Camouflage Research Articles

Predator responses to artificial aposematic and cryptic colouration in terrestrial isopods (Isopoda, Oniscidea)

Aposematism is a distinctive or warning signal that provides the animal with protection against a potential predator. Aposematic colouration is easier for a predator to remember and to avoid a dangerous and/or unpalatable prey in the future. We investigated whether distinctive colouration has an aposematic function in terrestrial isopods. The common rough woodlice (Porcellio scaber) were used as a model species of terrestrial isopods and the Italian wall lizard (Podarcis siculus) as a predatory species. To imitate the distinctive colouration on isopods we marked their dorsal plates with yellow dots. The control group of the woodlice were marked with grey spots. Differences in behaviour (observation, manipulation and consummation) and the lizards’ behaviour changes towards aposematically and cryptically coloured prey were analysed. Differences were found in prey observation both between sexes and between prey colours.

Natural and sexual selection and functional roles influence colouration but not the amount of variation in butterfly wing colour patterns

BackgroundTrait variation is shaped by functional roles of traits and the strength and direction of selection acting on the traits. We hypothesized that in butterflies, sexually selected colouration is more variable owing to condition-dependent nature and directional selection on sexual ornaments, whereas naturally selected colouration may be less variable because of stabilising selection. We measured reflectance spectra, and extracted colour parameters, to compare the amount of variation in sexually versus naturally selected colour patches across wing surfaces and sexes of 20 butterfly species across 4 families (Nymphalidae, Papilionidae, Pieridae, Lycaenidae).ResultsWe found that: (a) males had more conspicuous, i.e., brighter and more saturated colour patches compared with females (as expected of sexually selected traits but not necessarily of naturally selected traits), and (b) dorsal surfaces in both sexes had more conspicuous sexual ornaments as well as protective (aposematic/mimetic) colour patches on darker wing backgrounds, compared with ventral surfaces. However, colour patches did not differ in the amount of variation either in selection (ecological/sexual functions), sex or wing surface-specific manner.ConclusionsThese findings show that functional roles and selection influence colour parameters but not the amount of variation in butterfly wing colour patterns.

Immature stages of the Zebra Hairstreak butterfly, Arawacus separata (Lepidoptera: Lycaenidae): a model organism for studies on mimicry and mutualism

Hairstreak butterflies are model organisms in evolutionary biology due to the variety of predator-avoidance strategies they possess, including false head mimicry and symbiosis with ants, both of which Zebra Hairstreaks employ. Natural history information is basic for the generation of hypothesis-driven research in ecology and evolution, especially for holometabolous organisms. Here, the complete life cycle of the Zebra Hairstreak Arawacus separata is described for the first time. The natural history records, including citizen science, for other Zebra Hairstreaks species in Eumaeini were also reviewed. Host plant records for A. separata indicate that its caterpillars are oligophagous on Solanaceae, being locally specialized on the shrub Cestrum strigilatum (Solanaceae). Development from egg to adult was found to last ~30 days. Caterpillars underwent four instars with cryptic coloration and texture. The larval tegument is covered by short dendritic setae and pore cupola organs (PCOs), and, from the second instar on, shows a dorsal nectary organ (DNO). Caterpillars live on plants surrounded by ants throughout their entire ontogeny. Facultative symbiosis was observed in all instars with seven ant species in four genera. Myrmecophily is potentiated by honeydew-producing hemipterans and attractive sap of leaf lesions. Territory occupancy of males and non-aerial contests suggest a neglected role of sexual selection in the evolution of the false-head traits. Due to the typical false-head wing coloration pattern and myrmecophily, A. separata is proposed as a model organism to study mimicry and mutualism.

A macroevolutionary perspective of cryptic coloration in sexually dichromatic grasshoppers of the genus Sphenarium (Orthoptera: Pyrgomorphidae)

Background matching and disruptive coloration are defense mechanisms of animals against visual predators. Disruptive coloration tends to evolve in microhabitats that are visually heterogeneous, while background matching is favored in microhabitats that are chromatically homogeneous. Controlling for the phylogeny, we explored the evolution of the coloration and the marking patterns in the sexual dichromatic and widely distributed neotropical grasshoppers of the genus Sphenarium. These grasshoppers represent an excellent model to investigate the evolution of cryptic coloration on insects due to the heterogeneity of the environments where they have evolved. We found a correlation between the grasshoppers' coloration and disruptive markings with the chromatic properties of their environments that was inferred by the levels of precipitation during the rainy season. The results suggest that colors and marking patterns could evolve due to predation pressures. Color in both sexes could offer camouflage that is not perfectly background matched to a single habitat but instead offers a degree of resemblance to multiple backgrounds. Moreover, we found that males and females chromatic properties differ between them and precipitation levels where the species are found. This suggests that the sexes have diverged in their response to the environments, favoring the evolution of sexual dichromatism in these grasshoppers.

Predator perception of aposematic and cryptic color morphs in two Oophaga species.

Animals that are toxic often advertise their unprofitability to potential predators through bright aposematic colors while cryptic ones blend in with their natural background to avoid predators. In the poison dart frogs, Oophaga pumilio and O. granulifera, some populations in Costa Rica and Panama display cryptic green and aposematic red color morphs. We herein used reflectance spectra from the dorsum of red and green morphs of these frogs to estimate their perception by the visual systems of three potential predators (birds, lizards, and crabs) against three natural backgrounds (leaves, trunks and leaf litter). Statistical analyses revealed no strong differences in color contrast against backgrounds between the two frog species. However, strong effects of frog morph, predator, background, and their interactions were observed. When viewed against diverse backgrounds, red frogs of both Oophaga species are more color conspicuous to birds and Anoline lizards than to crabs. A strong effect of species was observed on luminance contrast. Concerning the latter, green frogs particularly in O. granulifera appear more conspicuous than red frogs, while birds perceive higher brightness contrasts than lizards or crabs. Our results further support the importance of birds and lizards as Oophaga predators and provide a first quantitative comparison of conspicuousness between these two frog species.

Discovery in leaf litter: uncovering the systematics of Porcelloderes (Heteroptera: Reduviidae: Phimophorinae)

Abstract The subfamily Phimophorinae includes ~113 species of cryptic assassin bugs found in the Neotropics and Paleotropics. Presumably due to its small size, cryptic coloration, and occurrence in the remote Eastern Arc Mountains (EAM), Porcelloderes impenetrabilis Rédei, 2012 (Heteroptera: Reduviidae: Phimophorinae), was only recently described as the first representative of this subfamily from mainland Africa. Previous morphology-based phylogenetic research on Phimophorinae (then known as Physoderinae or Epiroderinae) recovered Porcelloderes as sister taxon to the remaining epiroderine-lineage of Phimophorinae. Recent fieldwork in Tanzania has resulted in 241 additional specimens of Porcelloderes from 3 EAM) ranges. We used molecular and morphological analyses for these 241 specimens to (i) determine their species identity, (ii) test the phylogenetic position of Porcelloderes within Phimophorinae, and (iii) determine if divergence within Porcelloderes coincides with periods of climate-driven forest fragmentation in the EAM. Specimens from the Kimboza and Nguru Mountains likely represent P. impenetrabilis, but we here describe Porcelloderes harles, n. sp., from the Udzungwa Mountains. Our molecular phylogeny shows Porcelloderes nested within the epiroderine-lineage of Phimophorinae and as sister taxon to a Madagascar clade. We estimate that the epiroderine-lineage diverged from other Phimophorinae ~44 MYA. The divergence estimates for the 2 Porcelloderes species is ~15 MYA, consistent with proposed dates for other EAM assassin bugs and a period of forest fragmentation.

Overview of the history of the development of camouflage uniforms and its influence on the current state of camouflage

In the early stages of combat operations, the multi-colored coloring of the uniform served, along with other elements of visualization of the situation, to visually distinguish friendly troops from enemy troops, to separate troops by type and purpose, and not to ensure the secrecy of troops. The issue of camouflage of military equipment and structures, at this stage, has not yet been raised. With the increase in the range and accuracy of weapons, with the advent of automatic weapons, the field military uniform gradually lost the function of identification and acquired the function of camouflage. At first it was a monochromatic khaki coloring, which provides an imitation camouflage function, then a camouflage coloring that adds deforming properties to it. With the advent of military equipment on the battlefield, it had to be painted as well. And later, with the advent of reconnaissance and combat aviation, and other types of long-range weapons, it was necessary to ensure the secrecy of not only the objects of the battlefield, but also the objects of the rear. The article considers the history of the development of methods for increasing the secrecy of personnel through the use of protective coloring of uniforms and equipment. Other aspects of the application of methods for increasing stealth in the optical and other ranges, as well as their development in recent history, are also briefly touched upon.

Black-and-white pelage as visually protective coloration in colobus monkeys

Conspicuous coloration is often seen as the evolutionary consequence of either sexual selection or warning predators visually about prey defences, although not all conspicuous species fit this paradigm. Exceptions include several species of colobus monkeys whose black-and-white coloration, characteristic of larger colobines, has never been explained. Here, using photographs of black-and-white colobus (Colobus vellerosus) taken in the wild, quantitative image analysis, and vision modelling (acuity-corrected feline, chimpanzee, and raptor vision), we provide evidence that their coloration provides distance-dependent camouflage in natural forest environments. At all viewing distances, black-and-white colobus monkeys blend into their environment because of their high chromatic overlap with the background when viewed by ecologically relevant predator vision models which have low visual acuities. Additionally, for chimpanzee and felid vision, there was evidence of edge disruption at longer viewing distances. Our comparative analyses of different species of colobines do not support an association between black-and-white coloration and larger body mass or group size, but this may simply be due to the limited number of species within the family. We reason that black-and-white colobines gain visually protective coloration through background matching against felids, and also benefit through disruptive coloration against felids and chimpanzees but rely on these protective coloration mechanisms less against raptors.Significance statementConspicuous black-and-white coloration in colobus monkeys has long eluded an evolutionary explanation. Our research, employing photographs of colobus monkeys, image analysis, and vision modelling, unveils a novel approach to this coloration. We show that in their natural forest habitats, black-and-white colobus monkeys employ distance-dependent camouflage against ecologically relevant predators with low visual acuity, blending in with the background at increasing viewing distances. In summary, the evolution of black-and-white colobus coloration appears to be related to background matching against felids, with added benefits of disruptive camouflage against felids and chimpanzees, less so to raptors, offering fresh insights into the complex interplay of coloration and survival strategies in mammals.

Synopsis of the remarkable family Phloeidae (Hemiptera: Pentatomoidea): species identification, chromatic polymorphism and updated distribution

ABSTRACT The Neotropical family Phloeidae includes three species within two genera, Phloea Lepeletier and Serville, 1825 and Phloeophana Kirkaldy, 1908, distributed in South America. Due to their large size and notable morphological features, such as cryptic colouration, extreme body flattening and lateral expansions around the body, these insects became known as Neotropical bark bugs. These characteristics also make them easily recognisable; nonetheless, the correct identification of the species is still tricky, even more so for the nymphs. In this work, we clarify the identity of the species, present new diagnoses for the family, both genera and all species, and provide an updated identification key to both adults and nymphs of the three species. We also describe and illustrate chromatic variation in Phloea subquadrata Spinola, 1837, and high-resolution photos of the three species and important diagnostic characters are provided. Literature information is synthesised and updated, and an exhaustive synonymic list is provided for the three species, including two nomenclatural corrections: Phloeocoris paradoxus Burmeister, 1835 is removed from synonymy with Phloeophana longirostris (Spinola, 1837) and considered a new junior synonym of Phloea corticata (Drury, 1773); and Phlaea paradoxa Signoret, 1863 is removed from synonymy with Phloea corticata and considered a new junior synonym of Phloeophana longirostris. Lastly, we review the distribution of the species based on collection specimens and citizen science data and, for the first time, present distribution maps for the three species of Phloeidae.

The Sexually Dichromatic Use of Chromatophores for Cryptic Coloration in the Shrimp Neopontonides beaufortensis.

AbstractSexual dimorphism typically arises as a result of sexual selection or sex-specific natural selection. Species that exhibit cryptic coloration provide an excellent system for studying sex-specific selection for sexual dichromatism. In this study, we examined the sexually dichromatic use of chromatophores in the seawhip shrimp, Neopontonides beaufortensis (Borradaile, 1920), which commonly resides on colonies of Leptogorgia virgulata (Lamarck, 1815), a gorgonian octocoral that occurs in multiple color morphs. We documented the frequency of cryptic coloration in N. beaufortensis and tested colony color preference in relation to their current color. In the field, individuals always matched the color of the L. virgulata colony they were found on or were largely translucent. However, when given a choice, individuals chose colonies at random, independent of color. Additionally, we quantified locations across the bodies of males and females that differ most in chromatophore usage and tested the ability of both sexes to change color over 7 days. Females housed with L. virgulata colonies that differed in color from their starting color changed their coloration over the 7 days to better match the colony, while males remained translucent regardless of the color of colony they were housed with. Neopontonides beaufortensis individuals differed most in their coloration in regions corresponding to the saddle region and areas of the abdomen, locations in which females carry their eggs during development. These findings provide insight into the ecological factors underlying sexual dichromatism and shed light on the potential sex-specific selective mechanisms responsible for sexually dimorphic traits.

Estimating the effort required to detect Kirtland's snakes (Clonophis kirtlandii)

AbstractSnakes are difficult to study due to their cryptic coloration, minimal movements, and use of inaccessible habitats. Although well‐timed surveys during a species' active season can result in higher detection rates and conserve survey resources (i.e., time and money), survey effort may not ensure the detection of rare and cryptic species. Thus, in such instances, a strategic species‐specific sampling design is needed. The Kirtland's snake (Clonophis kirtlandii) is a rare, cryptic species assumed to be experiencing range‐wide declines. Naturalists have noted the disappearance of Kirtland's snakes from various habitats since the early 1970s. The primary objective of our study was to determine detection of Kirtland's snakes and the environmental and temporal factors influencing detection. We calculated the effort needed to detect individuals at sites by estimating detection probabilities of 3 known Kirtland's snake populations in Illinois from 2019 to 2021. Based on 77 Kirtland's snake detections over 226 site visits (34.1%) across 3 study sites, we found that high cloud cover, moderate air temperature, and low relative humidity enhanced the detection probability of this species. The middle of May to the beginning of July was the best time to conduct surveys when detection rates were highest. As our results suggested, it is imperative to establish strategic monitoring programs maximizing conservation resources to document populations for conservation action and range shifts for species of conservation concern, such as Kirtland's snakes.

Artificial light at night impacts night-time activity but not day-time behaviour in a diurnal coral reef fish

An important, yet overlooked form of anthropogenic pollution is sensory pollution, and one of the most pervasive forms of sensory pollution is artificial light at night (ALAN). Despite the growing use of ALAN across the globe, limited research has examined the impacts of ALAN on coral reef fish. This study aims to further our understanding of the behavioural impacts of light pollution on fish by exposing the humbug damselfish (Dascyllus aruanus) to ALAN (∼15–25 lux, white LED light) over a period of 14 days, in situ. We assessed nocturnal activity, and diurnal shelter use and emergence time following a simulated threat in natural (control) and ALAN conditions. D. aruanus colonies exposed to ALAN were active at night and were lacking cryptic colouration observed in control fish, however this altered nocturnal activity did not appear to impact the diurnal behaviours we measured. Our findings provide critical insight into the impact of ALAN exposure to nocturnal behaviour of a diurnal fish and highlight the potential for increased risk of nocturnal predation under ALAN. Further studies with a longer ALAN exposure time will help illuminate the extent of behavioural changes and implications caused by ALAN in shallow coral reef systems.

Dazzle: surface patterns that impede interception

Abstract ‘Dazzle coloration’ describes a wide variety of high-contrast patterns allegedly providing protection against attack during motion. Previous research falls into three broad groups. First, studies using humans demonstrate that certain surface patterns can cause significant misperceptions in controlled laboratory conditions, although the effects are inconsistent in both direction and magnitude. Second, experiments on target capture or tracking also show effects that are strongly dependent upon the test paradigm. It has not been established that these laboratory findings generalize to other species, or to the real world. Third, mainly comparative studies build a case for longitudinal striping being involved in escape strategies in some squamate reptiles. We suggest that: (1) the concept of dazzle conflates a description of appearance with presumed function; (2) some effects attributed to dazzle have not been distinguished clearly from other mechanisms of protective coloration; and (3) confusion persists over the evidence necessary to attribute a dazzle function to markings. We refine the definition of dazzle to exclude appearance: dazzle is coloration that interferes with target interception, as a result of misperception of its speed, trajectory and/or range. Our review clarifies discussion of dazzle, and sets out a coherent and practical framework for future research.

Pupal warning color development in above‐ground pupating species but cryptic color in ground‐surface pupating species of the nine‐spotted diurnal moths (Erebidae: Arctiinae: Syntomini)

AbstractInsects usually have cryptic colors to avoid detection by visually hunting predators. However, if the insects acquire toxic or repellent substances against predators, some of them develop conspicuous coloration to exhibit their unpalatability. Such warning colors allow insects to survive. In the nine‐spotted diurnal moths (Erebidae: Arctiinae: Syntomini), we found the above‐ground pupating species to have conspicuous colored pupae, but the ground‐surface pupating species to have cryptic colored pupae. In this study, the relationships between unpalatability and coloration of these pupae are examined among three species of Amata and one species of Syntomoides. Pupae of the two species (A. germana and A. flava) are conspicuous in their color pattern with seven black dotted lines longitudinally on their pale‐yellow bodies. These pupae are exposed to the aerial predators in a coarse silk mesh hanging from leaves and/or branches. The other two species (A. fortunei and S. imaon) pupate in spaces under stones, fallen twigs and leaves on the ground surface, and the pupae in a coarse silk cocoon is cryptic dark brown. Their pupation site selections are reproduced in the rearing glass vessels. Palatability assessment using lizards as a potential predator suggests that pupae of A. germana, A. flava and A. fortunei are unpalatable and the lizard's feeding response decreases with experience. However, pupae of S. imaon are all eaten (palatable). Finally, the possible evolutionary scenario of pupal colors of these four species is discussed in relation to pupation site selection and palatability.

A stabilizing eco-evolutionary feedback loop in the wild

There is increasing evidence that evolutionary and ecological processes can operate on the same timescale1,2 (i.e., contemporary time). As such, evolution can be sufficiently rapid to affect ecological processes such as predation or competition. Thus, evolution can influence population, community, and ecosystem-level dynamics. Indeed, studies have now shown that evolutionary dynamics can alter community structure3,4,5,6 and ecosystem function.7,8,9,10 In turn, shifts in ecological dynamics driven by evolution might feed back to affect the evolutionary trajectory of individual species.11 This feedback loop, where evolutionary and ecological changes reciprocally affect one another, is a central tenet of eco-evolutionary dynamics.1,12 However, most work on such dynamics in natural populations has focused on one-way causal associations between ecology and evolution.13 Hence, direct empirical evidence for eco-evolutionary feedback is rare and limited to laboratory or mesocosm experiments.13,14,15,16 Here, we show in the wild that eco-evolutionary dynamics in a plant-feeding arthropod community involve a negative feedback loop. Specifically, adaptation in cryptic coloration in a stick-insect species mediates bird predation, with local maladaptation increasing predation. In turn, the abundance of arthropods is reduced by predation. Here, we experimentally manipulate arthropod abundance to show that these changes at the community level feed back to affect the stick-insect evolution. Specifically, low-arthropod abundance increases the strength of selection on crypsis, increasing local adaptation of stick insects in a negative feedback loop. Our results suggest that eco-evolutionary feedbacks are able to stabilize complex systems by preventing consistent directional change and therefore increasing resilience.

Reproductive interference is stronger than expected in Heliconius butterflies

AbstractIn animals, reproductive interference associated with mimicry can result in the evolution of private communication channels, as suggested for Heliconius butterflies, where cryptic color wavelength would drive male preference for conspecific over intergeneric co‐mimics. Here, we tested this hypothesis in two co‐mimic pairs (intra and intergeneric) and measured the efficacy and symmetry of color pattern as a reproductive barrier in a non‐co‐mimic, possibly hybridizing pair of Heliconius species. We conducted pairwise experiments of preference where a group of males was presented to a conspecific and heterospecific female model made with real wings and free of chemical volatiles. We did not detect any indication of the expected use of cryptic recognition signals to mate choice in the intergeneric co‐mimic pair. Additionally, we detected an unexpected male preference for heterospecific female models between intrageneric co‐mimics towards the species with larger red patches, suggesting a supernormal stimulus based on a general preference for the red color. Finally, we found an asymmetry in the behavioral reproductive barrier between the non‐co‐mimic closely related species that also agrees with the hypothesis of a general preference for red and with an expected permeability of the reproductive barrier between them. Since the costs imposed by heterospecific courtships can limit the convergence of signaling phenotypes, our results contribute to explaining the maintenance of multiple aposematic color pattern between unpalatable and closely related sympatric Heliconius species.

Color restoration based on digital pathology image.

Protective color restoration of faded digital pathology images based on color transfer algorithm. Twenty fresh tissue samples of invasive breast cancer from the pathology department of Qingdao Central Hospital in 2021 were screened. After HE staining, HE stained sections were irradiated with sunlight to simulate natural fading, and every 7 days was a fading cycle, and a total of 8 cycles were experienced. At the end of each cycle, the sections were digitally scanned to retain clear images, and the color changes of the sections during the fading process were recorded. The color transfer algorithm was applied to restore the color of the faded images; Adobe Lightroom Classic software presented the histogram of the image color distribution; UNet++ cell recognition segmentation model was used to identify the color restored images; Natural Image Quality Evaluator (NIQE), Information Entropy (Entropy), and Average Gradient (AG) were applied to evaluate the quality of the restored images. The restored image color met the diagnostic needs of pathologists. Compared with the faded images, the NIQE value decreased (P<0.05), Entropy value increased (P<0.01), and AG value increased (P<0.01). The cell recognition rate of the restored image was significantly improved. The color transfer algorithm can effectively repair faded pathology images, restore the color contrast between nucleus and cytoplasm, improve the image quality, meet the diagnostic needs and improve the cell recognition rate of the deep learning model.

Taxonomy and Melanism Patterns of Freshwater Leeches in the Genus Glossiphonia (Hirudinea: Glossiphoniidae) from Northeast Asia

Freshwater leeches belonging to the genus Glossiphonia Johnson, 1816 are fairly common benthic annelids in freshwater ecosystems throughout Eurasia, but the taxonomy of this group remains poorly resolved, and the species content of some local faunas is unsatisfactorily known. For example, it was thought that the only widespread species, Glossiphonia complanata (Linnaeus, 1758), dwells in Northeast Asia. Here, we revise the Northeast Asian Glossiphonia leeches with an integrative taxonomic approach. This revision is based on the largest DNA-sequence and morphological datasets collected to date. Two Glossiphonia species are recorded from the region. First, Glossiphonia koreaensissp. nov., a putative regional endemic species, was discovered in South Korea. Second, a valid name and complete description are provided for Glossiphonia mollissima Moore, 1898 (non-Grube, 1871). The latter name was wrongly applied through misidentification and, according to ICZN (Article 49), is unavailable. Hence, we propose a new name, Glossiphonia mooreisp. nov., in memory of Dr. J. Percy Moore, who discovered this leech. It is a prospective trans-Beringian species, ranging through Eastern Siberia, the Russian Far East, and Alaska (although Alaskan records are based on nonsequenced samples), showing a significant proportion of melanic individuals in samples north of the Arctic Circle. The latter pattern may reflect substrate-induced cryptic coloration (camouflage), but this hypothesis needs to be statistically checked in the future. Finally, a complete checklist of Glossiphonia species is presented.

Reference genome of an iconic lizard in western North America, Blainville's horned lizard Phrynosoma blainvillii.

Genome assemblies are increasingly being used to identify adaptive genetic variation that can help prioritize the population management of protected species. This approach may be particularly relevant to species like Blainville's horned lizard, Phrynosoma blainvillii, due to its specialized diet on noxious harvester ants, numerous adaptative traits for avoiding predation (e.g. cranial horns, dorsoventrally compressed body, cryptic coloration, and blood squirting from the orbital sinuses), and status as Species of Special Concern in California. Rangewide decline since the early 20th century, the basis of its conservation status, has been driven mainly by habitat conversion, over-collecting, and invasion of a non-native ant that displaces its native ant prey base. Here, we report on a scaffold-level genome assembly for P. blainvillii as part of the California Conservation Genomics Project (CCGP), produced using Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology. The de novo assembly has 78 scaffolds, a total length of ~2.21 Gb, a scaffold N50 length of ~352 Mb, and BUSCO score of 97.4%. This is the second species of Phrynosoma for which a reference genome has been assembled and represents a considerable improvement in terms of contiguity and completeness. Combined with the landscape genomics data being compiled by the CCGP, this assembly will help strategize efforts to maintain and/or restore local genetic diversity, where interventions like genetic rescue, translocation, and strategic land preservation may be the only means by which P. blainvillii and other low-vagility species can survive in the fragmented habitats of California.

Ensuring the secrecy of objects in the conduct of armed conflicts of varying intensity, as an important aspect of their protection: history, status, development of the process

The object of the study is to ensure the security of objects during the conduct of military conflicts of varying intensity. The subject of the study is to increase security by increasing secrecy. Historical analysis shows that secrecy is provided mainly due to the coloring of military uniforms and objects. At the early stages of combat operations, the colors of uniforms served, along with other elements of visual visualization of the situation, to visually distinguish their troops from enemy troops, the separation of troops by gender and purpose, and the issue of masking combat and rear facilities was not relevant. With the increase in the range, accuracy and rate of fire of weapons, the field military uniform gradually lost the function of identification and acquired the function of disguise. At first it was a one-color "khaki" color, then a camouflage coloring. With the appearance of military equipment on the battlefield, it also had to be painted, masking turned from a poorly formalized process into one of the forms of ensuring combat operations – engineering. Subsequently, with the advent of reconnaissance and combat aircraft, and other types of long-range weapons, it was necessary to ensure the secrecy of not only the objects of the battlefield, but also the objects of the rear. Separate sections of masking – reducing the optical visibility of objects in the air and at sea. The article examines the history of the development of methods for increasing the secrecy of personnel, weapons and objects through the use of protective coloring of uniforms, equipment and military equipment. Other aspects of the application of methods of increasing stealth in optical and other ranges, their development in recent history are briefly touched upon.