First parturition of tigers in a semi-arid habitat,western India

Long-term data of large felids is important to understand their reproductive biology and behavior for effective conservation planning. We used camera trap data and direct sightings from 2005 to 2013 to estimate the age of the first parturition of Bengal tigers (Panthera tigris) in a semi-arid habitat in India. We monitored 11 females in the Ranthambhore Tiger Reserve (RTR) from when they were 2–6 months old. The mean age at first reproduction (impregnation leading to cubs) was 51.3?±?(SE) 4.5 months. The tiger population in RTR is an important source population and genetic pool in the western most distribution of tiger. Thus, continuous monitoring of tiger populations is important to develop an understanding of reproductive biology.     

Interbirth interval and litter size of free-ranging Bengal tiger (Panthera tigris tigris) in dry tropical deciduous forests of India

We studied the interbirth interval (IBI) and litter size of the population of free-ranging Bengal tigers (Panthera tigris tigris) in dry tropical deciduous forests in Ranthambhore Tiger Reserve (RTR), Rajasthan, and Pench Tiger Reserve (PTR), Madhya Pradesh, between April 2005 and June 2011. Data on 15 breeding females in RTR and nine breeding females in PTR were collected using camera trapping, direct observation and radio-telemetry. The mean?±?standard error of IBI (months) in RTR was 33.4?±?3.7 and in PTR was 25.2?±?1.8. A significant difference was observed between the mean IBI of tigresses in RTR and those in PTR (df?=?9, P?=?0.04). The estimated mean litter size in RTR was 2.3?±?0.1 and that in PTR was 2.9?±?0.2. There was a significant difference between the litter size in RTR and that in PTR (χ ²?=?12.04, P?=?0.017, df?=?4). Since RTR and PTR are the important source populations of tigers in the Western and Central Indian landscapes, we propose that the tigers in these reserves be monitored, particularly for reproductive traits that are essential for understanding aspects of their population ecology.     

Reproductive parameters of the common genet <Emphasis Type="Italic">Genetta genetta</Emphasis> (Linnaeus, 1758) in Southwest Europe

We used information from 148 litters belonging to 119 different wild and captive female common genets (Genetta genetta) in SW Europe over a period of almost 50 years to study certain reproductive parameters. Data were obtained from a combination of sources including carcasses, live captures, telemetry-based studies, captive genets, and reports in the literature. The circannual pattern of breeding was fairly similar in both wild and captive genets, with births occurring in all months except December, albeit with a large peak in spring and a secondary peak in autumn. The sex ratio at birth was near to 1:1, and mean litter size was 2.16 ± 0.76 cubs/litter with a range of 1–5 cubs. Litters of two cubs were the most frequent both in wild and captive settings. In captivity, we have observed the births of replacement litters and double litters; however, we did not find evidence of wild females that having two litters in the same year. We conclude that the possibility of breeding at any time of the year is facilitated by the continuous spermatogenesis of the males and by the ability of females to enter into estrus after losing a litter prematurely and to breed twice in the same year.     

Density and population structure of the jaguar (<Emphasis Type="Italic">Panthera onca</Emphasis>) in a protected area of Los Llanos,Venezuela, from 1 year of camera trap monitoring

Density is crucial for understanding large carnivore ecology and conservation, but estimating it has proven methodologically difficult. We conducted 1 year of camera trapping to estimate jaguar (Panthera onca) density and population structure in the Los Llanos region of Venezuela on the Hato Piñero ranch, where hunting is prohibited and livestock are excluded from half of ranch lands. We identified 42 different jaguars and determined their sex, age class, and reproductive status. We estimated adult jaguar densities with spatial capture-recapture models, using sex/reproductive state and session as covariates. Models without temporal variation received more support than models that allowed variation between sessions. Males, reproductive females, and nonreproductive females differed in their density, baseline detectability, and movement. The best estimate of total adult jaguar population density was 4.44 individuals/100 km². Based on reproductive female density and mean number of offspring per female, we estimated cub density at 3.23 individuals/100 km² and an overall density of 7.67 jaguars/100 km². Estimated jaguar population structure was 21% males, 11% nonreproductive females, 26% reproductive females, and 42% cubs. We conclude that extending the sampling period to 1 year increases the detectability of females and cubs and makes density estimates more robust as compared to the more common short studies. Our results demonstrate that the Venezuelan Llanos represent important jaguar habitat, and further, they emphasize the importance of protected areas and hunting restrictions for carnivore conservation.     

Reproductive life history of South African cheetahs (Acynonyx jubatus jubatus) at the San Diego Zoo Wild Animal Park, 1970–2005

We analyzed 35 years of data from a captive breeding program of cheetahs to determine basic reproductive life history characteristics of females. Breeding females ranged in age from 2.7–10.5 years. Sixteen females and over 13 males produced 129 cubs in 36 litters, with an average litter size of 3.6. Older females produced significantly fewer cubs per litter than younger females, but cub survivorship was comparable across female ages. Sex ratio was balanced at birth and 71% of infants survived the weaning period. Given that the reproductive output of captive cheetahs in our study is similar to that in other zoologic institutions and to cheetahs in the wild, we suggest that reproductive deficits in captive cheetahs arise from the inability of some pairs to breed, due to a lack of mating preference, rather than from a species‐wide problem. Zoo Biol 0:1–8, 2006. © 2006 Wiley‐Liss, Inc.     

Philopatric predisposition to predation-induced ecological traps: habitat-dependent mortality of breeding eiders

Because population size is sensitive to changes in adult survival, adult survival may be buffered against environmental variability. Philopatry may be adaptive in changing environments, but it could also constrain breeding habitat selection under changing conditions such as shifting predation regimes. Habitat preference and quality could become decoupled in long-lived philopatric species that evolved in stable environments when suddenly faced by increased adult predation risk, as dispersal may be triggered by past reproductive failure. We evaluated whether the Baltic eider (Somateria m. mollissima) population may currently face a predation-induced ecological trap. Eiders are philopatric and nest on open and forested islands. We hypothesized that open-nesting females would be disproportionately affected by increased predation. We compared female annual survival in these two habitats in 1996–2010. We also tested for effects of time trends, winter severity (NAO), female body condition, and habitat-specific predation pressure on survival. Our results revealed the lowest survival recorded for this species (Φ?=?0.720), and survival on open islands was significantly lower (Φ?=?0.679) than on forested islands (Φ?=?0.761). Nonetheless, only 0.7?% of females changed breeding habitat type despite ample availability of alternative islands, and breeding phenology in both habitats was similar. Female survival increased with body condition, while it was unrelated to winter climate and stable over time. Open islands had a higher predation pressure on incubating females. Breeding philopatry results in a predator-mediated ecological trap for open-nesting eiders. Our results contribute to explaining the drastic decline of the Baltic eider population.     

Batch fecundity and spawning frequency of invasive Hemiculter leucisculus (Basilewsky, 1855) in Erhai Lake,China

Hemiculter leucisculus are multiple spawners with indeterminate fecundity, although previous fecundity estimates have assumed a determinate spawning pattern. Batch fecundity and spawning frequency of H. leucisculus were studied in Erhai Lake, China, in which the fish, as an exotic species, has become a successful colonizer. Spawning frequency was 16.05 %, as determined from the percent of females with postovulatory follicles 12 to 36 h old during the peak reproductive period (from May 27 to August 8). The average interval between spawning was 6.2 days and there were more than 16 total spawning batches during the peak reproductive period. The average batch fecundity (mean ± SD) was 11,934?±?5,921 hydrated oocytes in 40 females (standard length or SL: 9.1–14.4 cm), while relative batch fecundity was 560?±?137 eggs g^?1 wet weight. The total potential annual fecundity was approximately 190,944 oocytes over the whole spawning season and was much higher than the estimated standing stock (31,585 oocytes) of yolked oocytes (36 females, SL: 9.5–16.2 cm) at the beginning of the spawning season in April 2010. This high annual fecundity is likely to have contributed to successful invasion of Erhai Lake by H. leucisculus.     

Reproductive aspects of American minks (Neovison vison) in central Spain: Testing the effects of prey availability

Some reproductive components of fitness (breeding times, litter size and the proportion of breeding females per year) of two feral populations of American minks in central Spain were investigated by means of direct observation from 2006 to 2010. The effects of prey availability were explored. Mating season was from February to March. Parturition dates did not differ between the two sites and pooled births took place between April (33.3%) and July (2.8%), peaking in May (40.3%). Mean litter size (the number of small cubs following their mother) was 3.43 ± 1.01 cubs (±SD; n = 30) with statistical significant differences between the two study sites. The strong seasonality in births and differences in litter size were related to prey availability (i.e. these are food-limited life-history traits), but in a complex non-linear fashion. A minimum value of prey abundance is necessary to breed. While litter size rises with prey abundance, there is a point where increasing prey did not result in an increase in litter size. Up to 75% of the females in the breeding pool reared cubs each year in both areas, which represents a somewhat high pool of breeding females. Delayed implantation is shorter than a month or does not exist in these populations. Such a short time-span seems to emerge because longer delays would have an important fitness cost to females. The breeding calendar and the litter size were similar to that reported previously from other areas.     

Detection of pregnancy in a hibernator based on activity data

Pregnancy and parturition are often difficult to detect in wild-living animals, especially in species that give birth to altricial young in burrows or caves. Current methods to detect pregnancy and birth in hibernating animals often entail disturbances that can affect the animals' reproductive success. We developed a new method to confirm pregnancy and parturition in hibernating brown bears (Ursus arctos) using activity data recorded in dual-axis motion sensors mounted on GPS–GSM neck collars on 30 brown bears during 52 hibernation seasons in Sweden. We adjusted recorded activity to the individual basal activity level for each bear. Pregnant females showed characteristic activity patterns during the period of pregnancy, with significantly higher daily activity levels and frequency of active periods during pregnancy than nonpregnant bears. Pregnant females were active on average 2.20 times more often during the pregnancy period than during the postpartum period, compared with 0.97 times for nonpregnant females. A pregnancy index was defined as the average of the proportion of mean daily activity levels and the proportion of activity events during the pregnancy period compared with the postpartum period. It averaged 2.61?±?1.73 (SD) for pregnant females and 0.94?±?0.24 for nonpregnant females. Using this method, we evaluated a group of adult females that had an unverified reproductive status but were classified as not pregnant because no cubs had been observed after den emergence. The results suggested that 35 % of those females had, in fact, been pregnant.     

Spatial ecology of shark-like batoids in a large coastal embayment

Understanding how spatial ecology varies between life stages, and whether there is an overlap of critical areas (e.g., nursery areas, breeding sites), may provide significant benefits to conservation planning. The present work examined the space use and residency of shark-like batoids (families Rhynchobatidae and Rhinobatidae) in a nearshore system. An array of 63 acoustic receivers deployed in Cleveland Bay, north Queensland, Australia, passively tracked 15 G. typus and 20 Rhynchobatus spp. between 2009 and 2011. Glaucostegus typus were monitored between 1 and 766 days (mean?=?333?±?69 days) and were present in the site from 1 to 198 days (mean 73?±?25 days). Both adult male and female G. typus exhibited philopatric behaviour patterns, leaving the bay and returning after periods of about 9–12 months to use the same areas where they were detected in previous years. Individuals with lower residency had larger activity spaces. Rhynchobatus spp. were monitored for 1 to 707 days (mean?=?231?±?50 days) and were present in the site from 1 to 350 days (mean 82?±?24 days). Rhynchobatus spp. exhibited no synchronicity in use of the bay. Both G. typus male and female residency changed with size of individuals, in comparison size had no effect on the residency of Rhynchobatus spp. The present study improves our understanding of shark-like batoid spatial ecology in nearshore waters and may provide useful information for the management of these populations.     

Forest corridors maintain historical gene flow in a tiger metapopulation in the highlands of central India

Understanding the patterns of gene flow of an endangered species metapopulation occupying a fragmented habitat is crucial for landscape-level conservation planning and devising effective conservation strategies. Tigers (Panthera tigris) are globally endangered and their populations are highly fragmented and exist in a few isolated metapopulations across their range. We used multi-locus genotypic data from 273 individual tigers (Panthera tigris tigris) from four tiger populations of the Satpura–Maikal landscape of central India to determine whether the corridors in this landscape are functional. This 45 000 km² landscape contains 17% of India''s tiger population and 12% of its tiger habitat. We applied Bayesian and coalescent-based analyses to estimate contemporary and historical gene flow among these populations and to infer their evolutionary history. We found that the tiger metapopulation in central India has high rates of historical and contemporary gene flow. The tests for population history reveal that tigers populated central India about 10 000 years ago. Their population subdivision began about 1000 years ago and accelerated about 200 years ago owing to habitat fragmentation, leading to four spatially separated populations. These four populations have been in migration–drift equilibrium maintained by high gene flow. We found the highest rates of contemporary gene flow in populations that are connected by forest corridors. This information is highly relevant to conservation practitioners and policy makers, because deforestation, road widening and mining are imminent threats to these corridors.     

Habitat selection and movement ecology of eastern Hermann’s tortoises in a rural Romanian landscape

Understanding wildlife movements and habitat selection are critical to drafting conservation and management plans. We studied a population of eastern Hermann’s tortoise (Testudo hermanni boettgeri) in a traditionally managed rural landscape in Romania, near the northern edge of the species geographic distribution. We used telemetry to radio-track 24 individuals between 2005 and 2008 and performed a Euclidian distance-based habitat selection analysis to investigate habitats preferred by tortoises at both landscapes (second-order order selection) and individual (third-order selection) home range scales. The home range size for tortoises in our study area was 3.79?±?0.62 ha and did not differ by gender or season (pre- and post-nesting seasons). Their movement ecology was characterized by short-distance movements (daily mean?=?31.18?±?1.59 m), apparently unaffected by habitat type. In contrast to other studies, movements of males and females were of similar magnitude. At the landscape (population home range) scale, grasslands and shrubs were preferred, but tortoises also showed affinity to forest edges. At the individual home range scale, tortoises selected grassland and shrub habitats, avoided forests, and used forest edges randomly. Creeks were avoided at both spatial scales. Our results suggest that tortoise home ranges contain well-defined associations of habitats despite a higher selection for grasslands. As such, avoiding land conversion to other uses and maintaining habitat heterogeneity through traditional practices (e.g., manual mowing of grasslands, livestock grazing) are critical for the persistence of tortoise populations.     

Litter dynamics and fine root production in Schizolobium parahyba var. amazonicum plantations and regrowth forest in Eastern Amazon

Forest plantations and agroforestry systems with Schizolobium parahyba var. amazonicum have greatly expanded in the Brazilian Amazon, generally as an alternative for reforesting degraded areas. To our knowledge there are no reports of above- and below-ground production in these forest systems. We quantified litter and fine root production in 6-yr old Schizolobium-based plantation forests (monospecific: MON, mixture: MIX, and agroforestry system: AFS) and in ~25-yr old regrowth forest (REG) over 8–12 months. We used litter traps and ingrowth cores to quantify litter and fine root production, respectively. Annual litter production was significantly lower in Schizolobium-based plantations (mean ± standard error, MON?=?5.92?±?0.15, MIX?=?6.08?±?0.13, AFS?=?6.63?±?0.13 Mg ha^?1 year^?1) than in regrowth forest (8.64?±?0.08 Mg ha^?1 year^?1). Schizolobium-based plantations showed significantly higher litter stock (MON?=?7.7?±?1.0, MIX?=?7.4?±?0.1 Mg ha^?1) than REG (5.9?±?1.3 Mg ha^?1). Total fine root production over an 8-month period was significantly higher in Schizolobium-based plantations (MON?=?3.8?±?0.2, MIX?=?3.4?±?0.2, AFS?=?2.7?±?0.1 Mg ha^?1) than in REG (1.1?±?0.03 Mg ha^?1). Six-yr old Schizolobium-based plantations and ~25-yr old regrowth forests showed comparable rates of litter + fine root production, suggesting that young forest plantations may be an interesting alternative to restore degraded areas due to early reestablishment of organic matter cycling under the studied conditions.     

Population dynamics, growth and reproduction of Corophium insidiosum (Crustacea: Amphipoda) at low salinities in Monolimni lagoon (Evros Delta, North Aegean Sea)

Distribution, population dynamics, growth and aspects of reproductive biology of Corophium insidiosum were investigated in Monolimni lagoon. Samples were collected in July 1997 (at 30 psu S) and during February 1998–May 1999 (at 0.1–5.7 psu S). Corophium insidiosumwas almost exclusively found in the outer part of the lagoon, which showed a higher water renewal rate. Population density gradually decreased during winter and spring, when salinity was lower than 1 psu and the amphipod finally vanished from the lagoon. Salinity increase during summer (1.2–5.7 psu) was followed by the re-occurrence of C. insidiosum with a time lag of 2–3 months. Population density increased in autumn and peaked in early winter at salinities 1.6–4.2 psu. Three cohorts appeared in the population during September 1998–March 1999. Breeding activity peaked in early autumn (14–21?°C, 4 psu S) and ceased after December (2–6.5?°C, ¡1.5 psu S). The preponderance of females in the large size classes resulted in a female- biased sex ratio in the whole population. The population showed a growth rate of 7.5–11.2 μm d^?1 being faster in autumn (9–21?°C, 3–4 psu S) than in winter (2–12?°C, 0.2–3 psu). An exponential relation existed between body length and cephalic length or dry body weight, while brood size was directly related to body length. Mean brood size was small (4.96 early embryos) and egg loss during development high (53%), possibly as a consequence of low salinities.     

Long-term monitoring of a Bengal tiger (<Emphasis Type="Italic">Panthera tigris tigris</Emphasis>) population in a human-dominated landscape of Central India

Long-term monitoring of tiger population is essential in any human-dominated landscape as globally their population is showing a declining trend due to unrelenting stress or stochastic events. In view of that, Bengal tiger population was monitored in Pench Tiger Reserve (Pench), Madhya Pradesh of Central India between May 2006 and April 2013. The population, age-sex ratios, survival rate, growth rate, and recruitment pattern of adult (≥36 month), subadult (≥18 to 36 month), and cubs (≤15 month) were studied using camera trap and radio-telemetry techniques. Overall, tiger density ± SE/100 km² using Maximum Likelihood Spatial Explicit Capture Recapture method was 5.5 ± 1.6 in first trapping period or year and 3.7 ± 0.8 in last or seventh trapping year. The estimated survival rate of all tiger (n = 66) was 0.66 (±0.04), whereas mean annual growth rate (±SE) was 1.15 (±0.11) i.e. 15%. The sex ratio (male/female) found to be female biased and more than 80% of overall recruitment was contributed by female tiger. The dispersal of subadults in the tiger population contributed gradual fluctuation in survival rate and annual growth rate, as resident adult tiger population remained almost stable over the study period. As the overall tigers are surviving in a small population size and operating at carrying capacity, the important corridors connecting with neighboring population of Kanha Tiger Reserve and Satpura Tiger Reserve may ensure constant emigration and immigration to reduce the chances of genetic drift or inbreeding in the Pench tiger population.     

The ecosystem engineering role of the Neotropical crab <Emphasis Type="Italic">Cardisoma guanhumi</Emphasis> on mangrove soil properties

The land crab Cardisoma guanhumi is one of the most common species in mangroves of the American Atlantic coast and Caribbean islands however, studies of its effects on the physical and chemical soil properties are scarce. This study compares specific physicochemical properties of soil between C. guanhumi burrows (B) and adjacent zones (AZ), and provides the first insights on their role as an ecosystem engineer in mangroves. The study was conducted in an estuarine system dominated by Rhizophora mangle, located at the Río Chico estuary, Miranda state of Venezuela. Random soil samples were taken digging each burrow until reaching the bottom and at the same depth for AZ. Data analysis was carried out using Bayesian inference. Credible mean differences between B and AZ, were found for sand (B?=?26.53?±?10.76, AZ?=?17.25?±?5.7%), silt (B?=?73.16?±?10.77, AZ?=?82.42?±?5.69%), pH (B?=?8.71?±?0.36, AZ?=?9.12?±?0.30), soil organic matter (SOM, B?=?0.43?±?0.21, AZ?=?0.17?±?0.06%), total N (TN, B?=?786?±?232, AZ?=?529?±?107 µg g^?1), Mg (B?=?4.42?±?0.60, AZ?=?3.48?±?0.71 cmol_c kg^?1) and K (B?=?0.12?±?0.05 AZ?=?0.06?±?0.02 cmol_c kg^?1). Chemical variables as SOM, K, Mg and TN showed the highest values of effect size (>?1.4). With the exception of the pH, all chemicals variables—which were different between B and AZ—showed strong and decisive evidences of correlations with SOM. When SOM variable was controlled, the relationships between pH–TN, TN–K and Mg–K decreased, even though the correlation evidence between each pair remained. Differences in chemical contents found in B respect to AZ suggest that the activities of C. guanhumi (feeding, moulting, excretion and defecation) within their burrows promote the spatial heterogeneity of mangrove soils.     

Life in Unpredictable Environments: First Investigation of the Natural History of Microcebus griseorufus

The dry spiny forest of southern Madagascar is a highly unpredictable environment in terms of the amount and distribution of rainfall. The region is also subject to marked El Niño oscillations. One of the inhabitants of the region is Microcebus griseorufus (Kollman, 1910), the reddish-grey mouse lemur. During the 4 yr of the study, the focal population underwent marked fluctuations in size and exhibited a relatively long reproductive season: September–May. Subjects used daily torpor and expressed opportunistic seasonal fattening when food availability was high. They fed mainly on gum, especially during periods of drought. The estimated sex-ratio of the population is 54% female. Young males dispersed. Females and less frequently, males, associated in same-sex pairs that sometimes joined to form larger sleeping groups. I observed both erratic and resident males, the latter sometimes associated with females in sleeping groups. Mating occurred from September to January and involved mate-guarding. Individual female home ranges (N?=?14) overlapped with, on average, 2.8?±?0.3 male home ranges (range 2–5), whereas individual male home ranges (N?=?12) overlapped with 4.7?±?0.4 female home ranges (range 2–7). Female estrus was not synchronized, even within the female pairs, allowing alloparental care. Gestation lasted 52 d in 1 female, and litter size could be as high as 3; 20 reproductive females out of 37 adult females raised only 1 or 2 young per year.     

Spawning seasonality and body sizes at sexual maturity in the bluespine unicornfish,Naso unicornis (Acanthuridae)

We herein evaluate several reproductive metrics of Hawaiian Archipelagic populations of the bluespine unicornfish (Naso unicornis), an economically and ecologically important, broadly distributed tropical Pacific reef fish, based on multi-year, fishery-dependent and fishery-independent collections. Sex-specific spawning seasonality was characterized for fish collected mostly from Oahu (Main Hawaiian Islands, MHI) using a gonadosomatic index. Histological slides preparations were used to score gonad developmental phase and to classify individuals of either sex as immature or mature. Sex-specific median body lengths at maturity (L₅₀) were estimated by logistic fits of proportion mature versus length class. Spawning was highly seasonal in Hawaii, with a single brief (May–June) peak spawning period. Proportionate gonad-to-body weight values were relatively low, averaging only about 0.1 % and 0.6 % across all months of year and 0.16 % and 1.03 % during May–June for males and females, respectively. Median lengths at sexual maturity differed between the sexes. L₅₀ values for fish collected throughout all months of year were 30.1 ± 0.5 (standard error) cm Fork Length (FL) for males and 35.5 ± 0.7 cm FL for females. Spawning seasonality and L₅₀ estimates for bluespine unicornfish in Hawaii suggest that the species spawns several months earlier in the calendar year and matures at larger body lengths in Hawaii versus Guam, the Northern Mariana Islands, and Pohnpei in the Federated States of Micronesia. Estimated lengths at sexual maturity are compared to the minimum length (14 inches or 35.6 cm FL) mandated for this species in Hawaii: median size at maturity occurs at a length appreciably less than (males) or approximately equal to (females) minimum legal size. A likely disproportionately large contribution of old females to population replenishment is discussed relative to the minimum size limit.     

First direct, site-wide penguin survey at Deception Island, Antarctica, suggests significant declines in breeding chinstrap penguins

Deception Island (62°57′S, 60°38′W) is one of the most frequently visited locations in Antarctica, prompting speculation that tourism may have a negative impact on the island’s breeding chinstrap penguins (Pygoscelis antarctica). Discussions regarding appropriate management of Deception Island and its largest penguin colony at Baily Head have thus far operated in the absence of concrete information regarding the current size of the penguin population at Deception Island or long-term changes in abundance. In the first ever field census of individual penguin nests at Deception Island (December 2–14, 2011), we find 79,849 breeding pairs of chinstrap penguins, including 50,408 breeding pairs at Baily Head and 19,177 breeding pairs at Vapour Col. Our field census, combined with a simulation designed to capture uncertainty in an earlier population estimate by Shuford and Spear (Br Antarct Surv Bull 81:19–30, 1988), suggests a significant (>50?%) decline in the abundance of chinstraps breeding at Baily Head since 1986/1987. A comparative analysis of high-resolution satellite imagery for the 2002/2003 and the 2009/2010 seasons suggests a 39?% (95th percentile CI?=?6–71?%) decline (from 85,473?±?23,352 to 52,372?±?14,309 breeding pairs) over that 7-year period and provides independent confirmation of population decline in the abundance of breeding chinstrap penguins at Baily Head. The decline in chinstrap penguins at Baily Head is consistent with declines in this species throughout the region, including sites that receive little or no tourism; as a consequence of regional environmental changes that currently represent the dominant influence on penguin dynamics, we cannot ascribe any direct link between chinstrap declines and tourism from this study.     

Individual Intake of Free-Choice Mineral Mix by Grazing Beef Cows May Be Less Than Typical Formulation Assumptions and Form of Selenium in Mineral Mix Affects Blood Se Concentrations of Cows and Their Suckling Calves

The objectives of this study were to determine (1) the individual ad libitum intake of mineral mix by beef cows managed under a year-long, fall-calving, forage-based production regimen and (2) if Se form in the mineral mix affected the blood Se concentrations of cows and suckling calves. Twenty-four late-gestation (6 to 8 months) Angus-cross cows (2.7?±?0.8 years; body weight [BW]?=?585?±?58 kg) were blocked by BW and randomly assigned (n?=?8) to a mineral supplement treatment (TRT) containing 35 ppm Se as either inorganic (ISe; sodium selenite), organic (OSe; Sel-Plex®), or a 1:1 combination of ISe/OSe (MIX). Cows commonly grazed a 10.1-ha predominately tall fescue pasture and had individual ad libitum access to TRT using in-pasture Calan gates. Cows calved from August to November and calves had common ad libitum access to creep feed and a mineral supplement that lacked Se. Cow jugular blood was taken at 28-day intervals (13 periods) and calf blood was taken with cows from birth through weaning. Individual cow mineral mix (mean?=?54.0?±?7.0 g/day, range?=?97.3 to 27.9?±?7.4 g/day) and Se (mean?=?1.82?±?0.25 mg/day, range?=?3.31 to 0.95?±?0.25 mg/day) intakes were affected by period (P?<?0.0001), but not by cow Se TRT (P?>?0.30). Cow blood Se (0.109 to 0.229?±?0.01 μg/mL) was affected (P?<?0.002) by period, Se form, and their interaction, with ISe?< MIX for periods 8 and 11, ISe?<?OSe for all periods except period 1, and MIX?<?OSe for periods 2 to 4, 7, 8, 10, and 12. Calf blood Se (in micrograms Se per milliliter) was correlated with cow blood Se and affected (P?<?0.0001) by cow Se TRT, with ISe (0.07 to 0.11)?<?MIX (0.10 to 0.15)?=?OSe (0.16 to 0.19). These data reveal that (1) mean supplemental ad libitum cow mineral intake was 36 % less than the typical formulation intake expectations (85 g/day) and, correspondingly, mean supplemental Se intake was 33 % less than that allowed by the FDA and (2) cow Se TRT differentially affected both cow and calf blood Se concentrations, resulting in adequate concentrations for all cows but inadequate concentrations for ISe calves.