Breeding Distribution Research Articles

Nesting habitat selection and distribution of an avian top predator in the Canadian Arctic

Detecting and planning for ecosystem changes from climate and land-use alteration is limited by uncertainty about the current distribution of many species. This is exacerbated in remote areas like the Arctic, where the impacts of climate change are the strongest and where industrial exploration and development are expanding. Using remotely-sensed environmental information and known nest sites, we estimated the breeding distribution and habitat selection of the peregrine falcon (Falco peregrinus) throughout most of Nunavut, a massive northern Canadian territory (>1.8 M km2) encompassing ∼15% of the world’s tundra biome. Our results show that peregrine falcons selected features of prior known importance such as rugged topography, but also sites with higher than average summer temperatures, more productive land classes, lower mean elevations, and lower mean summer precipitation. Our model identifies several areas of high relative probability of peregrine occurrence, some of which were unrecognized to date. Some of these areas may be targets for future industrial developments and are located in an area where some of the fastest climate changes are expected. Our model will allow managers to identify the areas that could be the most critical for monitoring in the context of future development and climate change.

Mackenzie River Peregrine Falcon Surveys 1966–2018

Abstract The author with assistants monitored the breeding distribution of Peregrine Falcons (Falco peregrinus) along the length of the Mackenzie River, Northwest Territories, Canada from 1966 to 2018. This river traverses a thousand miles (1600 km) of the western Canadian Arctic from Great Slave Lake to the Beaufort Sea and roughly parallels the eastern slope of the Mackenzie Mountain cordillera between latitudes 61 degrees N and 68 degrees N. All potential nest sites have been checked on each survey and counts of nest sites occupied (at least one bird seen) decreased from the count of 12 sites in 1966 to the lowest count of 7 in 1972. In 1990 the count was 37 and up to 2018 the highest count was 75 in 2010. A count of nest sites successfully producing young was variable with a low of 5 in 1972 to a high of 58 in 2011. Production of young averaged 2.43/successful site from 1990 until 2018 (excluding 2012). Production of young averaged 1.4/occupied site over this period. Recent increases in availability of passerine prey because of widespread fires in the last decades are felt to be the latest phenomena affecting these birds (pers.obs.) Prey utilized by Peregrines was studied over a period of four years and passerines composed 20% of their diet. Two species Lesser Scaup (Athya affinis) and Lesser Yellowlegs (Tringa flavipes) formed 25% of their diet.

First steps towards assessing the evolutionary history and phylogeography of a widely distributed Neotropical grassland bird (Motacillidae: Anthus correndera).

Grasslands in southern South America are extensive ecosystems which harbor a unique biodiversity; however, studies on the evolution of their taxa are scarce. Here we studied the phylogeography and population history of the Correndera Pipit (Anthus correndera), a grassland specialist bird with a large breeding distribution in southern South America, with the goals of investigating its phylogeographic history and relate it to the historical development of South American grasslands. The mitochondrial NADH dehydrogenase subunit II gene (ND2) was sequenced in 66 individuals from 19 localities and the intron 9 of the sex-linked gene for aconitase (ACOI9) was sequenced from a subset of those individuals, including all five subspecies of A. correndera, as well as the closely related A. antarcticus. Phylogenetic analysis revealed two distinct lineages within the complex: the first (A) corresponding to Andean subspecies A. c. calcaratus and A. c. catamarcae and the second (B) including birds traditionally assigned to A. c. correndera, A. c. chilensis, A. c. grayi and some individuals of A. c. catamarcae. A. antarcticus is nested within this second lineage. These results were also supported by evidence of niche divergence for variables associated with precipitation. The oldest split between clade A and B was estimated at c. 0.37 Mya, during the middle Pleistocene. Species distribution models for the present and the Last Glacial Maximum (LGM) suggest that grassland areas in southern South America remained relatively stable, in contrast to the general view of a reduction in grassland cover in South America since the LGM. Recent divergences and low phylogeographic structure (for lowland vs. highland geographic groups, intra-population genetic variance was greater than inter-groups; e.g., for ACOI9: 95.47% and ND2: 51.51% respectively), suggest widespread gene flow between lowland populations.

Documenting successful recruitment of monarch butterflies (Lepidoptera: Nymphalidae) at the extreme northern edge of their range

AbstractMonarch butterflies (Danaus plexippus (Linnaeus) (Lepidoptera: Nymphalidae)) in eastern North America migrate each year from overwintering areas in Mexico to cover a large breeding distribution across the United States of America and southern Canada. In 2012, monarch butterflies migrated well beyond their usual range, resulting in an extended breeding distribution compared to typical years. We used stable isotope (δ2H, δ13C) measurements in wing chitin to determine the area of natal origin of these butterflies. Most monarch butterflies collected in May, June, and July from Manitoba and Alberta, Canada had natal origins in the North American Midwest. Monarch butterflies collected in Alberta and Saskatchewan, Canada in August and September had local natal origins indicating successful recruitment of offspring from colonising individuals. However, it is unknown whether these offspring migrated successfully to overwintering areas. Our work highlights the ability of monarch butterflies to colonise distant breeding areas and demonstrates how stable isotopes can be used to understand the dynamics of range-edge populations.

Breeding birds in the Narta Lagoon (SW Albania) in 2016

Abstract The Narta Lagoon (59 km2) is one of the largest and most important coastal wetlands for migratory and wintering waterbirds in Albania. However, the breeding bird fauna of the site is still poorly studied. The current work aims to broaden the knowledge on the list of breeding bird species, their numbers, distribution and threats in the zone (with a focus on waterbirds). Relevant information for spring migrants is also provided. The survey consisted of two field visits in April and May 2016. The entire wetland area was covered and all its habitats were visited. In total, 136 bird species were observed. The total number of breeding birds was estimated at 6,400 pairs of 85 species. The most abundant breeders were the Little Tern Sternula albifrons with 377 breeding pairs (bp), Avocet Recurvirostra avosetta with 121 bp, and Kentish Plover Charadrius alexandrinus with 96 bp. In total, 3,461 individuals belonging to 80 species were recorded as non-breeders. At the species level, the most numerous were Kentish Plover with 1,100 individuals (ind.), Marsh Sandpiper Tringa stagnatilis with 600 ind., Greater Flamingo Phoenicopterus roseus with 321 ind., Common Shelduck Tadorna tadorna with 130 ind., Spotted Redshank Tringa erythropus with 120 ind. and Dunlin Calidris alpina with 100 ind. Breeding birds assemblages within the main studied habitats (salinas, lagoon, pine forests, mixed farmland, rocky hills with olive trees, and grasslands with bushes near the coast) and threats (the most significant of which were illegal shooting, trapping and dangerous power grid) are also described. Recommendations for future bird-friendly management, appropriate conservation activities and eco-tourism in the area are made.

Scripps's Murrelet at San Miguel Island, California: Status of a Small Population at the Northwest Limit of the Breeding Range

San Miguel Island (SMI) and its adjacent islets, Prince Island and Castle Rock, support a small population of Scripps's Murrelets (Synthliboramphus scrippsi) at the northwest limit of their breeding range. In 1994–1996, 2004, 2007, and 2015, we conducted at-sea surveys and nest searches to determine the breeding distribution and population size of the Scripps's Murrelet at the SMI group. During at-sea vocal surveys in 1994–1996, murrelet calls were heard at 4 stations around Prince Island (43–167 calls), 2 stations off Castle Rock (6 calls and 80 calls), and 4 stations off northeast SMI (5–123 calls), but none were detected at 8 stations off southern and northwestern SMI. At-sea spotlight surveys in 2004, 2007, and 2015 confirmed murrelet congregations off Prince Island and northeast SMI. Annual mean (±SD) spotlight counts on a standard transect off of northeast SMI and Prince Island were 9 ± 0 murrelets (n = 2) in 2004, 19 ± 4 (n = 3) in 2007, and 91 ± 15 (n = 2) in 2015; much higher spotlight counts at Prince Island accounted for the higher mean in 2015. We found murrelet nests in 4 of the 12 areas searched at SMI and Prince Island. In 2007 the first murrelet nests ever found on SMI proper were discovered at Harris Point, Bay Point, and Hoffman Point in isolated shoreline habitats that were inaccessible to endemic Island Foxes (Urocyon littoralis littoralis) but accessible to nonnative Black Rats (Rattus rattus). Using spotlight counts we estimated 100–263 breeding pairs at the SMI group in 2015, mainly at Prince Island (90%) where foxes and rats were absent. Spotlight surveys have not been conducted at Castle Rock, but <5 pairs were suspected. Introducing rats from SMI proper to the offshore islets is the most serious threat to murrelets at this remote island, although a large oil spill could also extirpate this population. Spotlight surveys and nest searches should be conducted at least every 5 years to confirm persistence of this vulnerable species at SMI and to detect major changes in population size.

What Do We Know About Black Skimmers? A Review on Its Annual-Cycle and Life-History Main Events

The Black Skimmer Rynchops niger is a New World's coastal migratory bird with three subspecies based on distinctive morphometrics, plumage, and breeding distribution. Its population is decreasing in North America while numbers are poorly known in South America. Here we conducted an extensive review of the literature on the Black Skimmer to fill gaps in the knowledge of each subspecies' natural history and suggest where future research should focus. We used 41,247 records collected from databases and literature to establish the overall occurrence and location of breeding colonies for each subspecies. We also collected information on the phenology of life-history events described in 150 papers and books to compare the annual cycle of the three subspecies. The North American subspecies R. n. niger breeds, migrates and stages along the coast with few records inland. The South American R. n. intercedens and Amazonian R. n. cinerascens subspecies breed inland and migrate mostly to coastal staging sites. The pre...

Distribution and Abundance of Breeding Striated Caracaras in the Falkland Islands (Malvinas)

We conducted surveys of breeding pairs of the endemic and globally “Near Threatened” Striated Caracara (Phalcoboenus australis) on 79 outer islands in the Falklands archipelago (Islas Malvinas) during the austral-summer breeding seasons of 2013–2014 and 2014–2015. A total of 354 breeding pairs (defined as pairs with evidence of egg-laying), or an archipelago-wide adult breeding population of at least 0.05 birds/km2 was recorded. An additional 477 probable breeding pairs also were found. The distribution of breeding pairs remains similar to that found during surveys in the 1990s and 2000s. Grand Jason, Steeple Jason, New Island, Beauchene Island, and Bird Island, the five islands with the highest numbers of breeding pairs, accounted for half of the total breeding population. “Vegetationally pristine” islands with dense areas of tussac grass (Poa flabellata) and high densities of small burrowing seabirds—namely Bird Island, Saddle Island, and Beauchene Island—supported the highest densities of breeding pairs. Eighty percent of all pairs occurred on National Nature Reserves or on privately owned nature sanctuaries. Our surveys suggest that sustained protection of key breeding sites is critical for the long-term conservation of this species. We recommend that populations of Striated Caracaras at Tierra del Fuego also be surveyed and that the global population status of the species be reassessed.

SEROEPIDEMIOLOGIC SURVEY OF CANINE LEPTOSPIROSIS IN NORTHERN TAIWAN DURING 2008–2015

Leptospirosis is an important infectious zoonosis that may cause life-threatening illness in both humans and animals. This study aimed to identify the serovars of Leptospira using the microscopic agglutination test (MAT) and the effect of season on serum-positive cases detected in National Taiwan University Veterinary Hospital from August 2008 to September 2015. This study also compared the characteristics of serum-positive and serum-negative cases. Among 159 suspected cases, 78 serum-positive (MAT titer [Formula: see text]) and 81 serum-negative cases were identified. In serum-positive cases, the most common pathogenic serovars were Canicola (18.2%), Icterohaemorrhagiae (23.6%), and Shermani (20.0%). Significantly more serum-positive cases were identified in fall (September to November) than other seasons ([Formula: see text]). Dogs aged 1–5 years (odds ratio [Formula: see text] 1.7) were more likely to be identified as being serum-positive cases of canine leptospirosis than serum-negative cases. However, no significant difference was observed regarding breed, gender, and regional distribution. The serum concentrations of liver enzymes, total bilirubin, blood urea nitrogen, and creatinine were elevated in both serum-positive and serum-negative cases, with no significance. White blood cell (WBC) counts of serum-positive cases were statistically higher than those of serum-negative cases ([Formula: see text]). In conclusion, more precaution must be taken with dogs aged 1–5 years because of their higher risk of leptospirosis; additionally, significantly elevated WBC count may be a suitable indicator in suspected cases of canine leptospirosis.

Marathon penguins - Reasons and consequences of long-range dispersal in Fiordland penguins / Tawaki during the pre-moult period.

Migratory species often roam vast distances bringing them into contact with diverse conditions and threats that could play significant roles in their population dynamics. This is especially true if long-range travels occur within crucial stages of a species’ annual life-cycle. Crested penguins, for example, usually disperse over several hundreds of kilometres after completing the energetically demanding breeding season and in preparation for the costly annual moult. A basic understanding of crested penguins’ pre-moult dispersal is therefore paramount in order to be able to assess factors affecting individual survival. The Fiordland penguin, or Tawaki, the only crested penguin species breeding on the New Zealand mainland, is currently one of the least studied and rarest penguin species in the world. We successfully satellite tracked the pre-moult dispersal of 17 adult Tawaki from a single colony located in the species’ northern breeding distribution. Over the course of 8–10 weeks the penguins travelled up to 2,500 km away from their breeding colony, covering total swimming distances of up to 6,800 km. During outbound travels all penguins headed south-west within a well-defined corridor before branching out towards two general trip destinations. Birds leaving in late November travelled towards the Subtropical Front some 800 km south of Tasmania, whereas penguins that left in December headed further towards the subantarctic front. Using K-select analysis we examined the influence of oceanographic factors on the penguins’ dispersal. Water depth, surface current velocity and sea level anomalies had the greatest influence on penguin movements at the subantarctic Front, while sea surface temperature and chlorophyll a concentration were key for birds travelling to the subtropical front. We discuss our findings in the light of anthropogenic activities (or lack thereof) in the regions visited by the penguins as well as the potential consequences of Tawaki pre-moult dispersal for the species’ breeding distribution on the New Zealand mainland.

A multi-isotope (δ13C, δ15N, δ34S, δ2H) approach to establishing migratory connectivity in lesser snow geese: Tracking an overabundant species.

Expanding populations of North American midcontinent lesser snow geese (Anser caerulescens caerulescens) have potential to alter ecosystems throughout the Arctic and subarctic where they breed. Efforts to understand origins of harvested lesser snow geese to better inform management decisions have traditionally required mark-recapture approaches, while aerial photographic surveys have typically been used to identify breeding distributions. As a potential alternative, isotopic patterns that are metabolically fixed within newly grown flight feathers following summer molting could provide inferences regarding geographic breeding origin of individuals, without the need for prior capture. Our objective was to assess potential to use four stable isotopes (δ13C, δ15N, δ34S, δ2H) from feather material to determine breeding origins. We obtained newly grown flight feathers from individuals during summer banding at three Arctic and two subarctic breeding colonies in 2014 (n = 56) and 2016 (n = 45). We used linear discriminant analyses to predict breeding origins from models using combinations of stable isotopes as predictors and evaluated model accuracy when predicting colony, subregion, or subpopulation levels. We found a strong inverse relationship between δ2H values and increasing latitude (R2 = 0.83), resulting in differences (F4, 51 = 90.41, P < 0.0001) among sampled colonies. No differences in δ13C or δ15N were detected among colonies, although δ34S in Akimiski Island, Baffin Island, and Karrak Lake were more enriched (F4, 51 = 11.25, P < 0.0001). Using δ2H values as a predictor, discriminant analyses improved accuracy in classification level as precision decreased [model accuracy = 67% (colony), 88% (subregion), 94% (subpopulation)]. Application of the isotopic methods we describe could be used to provide an alternative monitoring method of population metrics, such as overall breeding population distribution, region-specific productivity and migratory connectivity that are informative to management decision makers and provide insight into cross-seasonal effects that may influence migratory behavior.

Inventory of Lowland-Breeding Birds on the Alaska Peninsula

AbstractWe conducted the first systematic inventory of birds in the lowlands (areas ≤100 m above sea level) of the Alaska Peninsula during summers of 2004–2007 to determine their breeding distributions and habitat associations in this remote region. Using a stratified random survey design, we allocated sample plots by elevation and land cover with a preference for wetland cover types used by shorebirds, a group of particular interest to land managers. We surveyed birds during 10-min counts at 792 points across 52, 5 km × 5 km sample plots distributed from south of the Naknek River (58.70°N,157.00°W) to north of Port Moller (56.00°N,160.52°W). We detected 95 bird species including 19 species of shorebirds and 34 species (36% of total) considered at the time to be of conservation concern for the land managers in the region. The most numerous shorebirds on point counts were dunlin Calidris alpina, short-billed dowitcher Limnodromus griseus, and Wilson's snipe Gallinago delicata. We found the breeding-season endemic marbled godwit Limosa fedoa beringiae at 20 plots within a 3,000-km2 area from north of Ugashik Bay to just north of Port Heiden and east to the headwaters of the Dog Salmon and Ugashik rivers. The most abundant passerines on point counts were American tree sparrow Spizelloides arborea, Lapland longspur Calcarius lapponicus, and savannah sparrow Passerculus sandwichensis. Sandhill crane Antigone canadensis, glaucous-winged gull Larus glaucescens, and greater scaup Aythya marila were also relatively abundant. We categorized habitat associations for 30 common species and found that lowland herbaceous vegetation supported wetland-focused species including sandhill crane, marbled godwit, short-billed dowitcher, and dunlin; whereas, dwarf shrub-ericaceous vegetation supported tundra-associated species such as willow ptarmigan Lagopus lagopus, rock sandpiper Calidris ptilocnemis, and American pipit Anthus rubescens. Tall shrub vegetation was important to several species of warblers and sparrows, as well as one species of shorebird (greater yellowlegs Tringa melanoleuca). We found that point counts augmented with incidental observations provided an almost complete inventory of lowland-breeding species on the study area. These data form a baseline to monitor any future changes in bird distribution and abundance on the Alaska Peninsula.

A Video Surveillance System to Monitor Breeding Colonies of Common Terns (&lt;em&gt;Sterna Hirundo&lt;/em&gt;)

Many waterbird populations have faced declines over the last century, including the common tern (Sterna hirundo), a waterbird species with a widespread breeding distribution, that has been recently listed as endangered in some habitats of its range. Waterbird monitoring programs exist to track populations through time; however, some of the more intensive approaches require entering colonies and can be disruptive to nesting populations. This paper describes a protocol that utilizes a minimally invasive surveillance system to continuously monitor common tern nesting behavior in typical ground-nesting colonies. The video monitoring system utilizes wireless cameras focused on individual nests as well as over the colony as a whole, and allows for observation without entering the colony. The video system is powered with several 12 V car batteries that are continuously recharged using solar panels. Footage is recorded using a digital video recorder (DVR) connected to a hard drive, which can be replaced when full. The DVR may be placed outside of the colony to reduce disturbance. In this study, 3,624 h of footage recorded over 63 days in weather conditions ranging from 12.8 °C to 35.0 °C produced 3,006 h (83%) of usable behavioral data. The types of data retrieved from the recorded video can vary; we used it to detect external disturbances and measure nesting behavior during incubation. Although the protocol detailed here was designed for ground-nesting waterbirds, the principal system could easily be modified to accommodate alternative scenarios, such as colonial arboreal nesting species, making it widely applicable to a variety of research needs.

Breeding‐site vagrancy and hybridization in albatrosses

Given the rarity of hybridization in seabirds, which presumably relates to their very high philopatry, the degree of breeding‐site vagrancy should correspond with the incidence of mixed‐species pairing, although not necessarily with the production of hybrids if there are behavioural or genetic barriers to successful reproduction. Using molecular methods, we verified that two of the three chicks hatched by a vagrant male White‐capped Albatross Thalassarche steadi paired with a female Black‐browed Albatross Thalassarche melanophris at South Georgia were genuine hybrids (these chicks died before fledging, but a third chick – the result of an extra‐pair copulation – fledged successfully). In a wider review, we could find only five known or suspected mixed‐species pairs, and three different hybrids in albatrosses, mostly between closely related species. This appears to reflect behavioural barriers to hybridization in sympatric species and the low incidence of breeding‐site vagrancy (which mainly involves single individuals that invariably associate with the most phenotypically similar local taxon). Breeding‐site vagrancy is most frequent in the ‘shy‐albatross’ complex, which could explain why genetic divergence occurred more recently in this group than in other Thalassarche, and hence exploratory behaviour appears to be more important than numerical abundance or breeding distribution in driving colonization as well as hybridization processes in albatrosses.

Sample size considerations for satellite telemetry and animal distributions

ABSTRACTSatellite telemetry is a powerful tool used to follow animals through their annual life cycle, informing the understanding of behavior and distribution of many species. Because boreal‐ and arctic‐nesting North American sea duck populations are challenging to survey, satellite telemetry is important for describing breeding distributions and identifying breeding population structure. Accurate knowledge of breeding distributions is needed for effective habitat and harvest management, but satellite telemetry is expensive so it is important to consider the effort necessary to accurately map breeding distributions. We construct 3 theoretical breeding distributions using existing telemetry data from 3 species of sea ducks, Barrow's goldeneye (Bucephala islandica), surf scoter (Melanitta perspicillata), and black scoter (M. americana), by fitting kernel densities to approximate breeding locations of individual birds. Then we determined the minimum sample size needed to approximate these theoretical breeding distributions by assessing the overlap between breeding densities simulated by sampling from the distributions and the theoretical breeding densities. Diminishing information gains with additional effort (i.e., &lt;1–5% improvement in prediction) were reached with sample sizes ranging from 80 to 130. Sea duck mortality, transmitter failure, and exclusion of non‐breeding individuals resulted in an effective sample size smaller than the number of birds originally marked. For the cases we considered, obtaining breeding locations for 80–130 individuals would require marking 11–41% more birds than the sample size goal. Thus, although satellite telemetry provides valuable information on sea duck populations, our analysis suggests that accurately estimating the extent and relative use of breeding habitats requires substantial investment. © 2018 The Wildlife Society.

Distribution and Population Size of the Red-billed Tropicbird (Phaethon aethereus) in Mexico

The breeding distribution and population size of the Red-billed Tropicbird (Phaethon aethereus) in Mexico were reviewed. This species has been confirmed to breed on 14 and potentially breed on six Mexican Pacific islands: two in the North Pacific, 12 in the Gulf of California, and six in the Tropical Pacific. The breeding population has been estimated to be approximately 1,901–2,725 breeding pairs. This estimate includes between 507–713 pairs in the Gulf of California, 1,391–2,004 pairs in the Tropical Pacific, and the rest in the North Pacific. The largest colonies are Pena Blanca in Colima (1,250–1,650 pairs), Farallon de San Ignacio in Sinaloa (150–228 pairs), San Pedro Martir in Sonora (150–190 pairs), San Benedicto in the Revillagigedo archipelago (50–200 pairs), Isabel in Nayarit (87–155 pairs), and Morros El Potosi in Guerrero (100 pairs). The portion of the population that breeds in Mexico is numerically important at both regional (Pacific Ocean) and global scales, representing approximately 50% of eastern Pacific breeding pairs and 25% of the global population, respectively. Therefore, protection of these colonies can play an important role in the global conservation of this species.

Morphological Alterations in the External Gills of Some Tadpoles in Response to pH

Introduction Water pH affects the breeding, hatching, development, locomotion, mortality and habitat distributions of species in nature. The external gills of anuran tadpoles were studied by several authors in relation to abiotic factors. Exposure to low and high pH has been found to adversely affect the different tissues of various organisms. On that consideration, the present investigation was performed with tadpoles of the species Hyla annectans and Euphlyctis cyanophlyctis. Material and Methods The maximum and the minimum pH thresholds were determined prior to the detailed experiments on the effects of pH. The pH that demonstrated 50% mortality was taken as the minimum and maximum pH thresholds. The hatchlings of both the species were then subjected to different pH (based on the minimum and maximum pH thresholds). After 48 hours of exposure, the external gills of the hatchlings were anesthetized and observed under a scanning electron microscope. Results After 48 hours, clumping, overlapping and curling of the secondary filaments of the external gills and epithelial lesions in response to both acidic and alkaline pH were observed. The lengths of the secondary filaments were also affected by pH in both the species studied when compared with the control groups. Conclusion Scanning electron microscopic approaches are relevant in assessing the adverse effects of pH on the morphology of the external gills of H. annectans and E. cyanophlyctis tadpoles, which included problems with osmoregulation, acid-base balance and respiratory function.

Conservation prioritization with machine learning predictions for the black-necked crane Grus nigricollis, a flagship species on the Tibetan Plateau for 2070

Ongoing global climate change greatly alters the distribution of species, and such impacts are even amplified on the Tibetan Plateau. The black-necked crane (Grus nigricollis) is perceived as an environmental indicator and flagship species in the alpine wetland ecosystems. However, scientifically, sound knowledge about global change impact on its breeding habitats is still lacking. Therefore, based on the best available species data further linked with powerful machine learning methods (ensemble random forest model), we predicted the breeding distribution of the black-necked crane under 2070 climate scenarios and provided associated conservation solutions. Our models for 2070 showed that its breeding range would expand in the hinterland of the Tibetan Plateau, with the current breeding habitats slightly shrinking from exterior margins, and in 2070, the overall habitat suitability would be jeopardized by the dwindling high-suitability habitats. Furthermore, conservation prioritization analyses indicated that global change would impact future-focused conservation and management, whereas the conservation effectiveness of the existing reserve networks would be instead improved with aggravating climate change and that the missing high conservation value areas are also spatially consistent on the Tibetan Plateau. Consequently, one elaborately designed reserve network could be feasible to secure this unique alpine crane lineage as well as the overwhelming majority of water birds on the Tibetan Plateau, despite the serious climate change impacts in the next realizable 50 years.

Evaluating the importance of managed forests as habitat for the Semi-collared Flycatcher (Ficedula semitorquata)

Intensive forest management has caused a decline in the numbers of birds specialized on old growth. Understanding how forest stand attributes influence the distribution of these specialists has hence become a prerequisite for sustainable forest management. In this study, we evaluated the conservation value of managed forests for old-growth forest specialists using the poorly studied Semi-collared Flycatcher as an example. We applied a boosted generalized additive model to identify forest characteristics that determine the occurrence of the bird in Bulgaria. We found that on a national scale, forest stand age and percent cover of broad-leaved forests best explain the breeding distribution of the flycatcher. Although, forest stands became suitable habitat at an age of around 70 years for this species, stands in the interior forest featuring trees older than 160 years and composed of more than 80% broad-leaved trees were preferred by the species. At a local scale, the amount of dead wood positively influenced nest site choice of the flycatcher. In total, 22.3% of all studied broad-leaved forests in Bulgaria showed a predicted habitat suitability higher than 50%. High-stem forests that are old enough to develop old-growth characteristics had the highest potential to serve as habitat for the Semi-collared Flycatcher in Bulgaria. Therefore, we conclude that a decrease in logging of forests stands older than 160 years decreases the risk of decline of the Semi-collared Flycatcher.

Pathological features of intestinal T-cell lymphoma in Shiba dogs in Japan.

Intestinal T-cell lymphoma is being more frequently diagnosed in dogs owing to the wide availability of endoscopy and clonality analysis in veterinary medicine. However, no epidemiological study on intestinal T-cell lymphoma has been previously performed, and hence, information about dog breed, age and sex distributions of intestinal T-cell lymphoma has largely remained unclear. In this study, breed predisposition to canine intestinal T-cell lymphoma was determined by calculating odds ratios and 95% confidential intervals. Of the 43 breeds identified, 7 appeared to have an increased risk of developing intestinal T-cell lymphoma, including Shiba dogs, German shepherds, Cairn terriers, Boston terriers, Papillons, Pugs and Maltese. Immunohistochemistry of representative Shiba cases revealed ubiquitous cytotoxic immunophenotype in both large and small cell lymphomas. Interestingly, CD20 co-expression was observed in 11% of cases. It could potentially be aberrant expression of CD20 or neoplastic transformation of a normal subset of CD20-positive T-cells. A comparison of mean age between representative breeds revealed that Shiba dogs were slightly younger than Miniature Dachshunds (P < .05). However, there was no difference in survival between the 2 breeds. As Shiba dogs are predisposed to chronic enteropathy, there may be underlying inflammatory process contributing to lymphomagenesis of intestinal T-cell lymphoma in this breed. Our findings provide insights into the underlying pathogenesis of breed-specific canine intestinal T-cell lymphoma.