| |
Records |
Links |
|
Author |
Cameron, E.Z.; du Toit, J.T. |
|
| |
Title |
Winning by a neck: tall giraffes avoid competing with shorter browsers |
Type |
Journal Article |
| |
Year |
2007 |
Publication |
The American naturalist |
Abbreviated Journal |
Am Nat |
|
| |
Volume |
169 |
Issue |
1 |
Pages |
130-135 |
|
| |
Keywords |
Acacia/growth & development; Animals; Feeding Behavior/*physiology; Neck/*anatomy & histology; Plant Leaves/growth & development; Ruminants/*anatomy & histology/*physiology; South Africa |
|
| |
Abstract |
With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild. |
|
| |
Address |
Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1537-5323 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:17206591 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
410 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chappell, J.; Kacelnik, A. |
|
| |
Title |
Selection of tool diameter by New Caledonian crows Corvus moneduloides |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
|
| |
Volume |
7 |
Issue |
2 |
Pages |
121-127 |
|
| |
Keywords |
Animals; Behavior, Animal; *Choice Behavior; Discrimination Learning; *Feeding Behavior; Female; Functional Laterality; *Manufactured Materials; *Plant Leaves; *Problem Solving; *Songbirds; Technology |
|
| |
Abstract |
One important element of complex and flexible tool use, particularly where tool manufacture is involved, is the ability to select or manufacture appropriate tools anticipating the needs of any given task-an ability that has been rarely tested in non-primates. We examine aspects of this ability in New Caledonian crows-a species known to be extraordinary tool users and manufacturers. In a 2002 study, Chappell and Kacelnik showed that these crows were able to select a tool of the appropriate length for a task among a set of different lengths, and in 2002, Weir, Chappell and Kacelnik showed that New Caledonian crows were able to shape unfamiliar materials to create a usable tool for a specific task. Here we examine their handling of tool diameter. In experiment 1, we show that when facing three loose sticks that were usable as tools, they preferred the thinnest one. When the three sticks were presented so that one was loose and the other two in a bundle, they only disassembled the bundle when their preferred tool was tied. In experiment 2, we show that they manufacture, and modify during use, a tool of a suitable diameter from a tree branch, according to the diameter of the hole through which the tool will have to be inserted. These results add to the developing picture of New Caledonian crows as sophisticated tool users and manufacturers, having an advanced level of folk physics. |
|
| |
Address |
Department of Zoology, South Parks Road, OX1 3PS, Oxford, UK. jackie.chappell@zoo.ox.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1435-9448 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:15069612 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
2528 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chiandetti, C.; Regolin, L.; Sovrano, V.A.; Vallortigara, G. |
|
| |
Title |
Spatial reorientation: the effects of space size on the encoding of landmark and geometry information |
Type |
Journal Article |
| |
Year |
2007 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
|
| |
Volume |
10 |
Issue |
2 |
Pages |
159-168 |
|
| |
Keywords |
Animals; Chickens/*physiology; *Feeding Behavior; Male; Orientation/*physiology; Pattern Recognition, Visual/*physiology; *Space Perception |
|
| |
Abstract |
The effects of the size of the environment on animals' spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment. |
|
| |
Address |
Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, Via S. Anastasio 12, 34123, Trieste, Italy. cchiandetti@univ.trieste.it |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1435-9448 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:17136416 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
2433 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cleveland, A.; Rocca, A.M.; Wendt, E.L.; Westergaard, G.C. |
|
| |
Title |
Transport of tools to food sites in tufted capuchin monkeys (Cebus apella) |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
|
| |
Volume |
7 |
Issue |
3 |
Pages |
193-198 |
|
| |
Keywords |
Animals; *Association Learning; Cebus/*psychology; *Concept Formation; *Feeding Behavior; Female; Male; *Problem Solving |
|
| |
Abstract |
Tool use and transport represent cognitively important aspects of early hominid evolution, and nonhuman primates are often used as models to examine the cognitive, ecological, morphological and social correlates of these behaviors in order to gain insights into the behavior of our early human ancestors. In 2001, Jalles-Filho et al. found that free-ranging capuchin monkeys failed to transport tools (stones) to food sites (nuts), but transported the foods to the tool sites. This result cast doubt on the usefulness of Cebus to model early human tool-using behavior. In this study, we examined the performance of six captive tufted capuchin monkeys (Cebus apella) in a tool transport task. Subjects were provided with the opportunity to transport two different tools to fixed food reward sites when the food reward was visible from the tool site and when the food reward was not visible from the tool site. We found that the subjects quickly and readily transported probing tools to an apparatus baited with syrup, but rarely transported stones to a nut-cracking apparatus. We suggest that the performance of the capuchins here reflects an efficient foraging strategy, in terms of energy return, among wild Cebus monkeys. |
|
| |
Address |
Alpha Genesis, 95 Castle Hall Road, P.O. Box 557, Yemassee, SC 29945, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1435-9448 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:15022055 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
2539 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Clutton-Brock, T.H.; Russell, A.F.; Sharpe, L.L.; Brotherton, P.N.; McIlrath, G.M.; White, S.; Cameron, E.Z. |
|
| |
Title |
Effects of helpers on juvenile development and survival in meerkats |
Type |
Journal Article |
| |
Year |
2001 |
Publication |
Science (New York, N.Y.) |
Abbreviated Journal |
Science |
|
| |
Volume |
293 |
Issue |
5539 |
Pages |
2446-2449 |
|
| |
Keywords |
Animals; Breeding; Carnivora/growth & development/*physiology; *Cooperative Behavior; Feeding Behavior; Female; Male; Survival Rate; *Weight Gain |
|
| |
Abstract |
Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups. |
|
| |
Address |
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. thcb@hermes.cam.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0036-8075 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:11577235 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
414 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cohen, J.; Pardy, S.; Solway, H.; Graham, H. |
|
| |
Title |
Chunking versus foraging search patterns by rats in the hierarchically baited radial maze |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
|
| |
Volume |
6 |
Issue |
2 |
Pages |
93-104 |
|
| |
Keywords |
Animals; Exploratory Behavior; *Feeding Behavior; Male; *Maze Learning; Rats; Rats, Long-Evans |
|
| |
Abstract |
Rats were exposed to a radial maze containing six black smooth arms and six wire-grid-covered arms and a striped 'exit arm' in experiment 1. The probability of a black or grid arm being baited (5/6 vs 1/6) with sunflower seeds was associated with its proximal cue for some rats (the Relevant Arm Cue group) but not for others (the Irrelevant Arm Cue group). All rats could terminate a trial and receive a highly preferred morsel of apple by entering the exit arm only after having sampled all six seed-baited arms. Relevant Arm Cue rats usually chose some arms from the more densely baited set before choosing an arm from the less densely baited set and made fewer reentries than Irrelevant Arm Cue rats. Although such clustered, higher choice accuracy in the Relevant Arm Cue group corresponds to human clustered, better recall of verbal items from lists hierarchically organized by categories, these rats did not similarly exhaustively retrieve items (arm locations). That is, when required to terminate a trial by entering the 'exit' arm for an apple morsel after having sampled all seed-baited arms, both groups were equally unable to withhold making nonrewarded premature exits. This nonexhaustive foraging search pattern was maintained in the next two experiments in which the radial maze was reduced to three black and three grid arms along with the striped 'exit' arm and in which black and grid arm cues were paired with number of seeds (eight or one) in an arm for Relevant Arm Cue rats. Although Relevant Arm Cue rats displayed perfect clustering by entering all eight-seeded arms before a one-seeded arm, they made more premature exits and reentries into eight-seeded arms in experiment 2 or when forced to enter all eight-seeded arms in experiment 3 than did Irrelevant Arm Cue rats. These foraging tendencies prevent accurate estimations of the amount of information (i.e., arm locations) rats can 'chunk'. |
|
| |
Address |
Department of Psychology, University of Windsor, Windsor, Ontario N9B 3P4, Canada. jcohen@uwindsor.ca |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1435-9448 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:12720109 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
2574 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Collery, L. |
|
| |
Title |
Observations of equine animals under farm and feral conditions |
Type |
Journal Article |
| |
Year |
1974 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
6 |
Issue |
4 |
Pages |
170-173 |
|
| |
Keywords |
Aggression; Animals; Animals, Newborn; Breeding; Circadian Rhythm; Feeding Behavior; Female; Horses/*physiology; Housing, Animal; Humans; Male; Pregnancy; Puberty; Reproduction; Sexual Behavior, Animal; Social Dominance |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:4473340 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
680 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Crowell-Davis, S.L.; Houpt, K.A.; Carnevale, J. |
|
| |
Title |
Feeding and drinking behavior of mares and foals with free access to pasture and water |
Type |
Journal Article |
| |
Year |
1985 |
Publication |
Journal of animal science |
Abbreviated Journal |
J. Anim Sci. |
|
| |
Volume |
60 |
Issue |
4 |
Pages |
883-889 |
|
| |
Keywords |
Animals; *Drinking Behavior; *Feeding Behavior; Female; Horses/*physiology; Male; Poaceae; Seasons; Temperature; Time Factors |
|
| |
Abstract |
The feeding and drinking behavior of 11 mares and 15 foals living on pasture with free access to water was recorded during 2,340 15-min focal samples taken over 2 yr. Lactating mares on pasture spent about 70% of the day feeding. Foals began feeding on their first day of life. As they grew older, they spent progressively more time feeding, but still spent only 47 +/- 6% of the time feeding by 21 wk of age. Foals fed primarily during the early morning and evening. While grass formed the major proportion of the diet of both foals and mares, they also ate clay, humus, feces, bark, leaves and twigs. Almost all feeding by foals was done while their mothers were feeding. Movement to water sources was frequently, but not invariably, carried out by an entire herd. Frequency (P = .005) but not duration (P greater than .05) of drinking bouts by mares increased as the temperature increased. Frequency was greatest at 30 to 35 C, at which temperature mares drank once every 1.8 h. Frequency of drinking varied with the time of day (P less than .01), being rarest during the early morning (0500 to 0900 h eastern daylight time) and most frequent during the afternoon (1300 to 1700 h). Drinking by foals was very rare. The youngest age at which a foal was observed to drink was 3 wk, and 8 of 15 foals were never observed to drink before weaning. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-8812 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:3988655 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
54 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Danchin, E.; Giraldeau, L.-A.; Valone, T.J.; Wagner, R.H. |
|
| |
Title |
Public information: from nosy neighbors to cultural evolution |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Science (New York, N.Y.) |
Abbreviated Journal |
Science |
|
| |
Volume |
305 |
Issue |
5683 |
Pages |
487-491 |
|
| |
Keywords |
Animals; *Behavior, Animal; Cues; *Cultural Evolution; *Decision Making; Environment; Evolution; Feeding Behavior; Female; Genes; Humans; Male; Reproduction; Sexual Behavior, Animal |
|
| |
Abstract |
Psychologists, economists, and advertising moguls have long known that human decision-making is strongly influenced by the behavior of others. A rapidly accumulating body of evidence suggests that the same is true in animals. Individuals can use information arising from cues inadvertently produced by the behavior of other individuals with similar requirements. Many of these cues provide public information about the quality of alternatives. The use of public information is taxonomically widespread and can enhance fitness. Public information can lead to cultural evolution, which we suggest may then affect biological evolution. |
|
| |
Address |
U.P.M.C. CNRS-UMR7625, Bat A-7e etage-Case 237, 7 quai Saint Bernard, 75252 Paris Cedex 05, France. edanchin@snv.jussieu.fr |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1095-9203 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:15273386 |
Approved |
no |
|
| |
Call Number |
|
Serial |
2131 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
De Stoppelaire, G.H.; Gillespie, T.W.; Brock, J.C.; Tobin, G.A. |
|
| |
Title |
Use of remote sensing techniques to determine the effects of grazing on vegetation cover and dune elevation at Assateague Island National Seashore: impact of horses |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Environmental Management |
Abbreviated Journal |
Environ Manage |
|
| |
Volume |
34 |
Issue |
5 |
Pages |
642-649 |
|
| |
Keywords |
Animals; Animals, Wild; Conservation of Natural Resources; Ecosystem; Environmental Monitoring; *Feeding Behavior; *Horses; Maryland; Plants/*growth & development; Population Dynamics; Silicon Dioxide; *Soil |
|
| |
Abstract |
The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and vegetation cover were used for this study. Color-infrared imagery from 1998 and field measurements from 2001 indicated that there was a significant difference in vegetation cover between the fenced and unfenced plot-pairs over the study period. Fenced plots contained a higher percentage of vegetation cover that was dominated by American beachgrass (Ammophila breviligulata). Lidar surveys from 1997, 1999, and 2000 showed that there were significant differences in elevation and topography between fenced and unfenced plot-pairs. Fenced plots were, on average, 0.63 m higher than unfenced plots, whereas unfenced plots had generally decreased in elevation after establishment in 1993. Results demonstrate that feral horse grazing has had a significant impact on dune formation and has contributed to the erosion of dunes at Assateague Island. The findings suggest that unless the size of the feral horse population is reduced, grazing will continue to foster unnaturally high rates of dune erosion into the future. In order to maintain the natural processes that historically occurred on barrier islands, much larger fenced exclosures would be required to prevent horse grazing. |
|
| |
Address |
US Geological Survey, Center for Coastal and Watershed Studies, St. Petersburg, Florida 33701, USA. georgia.destoppelaire@my.FWC.com |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0364-152X |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:15633024 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1896 |
|
| Permanent link to this record |
