Birth Peak Research Articles

The bone collector: temporal patterns of bone-gnawing behaviour define osteophagia as a female prerogative in a large rodent

Calcium and phosphorous consumption is essential for bone development and maintenance throughout life, particularly to pregnant and lactating females. Bone consumption may provide mothers with the required supplemental amount of calcium and phosphorous. Osteophagia has been reported in a number of herbivore species as supplying such key mineral elements, although sound evidence is lacking for rodents. The diet of the crested porcupine is vegetarian and predominantly composed by roots and hypogeal storage organs. Gnawed bone residuals have often been observed in the surroundings of porcupine setts. This behaviour may have evolved to reduce the indefinite growth of incisor teeth, to increase calcium and phosphorous supply, or to fulfil both these functions. To clarify this issue, five setts were monitored for 3 years and bones in front of sett entries were counted and collected once a month. A total of 63 bones (mainly femurs and shins: 38.8%) was detected, mainly belonging to wild (46.03%) and domestic (28.57%) ungulates. The presence of gnawed bones in front of sett entries was recorded throughout the year, with a peak at the start of February. Camera-trapping data confirmed that areas surroundings house-farms, where most bones were probably collected, were only selected in the cold season. The peak of gnawed bone detection overlapped with the birth peak, suggesting that bones may be consumed by lactating females to increase the amount of minerals in their diet. This suggestion was further confirmed by the detection of no gnawed bones in front of the sett of the male-male pair. Porcupines are known to collect and gnaw bones in the surroundings of their setts, but ecological explanations and temporal patterns of this behaviour are unknown. We monitored five setts for 3 years, measuring and identifying gnawed bones in front of sett entries once a month. We then conducted an intensive camera-trapping session to monitor areas surrounding house-farms. Bone collection occurred throughout the year, with a peak in February, coinciding with the birth peak of this species. We therefore suggested that bone consumption could be a female prerogative, related to a supply of minerals in diet, as no gnawed bone was observed at the sett of a male-male pair.

Geographical Origin, Delayed Implantation, and Induced Ovulation Explain Reproductive Seasonality in the Carnivora.

Patterns of reproductive seasonality in the Carnivora are difficult to study comparatively, due to limited numbers of species for which information is available. Long-term databases of captive populations could overcome this difficulty. We apply a categorical description and a quantitative high-resolution measure (birth peak breadth, the number of days in which 80% of all births occur) based on daily observations in captivity to characterize the degree of reproductive seasonality in the Carnivora for 114 species with on average 1357 births per species. We find that the majority of species retained the birth seasonality displayed in the wild. Latitude of natural origin, delayed implantation, and induced ovulation were the main factors influencing reproductive seasonality. Most species were short-day breeders, but there was no evidence of an absolute photoperiodic signal for the timing of mating or conception. The length of the gestation period (corrected for body mass) generally decreased with birth seasonality but increased in species with delayed implantation. Birth seasons become shorter with increasing latitude of geographical origin, likely because the length of the favorable season declines with increasing latitude, exerting a strong selective pressure on fitting both the reproductive cycle and the interval offspring needs for growth following the termination of parental care into the short time window of optimal environmental conditions. Species with induced ovulation exhibit a less seasonal reproductive pattern, potentially because mates do not have to meet during a short time window of a fixed ovulation. Seasonal species of Carnivora shorten their gestation period so reproduction can occur during the short time window of optimal environmental conditions. Alternatively, other Carnivora species lengthen their gestation periods in order to bridge long winters. Interestingly, this occurs not by decelerating intrauterine growth but by delaying implantation.

A time to be born: Variation in the hour of birth in a rural population of Northern Argentina.

The present study aimed at investigating the timing of birth across the day in a rural population of indigenous and nonindigenous women in the province of Formosa, Argentina in order to explore the variation in patterns in a non-Western setting. This study utilized birth record data transcribed from delivery room records at a rural hospital in the province of Formosa, northern Argentina. The sample included data for Criollo, Wichí, and Toba/Qom women (n = 2421). Statistical analysis was conducted using directional statistics to identify a mean sample direction. Chi-square tests for homogeneity were also used to test for statistical significant differences between hours of the day. The mean sample direction was 81.04°, which equates to 5:24 AM when calculated as time on a 24-hr clock. Chi-squared analyses showed a statistically significant peak in births between 12:00 and 4:00 AM. Birth counts generally declined throughout the day until a statistically significant trough around 5:00 PM. This pattern may be associated with the circadian rhythms of hormone release, particularly melatonin, on a proximate level. At the ultimate level, giving birth in the early hours of the morning may have been selected to time births when the mother could benefit from the predator protection and support provided by her social group as well as increased mother-infant bonding from a more peaceful environment.

T198. A SCHIZOPHRENIA-LIKE BIRTH SEASONALITY AMONG MATHEMATICIANS AND AN OPPOSITE SEASONALITY AMONG BIOLOGISTS: MORE EVIDENCE IMPLICATING BIMODAL RHYTHMS OF GENERAL BIRTHS

BackgroundBased on early-20th century births, a pre-electric illumination time of comparatively normal human exposure to sunlight, studies of schizophrenia (SCZ) found a birth seasonality with two opposite effects: a SCZ-liability peak among subjects born around late-February and an equally significant SCZ-resistance peak among those born six months later, around late-August. We previously investigated this rhythm in connection with a sunlight-dependent bimodal rhythm of general births that, prior to the full advent of electric lighting (but not later), occurred ubiquitously in non-equatorial parts of the world. We found that the SCZ-liability peak coincided with a first, Feb-Mar peak of general-population births (the GP1) while the SCZ-resistance peak coincided with a second, Aug-Sep peak of those births (the GP2). Moreover, in a study of hand and visual-field preferences among professional baseball players, we found the SCZ-liability, GP1-coincident seasonality among players with preferences denoting cerebral asymmetry “deficits” (CADs) and the SCZ-resistance, GP2-coincident seasonality among those with preferences denoting cerebral asymmetry “excesses.” Also, in a study suggested by associations of CADs with artistic abilities, we found the SCZ-liability, GP1-coincident seasonality among groups representing visual, performing and literary art “creators” (VPL-Artists) and the SCZ-resistance, GP2-coincident seasonality among groups representing art critics, historians, curators and other art “observers” (Para-Artists). Together, these findings suggested, as one possibility (but see later), that the SCZ-liability, CAD effects and artistic abilities could all three represent traits genetically or otherwise selected into the GP1 excess population of newborns and out of the GP2 population. The present study of “scientists” was initially aimed at the purported arts/science antithesis.MethodsBirth seasonalities were examined among early-20th century born American scientists and among yet earlier European biologists and mathematicians.ResultsA group representing 1,925 American scientists showed the SCZ-resistance, GP2-coincident seasonality. However, this effect proved to be mostly due to biologists because biochemists, chemists, and physicists showed gradually less seasonality while mathematicians suggested an altogether artist-like, GP1-coincident seasonality. This intimation of a biologist-mathematician antithesis was pursued with an investigation of most major figures in the history of the two sciences from the 15th to the early-20th century. The two groups, numbering 576 mathematicians and 787 biologists, shared the same mean decade of birth, the 1780s, and essentially the same geographic origin in Western Europe. The mathematicians showed a very significant SCZ liability-like, GP1-coincident seasonality while the biologists showed an even more significant SCZ resistance-like, GP2-coincident seasonality. The latter effect was particularly strong among naturalists, anatomists and other groups representing biological “observationalism” as opposed to “experimentalism.”DiscussionThe findings are discussed in light of a) new evidence that the annual photoperiod is indeed alone responsible for both peaks of general births, with the GP1 and the GP2 being caused by maternal periconceptional exposure to, respectively, the summer-solstice sunlight maximum and the winter-solstice minimum, and b) an approach/withdrawal theory of lateralization of basic emotions where the left cerebral cortex would handle external stimuli eliciting complacent emotions towards external realities while the right cortex would handle internal stimuli eliciting disdain for those realities.

Características generales del comportamiento del venado cola blanca (Odocoileus virginianus) en semicautiverio en Cobán, Alta Verapaz, Guatemala

En Guatemala, el venado Cola Blanca es de los animales cinegéticos más importantes y sin duda de los más perseguidos a pesar de eso, se han realizado pocos estudios sobre él. En la actualidad, con la formación de la colección de la Fábrica de Municiones del ejército-FME-localizada en el municipio de Cobán, en el departamento de Alta Verapaz, se busca asegurar la conservación de esta especie. El estudio consistió en observaciones diarias para determinar el comportamiento general: social, productivo, reproductivo del venado y colectas de campo realizadas en las épocas de menor y mayor precipitación, con el objeto de obtener información acerca de la calidad de las principales plantas forrajeras, mediante análisis por el método de Weende. Se cuantificó la disponibilidad del forraje, utilizando porcentajes estimados de cubierta, para las plantas herbáceas y para arbustos y árboles se usó el muestreo sistemático por medio de parcelas de 10 x 10 m. Las plantas forrajeras principales fueron hierbas graminoides por existir en mayor disponibilidad (75%), luego los arbustos (22%), y por último las especies arbóreas (3%). Los forrajes consumidos fueron generalmente de calidad inferior que los forrajes de otras latitudes. Dentro de las especies arbustivas cabe mencionar como las más importantes para el venado del área, el clavel de Panamá (Hibiscus rosasimensis),pera (Pyrus communis) y Costa Rica (Bahuinia sp.). Estas especies junto con gramíneas como Andropogon bicornis, Panicum sellowii y Paspalum conjugatum, constituyen la base alimenticia del venado Cola Blanca en la FME. Los datos presentados sobre comportamiento social, sugieren diferencias en algunas estrategias sociales y de comportamiento a una edad temprana entre la población estudiada en semicautiverio y los reportes para poblaciones que habitan áreas silvestres o en completo cautiverio. Las hembras generalmente tienen sus crías en marzo, con un pico de nacimientos al final de dicho mes, aunque este es un período que puede prolongarse hasta mediados de abril. Lo que se observa en Cobán es una estacionalidad en la época de partos, lo cual concuerda con los factores climáticos que están relacionados con la sobrevivencia de los cervatos. Se infiere que los cervatos nacidos durante los meses de marzo y abril tendrán una mayor probabilidad de sobrevivencia que aquellos nacidos después o antes de la estación.Cuando las lluvias fuertes se presentan los cervatos son capaces fisiológicamente de utilizar los recursos vegetativos disponibles para su crecimiento y desarrollo. Por otra parte, las madres se recuperan de la tensión fisiológica como consecuencia de la lactancia.

Cattle grazing effects on mountain gazelles in Mediterranean natural landscapes

ABSTRACTFrequently, Mediterranean natural and semi‐natural areas will undergo cattle grazing as a form of fire fuel reduction management. We used a multi‐species approach to understand effects of cattle grazing on mountain gazelle (Gazella gazella) in relation to 2 potential predators of gazelle neonates: golden jackal (Canis aureus) and wild boar (Sus scrofa). We used light detection and ranging (LiDAR) data and a fine‐scale camera trap design (0.01‐km2 grid) in Ramat Hanadiv Nature Park in the Mediterranean region of Israel to determine gazelle habitat and patch preferences in response to grazing using N‐mixture models. Cattle grazing decreased female gazelle detectability and activity and attracted potential predators during the most sensitive time of the year for gazelle: parturition and the critical first 5 weeks of fawns' lives. Grazing management acts as a disturbance for gazelles and increases risk for neonates. Our results show the importance of understanding the broader mechanism behind predator–prey dynamics and how indirect human‐mediated management actions and direct predation may have adverse effects on wild populations. We recommend that cattle be allowed to enter natural areas only after the spring birth peak. © 2017 The Wildlife Society.

Angiotensin II-AT1–receptor signaling is necessary for cyclooxygenase-2–dependent postnatal nephron generation

Deletion of cyclooxygenase-2 (COX-2) causes impairment of postnatal kidney development. Here we tested whether the renin angiotensin system contributes to COX-2-dependent nephrogenesis in mice after birth and whether arescue of impaired renal development and function in COX-2-/- mice was achievable. Plasma renin concentration in mouse pups showed a birth peak and a second peak around day P8 during the first 10 days post birth. Administration of the angiotensin II receptor AT1 antagonist telmisartan from dayP1 to P3 did not result in cortical damage. However, telmisartan treatment from day P3 to P8, the critical time frame of renal COX-2 expression, led to hypoplastic glomeruli, a thinned subcapsular cortex and maturational arrest of superficial glomeruli quite similar to that observed in COX-2-/- mice. In contrast, AT2 receptor antagonist PD123319 was without any effect on renal development. Inhibition of the renin angiotensin system by aliskiren and enalapril caused similar glomerular defects as telmisartan. Administration of the AT1 receptor agonist L162313 to COX-2-/- pups improved kidney growth, ameliorated renal defects, but had no beneficial effect on reduced cortical mass. L162313 rescued impaired renal function by reducing serum urea and creatinine and mitigated pathologic albumin excretion. Moreover, glomerulosclerosis in the kidneys ofCOX-2-/- mice was reduced. Thus, angiotensin II-AT1-receptor signaling is necessary for COX-2-dependent normal postnatal nephrogenesis and maturation.

Impact of month of birth on the risk of development of autoimmune Addison's disease

Context: The pathogenesis of autoimmune Addison's disease (AAD) is thought to be due to interplay of genetic, immune, and environmental factors. A month-of-birth effect, with increased risk for those born in autumn/winter months, has been described in autoimmune conditions such as type 1 diabetes and autoimmune thyroid disease. Objective: Month-of-birth effect was investigated in 2 independent cohorts of AAD subjects. Design, Setting, and Patients: The monthly distribution of birth in AAD patients was compared with that of the general population using the cosinor test. A total of 415 AAD subjects from the United Kingdom cohort were compared with 8 180 180 United Kingdom births, and 231 AAD subjects from the Polish cohort were compared with 2 421 384 Polish births. Main Outcome Measures: Association between month of birth and the susceptibility to AAD. Results: In the entire cohort of AAD subjects, month-of-birth distribution analysis showed significant periodicity with peak of births in December and troug...

Impact of Month of Birth on the Risk of Development of Autoimmune Addison's Disease.

Context:The pathogenesis of autoimmune Addison's disease (AAD) is thought to be due to interplay of genetic, immune, and environmental factors. A month-of-birth effect, with increased risk for those born in autumn/winter months, has been described in autoimmune conditions such as type 1 diabetes and autoimmune thyroid disease.Objective:Month-of-birth effect was investigated in 2 independent cohorts of AAD subjects.Design, Setting, and Patients:The monthly distribution of birth in AAD patients was compared with that of the general population using the cosinor test. A total of 415 AAD subjects from the United Kingdom cohort were compared with 8 180 180 United Kingdom births, and 231 AAD subjects from the Polish cohort were compared with 2 421 384 Polish births.Main Outcome Measures:Association between month of birth and the susceptibility to AAD.Results:In the entire cohort of AAD subjects, month-of-birth distribution analysis showed significant periodicity with peak of births in December and trough in May (P = .028). Analysis of the odds ratio distribution based on month of birth in 2 cohorts of patients with AAD versus the general population revealed a December peak and May trough, and January peak and July trough, in the United Kingdom and Polish cohorts, respectively.Conclusion:For the first time, we demonstrate that month of birth exerts an effect on the risk of developing AAD, with excess risk in individuals born in winter months and a protective effect when born in the summer. Exposure to seasonal viral infections in the perinatal period, coupled with vitamin D deficiency, could lead to dysregulation of innate immunity affecting the risk of developing AAD.

Timing of reproduction and paternal cares in the crested porcupine

Old World porcupines are elusive, nocturnal rodents who pair for life, exhibiting frequent socio-sexual behaviour also outside the breeding period. Only anecdotal observations on captive individuals are available on the reproductive behaviour of the crested porcupine Hystrix cristata, a Sub-Saharan and North African large rodent probably introduced to Italy over 1500 years ago. Our work reports the first data on reproductive biology and paternal behaviour of free-living crested porcupines in Europe. A total of 44 litters was recorded at 4 den systems, over 3 years: 59% singletons, 32% twins, 9% triplets. Reproduction occurs throughout the year, but two significant birth peaks have been detected on February and October. The reproductive peak in October falls in the period of short rains in Sub-Saharan Africa, and coincides with the start of Autumn rains in Italy, thus preceding the vegetation regrowth in both areas, but especially in Africa. On the other hand, porcupines are unusual, as their “spring” peak of births in Central Italy falls actually in mid-winter (i.e. February), when snowfalls and the coldest temperatures tend to occur. By contrast, births in February anticipate the long rains in Sub-Saharan Africa by c. 30 days, when cubs leave the natal den for the first time and vegetation starts sprouting. Haphazard observations of cubs over 12 years (N=72) have confirmed this pattern. Both partners (N=2 radio-tagged pairs) share parental duties: alternation of cub guarding in den occurs in the first two months of life, i.e. when quills are still soft and relatively short, thus making cubs an easy prey for small and mesocarnivores.

Esophageal Atresia Repair - Can We Influence the Schedule?

The treatment of newborns with esophageal atresia (EA) and tracheoesophageal fistula (TEF) is associated with a great logistic effort. The aim of the presented study was to analyse the possibility to influence the time of surgery. Data from 30 neonates with EA and TEF regarding the date and mode of birth, biometric data and preoperative acid-base and blood gas values were collected retrospectively. The newborns were divided into two subgroups: birth between Monday and Thursday ("week"), and birth from Friday to Sunday ("weekend"). We observed a seasonal peak of births in November/December. The rate of prenatal ultrasound detection of polyhydramnions was 40%. In 14 of 16 cases with Caesarean section, maternal or foetal problems predicted the date and mode of delivery. In both groups, most newborns had an unimpaired postnatal adaptation. There were no significant differences regarding biometry. Delivery at the weekend was associated with later surgical repair (second vs. first day of life). Repeated estimations of acid-base and blood gas parameters over a median time span of 13 hours revealed a stable situation with a trend to normalisation. The time of birth is multifactorial and, in most cases, can neither be predicted nor influenced. Stable respiratory and metabolic parameters in the majority of patients allow a surgical intervention within a limited time frame during the first days of life. As it is hardly possible to plan the surgical procedure, an experienced team as well as neonatal intensive care facilities and operation room access must be available throughout the week.

How Rainfall Variation Influences Reproductive Patterns of African Savanna Ungulates in an Equatorial Region Where Photoperiod Variation Is Absent

In high temperate latitudes, ungulates generally give birth within a narrow time window when conditions are optimal for offspring survival in spring or early summer, and use changing photoperiod to time conceptions so as to anticipate these conditions. However, in low tropical latitudes day length variation is minimal, and rainfall variation makes the seasonal cycle less predictable. Nevertheless, several ungulate species retain narrow birth peaks under such conditions, while others show births spread quite widely through the year. We investigated how within-year and between-year variation in rainfall influenced the reproductive timing of four ungulate species showing these contrasting patterns in the Masai Mara region of Kenya. All four species exhibited birth peaks during the putative optimal period in the early wet season. For hartebeest and impala, the birth peak was diffuse and offspring were born throughout the year. In contrast, topi and warthog showed a narrow seasonal concentration of births, with conceptions suppressed once monthly rainfall fell below a threshold level. High rainfall in the previous season and high early rains in the current year enhanced survival into the juvenile stage for all the species except impala. Our findings reveal how rainfall variation affecting grass growth and hence herbivore nutrition can govern the reproductive phenology of ungulates in tropical latitudes where day length variation is minimal. The underlying mechanism seems to be the suppression of conceptions once nutritional gains become insufficient. Through responding proximally to within-year variation in rainfall, tropical savanna ungulates are less likely to be affected adversely by the consequences of global warming for vegetation phenology than northern ungulates showing more rigid photoperiodic control over reproductive timing.

Season of birth and multiple sclerosis in Tunisia

BackgroundRecent studies on date of birth of multiple sclerosis (MS) patients showed an association between month of birth and the risk of developing MS. This association has not been investigated in an African country. ObjectiveWe aimed to determine if the risk of MS is associated with month of birth in Tunisia. MethodsData concerning date of birth for MS patients in Tunisia (n=1912) was obtained. Birth rates of MS patients were compared with all births in Tunisia matched by year of birth (n=11,615,912). We used a chi-squared analysis and the Hewitt's non-parametric test for seasonality. ResultsThe distribution of births among MS patients compared with the control population was not different when tested by the chi-squared test. The Hewitt’s test for seasonality showed an excess of births between May and October among MS patients (p=0.03). The peak of Births of MS patients in Tunisia was in July and the nadir in December. ConclusionOur data does support the seasonality hypothesis of month of birth as risk factor for MS in Tunisia. Low vitamin D levels during pregnancy could be a possible explanation that needs further investigation.

Birth seasonality and pattern in black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Mt. Lasha, Yunnan.

Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a "V" style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.

Human birth seasonality: latitudinal gradient and interplay with childhood disease dynamics

More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on childhood disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.

Bayesian modelling of hunting data may improve the understanding of host–parasite systems: Wild boar diseases and vaccination as an example

Wildlife diseases are often studied using hunting data. In such studies, inferences about diseases are often made by comparing raw disease prevalence levels, ignoring complications like stochasticity in recruitment. We carried out a field trial to study the effectiveness of oral vaccination of wild boar (Sus scrofa) against classical swine fever (CSF) in the Vosges mountains (Northeastern France) for 3 years (2008–2010). Since August 2004, hunters had carried out three vaccination sessions per year in spring, summer and autumn. During our study period, we determined whether each wild boar hunted in our study area was immunized or not against CSF. We used a Bayesian approach to model the changes in the proportion of vaccinated animals in the population of young animals (i.e., <12 months old). This approach allowed to disentangle the effects of the birth peaks (leading to a decrease) and of both the vaccination sessions and natural infection (leading to an increase) on this proportion. We thus inferred, at the individual level, the probability that a non-immunized animal became vaccinated after a particular session. There was a high between-year variability in the effectiveness of the vaccination: the observed patterns were similar in 2008 and 2010, but 2009 was characterized by an overall greater effectiveness of the vaccination. Within a particular year, the spring vaccination session was more effective than the autumn session, probably because of the higher food availability in autumn that render the vaccination places less attractive to the animals. The vaccination effectiveness was rather low in summer, except in 2009, probably because of higher age identification error this year. This model also highlighted an immunisation of animals occurring outside vaccination periods, which suggests either the presence of the CSF virus in our study area, or the consumption of the vaccine outside the vaccination sessions. Finally, we observed a high spatial variability of the probability of vaccination. The effectiveness of the vaccination was indeed strongly related to both the distribution of the forests and the distribution of the vaccination places in our study area. This study highlights an optimal vaccination effort of 1.25 places per km2 to maximize the proportion of immune wild boar in that area.

Seasonal diet of black-backed jackal in the Eastern Karoo, South Africa

The ability of small canids to consume a variety of resources in an opportunistic manner has been cited as a reason for their wide distribution across many habitats. Black-backed jackals Canis mesomelas have varied diets that reflect changes in food availability as a result of seasonal fluctuations in resources. Seasonal fluctuations can include variations in food type availability, as well as variations in the phenology of food resources (i.e. ungulate birth peaks). Additionally, the presence of apex predators can affect opportunistic predator diets through the provision of carrion. We investigated the diet of black-backed jackals on a reserve in the semi-arid Karoo, South Africa. Ungulates (>5 kg) were the dominant prey item across all seasons, reflecting either active predation or scavenging. Most seasonal comparisons in percent occurrence of prey groups revealed significant seasonal fluctuations in black-backed jackal diet. However, in terms of biomass consumed, the diet remained stable, dominated by small ungulates across all seasons with no clear seasonal change in ungulate composition. These results suggest that in this study black-backed jackals, although being opportunistic in terms of diet composition, had a seasonally stable food resource, most likely facilitated by the presence of cheetahs Acinonyx jubatus providing scavenging opportunities.

Effects of Supplementary Selenium Source on the Blood Parameters in Beef Cows and Their Nursing Calves

Over 2 years, 32 beef cows nursing calves in southwest Arkansas were randomly selected from a herd of 120 that were managed in six groups and were assigned to six 5.1-ha bermudagrass (Cynodon dactylon [L.] Pers.) pastures. Treatments were assigned to pastures (two pastures/treatment) and cows had ad libitum access to one of three free-choice minerals: (1) no supplemental selenium (Se), (2) 26 mg of supplemental Se from sodium selenite per kilogram, and (3) 26 mg of supplemental Se from seleno-yeast per kilogram (designed mineral intake = 113 g/cow daily). Data were analyzed using a mixed model; year and pasture were the random effects and treatment was the fixed effect. At the beginning of the calving and breeding seasons, cows supplemented with Se had greater (P < 0.01) whole blood Se concentration (WBSe) and glutathione peroxidase activities (GSH-Px) than cows receiving no supplemental Se; cows fed seleno-yeast had greater (P ≤ 0.05) WBSe than cows fed sodium selenite, but GSH-Px did not differ (P ≥ 0.25) between the two sources. At birth and near peak lactation (late May), calves from cows supplemented with Se had greater (P < 0.01) WBSe than calves from cows fed no Se and calves from cows fed seleno-yeast had greater (P ≤ 0.01) WBSe and GSH-Px than calves from cows fed sodium selenite. Thyroxine (T4), triiodothyronine (T3), and the T4:T3 ratio in calves did not differ among treatments (P ≥ 0.35). At birth, insulin-like growth factor 1 (IGF-1) was greater (P = 0.02) in calves nursing cows with no supplemental Se than in ones with supplemental Se; in calves nursing cows with supplemental sodium selenite, IGF-1 did not differ (P = 0.96) from ones offered supplemental seleno-yeast. Selenium supplementation of gestating beef cows benefited cows and calves by increasing WBSe and GSH-Px. The use of seleno-yeast as a Se supplement compared to sodium selenite increased the WBSe of both cows and their calves without affecting the T4 to T3 conversion or IGF-1 concentrations.

Contraception can Lead to Trophic Asynchrony between Birth Pulse and Resources

Abiotic inputs such as photoperiod and temperature can regulate reproductive cyclicity in many species. When humans perturb this process by intervening in reproductive cycles, the ecological consequences may be profound. Trophic mismatches between birth pulse and resources in wildlife species may cascade toward decreased survival and threaten the viability of small populations. We followed feral horses (Equus caballus) in three populations for a longitudinal study of the transient immunocontraceptive porcine zona pellucida (PZP), and found that repeated vaccinations extended the duration of infertility far beyond the targeted period. After the targeted years of infertility, the probability of parturition from post-treated females was 25.6% compared to 64.1% for untreated females, when the data were constrained only to females that had demonstrated fertility prior to the study. Estimated time to parturition increased 411.3 days per year of consecutive historical treatment. Births from untreated females in these temperate latitude populations were observed to peak in the middle of May, indicating peak conception occurred around the previous summer solstice. When the post-treated females did conceive and give birth, parturition was an estimated 31.5 days later than births from untreated females, resulting in asynchrony with peak forage availability. The latest neonate born to a post-treated female arrived 7.5 months after the peak in births from untreated females, indicating conception occurred within 24–31 days of the winter solstice. These results demonstrate surprising physiological plasticity for temperate latitude horses, and indicate that while photoperiod and temperature are powerful inputs driving the biological rhythms of conception and birth in horses, these inputs may not limit their ability to conceive under perturbed conditions. The protracted infertility observed in PZP-treated horses may be of benefit for managing overabundant wildlife, but also suggests caution for use in small refugia or rare species.

Mating behavior and birth seasonality of black-and-white snub-nosed monkeys (&lt;I&gt;Rhinopithecus bieti&lt;/I&gt;) at Mt. Lasha

Copulation patterns are important to understanding male mating strategies and stabilization strategies of social organizations in primates. However, information on copulation patterns of Asian primates is relatively rare. This study was undertaken to collect data on mating behavior and birth seasonality of Black-and-white Snub-nosed monkeys (Rhinopithecus bieti) using all occurrence sampling and Focal animal-scan sampling methods at Mt. Lasha, between January and December, 2011. Our study focused on observing mating frequency and birth rates. Snub-nosed monkeys mate year round, with two observable peaks: one reproductive peak during the mating season, roughly from August to October, and a second non-breeding peak during the birth season. It is unclear what biological significance this non-reproductive mating peak has. During our observation, we noted a lower ratio of mount to ejaculation and rare ejaculatory copulations, which indicated that every mating would not result in ejaculation. This study corroborates the previous view that the Rhinopithecus bieti's copulatory pattern is likely multiple-mount ejaculation (MME) or at the upper part of mating continuum of single-mount ejaculation (SME) toward MME. More ejaculatory copulations initiated by males than females indicate that MME is not only a mating strategy of males, but that males can influence the position of their copulatory pattern on the continuum between SME and MME. The mating frequencies significantly correlated with the birth rates with a delay of 6 to 7 months. Monkeys gave birth within a strict seasonality with a birth peak of March, which confirms the previous view. Infants were born with a certain degree of synchronization, but different populations displayed different modes of synchronizations.