Timescale Analyses of Fluctuations in Coexisting Populations of a Native and Invasive Tree Squirrel

1. Competition from invasive species is an increasing threat to biodiversity. In Southern California, the western gray squirrel (Sciurus griseus, WGS) is facing increasing competition from the fox squirrel (Sciurus niger, FS), an invasive congener. 2. We used spectral methods to analyze 140 consecutive monthly censuses of WGS and FS within a 11.3 ha section of the California Botanic Garden. Variation in the numbers for both species and their synchrony was distributed across long timescales (> 15 months). 3. After filtering out annual changes, concurrent mean monthly temperatures from nearby Ontario Airport (ONT) yielded a spectrum with a large semiannual peak and significant spectral power at long timescales (> 30 months). Squirrel-temperature cospectra showed significant negative covariation at long timescales (> 35 months) for WGS and smaller significant negative peaks at 6 months for both species. 4. Simulations from a Lotka-Volterra model of two competing species indicates that the risk of extinction for the weaker competitor increases quickly as environmental noise shifts from short to long timescales. 5. We analyzed the timescales of fluctuations in detrended mean annual temperatures for the time period 1915-2014 from 1218 locations across the continental USA. In the last two decades, significant shifts from short timescales to long timescales have occurred, changing from less than 3 years to 4-6 years. 6. Our results indicate that (i) population fluctuations in co-occurring native and invasive tree squirrels are synchronous, occur over long timescales, and may be driven by fluctuations in environmental conditions; (ii) long timescale population fluctuations increase the risk of extinction in competing species, especially for the inferior competitor; and (iii) the timescales of interannual environmental fluctuations may be increasing from recent historical values. These results have broad implications for the impact of climate change on the maintenance of biodiversity.

Timescale Analyses of Fluctuations in Coexisting Populations of a Native and Invasive Tree Squirrel

1. Competition from invasive species is an increasing threat to biodiversity. In Southern California, the western gray squirrel (Sciurus griseus, WGS) is facing increasing competition from the fox squirrel (Sciurus niger, FS), an invasive congener. 2. We used spectral methods to analyze 140 consecutive monthly censuses of WGS and FS within a 11.3 ha section of the California Botanic Garden. Variation in the numbers for both species and their synchrony was distributed across long timescales (> 15 months). 3. After filtering out annual changes, concurrent mean monthly temperatures from nearby Ontario Airport (ONT) yielded a spectrum with a large semiannual peak and significant spectral power at long timescales (> 30 months). Squirrel-temperature cospectra showed significant negative covariation at long timescales (> 35 months) for WGS and smaller significant negative peaks at 6 months for both species. 4. Simulations from a Lotka-Volterra model of two competing species indicates that the risk of extinction for the weaker competitor increases quickly as environmental noise shifts from short to long timescales. 5. We analyzed the timescales of fluctuations in detrended mean annual temperatures for the time period 1915-2014 from 1218 locations across the continental USA. In the last two decades, significant shifts from short timescales to long timescales have occurred, changing from less than 3 years to 4-6 years. 6. Our results indicate that (i) population fluctuations in co-occurring native and invasive tree squirrels are synchronous, occur over long timescales, and may be driven by fluctuations in environmental conditions; (ii) long timescale population fluctuations increase the risk of extinction in competing species, especially for the inferior competitor; and (iii) the timescales of interannual environmental fluctuations may be increasing from recent historical values. These results have broad implications for the impact of climate change on the maintenance of biodiversity.

Analysis of a Brazilian Indigenous corpus using machine learning methods

In Brazil, several minority languages suffer a serious risk of extinction. The appropriate documentation of such languages is a fundamental step to avoid that. However, for some of those languages, only a small amount of text corpora is digitally accessible. Meanwhile there are many issues related to the identification of indigenous languages, which may help to identify key similarities among them, as well as to connect related languages and dialects. Therefore, this paper proposes to study and automatically classify 26 neglected Brazilian native languages, considering a small amount of training data, under a supervised and unsupervised setting. Our findings indicate that the use of machine learning models to the analysis of Brazilian Indigenous corpora is very promising, and we hope this work encourage more research on this topic in the next years.

EVALUATING CONSERVATION STATUS, THREATS AND POPULATION TRENDS OF LEUCADENDRON, A PLANT GENUS ENDEMIC TO THE CAPE REGION IN SOUTH AFRICA

Declines in endemic species have significant impact on global biodiversity loss. More efforts need to be harnessed to further protect endemic species from the current global extinction crisis. This study evaluated the current conservation status, factors responsible for risk of extinction and the trends in populations of Leucadendron, a plant genus endemic to the Cape region in South Africa. The SANBI (South African National Biodiversity Institute) Red List was employed in this study. The results revealed that over 50% of taxa in this genus are threatened and most of the species are exposed to habitat destruction and the presence of invasive species. It was also discovered that two species of this genus are currently extinct, which implies this genus is facing a high risk of extinction. More efforts, such as designing effective methods of controlling forces responsible for the risk of extinction of taxa in this genus, should be put in place to prevent their complete extirpation in future.

New data on the status and ecology of a galliform at risk of extinction: the Pyrenean grey partridge (Perdix perdix hispaniensis) in the Iberian System (Soria, Spain)

A study was conducted in 2008–2010 to gain knowledge on the status and ecology of the endangered subspecies of grey partridge (Perdix perdix hispaniensis), at its southernmost range edge. From an historic breeding range of 28,300 ha, 15 different coveys (adults with juveniles) were observed in an area comprising 5,550 ha, with an estimated minimum autumn population size of 103–113 birds and a maximum of 163–181 birds. Spring pair density was estimated at 2.3 pairs/1,000 ha, and when considering only coveys, 6.8 partridges/1,000 ha. The majority of birds were located at an altitude above 1,690 m a.s.l., mainly in mountain shrubland (especially Calluna vulgaris and Erica spp.). Habitat loss was the most important threat for the species’ conservation. In conclusion, efforts should prioritize urgent habitat recovery and monitoring in order to change the fate of the species.

New data on the status and ecology of a galliform at risk of extinction: the Pyrenean grey partridge (Perdix perdix hispaniensis) in the Iberian System (Soria, Spain)

A study was conducted in 2008–2010 to gain knowledge on the status and ecology of the endangered subspecies of grey partridge (Perdix perdix hispaniensis), at its southernmost range edge. From an historic breeding range of 28,300 ha, 15 different coveys (adults with juveniles) were observed in an area comprising 5,550 ha, with an estimated minimum autumn population size of 103–113 birds and a maximum of 163–181 birds. Spring pair density was estimated at 2.3 pairs/1,000 ha, and when considering only coveys, 6.8 partridges/1,000 ha. The majority of birds were located at an altitude above 1,690 m a.s.l., mainly in mountain shrubland (especially Calluna vulgaris and Erica spp.). Habitat loss was the most important threat for the species’ conservation. In conclusion, efforts should prioritize urgent habitat recovery and monitoring in order to change the fate of the species.

Wild birds as reservoirs of multidrug-resistant enterobacteria in Mulungu, Brazil

Caatinga is a biome unique to Brazil that is degraded by anthropogenic actions, which lead to the loss of biodiversity putting many species at risk of extinction. The Ceará State is located in the Caatinga and has a rich avifauna comprised of 433 species including 13 species that are threatened with extinction, which are found in the Baturité Massif. The aim of this study was to investigate the frequency and diversity of enterobacteria in wild birds and to determine their susceptibility to antimicrobials. Cloacal swab samples were collected from 50 individuals of 28 different species, including the Ceara Gnatheter ( Conopophaga cearae ) and Red-necked Tanager ( Tangara cyanocephala cearensis ), which are classified as vulnerable (VU) by the Brazilian Ministry of the Environment. A total of 55 isolates belonging to 14 different species of Enterobacteriaceae were identified. Among these, Pantoea agglomerans and Escherichia coli were the most prevalent species with isolation rates of 36% and 26%, respectively. The highest rate of antimicrobial resistance found was to ampicillin (41.8%), followed by nalidixic Acid (36.3%) and amoxicillin associated with clavulanic acid (32.7%). The drugs with the best efficacy were tobramycin (96.4%), ciprofloxacin (92.6%) and tetracycline (90.9%). Multidrug resistance was observed in 23.5% of the analyzed strains. This research provides important information about the composition of the cloacal microbiota of wild birds in Mulungu, Brazil, as well as their health status. In addition, these results demonstrate that they harbor multidrug-resistant strains of Enterobacteriaceae.

Present and Future Climate-Related Distribution of Narrow- versus Wide-Ranged Ostrya Species in China

The niche breadth–range size hypothesis states that geographic range size of a species is positively correlated with its environmental niche breadth. We test this hypothesis and examine whether the correlation varies with climate change and among taxa through modeling (processing Maximum entropy (Maxent)) potential distributions in present and future climate scenario of four sympatric Ostrya species in China and with different geographic range sizes, including extremely rare O. rehderiana. Potential geographical distributions of narrow- versus wide-ranged Ostrya species were predicted based on their niche breadths. Niche equivalency and similarity tests were performed to examine niche overlap between species pairs. Potential distribution areas of wide niche breadth species (O. japonica and O. trichocarpa) were significantly wider than those of narrow niche breadth species (O. multinervis and O. rehderiana) although niche divergence was hardly observed among them. In the future scenarios of global climate change, wide-ranged O. japonica would have wider potential distribution than in the current scenario, even expanding their geographic range. Conversely, suitable habitats of narrow-ranged O. multinervis and O. rehderiana would be reduced strikingly in future scenarios compared to in the current scenario, and they might be subjected to a high risk of extinction. Potential distribution range sizes of the Ostrya species would positively correlate with their niche breadths in future scenarios, and their niche breadths would determine their distribution variation with climate change. The Ostrya species having broader niche currently would be further widespread in future scenarios while narrowly distributed Ostrya species having narrower niche currently would further reduce their distribution range under changed climate and might be subjected to a high risk of extinction in future scenarios. Our results support the range size–niche breadth hypothesis both at present and future climate scenarios, and they provide useful reference for conservation of rare species like O. rehderiana.

Genetic Diversity of 17 Autochthonous Italian Chicken Breeds and Their Extinction Risk Status

The preservation of genetic variability of autochthonous poultry breeds is crucial in global biodiversity. A recent report revealed small breed size and potential risk of extinction of all native Italian poultry breeds; therefore, a correct assessment of their genetic diversity is necessary for a suitable management of their preservation. In this work, we provided an overview of the contribution to poultry biodiversity of some Italian autochthonous breeds reared in conservation centers devoted to local biodiversity preservation. The level of genetic diversity, molecular kinship, inbreeding, contribution to overall genetic diversity, and rate of extinction of each breed were analyzed with a set of 14 microsatellite loci in 17 autochthonous chicken breeds. To evaluate genetic variability, total number (Na), and effective number (Ne) of alleles, observed (Ho) and expected (He) heterozygosity, and F (Wright’s inbreeding coefficient) index were surveyed. The contribution of each analyzed breed to genetic diversity of the whole dataset was assessed using MolKin3.0; global genetic diversity and allelic richness contributions were evaluated. All the investigated loci were polymorphic; 209 alleles were identified (94 of which private alleles). The average number of alleles per locus was 3.62, and the effective number of alleles was 2.27. The Ne resulted lower in all breeds due to the presence of low-frequency alleles that can be easily lost by genetic drift, thus reducing the genetic variability of the breeds, and increasing their risk of extinction. The global molecular kinship was 27%, the average breed molecular kinship was 53%, and the mean inbreeding rate 43%, with a self-coancestry of 78%. Wright’s statistical analysis showed a 41% excess of homozygous due to breed genetic differences (34%) and to inbreeding within the breed (9%). Genetic variability analysis showed that 11 breeds were in endangered status. The contribution to Italian poultry genetic diversity, estimated as global genetic diversity, and ranged from 30.2 to 98.5%. In conclusion, the investigated breeds maintain a unique genetic pattern and play an important role in global Italian poultry biodiversity, providing a remarkable contribution to genetic variability.