Navigating discreetly: Spatial ecology of urban wild boar in Bordeaux City's landscape of fear, France

An exemplary urban adapter, the wild boar (Sus scrofa) has successfully colonized urban ecological niches worldwide. Improvement of strategies for optimal management of urban wild boar need to gather more empirical evidence of their spatial ecology. This study is based on GPS tracking and capture-mark-recapture (CMR) of 10 and 59 wild boar, respectively, captured in Bordeaux Metropolis (France). It shows that wild boar have become urban dwellers, with intra-urban home ranges varying from 1.3 to 64.6 km2 (MCP 100 %) and from 0.5 to 9.6 km2 (KDE 95 %), depending on urban conditions. CMR results confirm the low propensity to move away from urban areas (with a mean distance of 2 km between capture and recapture sites), despite a relatively low one-year survival rate since capture (47.5 %), primarily attributable to removal efforts. Wild boar strongly depended on urban woods, mostly during daytime resting, and highly frequented urban meadows during night foraging. Their use of urban agricultural areas was minimal, but they were mostly monitored following corn and grape harvests. Wild boar mitigated the risk associated with close proximity to humans by: a nocturnal activity (72.2 % of active locations registered from sunset to sunrise), which could also be partially attributed to their sensitivity to heat; a strong use of covered habitats, especially during daytime resting and when close to buildings and roads; and a low mobility during night-time foraging (1974 m average daily distance travelled). Moreover, we demonstrate high inter- and intra-individual variability in the spatio-temporal behaviour of urban wild boar. Finally, we discuss the gap between these results and the narratives surrounding the spatial ecology of urban wild boar. Our results not only confirm the species' ability to adapt to urban environments, but also highlight their behavioural flexibility, underscoring the relevance of significant changes in representations and management activities to mitigate human-urban wild boar conflicts.

A simulation-based evaluation of methods for estimating census population size of terrestrial game species from genetically-identified parent-offspring pairs

Estimates of wildlife population size are critical for conservation and management, but accurate estimates are difficult to obtain for many species. Several methods have recently been developed that estimate abundance using kinship relationships observed in genetic samples, particularly parent-offspring pairs. While these methods are similar to traditional Capture-Mark-Recapture, they do not need physical recapture, as individuals are considered recaptured if a sample contains one or more close relatives. This makes methods based on genetically-identified parent-offspring pairs particularly interesting for species for which releasing marked animals back into the population is not desirable or not possible (e.g., harvested fish or game species). However, while these methods have successfully been applied in commercially important fish species, in the absence of life-history data, they are making several assumptions unlikely to be met for harvested terrestrial species. They assume that a sample contains only one generation of parents and one generation of juveniles of the year, while more than two generations can coexist in the hunting bags of long-lived species, or that the sampling probability is the same for each individual, an assumption that is violated when fecundity and/or survival depend on sex or other individual traits. In order to assess the usefulness of kin-based methods to estimate population sizes of terrestrial game species, we simulated population pedigrees of two different species with contrasting demographic strategies (wild boar and red deer), applied four different methods and compared the accuracy and precision of their estimates. We also performed a sensitivity analysis, simulating population pedigrees with varying fecundity characteristics and various levels of harvesting to identify optimal conditions of applicability of each method. We showed that all these methods reached the required levels of accuracy and precision to be effective in wildlife management under simulated circumstances (i.e., for species within a given range of fecundity and for a given range of sampling intensity), while being robust to fecundity variation. Despite the potential usefulness of the methods for terrestrial game species, care is needed as several biases linked to hunting practices still need to be investigated (e.g., when hunting bags are biased toward a particular group of individuals).

Effect of Oral Supplementation of Healthy Pregnant Sows with Sucrosomial Ferric Pyrophosphate on Maternal Iron Status and Hepatic Iron Stores in Newborn Piglets

Simple Summary

In most mammals, including humans, the need for iron increases rapidly in the last period of pregnancy. Therefore, in compliance with World Health Organization (WHO) recommendations, iron supplementation has become a standard procedure even in healthy pregnant women although it carries the risk of iron toxicity and dysregulation of systemic iron homeostasis. Due to physiological and genomic similarities between swine and humans, pigs constitute an useful animal model in nutritional studies during pregnancy. Here, healthy pregnant sows were supplemented with sucrosomial ferric pyrophosphate (SFP), a new non-heme iron formulation, to study its effect on their iron metabolism and that of their progeny. In particular, we aimed at verifying whether supplementation of pregnant sows with SFP will increase the level of low hepatic iron stores in newborn piglets. Results of our study show that SFP does not significantly alter neither systemic iron homeostasis in pregnant sows, nor hepatic iron stores in newborn piglets, which can be used during neonatal period for the maintenance of hematological status. We hypothesize that supplemental iron given orally to pregnant sows is poorly transferred across the placenta.

Abstract

Background: The similarities between swine and humans in physiological and genomic patterns, as well as significant correlation in size and anatomy, make pigs an useful animal model in nutritional studies during pregnancy. In humans and pigs iron needs exponentially increase during the last trimester of pregnancy, mainly due to increased red blood cell mass. Insufficient iron supply during gestation may be responsible for the occurrence of maternal iron deficiency anemia and decreased iron status in neonates. On the other hand, preventive iron supplementation of non-anemic mothers may be of potential risk due to iron toxicity. Several different regimens of iron supplementation have been applied during pregnancy. The majority of oral iron supplementations routinely applied to pregnant sows provide inorganic, non-heme iron compounds, which exhibit low bioavailability and intestinal side effects. The aim of this study was to check, using pig as an animal model, the effect of sucrosomial ferric pyrophosphate (SFP), a new non-heme iron formulation on maternal and neonate iron and hematological status, placental transport and pregnancy outcome; Methods: Fifteen non-anemic pregnant sows were recruited to the experiment at day 80 of pregnancy and randomized into the non-supplemented group (control; n = 5) and two groups receiving oral iron supplementation—sows given sucrosomial ferric pyrophosphate, 60 mg Fe/day (SFP; n = 5) (SiderAL^®, Pisa, Italy) and sows given ferrous sulfate 60 mg Fe/day (Gambit, Kutno, Poland) (FeSO₄; n = 5) up to delivery (around day 117). Biological samples were collected from maternal and piglet blood, placenta and piglet tissues. In addition, data on pregnancy outcome were recorded.; Results: Results of our study show that both iron supplements do not alter neither systemic iron homeostasis in pregnant sows nor their hematological status at the end of pregnancy. Moreover, we did not detect any changes of iron content in the milk and colostrum of iron supplemented sows in comparison to controls. Neonatal iron status of piglets from iron supplemented sows was not improved compared with the progeny of control females. No statistically significant differences were found in average piglets weight and number of piglets per litter between animals from experimental groups. The placental expression of iron transporters varied depending on the iron supplement.

High Frequency of Multiple Paternity in Eastern Red Bats, Lasiurus borealis, Based on Microsatellite Analysis

Most species of bats give birth to only 1 pup each year, although Eastern red bats (Lasiurus borealis) can produce up to 5 pups per litter. Offspring in a single litter have been documented to be at different stages of development, suggesting that multiple paternity occurs. We tested the null hypothesis of genetic monogamy in red bats using 6 autosomal microsatellites and 1 X-linked microsatellite from 31 parent/offspring groups for a total of 128 bats. We sampled both pregnant females and mothers with pups that were obtained from bats submitted to departments of health in Oklahoma and Texas for rabies testing. Multiple paternity was assessed using a maximum-likelihood approach, hypothesis testing, and X-linked locus exclusion. The mean polymorphic information content of our markers was high (0.8819) and combined non-exclusion probability was low (0.00027). Results from the maximum-likelihood approach showed that 22 out of 31 (71%) parent/offspring groups consisted of half siblings, hypothesis testing rejected full sibship in 61% of parent/offspring groups, and X-linked locus exclusion suggested multiple paternity in at least 12 parent/offspring groups, rejecting our hypothesis of genetic monogamy. This frequency of multiple paternity is the highest reported thus far for any bat species. High levels of multiple paternity have the potential to impact interpretations of genetic estimates of effective population size in this species. Further, multiple paternity might be an adaptive strategy to allow for increased genetic variation and large litter size, which would be beneficial to a species threatened by population declines from wind turbines.

Relationship among ovarian follicular status, developmental competence of oocytes, and anti-Müllerian hormone levels: A comparative study in Japanese wild boar crossbred gilts and Large White gilts

The aim of this study was to investigate the ovarian follicular development, developmental competence of oocytes, and plasma anti-Müllerian hormone (AMH) levels of Japanese wild boar crossbred (wild hybrid) gilts, whose litter size is inferior to that of European breeds. Ovary and plasma samples were collected from two different breeds of gilts (wild hybrid and Large White breeds). The ovaries from the wild hybrid gilts had a lower average numbers of secondary follicles and vesicular follicles in ovarian cross-sections and of good quality oocytes collected from ovarian follicles as compared with those from Large White gilts (p < 0.05). The development rate to the blastocyst stage of good quality oocytes after in vitro maturation, fertilization and culture was also lower (p < 0.05) in wild hybrid gilts than in Large White gilts. Plasma AMH levels with >0.16 ng/ml were detected in 8.3% of the examined wild hybrid gilts and 33% of the Large White gilts. These results indicate that the low reproductive performance of wild hybrid breed may result in part from low numbers of vesicular follicles and good quality oocytes, and low developmental competence of oocytes. Moreover, plasma AMH levels may support low number of vesicular follicles in ovaries of wild hybrid gilts.