Mammal Tracks Research Articles

A new mammal track from the Laramie Formation (Maastrichtian) at the Fossil Trace locality, Golden, Colorado

A previously unknown and morphologically distinct pentadactyl mammal track was recovered from the Upper Cretaceous (Maastrichtian) Laramie Formation at the Fossil Trace site, a National Natural Landmark which is the type locality for Schadipes crypticus, the only named mammal track known from North America. The track is different, and larger than S. crypticus, and thus is evidence of a diversity of mammal trackmakers at this site. Although Cretaceous mammal tracks are very rare, preliminary indications are that those currently known are all morphologically distinct and therefore indicative of a global diversity of different trackmakers, as the body fossil record suggests. Lack of well-preserved mammal trackways with morphologically distinct manus and pes footprints hampers efforts to name diagnostic ichnotaxa.

Marine mammal tracks from two-hydrophone acoustic recordings made with a glider

Abstract. A multinational oceanographic and acoustic sea experiment was carried out in the summer of 2014 off the western coast of the island of Sardinia, Mediterranean Sea. During this experiment, an underwater glider fitted with two hydrophones was evaluated as a potential tool for marine mammal population density estimation studies. An acoustic recording system was also tested, comprising an inexpensive, off-the-shelf digital recorder installed inside the glider. Detection and classification of sounds produced by whales and dolphins, and sometimes tracking and localization, are inherent components of population density estimation from passive acoustics recordings. In this work we discuss the equipment used as well as analysis of the data obtained, including detection and estimation of bearing angles. A human analyst identified the presence of sperm whale (Physeter macrocephalus) regular clicks as well as dolphin clicks and whistles. Cross-correlating clicks recorded on both data channels allowed for the estimation of the direction (bearing) of clicks, and realization of animal tracks. Insights from this bearing tracking analysis can aid in population density estimation studies by providing further information (bearings), which can improve estimates.

Lack of Response to Olfactory Lures Among Mammals in Riparian Habitat in Southern Wisconsin

Non-invasive mammal surveys often employ olfactory stimuli on the assumption that they will attract mammals and increase the success of monitoring projects. However, information on the effectiveness of scent lures is variable and often relies on data generated from mammal tracks or sign, which can be challenging to quantify. Therefore, we sought to determine whether certain olfactory stimuli are more effective than others at eliciting a response from mammals along riparian corridors in Southern Wisconsin, using camera traps to monitor response to four scents and a control of de-ionized water. We recorded the number of times each species responded as well as the length of time spent investigating scents (Muskrat gland, mink gland, Red fox urine, crayfish oil) and the control. We recorded 2812 passes by 16 mammal species during our 12-month study, with Virginia Opossum (Didelphis virginiana), Woodchuck (Marmota monax), Eastern Gray Squirrel (Sciurus carolinensis), Eastern Fox Squirrel (Sciurus niger), Raccoon (Procyon lotor), Coyote (Canis latrans), and White-tailed Deer (Odocoileus virginianus)observed on cameras most frequently. However, 72% of observations involved mammals passing through without investigating any scents or the control, and among the 28% of observations where mammals did investigate, we found no significant differences in their response to specific scents or the control or in response by season. Further analysis revealed no significant differences in the time mammals spent investigating individual scents or the control. The lack of response suggests that factors other than scent may have attracted wildlife to our stations. Although under some circumstances olfactory attractants may increase the level of response to monitoring stations, we suggest that attraction to our stations was largely a behavioural response to novel stimuli in the environment.

Diversidad, abundancia relativa y patrones de actividad de mamíferos medianos y grandes en una selva seca del Istmo de Tehuantepec, Oaxaca, México

The use of camera traps and mammal track search are complementary methods to monitoring species of which is not well documented their natural history, as in the case of medium and large mammals. To ensure its conservation and good management, it is necessary to generate information about the structure of the community and their populations. The objective of the present study was to estimate the diversity, relative abundance and activity patterns of medium and large mammals in a tropical deciduous forest located in the Isthmus of Tehuantepec, Oaxaca, Mexico. Samplings were conducted in three month intervals, from September 2011 to May 2013. We used photographic-sampling and track search, two complementary sampling methods. For photographic-sampling, 12 camera traps were placed covering an area of 60 km2, while for the tracks search a monthly tour of four line-transect surveys of three kilometers length each was undertaken. We obtained a total of 344 pictures with 5292 trap-days total sampling effort; in addition, 187 track records in a total of 144 km. With both methods we registered 21 species of mammals, in 13 families and seven orders, and five species resulted in new records to the area. The diversity index of Shannon-Wiener obtained with the method of tracks was H' = 2.41, while the most abundant species were Urocyon cinereoargen- teus (IAR = 0.23) and Pecari tajacu (IAR = 0.20). By the method of trap the most abundant species were P. tajacu (IAR = 2.62) and Nasua narica (IAR = 1.28). In terms of patterns of activity P. tajacu, N. narica and Odocoileus virginianus were primarily diurnal species; Canis latrans and Leopardus pardalis did not show preference for any schedule in particular, and Didelphis virginiana and Dasypus novemcinctus preferred to have nocturnal activity. This information can be of help to the creation of programs of management and conservation of mam- mals of medium and large in the Isthmus of Tehuantepec, Oaxaca, México.

How many seabirds do we need to track to define home‐range area?

Summary In recent years, marine predator and seabird tracking studies have become ever more popular. However, they are often conducted without first considering how many individuals should be tracked and for how long they should be tracked in order to make reliable predictions of a population's home‐range area. Home‐range area analysis of two seabird‐tracking data sets was used to define the area of active use (where birds spent 100% of their time) and the core foraging area (where birds spent 50% of their time). Analysis was conducted on the first foraging trip undertaken by the birds and then the first two, three and four foraging trips combined. Appropriate asymptotic models were applied to the data, and the calculated home‐range areas were plotted as a function of an increasing number of individuals and trips included in the sample. Data were extrapolated from these models to predict the area of active use and the core foraging area of the colonies sampled. Significant variability was found in the home‐range area predictions made by analysis of the first foraging trip and the first four foraging trips combined. For shags, the first foraging trip predicted a 56% smaller area of active use when compared to the predictions made by combining the first four foraging trips. For kittiwakes, a 43% smaller area was predicted when comparing the first foraging trip with the four combined trips. The number of individuals that would be required to predict the home range area of the colony depends greatly on the number of trips included in the analysis. This analysis predicted that 39 (confidence interval 29–73) shags and 83 (CI: 109–161) kittiwakes would be required to predict 95% of the area of active use when the first four foraging trips are included in the sample compared with 135 (CI 96–156) shags and 248 (164–484) kittiwakes when only the first trip is included in the analysis. Synthesis and applications. Seabird and marine mammal tracking studies are increasingly being used to aid the designation of marine conservation zones and to predict important foraging areas. We suggest that many studies may be underestimating the size of these foraging areas and that better estimates could be made by considering both the duration and number of data logger deployments. Researchers intending to draw conclusions from tracking data should conduct a similar analysis of their data as used in this study to determine the reliability of their home‐range area predictions.

Mammal and Bird Tracks from the Eocene Puget Group, Northwest Washington, USA

In 1997, coal extraction at the John Henry Mine in western King County, Washington, USA, exposed bedding planes in Eocene sandstone that contained numerous bird and mammal tracks. By the time scientists arrived at the site several months later, the track-bearing surfaces had mostly been obliterated by landslides. Several track specimens were collected but not curated, described, or studied. In 2011, the specimens were found in a storage room at the University of Washington Burke Museum of History and Culture, triggering an investigation that yielded many photographs of the fossil site taken at the time of the 1997 discovery. Perissodactyl mammal tracks are named herein as Oplidcatylapes eocenica ichnogenus and ichnospecies nov. Photographs also show a trackway containing eight footprints that have prominent claw impressions. These tracks are inferred to have been made by a creodont, but because of the absence of specimens or track casts to serve as holotypes, ichnotaxonomic names have not been assigned.

The success of GPS collar deployments on mammals in Australia

Global Positioning System (GPS) wildlife telemetry collars are being used increasingly to understand the movement patterns of wild mammals. However, there are few published studies on which to gauge their general utility and success. This paper highlights issues faced by some of the first researchers to use GPS technology for terrestrial mammal tracking in Australia. Our collated data cover 24 studies where GPS collars were used in 280 deployments on 13 species, including dingoes or other wild dogs (Canis lupus dingo and hybrids), cats (Felis catus), foxes (Vulpes vulpes), kangaroos (Macropus giganteus), koalas (Phascolarctos cinereus), livestock guardian dogs (C. l. familiaris), pademelons (Thylogale billardierii), possums (Trichosurus cunninghami), quolls (Dasyurus geoffroii and D. maculatus), wallabies (Macropus rufogriseus and Petrogale lateralis), and wombats (Vombatus ursinus). Common problems encountered were associated with collar design, the GPS, VHF and timed-release components, and unforseen costs in retrieving and refurbishing collars. We discuss the implications of collar failures for research programs and animal welfare, and suggest how these could be avoided or improved. Our intention is to provide constructive advice so that researchers and manufacturers can make informed decisions about using this technology, and maximise the many benefits of GPS while reducing the risks.

Assessing effects of radiation on abundance of mammals and predator–prey interactions in Chernobyl using tracks in the snow

To test whether radioactive contamination reduced the abundance of mammals, and whether species differed in susceptibility to radiation, we censused mammals by counting tracks in the snow along 161 100-m line transects around Chernobyl during February 2009. The abundance of mammal tracks was negatively related to level of background radiation, independent of the statistical model, with effects of radiation accounting for a third of the variance. The effect of radiation differed significantly among species. There was a positive relationship between abundance of predators and abundance of prey, modified by the level of background radiation because the number of predators increased disproportionately with the number of prey at high levels of radiation. These findings suggest that predatory mammals aggregate in areas with abundant prey, especially when prey are exposed to high levels of radiation. This study emphasizes the negative effects of level of background radiation on the abundance of mammals and predator–prey interactions.

Passive acoustic monitoring of North Atlantic right whales in Cape Cod Bay

Passive acoustic techniques have been applied extensively to marine mammal monitoring, localization, and tracking. An acoustic fieldwork using hydrophone arrays and free-floating buoys was conducted in Cape Cod Bay in the spring of 2011 for monitoring North Atlantic right whales. Three vertical hydrophone arrays were deployed to form a large triangular network with approximately 12 km on each side, and one horizontal array was mounted on the seafloor at one station. The passive hydrophone arrays operated for 25 days and recorded a vast amount of vocalizations made by humpback, fin, sei, minke, and, most importantly, right whales. These data can be used for localizing these endangered animals and tracking their movements in the bay with a large spatial coverage. Acoustic buoys, the real-time acoustic tracking system, were deployed on two one-day cruises for several hours at a time to triangulate calling whales over small spatial scales, and can be used to ground truth long-range whale localizations derived from the array network. Results from different passive acoustic techniques will be presented and compared. [Work supported by the Ocean Life Institute and the Marine Mammal Center of the Woods Hole Oceanographic Institution.]

Comparing the effectiveness of tracking methods for medium to large-sized mammals of Pantanal

Most Neotropical mammals are not easily observed in their habitats, and few studies have been conducted to compare the performance of methods designed to register their tracks. We compared the effectiveness of track registry between sand plots and two tracking methods that use artificial materials to record tracks: the sooted paper, and the plastic board methods. The latter is described here for the first time. From 2002 to 2005, we conducted two experiments in three study sites in the Pantanal region of Brazil. We compared the artificial methods with the sand plot by registering track presence/absence, the number of identifiable tracks, and the total number of tracks (identifiable and unrecognizable) in each tracking plot. Individuals avoided artificial tracking plots either by not stepping on them or by doing it fewer times than on the sand plots. The use of artificial materials to register mammal tracks resulted in underestimates that are especially relevant to short-term ecological studies. We recommend the use of the traditional sand plot method whenever possible and the development of detailed studies on the efficiency of artificial methods under a variety of environmental conditions and time lengths. Despite their relatively lower efficiency, we believe that artificial methods are useful under specific conditions and may be more efficient if used in more comprehensive sampling efforts.

Sound propagation modeling in the ocean for bioacoustics.

A variety of models are available to predict how sound is affected by the ocean channel. The precise waveform may be propagated, leading to distortions within the ocean itself, as well as reflections from the ocean boundaries, and sub-bottom layers. Alternatively, the models can directly predict simpler measures of the waveforms, such as their loudness. The approaches will be surveyed with an ear to which are appropriate for different applications, including marine mammal tracking and modeling soundscapes.

Using model-based tracking methods to reduce position uncertainty.

Many marine mammal tracking methods rely on the assumption of a homogeneous sound speed profile. This assumption greatly simplifies the localization problem since solutions can be re-cast as a set of linear equations with closed form solutions for well-defined problems. However, it also leads to increased uncertainties in position estimates. As long as they are accounted for and understood, these uncertainties are often acceptable and the benefits of homogeneous sound speed assumptions outweigh the drawbacks. However, in some cases and applications (such as in shallow water or over long ranges), it is beneficial to use model-based tracking methods that incorporate sound speed profiles. This talk explains some of the concepts and practical issues associated with model-based tracking. It uses simulations and real datasets to investigate and demonstrate the effects of homogeneous sound speed profile assumptions on animal position estimates. [Work supported by ONR.]

Vertebrate Footprints from the Miocene Upper Red Formation, Shokorchi Area, Zanjan Province, NW Iran

Bird, carnivore, and artiodactyl mammal footprints were found in the Miocene Upper Red Formation in the Shokorchi area, west Zanjan, NW Iran. The Upper Red Formation section (about 50 m thick) to the east of Shokorchi village is mainly composed of marls and hard, thin- to thick-bedded sandstone layers. Sinuous ripple marks, mud cracks, and raindrop prints are common on the bedding planes, and flute casts and ripple marks show north-northwest to south-southeast paleocurrent directions. The bird tracks include digitigrade tridactyl footprints without hallux or metatarsus imprints and are assigned to Iranipeda, Antarctichnus and Avipeda isp. These bird tracks were made mainly by charadriiform birds such as sandpipers or snipes and large birds such as cranes. Mammal tracks include carnivore footprints with manus and pes imprints. The manus imprints are better preserved than the pes imprints and are semiplantigrade with five short digits. Digit V is clearly distinct from digits I-IV. The tips of manus digit traces are rounded without claw marks. The pes imprints are poorly preserved as a rounded or oval shape with no digit imprints and only one or two depressions in the mid to front parts of pes imprints. It seems that these footprints belonged to a carnivore in which the forefeet supported most of the animal's weight. These imprints determined as Platykopus ilycalcator and were made by large ursid. Artiodactyl footprints vary from wedge to rounded rectangular or heart shaped. Digits III and IV imprints are distinct with interungual ridges in the median or posterior region. The artiodactyl footprints are Pecoripeda (Gazellipeda) gazella, and because of the high density of tracks, distinguishing pes and manus imprints are impossible. These may have been made by a herd of artiodactyls that traversed a broad area.

Early Oligocene Mammal Tracks from Southeastern France

Two new sites with mammalian footprints in the early Oligocene of southeastern France are described here. They represent one of the best preserved and more numerous record of tracks and trackways in the world with more than 320 ichnites. Many of those are arranged in trackways and sometimes show pes-manus impressions, a quite rare feature in mammalian ichnology. The ichnotaxonomic study indicates the presence of perissodactyls tracks referred to as Rhinoceripeda voconcense (Demathieu et al., 1984), artiodactyls footprints referred to as Megapecoripeda velox (Demathieu et al., 1984) and a carnivore footprint referred to as Bestiopeda sp. Vialov (1966). They can be attributed to early Rhinocerotids, Lophiomerycids and/or Entelodonts and Mustelid-like carnivore, respectively. This study also aims at homogenizing the ichnotaxonomy used for mammal tracks where several genera were erected without a full review of the literature. All this taken together reveals a rich mammalian ichnofauna at a time period when no other fossils of mammals are known in the area and represents a good opportunity to provide state-of-the-art concerning the worldwide known sites that yielded mammalian footprints.

A Brief Sketch of the Monte Hermoso Human Footprint Site, South Coast of Buenos Aires Province, Argentina

Tracksites representing early human occupation are rare in South America. However, they have been reported in association with mammal and bird tracks from two coastal sites in Buenos Aires Province, Argentina. Both sites are reported in separate papers in this volume. In this paper a brief summary of the better known site is given on the basis of published information and the author's observations.

In the Footprints of Our Ancestors: An Overview of the Hominid Track Record

Hominid footprints are particularly appealing and evocative of the living activity of our ancestors. The most famous and oldest (Late Pliocene, ca. 3.7 Ma) hominid footprints, from Laetoli in East Africa, have been attributed, with some uncertainly, to genus Homo or Australopithecus. The African track record also yields Early Pleistocene (∼1.5 Ma) tracks attributable to Homo erectus. The only well-documented Middle Pleistocene tracks (age ∼325,000-385,000 yrs) are reported from Italy and presumably represent a pre-Homo sapiens species. The oldest Late Pleistocene tracks (∼117,000 yrs), from southern Africa, may represent modern humans. However, the majority of Late Pleistocene sites are European, associated with caves in Romania, Greece, France and elsewhere, where hominid track preservation is often of high quality. Dates range from ∼10,000 to ∼62,000 BP Cavesite mammal tracks are almost exclusively those of carnivores, thus representing a distinctive underground ecology. Late Pleistocene open air sites are reported from widely scattered locations in Africa, Turkey, Tibet, Korea, Australia and even in the New World (Chile, Argentina and Mexico). Early to Middle Holocene sites (> ∼4,000 yrs BP) mainly occupy riparian, lacustrine, estuarine and littoral settings where the ichnofaunas are dominated by ungulates and shorebirds. Among these sites from England, Nicaragua, Argentina and Mexico and the United States, a few have been described in some detail. Younger Holocene sites are frequently associated with specified cultural periods (e.g., Neolithic, Bronze Age) or specific indigenous cultures, where supplemental archeological evidence may be directly associated with the footprint evidence. At most surficial and some subterranean hominid tracksites, mammal and/or bird tracks are quite common and of use in creating a paleoecological picture of local faunas. The global distribution of human and hominid tracks is consistent with body fossil evidence and the record of archeological, cultural artifacts. However, in a few cases tracks suggest colonization of certain regions (Tibetan Plateau and the New World) earlier than previously thought. Tracks also give clues to behavior, age and health status of the trackmakers.

A new method to estimate species and biodiversity intactness using empirically derived reference conditions

Critical to the conservation of biodiversity is knowledge of status and trends of species. To that end, monitoring programmes have reported on the state of biodiversity using reference conditions as comparison. Little consensus exists on how reference conditions are defined and how such information is used to index intactness. Most use protected areas or an arbitrary year as reference. This is problematic since protected areas are often spatially biased, while arbitrarily defined reference years are often not sufficiently distant in time. We propose an alternative that relies on empirical estimates of reference conditions. Statistical ranges of reference are estimated and compared with observed occurrence and abundance to index status of individual species. When averaged among species, overall intactness is estimated. We demonstrate the approach using 202-winter mammal tracking sites from the boreal forest of Alberta, Canada. Intactness was estimated at 89 out of 100 with the southern boreal having lowest intactness and greatest human footprint. We suggest empirical predictions of reference conditions be used as baselines for comparing changes in the state of species and biodiversity. Reporting can occur at any spatial (e.g., ecosystem) or hierarchical (e.g., species, guilds, taxonomic group, or overall biodiversity) scale and is easily interpreted (scaled from 0-degraded to 100-intact). When used in a long-term monitoring framework, statistical trends in biodiversity intactness can be estimated, individual status of species assessed, and relevant policy evaluated.

Efficiency of fluorescent powder tracking for studying use of space by small mammals in an African rainforest

The aim of this study was to test the efficiency of a fluorescent powder tracking technique for studying the use of space by nocturnal small mammals in an African rainforest. We examined 53 trails of 40 individuals (34 small rodents and six shrews). This method of small mammal tracking is less efficient in rainforest than in drier habitats, because rainfall and relative humidity adversely affect the traceability of the powder trail. Moreover, following a trail is time consuming, because of the density of the rainforest undergrowth. Despite these difficulties, this technique provides interesting data on vertical use of habitat by small mammals, the localization of their shelters and their microhabitat use.

Assessing Small Mammal Abundance with Track-Tube Indices and Mark–Recapture Population Estimates

We compared track-tube sampling with mark–recapture livetrapping and evaluated a track-tube index, defined as the number of track tubes with identifiable small mammal tracks during a 4-night period, as a predictor of small mammal abundance estimates in North Dakota grasslands. Meadow voles (Microtus pennsylvanicus) were the most commonly recorded species by both methods, but were underrepresented in track-tube sampling, whereas 13-lined ground squirrels (Spermophilus tridecemlineatus) and Franklin’s ground squirrels (S. franklinii) were overrepresented in track-tube sampling. Estimates of average species richness were lower from track tubes than from livetrapping. Regression models revealed that the track-tube index was at best a moderately good predictor of small mammal population estimates because both the form (linear versus curvilinear) and slope of the relationship varied between years. In addition, 95% prediction intervals indicated low precision when predicting population estimates from new track-tube index observations. Track tubes required less time and expense than mark–recapture and eliminated handling of small mammals. Using track tubes along with mark–recapture in a double sampling for regression framework would have potential value when attempting to estimate abundance of small mammals over large areas.

Mammal Tracks and Sign —A Guide to North American Species

M Elbroch. 2003. Mammal Tracks and Sign—A Guide to North American Species. Stackpole Books, Mechanicsburg, Pennsylvania, 779 pp. ISBN 0-8117-2626-6, price (paper) $44.95. A sticker on the cover indicates that this book has been a winner of the National Outdoor Book Award, and it is easy to see why. With more than 1,000 high-quality color photographs, another 300+ well-drawn illustrations, and numerous detailed descriptions with painstaking measurements, it is unmatched in encyclopedic breadth by anything that has come before. That will be positive for some potential users, but a distinct liability for others. Although built like a field guide, with heavy paper and a tough cover, at 14 × 21 ×4 cm it is 2.5 times the volume of Murie (1954) original in the Peterson field guide series and, at 1.25 kg, is 3.5 times heavier. In practical terms, most users will probably want to take mammal “sign” to the book rather than the book to sign. With the advent and proliferation of compact digital cameras, that may now be easier to accomplish than it used to be. In a lengthy introduction and in Chapter 1 ( Getting Started ), the author makes clear his passion for tracking and offers a variety of perspectives on the physical, mental, and sometimes metaphysical aspects involved. Although he mentions and strongly advocates use of tracking in scientific study, examples provided are mostly from …