Pelage Patterns Research Articles

The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis

Across their range jaguars Panthera onca are important conservation icons for several reasons: their important role in ecosystems as top carnivores, their cultural and economic value, and their potential conflicts with livestock. However, jaguars have historically been difficult to monitor. This paper outlines the first application of a systematic camera trapping methodology for abundance estimation of jaguars. The methodology was initially developed to estimate tiger abundance in India. We used a grid of camera traps deployed for 2 months, identified individual animals from their pelage patterns, and estimated population abundance using capture-recapture statistical models. We applied this methodology in a total of five study sites in the Mayan rainforest of Belize, the Chaco dry forest of Bolivia, and the Amazonian rainforest of Bolivia. Densities were 2.4–8.8 adult individuals per 100 km2, based on 7–11 observed animals, 16–37 combined ‘captures’ and ‘recaptures’, 486–2,280 trap nights, and sample areas of 107–458 km2. The sampling technique will be used to continue long-term monitoring of jaguar populations at the same sites, to compare with further sites, and to develop population models. This method is currently the only systematic population survey technique for jaguars, and has the potential to be applied to other species with individually recognizable markings.

One thousand jaguars (Panthera onca) in Bolivia's Chaco? Camera trapping in the Kaa‐Iya National Park

AbstractThis paper reports on efforts to trap jaguars Panthera onca on camera in the dry forests of the Kaa‐Iya del Gran Chaco National Park in Bolivia. Ad hoc camera trapping provided certain information on jaguar presence and habits, but was limited in application. Activity patterns showed that jaguars are active all day, particularly at one of three sites, with peaks in the morning and evening the more common pattern. Minimum observed home range was variable, with males (up to 65 km2) occupying more area than females (up to 29 km2). The authors adapted systematic methodologies first developed to survey tigers in India, based on individually distinctive pelage patterns in tigers and jaguars. Abundance is estimated using capture–recapture statistical analysis, and a sample area defined based on the maximum distance that individual jaguars move during the sample period. The methodology has proved successful for jaguars in dry Chaco forest, population densities of 1/30–45 km2 and 1/20 km2 are estimated in the two most extensive landscape systems of Kaa‐Iya. The entire 34 400 km2 protected area is estimated to sustain a population of over 1000 adult and juvenile jaguars, the largest single population of jaguar reported anywhere, and a viable population for long‐term jaguar conservation.

COMPUTER-AIDED PHOTOGRAPH MATCHING IN STUDIES USING INDIVIDUAL IDENTIFICATION: AN EXAMPLE FROM SERENGETI CHEETAHS

Photographic identification of naturally marked animals is a powerful and nonintrusive technique for obtaining information on behavior, population size, and life-history parameters in wild populations. Yet handling large quantities of photographs is time consuming and prone to error. Computer-aided matching can limit the number of photographs that must be examined visually to confirm that 2 sightings are the same individual. To identify individuals, I used a 3-dimensional (3-D) computer-matching system to aid in matching nearly 10,000 photographs of Serengeti cheetahs, Acinonyx jubatus, taken over 25 years. Accuracy in matching 2 photographs increased to 100% as the computer-generated similarity coefficient increased to 0.600 on a scale from 0 to 1. Probability of missing a match decreased to 6.4% when I used a threshold of similarity of 0.450. Poor quality of photographs decreased accuracy and resulted in up to 33% of matches being missed. Comparisons of photographs at skewed camera angles generally reduced similarity coefficients. Similarity coefficients were no higher for related or unrelated animals, suggesting that the technique is not appropriate for distinguishing subtle similarities. Because 3-D computer-aided matching does not require familiarity with distinctive features of the particular study animal, it is robust to matcher inexperience. This technique can be modified for other species that have complex and variable pelage patterns.

Seasonal occurrence and diet of leopard seals (Hydrurga leptonyx) at Bird Island, South Georgia

Seasonal haul-out patterns and diet of individually marked leopard seals (Hydrurga leptonyx) were investigated at Bird Island, South Georgia during the 1983–96 winters. A total of 2956 leopard seal sightings were made, and 121 seals were tagged during the study, mainly between 1993 and 1996. Photographs of scars and pelage patterns were also used to identify a subset of these individuals across years, which provided no evidence of tag loss between or within years. Leopard seals were observed between April and November; the mean time between the first and last sightings in each year was 208 d (s d ± 48). Between 1993–96, eight seals were resident around the island for more than 100 d, and the longest recorded residence was 130 d. The proportion of tagged seals resighted was 0.35 and 0.17 in 1995 and 1996 respectively. Based on estimates of body length, <5% of the seals were juveniles (0–1 years) and >70% were not sexually mature. There was considerable inter-annual variation in abundance, with a maximum of 502 sightings during 1994, compared with a minimum of 21 during 1986 and 1989. Antarctic fur seals (Arctocephalus gazella) were the main prey item (58% of kills observed and 53% of scats). Other items included penguins (28% of kills observed and 20% of scats) and fish (24% of scats). Antarctic krill (Euphausia superba), southern elephant seals (Mirounga leonina) and seabirds other than penguins were also present in the diet in small quantities.

Morphological and pelage characteristics of wild living cats in Scotland: implications for defining the ‘wildcat’

AbstractThe indigenous wildcat, Felis silvestris Schreber, 1775, and the introduced domestic cat, F. catus L., have been sympatric in Britain for more than 2000 years. As a result of interbreeding, any distinction between these two forms has become obscured, although a range of morphological criteria (pelage patterns, body measurements, gut lengths, skull morphometrics) and genetic techniques (immunological distances, electrophoresis, DNA hybridization) have been used previously to distinguish between them.A sample of 333 wild‐living cats in Scotland was assessed for coloration and markings of pelage, standard body measurements and weights, and (for carcasses only) limb bone lengths, intestine lengths, and skull measurements. These cats were also classified as wildcat, hybrid, or domestic cat according to traditional pelage criteria.Multivariate analyses on these variables, for adult cats, failed to show any clearly distinct groups. When each of the variables was analysed separately, only the distribution of limb bone and intestine length measurements suggested the possibility that two groups might exist. Group 1 cats had short intestines and long limb bones. Group 2 consisted of cats with long intestines and short limb bones. Although the characteristics defining cats in Group 1 were similar to those traditionally associated with wildcats, they exhibited a much broader range of pelage and coloration than traditionally described.The groups exhibited a degree of geographical separation. The distribution of Group 1 cats was found to be related to certain environmental variables, namely mean annual temperature and land with poor potential for forestry and agriculture, suggesting that there may be a biological basis for the separation. The implications of these results on the identification and taxonomy of the wildcat are significant. The concept of the wildcat and the domestic cat as separate species can be challenged. The paper highlights the complexity and difficulties for conventional taxonomy when used as a means for distinguishing between a wild type and its domesticated form where there is interbreeding.

Physical Characteristics of Iberian Lynxes (Lynx pardinus) from Donana, Southwestern Spain

External and cranial measurements were determined for live-trapped Iberian lynxes and lynx skulls from Doñana National Park, Spain, and its surroundings. Skins of Iberian lynxes from the same population collected between 1895 and 1986 were examined to determine pelage-pattern characteristics. Adult (≥2 years old) males were larger and heavier (27.3%) than adult females. Age-classes were statistically different for most skull measurements. Considerable variation was found between juveniles (0.5–1 year old) and subadults (1–2 years old). In 10 of the 19 skull measurements, adult males were significantly larger than adult females, including length of ml, mandibular fossa—length of P4, height of mandible, length of skull, and condylobasal length. Iberian lynxes were similar in size to the Nearctic bobcat (L. rufus) and the Canadian lynx (L. canadensis). Three main pelage patterns were present in the Doñana population until 1960. Genetic variation of this population may have decreased during the past 3 decades as exemplified by the loss of the two rarest pelage patterns.

Geographical Variation in the Fork-Marked Lemur, Phaner furcifer (Primates, Cheirogaleidae)

The fork-marked lemur, Phaner furcifer, is discontinuously distributed through Madagascar, but is traditionally viewed as a monotypic species. Reexamination of variations in pelage color and pattern, size and body proportions among museum specimens reveals that several geographically discrete morphs exist within the species, which is clearly polytypic. We identify and name 2 new subspecies in western Madagascar, and 1 in the north of the island. The nominate subspecies is thought to be derived from the northeastern region, and it is possible that more discrete variants are present in that region than are formally recognizable on the basis of the current inadequate documentation. The limited nature of color variation in nocturnal lemurs relative to diurnal forms may have resulted in a general tendency to underestimate subspecific diversity in the former.

Morphometric analyses of Ateles: systematic and biogeographic implications.

This study examined the cranial and dental morphometric patterns among South American spider monkey taxa (Ateles), using various multivariate data reduction techniques to corroborate or falsify the predictions of alternative vicariance or parapatric models for explaining neotropical biodiversity. Data from 284 specimens were standardized to eliminate sex differences and then transformed by factor analysis to obviate the effects of body size on shape relationships. We found the independent discriminant analyses of dental and cranial data to be not at all dissimilar, nor did body size appear to distort geographical relationships. Thus a pooled data set of 50 measurements was further reduced by cluster analysis to produce a dendrogram of taxonomic relationships that is discordant with current classification. Three independent taxa are indicated, with the Guianan samples being most distinct, followed by the animals of northwest Venezuela and adjacent Colombia. Elsewhere, the samples describe a cline of relationships around Amazonia that resembles a ring species. Of particular interest is the apparent clinal intergradation across major tributaries of the Amazon, which is inconsistent with the concept of these rivers as barriers in their present form. Instead these observations, and the congruence between the multivariate clusters and previously identified centers of endemism, support both tierra firme and forest refugia models of historical biogeography. However, the latter model is somewhat falsified within Amazonia by character stability for alternative pelage patterns on opposite sides of the same major rivers that showed morphometric intergradation, but not as predicted within the refugia. This parapatric enhancement of pelage differences, which originated presumably in allopatry, suggests a mechanism of incipient speciation by frequency-dependent assortative mating with no apparent hybrid disadvantage or disruption of widespread gene flow.

The taxonomy of south American sakis, genus Pithecia (Cebidae, Platyrrhini): A preliminary report and critical review with the description of a new species and a new subspecies.

The report begins with a key based on external characters and a tabulation of diagnostic cranial characters for separating Pithecia from Chiropotes and Cacajao of the subfamily Pitheciinae. The description of Pithecia is based on external, cranial, dental, and certain postcranial characters with particular attention to limb proportions and the femoral third trochanter. The species of Pithecia are arranged in the Pithecia pithecia group with P. p. pithecia and P. p. chrysocephala, and the Pithecia monachus group with P. m. monachus, P. m. milleri, P. irrorata irrorata, P. i. vanzolinii (new subspecies), P. aequatorialis (new species), and P. albicans. The discussion on nomenclature compares the usage of names by various authors for the different taxa. The species previously identified by Hershkovitz [Hershkovitz, 1979] as Pithecia monachus proves to be the new species P. aevuatorialis, whereas the sympatric species he called P. hirsut Spix (1823)s the same as true P. monachus É. Geoffroy (1812). Speciation among sakis is expressed, for the most part, by marked differentiation in coloration and head pelage patterns in males. Females of corresponding males diverged along the same lines but to such lesser degree that specific discrimination between them is complicated. Details of sexual dimorphism in coloration and pelage patterns are described, and those of size are documented by summaries of weights and by measurements of external, cranial, dental, and skeletal characters for each sex of each taxon. A key to the species and subspecies of Pithecia is followed by an account of each taxon that includes statements of taxonomic history or synonymy, type specimen, type locality, and geographic distribution. A full description with the addition of accounts of diagnostic characters, variation, comparisons, measurements, list of specimens examined, and other matters, is provided only or the new forms Pithecia aequatorialis and P. irrorata vanzolinii. Comparable descriptions of all taxa are contained in Volume 2 of Living New World Monkeys, currently in preparation. The gazetteer, however, includes complete data for all saki collecting and recorded localities plotted on the range maps.

Uacaries, new world monkeys of the genus Cacajao(Cebidae, Platyrrhini): A preliminary taxonomic review with the description of a new subspecies.

The two known species of uacaries, inhabitants of the upper Amazonian region, are the black head Cacajao melanocephalus with subspecies C. m. melanocephalus Humboldt and C. m. ouakary Spix, and the larger bald head uacari C. calvus with subspecies C. c. ucayalii Thomas, C. c. rubicundus I. Geoffroy and Deville, C. c. calvus I. Geoffroy, and C. c. novaesi described as new. The diagnostic generic characters described are the external, cranial, dental, some postcranial, and cytogenetic. The species are described and compared and their geographic distribution plotted with those of their subspecies delimited. Sexual differences are outlined. Apart from size-related characters, the species and subspecies are distinguished by pelage pattern of head and coloration in general. It is shown that both species could have diverged from a hairy-headed melanistic ancestral form. Pelage divergence in the descendants was expressed by the more pilose head of C. melanocephalus, and less pilose of C. calvus. Coloration differentiation was geographic and followed metachromic lines with mutation from eumelanism to partial pheomelanism (reddish or golden) in C. melanocephalus and to virtually complete pheomelanism in C. calvus. The subspecies of each species are distinguished by color patterns resulting from selective bleaching or dilution of the pheomelanin fields. The most saturate pheomelanic subspecies of C. calvus is C. c. ucayalii and the most dilute is the albinotic C. c. calvus. Correlation between coloration and environment is not evident. A gazetteer identifies all locality records plotted by numbers on the geographic distribution maps.

Two new species of night monkeys, genus Aotus (Cebidae, platyrrhini): A preliminary report on Aotus taxonomy.

The nine allopatric species of Aotus recognized represent two natural groups distinguished by karyotype, color, and pelage patterns. Correlated with these group characters are reported differences in serum proteins and degrees of susceptibility or immunity to experimental infection with malarial parasites. The primitive gray-neck species group of Aotus contains A. brumbacki (new species), A. lemurinus (with subspecies lemurinus and griseimembra), A. trivirgatus, and A. vociferans. The derived red-neck group contains A. nancymai (new species), A. miconax. A. infulatus, and A. azarae (with subspecies azarae and boliviensis). Only the two new species are described but a key to the species and subspecies gives the diagnostic characters of each. The gray-neck group occurs almost entirely north of the Amazon, the red-neck group almost entirely south. The distributional exceptions are enclave populations resulting from river bend cutoffs. Formation of an enclave population of A. nancymai is discussed and available information on the biology of this species is reported.

Variation and Evolution of Gulf Coast Populations of Beach Mice, Peromyscus polionotus

Inadequate taxonomic research has resulted in misinterpretation of the course of evolution in these beach mice. Five new subspecies are here described. Pelage patterns are described and in the case of the three primary hair-tip rump patterns, preliminary results of laboratory breeding experiments are given, along with a model based on four postulated genes. Basal-hair melanin patterns appear to be under separate control from the hair-tip xanthophyll pigment patterns. Disharmonious interactions between two presumed phylogenetic lines with different hair-base patterns are described and discussed. Zonal variance in width of dorsal body pigment in certain specimens is attributed to epigenetic interaction during molt and an approximate molt sequence is given. Variations in color, relative paleness, and body dimensions are also discussed. Polymorphism occurs in some subspecies. Several of the pelage pattern traits that characterize different beach mouse populations have been discovered also in occasional specimens of P. maniculatus, and it is believed that many, if not all of the genes responsible for pigment reduction in intensity and extensity in the beach mice, were already present before the species came in contact with the beach dune habitat. Evolutionary sequences are discussed and certain partial reproductive barriers are noted. The species appears to be in process of splitting into two species along a line initiated by a topographical barrier during the Yarmouth interglacial stage of the Pleistocene. The two ends of a circular overlap appear to be sympatric, and a partial break in the middle of the chain of subspecies is also manifest.

Identification of individual weasels Mustela nivalis using the ventral pelage pattern

Journal of ZoologyVolume 148, Issue 4 p. 583-585 Identification of individual weasels Mustela nivalis using the ventral pelage pattern Ian Linn, Ian Linn Department of Zoology, University of Exeter, DevonSearch for more papers by this authorM. G. Day*, M. G. Day* Department of Zoology, University of Exeter, Devon *Department of Zoology, University of Manitoba, Winnipeg, Manitoba, Canada.Search for more papers by this author Ian Linn, Ian Linn Department of Zoology, University of Exeter, DevonSearch for more papers by this authorM. G. Day*, M. G. Day* Department of Zoology, University of Exeter, Devon *Department of Zoology, University of Manitoba, Winnipeg, Manitoba, Canada.Search for more papers by this author First published: April 1966 https://doi.org/10.1111/j.1469-7998.1966.tb02975.xCitations: 4 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume148, Issue4April 1966Pages 583-585 RelatedInformation

A mosaic (dark-eyed intense—pink-eyed dilute) coat colour of the house mouse

Two cases of mosaic (dark-eyed intense—pink-eyed dilute) pelage patterns are reported in the house mouse. The unusual colour was not inherited by descendants. A direct correlation between the mosaic pattern of the coat and the pattern of piebald white-spotting in this strain of mice was observed. Aberrant chromosome division in somatic tissue is suggested as an explanation of these mosaics.