用粪便形态特征初步研究新疆塔里木马鹿种群年龄和性别

塔里木马鹿分布在干旱地区,是唯一的适应干旱荒漠环境的特殊马鹿亚种之一.目前,塔里木马鹿种群面临着栖息地退缩和片段化的双重影响,这不仅导致了种群数量的锐减,而且也因物种遗传漂变和近亲繁殖的不断增加,进一步加剧其濒危程度.为了有效地保护该物种,全面了解种群结构是至关重要.对塔里木马鹿粪便的长度、宽度、长度/宽度比例和体积等参数进行了测量,并采用判别分析方法划分种群年龄.结果表明,塔里木马鹿粪便形态在不同性别之间有差异,一般雌性的粪便大于雄性(P<0.05).同时根据粪便形态对种群年龄划分为成年雄性、成年雌性和幼体等3个年龄组.     

Correlates and Consequences of Dominance in a Social Rodent

In harem‐polygynous societies, body condition is often correlated with dominance rank. However, the consequences of dominance are less clear. High‐ranking males do not inevitably have the highest reproductive success, especially in systems where females mate with multiple males. In such societies, we expect male reproductive success to be more highly skewed than female reproductive success, but reproductive skew in females can still arise from rankings established within matrilineal societies. Dominance can also impact life‐history decisions by influencing dispersal patterns in yearlings. To better understand the function of dominance in harem‐polygynous societies, we studied the causes and consequences of dominance in yellow‐bellied marmots (Marmota flaviventris), a social rodent with skewed male reproductive success and female reproductive suppression. Specifically, we examined body condition as a predictor and the probability of breeding, number of offspring, and dispersal as outcomes of dominance. Additionally, we looked at variation in dominance between males and females and adults and yearlings, because marmots can engage in distinct interactions depending on the type of individuals involved. We found that marmots in better body condition have higher dominance rank than those in poorer condition. In addition, adults are dominant over yearlings. Within yearlings, dominance does not influence dispersal, but those in better body condition are less likely to disperse. Within all adults, individuals in better condition produce more offspring per year. Within adult males, more dominant males have greater reproductive success. Despite previous evidence of reproductive suppression in females, we found no effects of dominance rank on female reproductive success in the current study. The function of dominance in female marmots remains enigmatic.     

Identification and breeding of yearling Piping Plovers

ABSTRACT Age of first breeding is an important life history trait. Many Piping Plovers (Charadrius melodus) do not breed as yearlings, but little information is available concerning the age of first breeding. From 2000 to 2006, we marked 991 chicks in three areas in Saskatchewan, Canada, and subsequently determined when 102 (49 females and 53 males) first bred. Females bred significantly earlier, on average, than males. More females (68%) bred as yearlings than did males (41%; P= 0.04), with most others first nesting when 2‐yr old (29% of females and 50% of males). As expected from differences between the sexes in age of first breeding, younger females were more likely to pair with older males than were younger males with older females. Chicks that hatched early in the breeding season did not breed at an earlier age than those that hatched late in the year. Unlike older birds, juvenile Piping Plovers do not replace flight feathers during their first winter. As a result, 18 of 27 yearlings (67%) had worn outer primaries, whereas only one of 123 (1%) older birds had worn primaries. In addition, whereas 20 of 24 yearlings (83%) retained a few buff‐tipped median coverts, none of 119 known older birds had such coverts. As a result, we were able to identify all yearlings by their worn primaries, buff‐tipped median wing coverts, or both. Wing lengths of yearling Piping Plovers were 3% shorter than those of older birds, presumably due to wear. Because there is no evidence of differences in adult survival rates between the sexes and breeding habitat is available, we speculate that fewer yearling males than females breed because primary wear may reduce the ability of yearling males to perform aerial breeding displays.     

Mutual benefits of associations between breeding and non-breeding White-fronted Geese Anser albifrons

The relationships between yearlings and adult pairs of White-fronted Geese Anser albifrons were studied during pre-nesting, laying and early incubation in the central Canadian Arctic. Prior to nesting, females of lone pairs spent 75–81% of their time feeding, while males spent only 42–47% of time feeding and 46–50% alert. In pairs with one or more associated yearlings, both females and males fed significantly more and spent less time vigilant. Yearlings spent significantly less time (59%) feeding when alone compared with 71–76% when with pairs. Associations between yearlings and paired adults were most frequent before adult females began prospecting for nest sites. No prospecting pairs were associated with yearlings. After the egg-laying period, groups of geese, predominantly yearlings, made distraction flights over humans and terrestrial predators approaching nests, in contrast to the more cryptic behaviour of nesting pairs. The presence of groups of geese associated with some nest sites suggests that continuing parent-offspring relationships may involve assistance with nest defence.     

Sexual dimorphism in longnose gar Lepisosteus osseus

The present study of Lepisosteus osseus dimorphism expands upon previous work by examining a broader array of morphometric characters while removing the bias associated with overall body length. A stepwise discriminant function analyses (swDFA) found that five characters best distinguish the sexes: head width, mid-snout width, anal-fin height, anal-fin width and prepectoral-fin length. Discriminant function analyses (DFA) with the five characters yields misclassification rates of 23·5% for females and 9·7% for males. Subsequent DFA using these five characters plus standard length yields misclassification rates of only 8·8% for females and 6·2% for males. The data presented here reveal differences in head and anal-fin shape between male and female L. osseus that may have evolved to enhance predatory abilities or competitive abilities during reproduction. This study is the first to find that L. osseus exhibits sexual dimorphism in characters without the biases of overall size.     

Sex-specific differences in body condition indices and seasonal mass loss in Tufted Puffins

ABSTRACT.   Reduced prey availability can affect the growth and survival of nestling seabirds. However, few studies have demonstrated similar effects on indices of adult body condition. We examined body condition and seasonal mass loss of breeding adult male and female Tufted Puffins ( Fratercula cirrhata ) at Chiniak Bay, Kodiak Island, Alaska, in 2004–2005. We determined sex using genetic analysis, developed a discriminant function to determine sex using morphometric measurements, and examined the body condition of adult males and females relative to the growth rates of their offspring. We found that morphological measurements were only moderately useful for sexing Tufted Puffins, with 74% of adults ( N = 176) correctly classified. We also found that the relationship between adult body mass and size differed between sexes and conclude that body condition indices must be calculated separately for each sex to avoid inter- and intrasexual bias. Body condition of male and female Tufted Puffins declined during the chick-rearing period. However, body condition of females did not differ between years, whereas male condition declined to a greater degree during 2004 when the mass of young at fledging was significantly lower. Although these results suggest that adult male Tufted Puffins sacrifice their own body condition in years of diminished nestling growth and females do not, reasons for this apparent intersexual difference in reproductive strategies remain unclear.     

Sexing adult Northern Shrikes using DNA, morphometrics, and plumage

ABSTRACT.   Northern Shrikes ( Lanius excubitor ) are predatory songbirds found primarily in taiga regions throughout their Holarctic breeding range. The species is poorly known, especially in North America, and is generally thought to be sexually monomorphic. From 2004 to 2007, we captured 50 adults in northern Wisconsin during the nonbreeding season (December–March) and determined sex using DNA extracted from feather samples. Males had significantly longer wings, longer tails, and less black in the outer rectrix than females, but body mass did not differ between the sexes. A discriminant function equation using tail length and extent of black on the outer rectrix correctly assigned the sex of 97.4% of captured adults. Plumage dimorphism was also evident, with males having paler gray heads and backs without brown tones, whiter underparts with lighter barring, and a more distinct and horizontal border at the base of the sixth primary feather. The ability to accurately determine sex will provide opportunities to examine possible inter- and intrasexual differences in the behavior and ecology of adult Northern Shrikes.     

A new method for sexing Oriental White Storks

ABSTRACT.   For species where males and females are monomorphic, or nearly so, determining the sex of individual birds generally requires either capturing birds or collecting samples, such as feathers, for DNA analysis. We developed a new method, involving the use of photographs, to determine the sex of endangered Oriental White Storks ( Ciconia boyciana ). Using photographs, we analyzed the lateral features of the heads of 25 captive storks of known sex (12 males and 13 females) and found differences between males and females in the distance from the bill tip to the nape and the distance from the bill tip to the commissural point. These differences were used to generate a discriminant function that was then tested on 22 captive storks at Hyogo Homeland Park (Toyooka, Japan), and we correctly determined the sex of 18 individuals (82%). In addition, the sex of two wild storks was correctly assigned. Our results suggest that good-quality photographs can be useful for determining the sex of both captive and wild Oriental White Storks and, further, that similar methods may prove useful for determining sex in other species of birds.     

Sex determination of African Penguins Spheniscus demersus using bill measurements: method comparisons and implications for use

African Penguins Spheniscus demersus are sexually dimorphic; on average, males are larger than females but measurements overlap making sex determination difficult through observations alone. We developed a discriminant function, using bill length and depth from a sample of birds sexed from gonad visualisation during post-mortem, which correctly classified 93% of the individuals. Cross-validation correctly assigned 90% of DNA-sexed birds and 91% of birds sexed by partner measurement comparisons. The use of discriminant function score cutpoints, while leaving 16% and 29% of birds unclassified, improved accuracy of birds sexed by DNA to 97% and of those sexed by partner comparison to 99%. Bill depth was found to be a discriminating variable. However, two techniques for measuring bill depth are currently in use for African Penguins. While these measurements are correlated (r = 0.85), they differ on average by 1.4?mm hindering accuracy of sex determination when using a discriminant function developed from the other bill depth measurement. Exploration of adult bill morphology of birds sexed from DNA at different colonies suggests the discriminant functions can be applied throughout the African Penguins’ South African range.     

Egg morphology fails to identify nests parasitized by conspecifics in common pochard: a test based on protein fingerprinting and including female relatedness

Conspecific brood parasites lay eggs in nests of other females of the same species. A variety of methods have been developed and used to detect conspecific brood parasitism (CBP). Traditional methods may be inaccurate in detecting CBP and in revealing its true frequency. On the other hand more accurate molecular methods are expensive and time consuming. Eadie developed a method for revealing CBP based on differences in egg morphology. That method is based on Euclidean distances calculated for pairs of eggs within a clutch using standardized egg measurements (length, width and weight). We tested the applicability of this method in the common pochard Aythya ferina using nests that were identified as parasitized (39 nests) or non‐parasitized (16 nests) based on protein fingerprinting of eggs. We also analyzed whether we can distinguish between parasitic and host eggs in the nest. We found that variation in MED can be explained by parasitism but there was a huge overlap in MED between parasitized and non‐parasitized nests. MED also increased with clutch size. Using discriminant function analysis (DFA) we found that only 76.4% of nests were correctly assigned as parasitized or non‐parasitized and only 68.3% of eggs as parasitic or host eggs. Moreover we found that MED in parasitized nests increased with relatedness of the females that laid eggs in the nest. This finding was supported by positive correlation between MED and estimated relatedness in female–female pairs. Although variation in egg morphology is associated with CBP, it does not provide a reliable clue for distinguishing parasitized nests from non‐parasitized nests in common pochard.     

Movements of white-tailed deer in riparian habitat: Implications for infectious diseases

Movements of male white-tailed deer (Odocoileus virginianus) are of great concern with respect to spread of chronic wasting disease (CWD) across landscapes because most yearlings males disperse and adult males have higher prevalence of CWD than do females and younger deer. We radiocollared and monitored 85 male white-tailed deer in the middle Missouri River Valley of eastern Nebraska and western Iowa, USA from 2004 to 2008. Average size (±SE) of fixed-kernel annual home ranges (95%) and core areas (50%) for resident deer were 449 (±32) ha and 99 (±7) ha, respectively. Resident deer exhibited a high-degree of fidelity to their home ranges. Mean overlap between consecutive annual home ranges and core areas was 81% and 74%, respectively. Average dispersal distance was 17.7 ± 4.5 km (range = 3–121 km) for 22 radio-marked and 6 ear-tagged yearlings. Mean spring dispersal distance (25 km) was 150% greater than fall (10 km). Dispersal direction from Desoto National Wildlife Refuge (DNWR) was bimodal on a northwest to southeast axis that followed the Missouri River corridor. Of 22 yearlings that dispersed, 18 (82%) established adult home ranges within the river valley. Dispersal movements of yearling males represent the greatest risk for rapid spread of diseases from infected source populations. Disease management efforts in riparian habitats should target male fawns and yearling males for removal in areas within or immediately adjacent to river corridors. © 2011 The Wildlife Society.     

Testing acoustic versus physical marking: two complementary methods for individual-based monitoring of elusive species

Individuals of some species differentiate each other on the basis of the acoustic features of their vocalizations, and this can be used in individual‐based population monitoring studies. No research has tested for the effectiveness of individual marking through voice recognition as compared to traditional monitoring methods relying on physical marks. We compared voice recognition and physical marking using the Dupont's lark Chersophilus duponti as a study species. This bird needs to be attracted with playback in order to be seen (or captured). We first demonstrated that the territorial calls from a sample of banded males were individually distinctive and constant over time by means of discriminant function analysis, which correctly classified 100% of marked males. Then, we applied similarity techniques on call spectrotemporal features to define a threshold value of similarity within banded individuals, to be combined with qualitative spectrogram inspection for the classification of all recorded birds. Eventually, we compared the voice and the capture samples, to test for differences in relation to re‐location rate, territory fidelity and dispersal movements both within and between years. Voice recognition was less time‐consuming than capture‐recapture method in the field, but it was useless for monitoring yearlings in call development stage. The two methods provided the same results in terms of territory fidelity and dispersal movements, but differed in re‐location rates, which were significantly greater in the case of voice recognition method. By means of physical captures we possibly trapped a large sample of young and silent floaters, with low probability of recapture or recording. This mismatch between methods could bias the estimates of annual survival, which strongly depend on re‐location rates. We suggest considering the two methods as complementary rather than alternatives for monitoring populations. Each technique offers unique information, and the two sources should be combined to provide correction factors that would eventually sharpen our knowledge on bird population ecology.     

An approach to sexing young Great Bustards Otis tarda using discriminant analysis and molecular techniques

Adult Great Bustards Otis tarda are sexually dimorphic, males weighing more than twice as much as females. However, there is no practical way to distinguish sex in chicks by their morphology. In this paper we describe a discriminant function, Tail Length/Weight, which correctly sexed 98.2% of 165 Great Bustard chicks at two study areas in Spain, the Wildlife Reserve of Lagunas de Villafáfila and the province of Madrid. The value for Tail Length/Weight separating the sexes was 0.099: Tail Length/Weight for males < 0.099 < Tail Length/Weight for females. We also show that the recently described PCR-based sex determination technique using genomic DNA is valid for the Great Bustard. Both approaches should be useful for sexing young Great Bustards in captive breeding programmes and studies on wild populations.     

Seasonality of reproduction in the European badger Meles meles in south-west England

The reproductive cycle of male and female badgers in the south-west of England was studied by post-mortem examination of 1875 badgers collected in 1973–80. The sample was obtained by several methods and showed that animals obtained as road casualties were not representative of the total population samples. Active spermatogenesis was present throughout the year, and in some males aged 8–9 months. A few females first ovulated as yearlings but most primiparous females were adults. Births were in general confined to the early part of the year, but ovulations and matings also occurred at other times. Almost all (97%) adult females possessed corpora lutea. Unimplanted blastocysts were found in females for 11 months of the year (over 80% of adult females in July-November). Implanted embryos were found in only 32% of adults in January and February: the number of blastocysts per female and the number of implanted embryos per female were not significantly different, indicating that sows implanted all blastocysts or none. Foetal mortality was 36% and post-natal losses were estimated at 42% from the proportion of lactating females.     

Geographic morphological variation of Gentoo penguin (Pygoscelis papua) and sex identification: using morphometric characters and molecular markers

Gentoo penguins Pygoscelis papua have sexual dimorphism, which females have smaller morphological measurements than males. P. papua also shows a geographic morphological variation, decreasing in size toward southern latitudes. Therefore, morphological measurements may vary in space and overlap in the distribution of traits between females and males, which could lead to sex misidentification. A total of 300 blood samples and eight measurements and weight were obtained for Gentoo penguins from three localities in the South Shetland Islands and the Antarctic Peninsula. The molecular sex was identified for all individuals using two primer pairs (P2/P8 and PL/PR). We obtained higher success amplification for P2/P8 compared to PL/PR. We used 172 adults to create a morphological discriminant function using the backward stepwise method. We established a discriminant function for sex identification of each locality due to significant morphological differences found between sexes and between the three studied localities for adult Gentoo penguins. Using these functions, the percentages of individuals correctly assigned was 93.87 % in Ardley Island, 88.09 % in Bernardo O’Higgins, and 83.95 % in Gabriel Gonzalez Videla. The most southern locality studied was the most morphologically divergent from the others and with low divergence between sexes. Moreover, we also established a general function for the Gentoo penguin, which can be used to identify the sex of penguins from a broad number of localities. Therefore, molecular and biometric are useful techniques for sexing Gentoo penguins.     

Brief communication: Sexual dimorphism of the juvenile basicranium

The purpose of this article is to examine the level of sexual dimorphism exhibited in the foramen magnum and occipital condyles of juveniles, and to test the utility of this sexual dimorphism for estimating sex. Using five basicranial measurements taken from 36 juveniles of known sex and age from the Lisbon documented collection (Portugal), we evaluated sexual dimorphism in the juvenile cranial base. Our application of a method previously applied solely to adults indicated that the basicranium is sexually dimorphic in juveniles, with larger foramen magnum and occipital condyle dimensions observed in males. Significant univariate differences between males and females were found for length and breadth of the foramen magnum, and breadth of the left occipital condyle. Using these measurements, multivariate discriminant analysis indicated that sex was correctly assigned 75.8% of time. Obtained accuracy, however, was lower than reported by previous studies of adult samples. We suggest that this discrepancy is a result of population variability rather than age. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.     

Male red deer (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) dispersal during the breeding season

Breeding dispersal can be of significant ecological and evolutionary importance. Yet, it is seldom considered in mammals. I present data on male red deer (Cervus elaphus) movements between sub-populations in southern Sweden during the rut. I investigated whether these movements could be breeding dispersal driven by mate competition. During the ruts of 1998–2009, I recorded 91 movements of males. The longest movement distance was 18.5 km. Dispersal was not restricted to yearlings or sub-adults, but also observed among adult stags. Of 91 movements observed, 7 were made by yearlings, 46 by sub-adults and 38 by adults. There was a significant move among yearlings and sub-adults towards areas with a higher ratio of females/adult males and towards areas with more females. The movements between rutting areas thereby seemed driven by sexual competition.     

Multivariate sexing of the viscercranium inCercopithecus pygerythrus

One hundredCercopithecus pygerythrus crania were subjected to canonical and stepwise discriminant analyses utilizing four viscerocranial measurements and two indices to determine specific characteristics useful in sexual distinction of skeletal material. The maxillo-alveolar length alone accounted for correct classification of 96.33% of males and 93.75% of females. Addition of the bimaxillary breadth enables 98.17% of males and 95.83% of females to be correctly assigned. From the observed contrast between univariate and multivariate analyses of the data set, it is concluded that both methods should routinely be combined in the evaluation of skeletal material.     

Sex determination of Pohnpei Micronesian Kingfishers using morphological and molecular genetic techniques

ABSTRACT.   Conservation-oriented studies of Micronesian Kingfishers ( Todiramphus cinnamominus ) have been hindered by a lack of basic natural history information, despite the status of the Guam subspecies ( T. c. cinnamominus ) as one of the most endangered species in the world. We used tissue samples and morphometric measures from museum specimens and wild-captured Pohnpei Micronesian Kingfishers ( T. c. reichenbachii ) to develop methods for sex determination. We present a modified molecular protocol and a discriminant function that yields the probability that a particular individual is male or female. Our results revealed that females were significantly larger than males, and the discriminant function correctly predicted sex in 73% (30/41) of the individuals. The sex of 86% (18/21) of individuals was correctly assigned when a moderate reliability threshold was set. Sex determination using molecular genetic techniques was more reliable than methods based on morphology. Our results will facilitate recovery efforts for the critically endangered Guam Micronesian Kingfisher and provide a basis for sex determination in the 11 other endangered congeners in the Pacific Basin.     

Sex determination using the scapula in medieval skeletons from East Anatolia

Sex determination from skeletal human remains by discriminant function analysis is one of the methods utilized in the forensic and osteoarcheological sciences. The purpose of the present study is to establish metric standards for sex determination for medieval Anatolian populations using scapular measurements. The database for this research consisted of 93 adult skeletal remains (47 males and 46 females) from the Dilkaya medieval collection. Four measurements were taken: maximum scapular height, maximum scapular breadth, glenoid cavity height, glenoid cavity breadth, and subjected to discriminant function analysis. All measurements demonstrated some degree of sexual dimorphism, with the highest accuracy of sex determination (94.8%) obtained using maximum scapular breadth. Overall accuracies of the functions ranged from 82.9% to 95.0%, with a higher accuracy rate obtained for female skeletons than for males. Population specific discriminant formulas were developed using combinations of measurements, which can be used in ancient Anatolian populations.