Martin G Frixione | Centro Nacional Patagónico CONICET (original) (raw)

Papers by Martin G Frixione

Ornitologia Neotropical, Oct 7, 2016

Science of The Total Environment

Journal of Raptor Research

Overwintering areas can act as reservoirs for haemosporidians, and their blood-sucking vectors ma... more Overwintering areas can act as reservoirs for haemosporidians, and their blood-sucking vectors may easily survive and flourish in warm climates. The American Kestrel (Falco sparverius) is a small-sized raptor that includes both resident and migratory individuals that overwinter in agriculture areas of the Baja California peninsula, Mexico. We measured and collected blood samples from 54 individual kestrels captured in a fragmented habitat located within a matrix of agricultural and native scrub in the southern part of the peninsula during the autumn and winter of 2018–2019 and 2019–2020. We identified and quantified haemosporidians in blood smears of each individual. We used decision tree classification models of prevalence and intensities of haemosporidians to assess the importance of season, host body size, and environmental characteristics of the capture site (proximity to the nearest infected host, number of ponds used for irrigation, Normalized Difference Vegetation Index [NDVI...

Ornitología Neotropical

∙ Most populations of large flightless birds have declined since the last century. In arid ecosy... more ∙ Most populations of large flightless birds have declined since the last century. In arid ecosystems, overgrazing and climate change are particularly detrimental to soil health. In arid Patagonia these processes may lead to a reduction in primary productivity, potentially affecting the populations of herbivorous flightless birds, such as rheas (family Rheidae). We surveyed Lesser Rhea (Rhea pennata pennata) abundance during the breeding and post‐breeding seasons of 2012/2013 and 2013/2014 in Península Valdés Protected Area, Province of Chubut, Patagonia, Argentina. Linear transect surveys were conducted in September and December (breeding) and in late summer (post‐breeding). Density estimates were corrected by detectability in each kind of habitat. Density was substantially lower for the 2012/2013 season than 2013/2014, probably due to the combination of severe drought and ash‐deposition from the eruption of the Puyehue‐Caulle volcano in 2011. Lesser Rhea adult group size increase...

El Hornero, 2010

We describe the distribution and breeding abundance of the Imperial Shag (Phalacrocorax atriceps)... more We describe the distribution and breeding abundance of the Imperial Shag (Phalacrocorax atriceps) in the northern portion of the Nahuel Huapi Lake (northwestern Patagonia, Argentina) during the 2006-2007 and 2007-2008 reproductive seasons. We recorded low population numbers and null breeding success in both seasons. Attacks from several scavenging birds were recorded, and breeding activities were interrupted abruptly. Future studies should consider the potential threats from scavenging birds, subsidized by urban garbage dumps, over this freshwater shag.

Food Webs, 2020

The golden cownose ray (Rhinoptera steindachneri) and the whale shark (Rhincodon typus) are two e... more The golden cownose ray (Rhinoptera steindachneri) and the whale shark (Rhincodon typus) are two elasmobranch species commonly found in Bahía de La Paz, Baja California Sur, Mexico. There are no records of the species sharing the same sites, as their prey, ecology and migration sites normally deviate. Both are listed as endangered and vulnerable species, respectively, under Mexican and international regulations. We took images by a quad-copter near Mogote Beach and recorded whale sharks during late July, alongside a group of golden cownose rays, although earlier research suggests that the main whale shark feeding season starts in late August or September. These recordings showed for the first time, the co-occurrence of these two vulnerable elasmobranch species while feeding possibly simultaneously. This indicates that there might be a relation between the presence of the two species and the interannual variability in zooplankton abundance. The latter may have implications for possible resource overlapping, a current topic in elasmobranch research. Furthermore, these findings highlight the usefulness of drones when capturing biological data. This information is important in the understanding of the ecology and trophic interactions of threatened species and is a step forward towards their understanding and conservation.

Journal of Natural History, 2020

ABSTRACT We analysed the diet of the Burrowing Owl (Athene cunicularia) and the American Kestrel ... more ABSTRACT We analysed the diet of the Burrowing Owl (Athene cunicularia) and the American Kestrel (Falco sparverius) in a fragmented habitat and natural surroundings in the arid ecosystem of the Baja California peninsula, Mexico. Both small-sized raptors are considered in the same trophic guild, and as keystone species, interactions between them could be of interest for wildlife management in fragmented landscapes for agricultural activities. The diet analysis of these top predators could be a good monitor of prey abundance, some of which may be considered detrimental for agricultural activities. Prey frequencies in owl pellets were higher for arthropods (53.1%) and rodents (32.4%), but rodents were the most abundant item in terms of biomass (34.5%). Arthropods also showed higher relative frequencies in kestrel pellets (36.4%), but reptiles were the second in order of importance (28.4%) and contributed the most (64.7%) to the total prey biomass. The biomass contribution (66.1%) of vertebrates in the diet of the Burrowing Owl was lower than for the American Kestrel (95.6%) in a fragmented habitat area. Most prey types were present in the diet of both raptors, but we found significant differences in the biomass contributions of each category. Reptiles and rodents were the prey items that contributed most to the differences in the raptors’ diets, in terms of biomass (33% and 20.3%, respectively). Close nesting surroundings (0.5 km and 1 km radius) evidenced a higher proportion of natural vegetation in the kestrel’s (50.6% and 38.9%, respectively) than in owl’s potential home range (25.8% and 16.4%). The differences in diet suggest some degree of niche partitioning of these species likely due to the more flexible owl’s nesting habitat requirements and to the extended nocturnal activity of the species. These results reflect the capability of being complementary species, both exploiting some pests that are harmful for agriculture, and evidencing the importance of both species as regulators of agro-ecosystems in the peninsula of Baja California.

Environmental Science and Pollution Research, 2020

Raptors as top predators have been used as effective sentinels of environmental stressors in agri... more Raptors as top predators have been used as effective sentinels of environmental stressors in agricultural areas worldwide. Pollutants in agricultural areas have negative effects on top predator populations. Biomarkers such as erythrocyte nuclear abnormalities have been used as an effective measure of genotoxicity caused by exposure—particularly short-term exposure—to pollutants. We took blood samples from 54 wild specimens of American kestrel (Falco sparverius) captured in an agricultural area in Valle de Santo Domingo, Baja California Sur, Mexico in the autumns of 2018 and 2019 (n = 25) and the winters of 2019 and 2020 (n = 29). We prepared and examined blood smears to look for erythrocyte abnormalities as a means to evaluate genotoxicity. The number of abnormality types and the total frequency of abnormalities (MNs and NAs: notched, symmetrically or asymmetrically constricted, displaced, or indented nuclei) per 10,000 erythrocytes were calculated for all the specimens. We found a high frequency of abnormalities in numerous individuals, similar to those found in raptors from highly polluted areas. The best-fit generalized linear model for the number of abnormality types included season-of-the-year as the main significant predictor; the model for the total frequency of abnormalities included season and wing chord, an indicator of body size and health condition, as significant predictors. MNs frequencies were significantly related to season; NAs frequencies were related to season, wing chord length, and coverage of native vegetation around the area where the birds were captured. Abnormalities observed in the autumn closely coincide with the time when agrochemicals are applied in the area, mainly after the rains and during hot spells in late summer and early autumn. Small-sized kestrels showed higher frequencies of NAs, with an additional impact if native vegetation had been cleared for agriculture; this suggests both that resident birds are more exposed, and the observed genotoxicity has a local origin. These results, together with the ecological and physiological characteristics of the American kestrel suggest that this charismatic and widely distributed species might constitute a suitable biomonitor of genotoxicity in rural landscapes.

Journal of Helminthology, 2017

Procyrnea choique n. sp. is described from the lesser rhea, Rhea pennata d´Orbigny (Aves: Rheidae... more Procyrnea choique n. sp. is described from the lesser rhea, Rhea pennata d´Orbigny (Aves: Rheidae), from the Protected Natural Area Península Valdés, Chubut province, Argentina. The new species resembles P. ficheuri, P. murrayi, P. excisiformis, P. dollfusi, P. haliasturi, P. anterovulvata, P. graculae, P. brevicaudata, P. uncinipenis, P. javaensis, P. ameerae, P. ornata, P. aegotheles, P. spiralis, P. ruschii and P. aptera, mainly in the absence of lateral alae; but differs from its congeners by having a left spicule without barbs, the position of the vulva which is post-equatorial, the absence of lateral ridges, absent median precloacal papilla, asymmetrical caudal alae, males more than 6 mm long, left spicule 1 mm long and spicule ratio 1:3. Our results extend the taxonomy of Procyrnea Chabaud, 1958 and comprise the first report of a habronematid from R. pennata. A key to species of Procyrnea is presented.

Neotropical Ornithology, 2016

Drones

The use of drones has expanded the boundaries of several activities, which is expected to be util... more The use of drones has expanded the boundaries of several activities, which is expected to be utilized intensively in the near future. Interactions between urbanity and naturalness have been increasing while urban expansion amplifies the proximity between urban and natural areas. In this scenario, the interactions between drones and fauna could be augmented. Therefore, the aim of this study was to depict and evaluate the responses of the opportunistic and territorial seagull Larus livens to a small-sized drone during the non-breeding stage in urban areas and natural surroundings. The results evidenced that gulls do not react to drone sounds, coloration, or distance between them and the drone take-off spot. Clearly, the take-off vertical movement triggers an agonistic behavior that is more frequent in groups conformed by two adults, evidencing some kind of territorial response against the device, expressed as characteristic mobbing behavior. Thus, adult settled gulls in touristic and ...

Revista Argentina de Parasitología, Feb 19, 2014

ABSTRACT Feces of wild Lesser Rhea (Rhea pennata) were collected during reproductive season 2012/... more ABSTRACT Feces of wild Lesser Rhea (Rhea pennata) were collected during reproductive season 2012/2013 in the protected area Peninsula Valdés (Patagonia, Argentina). Samples were examined by traditional coproparasitological methods for identification and quantification of eggs and cysts. The blood-feeder nematode Deletrocephalus dimidiatus (Strongyloidae) has been consistently identified by egg morphometry and is for the first time recorded in wild R. pennata. Also we found the nematode Heterakis dispar-like (Oxiuridae), the cestodesMonoecocestus rheiphilus and Moniezia sp.-like (Anoplocephalidae) recorded for the first time in Patagonia, and the already registered protozoans Eimeira sp. (Eimeriidae) and Balantidium coli sp. (Cilliophora).Deletrocephalus dimidiatus parasite load and frequencies suggest it is a very common parasite during reproductive period en NE Patagonia, with a 70,8% of frequency in the adult/sub adult samples and a 20,8% in chick samples. The critical breeding stages, incubation and early breeding, showed the highest EPG levels and frequencies in adult/sub adult feces for the nematode D. dimidiatus. The information obtained in this study has implications in animal health and conservation that can be applied in management of Rhea pennata populations.