Naïve orangutans (Pongo abeliiand Pongo pygmaeus) individually acquire nut‐cracking using hammer tools

Nut-cracking with hammer tools (henceforth: nut-cracking) has been argued to be one of the most complex tool-use behaviors observed in nonhuman animals. So far, only chimpanzees, capuchins, and macaques have been observed using tools to crack nuts in the wild (Boesch and Boesch, 1990; Gumert et al., 2009; Mannu and Ottoni, 2009). However, the learning mechanisms behind this behavior, and the extent of nut-cracking in other primate species are still unknown. The aim of this study was two-fold. First, we investigated whether another great ape species would develop nut-cracking when provided with all the tools and appropriate conditions to do so. Second, we examined the mechanisms behind the emergence of nut-cracking by testing a naïve sample. Orangutans (Pongo abelii and Pongo pygmaeus) have the second most extensive tool-use repertoire among the great apes (after chimpanzees) and show flexible problem-solving capacities. Orangutans have not been observed cracking nuts in the wild, however, perhaps because their arboreal habits provide limited opportunities for nut-cracking. Therefore, orangutans are a valid candidate species for the investigation of the development of this behavior. Four nut-cracking-naïve orangutans at Leipzig zoo (P. abelii; Mage = 16; age range = 10–19; 4F; at the time of testing) were provided with nuts and hammers but were not demonstrated the nut-cracking behavioral form. Additionally, we report data from a previously unpublished study by one of the authors (Martina Funk) with eight orangutans housed at Zürich zoo (six P. abelii and two P. pygmaeus; Mage = 14; age range = 2–30; 5F; at the time of testing) that followed a similar testing paradigm. Out of the twelve orangutans tested, at least four individuals, one from Leipzig (P. abelii) and three from Zürich (P. abelii and P. pygmaeus), spontaneously expressed nut-cracking using wooden hammers. These results demonstrate that nut-cracking can emerge in orangutans through individual learning and certain types of non-copying social learning

PENGARUH MEDIA PEMBELAJARAN EDMODO TERHADAP HASIL BELAJAR SISWA DI SMA PASUNDAN 2 BANDUNG (Studi Eksperimen pada Mata Pelajaran Ekonomi Materi Pokok BUMN dan BUMD di Kelas Lintas Minat X MIPA 5 Tahun Ajaran 2017/2018)

Penelitian ini berjudul: Pengaruh Media Pembelajaran Edmodo terhadap Hasil Belajar Siswa di SMA Pasundan 2 Bandung. Tujuan dari penelitian ini adalah: (i) untuk mengetahui bagaimana hasil belajar siswa sebelum diterapkannya media pembelajaran Edmodo (pretest), (ii) untuk mengetahui bagaimana hasil belajar siswa setelah diterapkannya media pembelajaran Edmodo (posttest), (iii) untuk mengetahui perbedaan hasil belajar siswa pada pengukuran awal (pretest) dan pengukuran akhir (posttest), dan (iv) untuk mengetahui seberapa besar pengaruh media pembelajaran Edmodo terhadap hasil belajar siswa pada kelas lintas minat X MIPA 5 di SMA Pasundan 2 Bandung. Metode yang digunakan dalam penelitian ini adalah pra-eksperimen dengan desain penelitian one-group pretest-posttest. Sampel penelitian ini adalah seluruh siswa kelas lintas minat X MIPA 5 SMA Pasundan 2 Bandung. Instrumen penelitian yang digunakan berupa tes. Tes yang digunakan berupa pilihan ganda (pretest dan posttest) dan telah diuji validitas serta reliabilitasnya. Berdasarkan data hasil nilai rata -rata pretest dan posttest diketahui N-Gain sebesar 0,70 dengan interpretasi tinggi, dan diperoleh kesimpulan bahwa terdapat perbedaan hasil belajar siswa sebelum dan setelah penerapan media pembelajaran Edmodo. Pembelajaran menggunakan media Edmodo memberikan pengaruh terhadap hasil belajar siswa kelas lintas minat X MIPA 5 sebesar 27,2% dengan interpretasi cukup. Pengaruh lainnya sebesar 72,8%. Hal ini dapat dipengaruhi oleh beberapa faktor yaitu motivasi, kompetensi guru, lingkungan, dan model pembelajaran. Sebagai penutup, penulis menyampaikan saran sebaiknya guru menggunakan media pembelajaran yang beragam. Salah satunya menggunakan media pembelajaran Edmodo, karena media tersebut dapat meningkatkan hasil belajar siswa. Kata Kunci: Media Pembelajaran, Edmodo, Hasil Belaja

Inhibitory control, but not prolonged object-related experience appears to affect physical problem-solving performance of pet dogs

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance

A reversed-reward contingency task reveals causal knowledge in chimpanzees (Pan troglodytes)

In the reversed-reward contingency task, subjects are required to choose the less preferred of two options in order to obtain the more preferred one. Usually, this task is used to measure inhibitory skills, but it could also be used to measure how strong the subjects' preferences are. We presented chimpanzees with support tasks where only one of two paper strips could physically bring food into reach. Subjects were rewarded for choosing the non-functional strip. In Experiment 1, subjects failed to pick the non-baited strip. In Experiment 2, subjects failed to pick the broken strip. Chimpanzees performed worse in these tasks than in other similar tasks where instead of paper strips, there were similar shapes painted on a platform. The fact that subjects found the reversed-reward contingency task based on causality more difficult to solve than a perceptually similar task with no causality involved (i.e., arbitrary) suggests that they did not treat real strips as an arbitrary task. Instead, they must have had some causal knowledge of the support problem that made them prefer functional over non-functional strips despite the contrary reward regime

A reversed-reward contingency task reveals causal knowledge in chimpanzees (Pan troglodytes)

In the reversed-reward contingency task, subjects are required to choose the less preferred of two options in order to obtain the more preferred one. Usually, this task is used to measure inhibitory skills, but it could also be used to measure how strong the subjects' preferences are. We presented chimpanzees with support tasks where only one of two paper strips could physically bring food into reach. Subjects were rewarded for choosing the non-functional strip. In Experiment 1, subjects failed to pick the non-baited strip. In Experiment 2, subjects failed to pick the broken strip. Chimpanzees performed worse in these tasks than in other similar tasks where instead of paper strips, there were similar shapes painted on a platform. The fact that subjects found the reversed-reward contingency task based on causality more difficult to solve than a perceptually similar task with no causality involved (i.e., arbitrary) suggests that they did not treat real strips as an arbitrary task. Instead, they must have had some causal knowledge of the support problem that made them prefer functional over non-functional strips despite the contrary reward regime

Erratum: Great apes track hidden objects after changes in the objects' position and in subject's orientation

This article corrects: Great apes track hidden objects after changes in the objects' position and in subject's orientation. - Vol. 72, Issue 4, 349–359, Article first published online: 5 JAN 201