Protected areas are central to global biodiversity conservation, yet their effectiveness in safeguarding species remains debated, particularly in highly anthropogenic landscapes. In Europe, the Natura 2000 network is the largest protected-area system, designed to ensure the survival of threatened species and habitats, but its capacity to halt biodiversity loss and host large fractions of species populations remains unclear. The Basque Country (northern Spain) is one of the most industrialized and densely populated regions in Europe, situated at a climatic and biogeographic transitional area between the Mediterranean and Atlantic domains. Using fine-scale data from the recent breeding bird atlas, we assessed the effectiveness of Natura 2000 sites in conserving regional breeding bird populations. The analysis of 127 native breeding species revealed that only 18.6% of their total breeding populations occurred inside Natura 2000, slightly below the 23% of land it covers. Species associated with mountains, wetlands, and marine cliffs were proportionally overrepresented, whereas those inhabiting urban, agricultural and forest landscapes were underrepresented. Species with increasing population trends, and those listed as threatened regionally or in Annex I of the Birds Directive, showed higher representation, reflecting partial policy success but persistent habitat-specific gaps. We also evaluated the role of body size, which was found to show no clear association with population representation in Natura 2000. These findings demonstrate that Natura 2000 plays an important role in conserving species of concern and in less disturbed habitats, but is insufficient to secure populations in agricultural, urban, and forest landscapes. In an industrialized and densely populated region, effective conservation requires stronger integration of protected areas with agricultural, forestry, and urban policies to achieve EU biodiversity goals.

Urban expansion alters animal communities through habitat fragmentation, environmental filtering and functional homogenisation. Understanding how urban habitats shape species assemblages is essential for urban planning that balances development with biodiversity conservation. We analysed the breeding bird community in Pamplona, northern Spain, a Mediterranean city that has experienced 40

Protected areas represent cornerstones of biodiversity conservation on oceanic islands, yet their effectiveness for endemic species remains poorly evaluated. We assessed how various territorial protection categories conserve an endemic oceanic bird by comparing periods of population maxima and minima in Fuerteventura. Using 500-m transects across the island, we analyzed local abundance differences inside versus outside protected areas, identified proportions of populations within protection boundaries, and examined cohabitation patterns with other avian species. Local stonechat abundance was significantly higher only inside Special Areas of Conservation (SACs) (non-targeted to birds), with no advantage in Special Protection Areas for Birds (SPAs), despite their avian conservation purpose (i.e., targeted to birds). Temporal analyses revealed a sharper decline in stonechat abundance inside SACs compared to unprotected areas, and similar changes outside and inside SPAs. Approximately 42% of the stonechat population and 72% of its occupancy area remained outside SPA boundaries during both periods, demonstrating inefficient spatial alignment with the species' distribution. Unprotected areas gained critical significance during the 2024 population minimum, as static boundaries failed to capture the species' shifting distribution patterns. The stonechat showed positive associations with five other endemic subspecies but no spatial overlap with emblematic "flagship" species that typically drive conservation decisions. Conservation planning must adopt more dynamic approaches that not only account for species' spatial distributions under optimal conditions but also identify and protect key refugia during population declines. This is particularly critical for improving the effectiveness of protected areas for island endemics with restricted and environmentally sensitive habitat requirements.

Translocation programs are vital conservation tools for endangered species with restricted and isolated populations. Assessing the establishment phase is crucial to understand how translocated individuals adapt to new environments and overcome ecological constraints, especially during winter, the most challenging period of the annual cycle. This study focused on the endangered Gran Canaria blue chaffinch (Fringilla polatzeki), an endemic woodland bird species with a highly restricted natural range. Nine years after initiating a translocation program to a new pine forest (La Cumbre), we examined the blue chaffinch's winter biology during its establishment phase, assessing how limiting the winter season could be in this new habitat, by investigating dependence on supplementary feeding and the intensity of competitive interactions. Our findings reveal minimal reliance on supplementary feeding, unaffected by temperature, with chaffinches allocating only 5.2% of their daily time to feeders, primarily in the afternoon. The species demonstrated competitive dominance over other seed-eating birds unique to La Cumbre, suggesting that interspecific competition does not constrain resource access. Additionally, intraspecific competition was minimal, with few aggressive interactions and no differences in feeder access related to sex or age within the dominance hierarchy. These results indicate that La Cumbre's winter conditions do not significantly limit the blue chaffinch foraging activities during the critical establishment phase. Combined with prior evidence of comparable physical condition, reproductive success, and genetic variability between translocated and natural populations, our study supports La Cumbre as a suitable translocation area. This research highlights the importance of ecological assessments beyond the breeding season to ensure the longterm success and persistence of translocated populations.

European steppe birds are facing unprecedented declines, positioning among the most threatened bird groups. We provide a comprehensive review and synthesis of the available knowledge on Western European (WE) steppe birds, focusing on their ecology, functional traits, population range trends and major threats. Using an expert-based participatory approach, we first created a consensual list of 37 WE species and reviewed the current knowledge on these key topics. Although 67.6 % of species show declining population ranges, only 18.9 % are classified as Endangered or Vulnerable according to the European IUCN Red List. Notably, several species exhibit range contractions over 5 % yet remain listed as Least Concern, indicating a need for re-evaluation based on the most up-to-date data. Threatened species have distinct functional traits compared to non-threatened species, typically being sedentary, large-bodied, long-lived, and exhibiting ground-foraging and ground-nesting behaviours. This highlights the potential for functional diversity loss if threatened species become extinct. Species experiencing the greatest range contractions share many of these traits or exhibit arboreal or aerial lifestyles, carnivorous diets and partial to fully migratory behaviours. Experts identified land use change and human-caused mortality as the main threats, followed by pollution and climate change, although the effects of the latter remain poorly understood for most species. Because significant knowledge gaps on climate and pollution effects remain for most species, these two threats should be the focus of future investigations. This synthesis enhances our understanding of the threats faced by WE steppe birds and provides guidance for prioritizing future research and conservation efforts.

Developing comprehensive mammal inventories in protected areas with human presence is essential for effective biodiversity conservation yet remains challenging, particularly for elusive species. Camera trapping has emerged as a valuable tool for documenting mammal diversity, complementary to or as an alternative to traditional direct observation methods. We studied the Dindefelo Community Nature Reserve (Senegal), encompassing a mosaic of vegetation types with a climate characterised by marked seasonality. The local human population depends on its natural resources for subsistence, and livestock roam freely throughout the reserve. Using camera traps, we conducted a 2-year monitoring program across 29 sampling locations, accumulating 3072 trapping days (approximately 60,000 h of observation). We evaluated how vegetation types, seasonality and anthropogenic factors influenced mammal species richness and vegetation type use. We confirmed the presence of 28 medium- and large-sized mammal species. Mammal species richness varied subtly with vegetation types and seasons but no pronounced differences emerged. Human presence within the reserve had limited negative impacts on mammal species richness. Interestingly, livestock presence, exhibited a positive association with wild mammal diversity, suggesting shared resource use or similar environmental preferences. These results highlight complex interactions between wildlife and human activities. They also emphasise the importance of ongoing monitoring to detect additional rare or elusive species, improving conservation strategies in protected savannahs of western Africa where wildlife and human communities coexist.

Determining the effectiveness of conservation actions is a priority in conservation biology, especially in island ecosystems which can host large numbers of endemic and often threatened species. In this study, we have brought together a genetic, body condition and breeding success assessment with the aim of evaluating the viability of a newly founded population of the endangered Gran Canaria blue chaffinch ( Fringilla polatzeki ), the forest passerine species with the most restricted distribution in the Western Palearctic. The species occurs exclusively in the Canary pine forests ( Pinus canariensis ) of the island of Gran Canaria, with the Inagua nature reserve harbouring the highest number individuals. In 2010, a translocation program was initiated within the same island in the nearby pine forests of La Cumbre with the goal of establishing a viable breeding population. Genetic results revealed that La Cumbre shows genetic parameters (diversity, inbreeding, and relatedness) similar to the core source of Inagua, which contrasts with the reduced genetic diversity expected due to the small size of the newly founded population. The biometric and body condition results (wing and tarsus length, body mass, and length asymmetry of the tail feathers), together with the breeding success (nest survival and number of fledglings per successful breeding attempt), were also similar in both populations. Overall, these findings suggest that the translocation program has been successful and provide insights on the effectiveness of the actions performed. Our evaluation also delivers future avenues for the conservation planning in other upland forest endangered avian species inhabiting island ecosystems, especially those threatened by the effects of global warming.

The environmental and trophic conditions of cities often give rise to very large populations of urban pigeons Columba livia f. domestica, which can cause local health and heritage problems due to accumulations of their droppings. Estimating the size of pigeon populations and defining their spatial patterns of abundance are therefore crucial for effective pigeon management in built-up areas. This article estimates the abundance of pigeons in Pamplona and the factors that explain the variability of pigeon abundance at local level. The Random Forest model of abundance at a local scale of 0.25 km2 cells had very high explanatory power, although its predictive power decreased due to this species’ gregariousness. Abundance decreased with increasing distance from the city centre, and from historic buildings and large parks, but increased as the proportion of the area covered by parks and built-up areas increased. The rock pigeon population in Pamplona was estimated at 8,030 individuals (95% CI: 6,483–9,860). The estimated density of urban pigeons for Pamplona as a whole was, on average, 218 birds/km2, although this figure varied considerably between habitats and areas: the highest values were measured in urban areas with historic buildings (exceeding 600 individuals/km2; in 35.8% of the 0.25 km2 cells, more than 200 individuals were estimated). Pigeon densities fell to ca. 250 birds/km2 in urban areas lacking large parks or green spaces whether near or far from historic buildings. In the peri-urban areas (i.e. arable fields, scrub and woodland), densities decreased to around 10–50 individuals/km2. In the city of Pamplona, although the population density of urban pigeons did not reach the numbers observed in other northern Spanish cities such as Barcelona, the habitat preference patterns in urban gradients are consistent with those documented in other European regions. We identify specific urban areas for population control and recommend measures such as feeding bans and waste and facade management to make it difficult for urban pigeons to access roosting and breeding sites in buildings.

The Gran Canaria Blue Chaffinch is the rarest forest passerine in the western Palaearctic with a population reduced to a single locality, Inagua, in the west of the island. After a forest fire, some birds were established in another location and a reinforcement programme was launched with the aim of consolidating this new population. Between 2010 and 2019, 194 Blue Chaffinches were released in the pine forest of La Cumbre, in the centre of the island and at a higher altitude than the previous one. Birds of two origins were used for this action: captive-bred birds were released using “soft” release methods, and wild-caught birds from the Inagua source population were released using “hard” release methods. Survival of radio-tagged birds (20–42 days of battery life) was high and similar between the two groups. Wild-caught birds occupied 12–15 times more surface area than captive-bred birds that remained close to supplementary feeding sites. All translocated birds displayed breeding behaviour in the following breeding season, although the rate of contribution to the new population was significantly lower for wild-caught birds (21

Arid island environments harbour a unique biota characterised to have adaptive features that enable them to thrive in such harsh habitats. However, our understanding of how anthropogenic climate change compromises the biodiversity and sustainability of these ecosystems is greatly unknown. Here we used fine-grained field data to evaluate the effects of extreme weather on the population size, distribution, and habitat preferences of an endemic bird species inhabiting an arid Atlantic island, across two temporal windows spanning approximately 20 years (2005–2024). Population size declined sharply (63 %–70 %) between periods, according to a distance-based sampling design and a habitat suitability modelling approach, with the number of individuals estimated in 2024 being 4650 (CI 95 %: 3600–5950) and 4150 (CI 95 %: 3600–4800) respectively. The density of this species in 2024 was reduced by approximately three times compared to the previous study period. The results revealed that in 2024 a larger island area (246 km2 and 514 km2) was necessary to encompass 50 % and 75 % of all individuals of this species, respectively, compared to the previous period (195 km2 and 434 km2). Such a population collapse was associated with the decrease in rainfall on the island, which is closely related to the reproductive success in this species. We recorded a pattern of continuous decrease in rainfall since 2005–2006, which included several extremely dry years immediately before the 2024 study. We also found strong evidence for the population decline of other native bird species of the same foraging guild. Overall, our data emphasizes the significance of recurrent and extreme climatic events on arid island bird species in driving population declines and reducing their distribution ranges; and highlights how fragile such unique taxa can be under longer dry periods, with uncertain consequences for their future viability.

Summary The Gran Canaria Blue Chaffinch Fringilla polatzeki is a threatened, endemic, forest‐dwelling bird species of the Canary Islands, whose core population at the end of the 20th century was restricted to the pine forests of Inagua Nature Reserve (38 km 2 ). A translocation programme released birds from a breeding centre into the nearby (<3 km) pine forests of La Cumbre in the years following 2010. From 2015 to 2019 the La Cumbre population was reinforced by translocation of wild juveniles from the source population of Inagua. We estimate the population size, the spatial variation of abundance, and recent temporal changes in density of the species in Inagua and La Cumbre by means of line transects, distance sampling, and habitat suitability modelling using random forests. The average density of the Blue Chaffinch in Inagua Nature Reserve was 10.2 birds/km 2 in spring 2019, with a population estimated at 362 birds (95% CI: 257–489). The most important variables affecting the distribution of the Blue Chaffinch in Inagua were the amount of precipitation during the summer (July–September), the solar radiation in June, and the northern position in the reserve, highlighting the importance of abiotic factors related to thermal and hydric stress during the breeding season. The density was considerably lower in the translocated population inhabiting 21 km 2 of pine forests in La Cumbre (3.3 birds/km 2 ), with an estimate of 68 Blue Chaffinches (35–141) breeding freely in the wild. The translocation programme successfully contributed to the establishment of a second viable nucleus, accounting for 16% of the total population within a time span of 10 years. This result reinforces the role of translocations in preventing extinctions of endangered species with very low population sizes restricted to only one isolated area.

The estimation of the post-mortem interval is crucial to accurately provide bird collision rates against manmade infrastructures. Standard methodologies recommend initially clearing all carcasses to ensure that subsequent collisions can be attributed to known time intervals. In this study, we propose a more cost-efficient approach aiming to link the decomposition stages as unequivocally as possible to the most likely time elapsed since death. Factors influencing the decomposition stages of bird carcasses were evaluated by means of two experiments. Firstly, we examined carcasses of large birds in three seasons differing in temperature, sun radiation and humidity: summer, autumn and spring. Secondly, we tested the influence of body mass in the same season (spring) using small, medium-sized and large bird carcasses. Results showed that the decomposition score increased monotonically with time, attaining the highest magnitude effect. A carcass with a decomposition score ≥ 4 (skeletal reduction) was in the field for ≥ 15 days, whereas a carcass with a score < 3 (fresh or emphysematous) was exposed < 3 days. Decomposition scores were higher in summer and did not differ among carcass sizes. This study provides an alternative protocol to estimate the post-mortem interval in wild birds in studies in search of bird fatalities.

Extensive bird monitoring programmes are fundamental for estimating inter-annual population trends using data provided by thousands of observers through standardised fieldwork. Gordo (2018) has proposed that abundance data recorded by common bird monitoring schemes (e.g. SACRE programme) should he used cautiously due to its potential inaccuracy, because two surveys per spring are not enough to record the actual maximum number of individual birds at a sampling location. We carried out numerical simulations and analysed the interspecific pattern of statistical significance of the published population trends of the Spanish common birds census, the SACRE programme (1998-2011), in order to test how the number of repetitions of censuses per year affects the power of tests: (i.e. the probability of detecting significant trends that are in fact true), and the probability of obtaining low false discovery rates: i.e. identifying significant changes that are actually false, when estimating yearly population changes. We agree with Gordo (2018) that two surveys of the same sampling stations per year are unable to detect the maximum number of birds throughout a breeding season. Nevertheless, the goal of monitoring programmes is not to obtain the maximum number of birds at each sampling unit over a long time span but to measure reliable population trends. Our results demonstrate that the average number of birds recorded in two surveys per season provides a highly reliable indication of population trends for abundant and widely distributed bird species, the focal taxa in common birds monitoring schemes, especially of long-term average trends > +/- 2.5% change annually. The actual population trends for very rare species, such as those with data from fewer than 50 UTM squares and < 5 individual birds per census and UTM cell, are hard to detect unless they show yearly percentage population changes greater than +/- 5%.

Carcass counts notably underestimate avian collision rates due to three main bias sources: imperfect detection, carcass removal by scavengers and carcass dispersion in unsearched areas. We assessed these sources of bias at electric lines of two Canary Islands, Lanzarote and Fuerteventura, quantifying the factors influencing them. We also carried out a cost-effectiveness assessment of carcass search done perpendicularly to electric line axis. We surveyed 230km of three types of electric lines (high-voltage, medium voltage and telephone lines) during three periods (July 2015, November-December 2015 and March 2016) searching for collision fatalities (N = 431), recording the species, the carcass distance from the electric line, mean cable height, carcass detection distance and decomposition state. In addition, we carried out a disappearance rate experiment to estimate carcass removal by scavengers. A generalised least squares model was used to analyse dispersion distance of carcass from electric lines, in relation to species body mass, mean cable height and line typology. Detection probability functions were fitted to estimate carcass detectability, incorporating body mass, decomposition state and habitat structure as covariates. A Generalised Mixed-Effects model was carried out to analyse carcass disappearance in relation to time elapsed since carcass placement, carcass size, season and island. Dispersion distance decreased with body mass and increased with cable height, being further at high-voltage lines. Overall, detection probability was 0.134, increasing with carcass size, decreasing with decomposition state and being lower in rocky areas which offered a significant challenge when walking through rough terrain. Disappearance rates differed between islands probably due to differences in avian scavenger abundance, increased with time elapsed and decreased with bird size. This study provides correction factors to obtain unbiased estimates of avian mortality rates within sparsely vegetated landscapes. Moreover, it identifies a 27m threshold distance at which the cost-effectiveness of searching for carcasses is optimised.

This study investigates how precipitation, temperature and seasonality (as a proxy of plant productivity) affect the temporal and spatial variability of soil CO2 efflux in two dry semiarid grasslands with different degrees of land degradation. We measured soil CO2 efflux over four years under plant, biological soil crust and bare soil patches and estimated annual soil carbon losses in both, a natural and a degraded grassland, by means of generalised additive mixed models considering temporal autocorrelation in the data. Soil CO2 efflux ranged from 0.08 to 3.70 and from 0.10 to 3.01 μmol CΟ2 m−2 s−1 in the natural and degraded grasslands, respectively. Daily soil CO2 efflux was mostly affected by moisture in the degraded grassland (25.4%), while in the natural grassland was affected jointly by seasonality, temperature and moisture (27.5%). Overall, the highest soil carbon fluxes were measured in soils covered by biological soil crusts (1.24 ± 0.02 and 1.10 ± 0.02) and the lowest in bare soils (1.11 ± 0.02 and 0.82 ± 0.02 μmol CΟ2 −2 s−1) in the natural and degraded sites, respectively. Cumulative soil carbon fluxes were mainly driven by temperature and previous precipitation (over three months). The highest soil carbon losses were estimated in the driest year (2009) and the lowest in the wettest (2010) with almost twice the amount of rainfall. The main difference between these years was the timing of the events that mostly occurred in the moments of maximum plant activity with optimum temperatures in spring in the dry year. Changes in precipitation patterns will affect soil carbon fluxes more than rainfall amount, particularly in degraded grasslands. Therefore, considering all climate drivers together with plant activity is essential to predict how climate change will affect soil biological processes in drylands.

Infectious diseases are considered major threats to biodiversity, however strategies to mitigate their impacts in the natural world are scarce and largely unsuccessful. Chytridiomycosis is responsible for the decline of hundreds of amphibian species worldwide, but an effective disease management strategy that could be applied across natural habitats is still lacking. In general amphibian larvae can be easily captured, offering opportunities to ascertain the impact of altering the abundance of hosts, considered to be a key parameter affecting the severity of the disease. Here, we report the results of two experiments to investigate how altering host abundance affects infection intensity in amphibian populations of a montane area of Central Spain suffering from lethal amphibian chytridiomycosis. Our laboratory-based experiment supported the conclusion that varying density had a significant effect on infection intensity when salamander larvae were housed at low densities. Our field experiment showed that reducing the abundance of salamander larvae in the field also had a significant, but weak, impact on infection the following year, but only when removals were extreme. While this suggests adjusting host abundance as a mitigation strategy to reduce infection intensity could be useful, our evidence suggests only heavy culling efforts will succeed, which may run contrary to objectives for conservation.

Infectious disease and climate change are considered major threats to biodiversity and act as drivers behind the global amphibian decline. This is, to a large extent, based on short-term studies that are designed to detect the immediate and strongest biodiversity responses to a threatening process. What few long-term studies are available, although typically focused on single species, report outcomes that often diverge significantly from the short-term species responses. Here, we report the results of an 18-year survey of an amphibian community exposed to both climate warming and the emergence of lethal chytridiomycosis. Our study shows that the impacts of infectious disease are ongoing but restricted to two out of nine species that form the community, despite the fact all species can become infected with the fungus. Climate warming appears to be affecting four out of the nine species, but the response of three of these is an increase in abundance. Our study supports a decreasing role of infectious disease on the community, and an increasing and currently positive effect of climate warming. We caution that if the warming trends continue, the net positive effect will turn negative as amphibian breeding habitat becomes unavailable as water bodies dry, a pattern that already may be underway.

Risks of parasitism vary over time, with infection prevalence often fluctuating with seasonal changes in the annual cycle. Identifying the biological mechanisms underlying seasonality in infection can enable better prediction and prevention of future infection peaks. Obtaining longitudinal data on individual infections and traits across seasons throughout the annual cycle is perhaps the most effective means of achieving this aim, yet few studies have obtained such information for wildlife. Here, we tracked spiny common toads (Bufo spinosus) within and across annual cycles to assess seasonal variation in movement, body temperatures and infection from the fungal parasite, Batrachochytrium dendrobatidis (Bd). Across annual cycles, toads did not consistently sustain infections but instead gained and lost infections from year to year. Radio-tracking showed that infected toads lose infections during post-breeding migrations, and no toads contracted infection following migration, which may be one explanation for the inter-annual variability in Bd infections. We also found pronounced seasonal variation in toad body temperatures. Body temperatures approached 0 °C during winter hibernation but remained largely within the thermal tolerance range of Bd. These findings provide direct documentation of migratory recovery (i.e., loss of infection during migration) and escape in a wild population. The body temperature reductions that we observed during hibernation warrant further consideration into the role that this period plays in seasonal Bd dynamics.

The evolutionary distinctiveness (ED) score is a measure of phylogenetic isolation that quantifies the evolutionary uniqueness of a species. Here, we compared the ED score of parasitic and non-parasitic cuckoo species world-wide, to understand whether parental care or parasitism represents the largest amount of phylogenetic uniqueness. Next, we focused only on 46 cuckoo species characterized by brood parasitism with a known number of host species, and we explored the associations among ED score, number of host species and breeding range size for these species. We assessed these associations using phylogenetic generalized least squares (PGLS) models, taking into account the phylogenetic signal. Parasitic cuckoo species were not more unique in terms of ED than non-parasitic species. However, we found a significant negative association between the evolutionary uniqueness and host range and a positive correlation between the number of host species and range size of parasitic cuckoos, probably suggesting a passive sampling of hosts by parasitic species as the breeding range broadens. The findings of this study showed that more generalist brood parasites occupied very different positions in a phylogenetic tree, suggesting that they have evolved independently within the Cuculiformes order. Finally, we demonstrated that specialist cuckoo species also represent the most evolutionarily unique species in the order of Cuculiformes.

1. Animal pigmentation has evolved because of several adaptive functions. In the case of pigmentation produced by melanins, the most common pigments in animals, the main function is protection against UV radiation. However, pigmentation also affects animal surface's ability to absorb solar radiation and gain heat, which may represent a thermal constraint for endotherms due to their relatively high and constant body temperatures. 2. As darker colours absorb more radiation than lighter colours, dark-pigmented endotherm animals may exhibit limited performance under high ambient temperatures and thus be constrained at occupying hot environments. While the influence of pigmentation on the determination of the thermal niches of ectotherms, particularly reptiles, has been the focus of several studies, this remains an unexplored issue for endotherm animals. 3. Here, we made a detailed quantification of the expression of pigmentation phenotypes produced by melanins in 96 species of birds inhabiting the Spanish sector of the Iberian Peninsula and estimated their climate niche position by calculating the effects of ambient temperature, insolation and precipitation on bird occurrence at a fine 10 x 10 km spatial scale. 4. After controlling for the body size and the nocturnal condition of species, and for phylogenetic and spatial effects, we found a positive association between plumage reflectance and the functional response of bird distribution to spring-summer ambient temperature and insolation but not to precipitation. Thus, bird species preferentially occupying the hotter and sunnier areas of Spain exhibit lighter plumage pigmentation. 5. Our findings suggest that darker birds are limited from occupying environments with high temperatures, unveiling a constraint in endotherms imposed by their pigmentation phenotype.