissue dynamics associated with trap closure were not simply reversed during reopening. Although the precise cell movements that provided driving force for trap morphological change were not delineated in this study, comparison of NCL data suggested that tissues in the trap lobe were alternately “active” and “quiescent” in temporally and regionally complex patterns. Changes in the NCL of analogous tissues on opposite sides of the mid-trap tissues within a trap region showed high positive correlation values, which indicated the possibility of coordinated activity in opposing tissues.     

Soil fertilization enhances growth of the carnivorous plant Genlisea violacea

In a 116-d greenhouse growth experiment on a terrestrial carnivorous plant Genlisea violacea (Lentibulariaceae), mild fertilization of a peaty soil led to a 2.4 fold increase in total plant biomass as compared to the controls. Tissue P and K content in fertilized plants was significantly higher than that in the controls.     

In search of better strategies of using activity traps to collect Dytiscidae and Noteridae (Coleoptera): a case study of a local fauna in central European Russia

Activity traps (ATs) are a widely used method of sampling water beetles (Coleoptera). This case study attempts to investigate the effect of mouth size and trapping effort on the performance of the ATs and reveal sex ratios and proportions of morphs in dimorphic females in populations of Dytiscidae and Noteridae in one particular area of Udomelsky District, Tver Oblast, Russia. ATs are more selective compared to hand netting but make it possible to collect a greater number of abundant species with relatively little expenditures of effort and time. The width of the trap mouth has no effect on efficiency. Long-time (48?h exposure) traps are not more efficient than short-time (24?h) ones, in terms of the relative intensity of collecting individuals and species. The applied number of ATs (up to 330 trap-days) was not sufficient to reveal the full diversity of diving beetles in the studied waterbodies.