The use of passive infrared (PIR) triggered camera traps has dramatically increased in recent decades. Unfortunately, technical descriptions of how PIR triggered camera traps operate have not been sufficiently clear. Descriptions have often been ambiguous or misleading and in several cases are demonstrably wrong. Such descriptions have led to erroneous interpretations of camera trapping data. This short communication clarifies how PIR sensors operate. We clarify how infrared radiation is emitted and transmitted, and we describe the parts of the PIR sensor and how they detect infrared radiation and, by extension, fauna. Several problematic descriptions of PIR sensors are drawn on to highlight flawed descriptions and demonstrate where erroneous interpretations of camera trapping data occurred. By clarifying the language and the description of PIR triggered camera traps, this paper ensures that wildlife researchers and managers using camera traps will avoid flawed interpretations of their data. Avoiding flawed interpretations of data should reduce wasted effort and resources that would otherwise come about as researchers attempt to test flawed hypotheses. Furthermore, this paper provides a thorough technical reference for camera trapping practitioners, which is not present elsewhere in the wildlife research literature.

Context Biodiversity studies often require wildlife researchers to survey multiple species across taxonomic classes. To detect terrestrial squamate and mammal species, often multiple labour-intensive survey techniques are required. Camera traps appear to be more effective and cost-efficient than labour-intensive methods for detecting some mammal species. Recent developments have seen camera traps used for detecting terrestrial squamates. However, the performance of camera traps to survey terrestrial squamate and mammal species simultaneously has not been evaluated. Aim We compared the effectiveness and financial cost of a camera trapping method capable of detecting small squamates and mammals with a set of labour-intensive complementary methods, which have been used in a long-term monitoring program. Methods We compared two survey protocols: one employed labour-intensive complementary methods consisting of cage traps, Elliott traps and artificial refuges; the second utilised camera traps. Comparisons were made of the total number of species detected, species detectability, and cost of executing each type of survey. Key results Camera traps detected significantly more target species per transect than the complementary methods used. Although camera traps detected more species of reptile per transect, the difference was not significant. For the initial survey, camera traps were more expensive than the complementary methods employed, but for realistic cost scenarios camera traps were less expensive in the long term. Conclusions Camera traps are more effective and less expensive than the complementary methods used for acquiring incidence data on terrestrial squamate and mammal species. Implications The camera trapping method presented does not require customised equipment; thus, wildlife managers can use existing camera trapping equipment to detect cryptic mammal and squamate species simultaneously.

Whether chromosomal rearrangements promote speciation by providing barriers to gene exchange between populations is one of the long-standing debates in evolutionary biology. This question can be addressed by studying patterns of gene flow and selection in hybrid zones between chromosomally diverse taxa. Here we present results of the first study of the genetic structure of a hybrid zone between chromosomal races of morabine grasshoppers Vandiemenella viatica, P24(XY) and viatica17, on Kangaroo Island, Australia. Chromosomal and 11 nuclear markers revealed a narrow hybrid zone with strong linkage disequilibrium and heterozygote deficits, most likely maintained by a balance between dispersal and selection. Widths and positions of clines for these markers are concordant and coincident, suggesting that selection is unlikely to be concentrated on a few chromosomes. In contrast, a mitochondrial marker showed a significantly wider cline with centre offset toward the P24(XY) side. We argue that the discordance between the mitochondrial and nuclear/chromosomal clines and overall asymmetry of the clines suggest a secondary origin of the contact zone and potential movement of the zone after contact. Genome-wide scans using many genetic markers and chromosomal mapping of these markers are needed to investigate whether chromosomal differences directly reduce gene flow after secondary contact. Hybrid zones have been found in a wide range of organisms and have been extensively studied as "natural laboratories" to investi-5

Summary New evidence of impacts by feral horses in Australia's alpine parks systems confirms they endanger threatened species and extensively damage critically endangered bog communities that could take millennia to recover. These impacts are not confounded by effects of deer and accumulate over time, even when only a small number of feral horses (~100) are present. With protected areas representing only a small proportion of the area of the Australian states of New South Wales (9.3%) and Victoria (17%), allowing feral horses to degrade reserves is not a reasonable management compromise, is contrary to the purpose of the protected area system and conflicts with international obligations. Modelling and decades of management experience indicate that trapping alone does not control feral horse numbers. Trapping and fertility control can work in small populations, but not when there are several thousand horses in remote areas. Aerial culling is needed to cost‐effectively and humanely control feral horse populations. The relatively small amount of suffering feral horses experience during a cull is outweighed by (i) avoiding suffering and death of horses from starvation and thirst, (ii) avoiding the suffering of native animals displaced by horses and (iii) avoiding the ethical concerns of driving threatened species towards extinction. Objections to aerial culling on welfare and cultural grounds are contradicted by evidence. Improving knowledge in the general community about what is at stake is long overdue because without this knowledge, small groups with vested interests and unfounded claims have been able to dominate debate and dictate management actions. As a result of ineffective management, horse populations are now expanding and causing well‐documented damage to Australia's alpine parks, placing at risk almost $10M spent on restoration after livestock grazing ended. The costs of horse control and restoration escalate the longer large horse populations remain in the alpine parks. It is crucial that feral horse numbers are rapidly reduced to levels where ecosystems begin to recover. Aerial culling is needed as part of the toolbox to achieve that reduction.

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Context. Reliable information about the occurrence and distribution of threatened forest-dwelling mammals is critical for developing effective conservation plans. To optimise limited resources, advances need to be made to the toolkit available for detecting rare and cryptic fauna.Aims. We trialled three bait attractants (peanut butter with oats, live mealworms and black truffle oil) in combination with infrared digital cameras to determine whether detection rates of forest-dwelling native mammals in south-eastern Australia were influenced by: (1) bait type; (2) previous visits by conspecifics; (3) previous visits by Rattus; and (4) duration of bait deployment.Methods. Bait attractants were set at 40 camera stations in combination with odourless controls. Over two fortnight-long deployments, 1327 images were captured of 22 mammal and bird species. From these data, detailed statistical analyses were conducted of six mammal genera.Key results. Peanut butter with oats was found to be a significantly better attractant than empty bait holders for Antechinus, Isoodon, Perameles and Rattus, but not for Potorous or Pseudocheirus. Truffle oil and mealworms were also significantly better attractants than the control for Rattus but not the other five genera. When Antechinus, Isoodon, Potorous or Rattus were detected at a bait station there was a significant likelihood they had been detected there during the previous 24 h. This was not the case for Perameles or Pseudocheirus. A prior visit by Rattus to a station had no significant influence on the detection probabilities of Antechinus, Isoodon, Perameles, Potorous and Pseudocheirus during the subsequent 24 h. Detection probabilities for Isoodon and Rattus declined significantly during the fortnight-long deployments but trends for the other genera were not significant.Conclusions. Peanut butter with oats is an excellent general purpose bait for detecting small to medium-sized mammals. However, scope exists for using other baits to target species. For example, truffle oil baits may reduce by-catch of non-target Rattus in labour intensive cage trapping of bandicoots. Regardless of bait type, longer deployments are necessary to detect Perameles, Potorous or Pseudocheirus than Antechinus, Isoodon or Rattus.Implications. Targeted detection of predominantly ground-dwelling mammals may be improved by better understanding the attraction of species to baits and required bait deployment times.Additional keywords: bait attractants, bandicoots, infrared digital cameras, potoroos.

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The temperate woodlands of the northern Australian Capital Territory and bordering the New South Wales region of eastern Australia have been extensively disturbed by agriculture and urbanization. Small patches of woodland are now embedded in a pastoral or suburban matrix. Birds within landscapes of this region are threatened by a reduction in habitat area, increased isolation, and declining habitat condition. Within this setting, we assessed Lambeck's (1997) "focal species" approach for its ability to identify the minimum patch size, habitat structural complexity, and landscape connectivity required to accommodate existing woodland birds. Presence/absence data were gathered for 72 woodland remnants that varied in size, isolation, and habitat structural complexity. The Hooded Robin ( Melanodryas cucullata ) was identified as the focal species for the threats of area and resource limitation because it had the most demanding requirements for area ( Ͼ 100 ha) and habitat complexity. The eastern Yellow Robin ( Eopsaltria australis ) was the species most threatened by isolation of remnants. A landscape designed to meet the habitat requirements of these birds should encompass the requirements of all other woodland bird species that are sensitive to similar threats. A revegetation scenario based on the requirements of these two focal species is not feasible because the majority ( Ͼ 95%) of woodland remnants within the study area are too small, too lacking in habitat structural complexity, and too isolated to meet the requirements of the focal species. If woodland management guidelines concentrate on increasing small remnants to 10 ha in size and on ensuring that these remnants have complex shrub and ground-layer vegetation and are not isolated by more than 1.5 km from neighboring remnants, the needs of at least 95% of the resident woodland bird species in the region should be accommodated. The focal-species approach was effective for rapidly developing planning guidelines for the conservation of woodland birds in these variegated landscapes, and the approach is likely to be useful for guiding landscape reconstruction in other environments. Evaluación de la Aproximación de Especie Focal para la Conservación de Aves en Paisajes Variegados en el Sureste de AustraliaResumen: Los bosques templados del norte del Territorio Australiano Capital y de la región circundante de Australia oriental han sido perturbados extensivamente por la agricultura y la urbanización. Actualmente, pequeños fragmentos de bosque están en medio en una matriz ganadera o suburbana. Las aves en los paisajes de esta región están amenazadas por la reducción del área de su hábitat, incremento de aislamiento y declinación de las condiciones del hábitat. En este contexto, evaluamos la aproximación "especie focal" de Lambeck (1997) en su habilidad para identificar el tamaño mínimo del fragmento, la complejidad estructural del hábitat y la conectividad del paisaje requerida para albergar a las aves de bosque existentes. Se recolectaron datos de presencia/ausenc...