The Annual Cycle for Whimbrel Populations using the Western Atlantic Flyway

Many long-distance migratory birds use habitats that are scattered across continents and confront hazards throughout the annual cycle that may be population-limiting. Identifying where and when populations spend their time is fundamental to effective management. We tracked 34 adult whimbrels (Numenius phaeopus) from two breeding populations (Mackenzie Delta and Hudson Bay) with satellite transmitters to document the structure of their annual cycles. The two populations differed in their use of migratory pathways and their seasonal schedules. Mackenzie Delta whimbrels made long (22,800 km) loop migrations with different autumn and spring routes. Hudson Bay whimbrels made shorter (17,500 km) and more direct migrations along the same route during autumn and spring. The two populations overlap on the winter grounds and within one spring staging area. Mackenzie Delta whimbrels left the breeding ground, arrived on winter grounds, left winter grounds and arrived on spring staging areas earlier compared to whimbrels from Hudson Bay. For both populations, migration speed was significantly higher during spring compared to autumn migration. Faster migration was achieved by having fewer and shorter stopovers en route. We identified five migratory staging areas including four that were used during autumn and two that were used during spring. Whimbrels tracked for multiple years had high (98%) fidelity to staging areas. We documented dozens of locations where birds stopped for short periods along nearly all migration routes. The consistent use of very few staging areas suggests that these areas are integral to the annual cycle of both populations and have high conservation value

Assessment of Black Rail Status in Georgia, Breeding Season 2017 and 2018 Summaries

The Black Rail (Laterallus jamaicensis) is the most secretive and least understood marsh bird in North America with the Eastern Black Rail (L. j. jamaicensis), one of two subspecies that occur here, listed as endangered in six states along the Atlantic Coast and proposed for federal listing under the Endangered Species Act (USFWS–R4–ES–2018–0057, 2018). Black Rails require dense vegetation for cover during all stages of their life cycle. They require wetlands with minimal water coverage during the breeding season. Historic population size for the Eastern subspecies was likely in the tens of thousands (25,000 to 100,000; Delaney and Scott 2002) but is now believed to be in the hundreds to low thousands. Eastern Black Rails breed within three geographic areas within North America including the Atlantic Coast, the Gulf Coast, and the Midwest. The Atlantic Coast has generally been considered to support the largest breeding population throughout the range with pairs mostly confined to the highest elevations within tidal salt marshes. Breeding range along the Atlantic Coast has contracted south more than 450 kilometers and the population is estimated to be declining by 9% annually (Watts 2016). The primary driver of declines over the past three decades is believed to be sea-level rise and associated tidal inundation during the nesting season. Georgia is noticeably missing from most of the early descriptions of Eastern Black Rail distribution (e.g. Allen 1900, Bent 1926, Forbush 1929). Early authors describing Eastern Black Rail status in the state (Burleigh 1938, Greene et al. 1945, Burleigh 1958) indicate that the species was perhaps more common and widespread in previous decades. As in all states within the breeding range, the lack of status and distribution information is certainly facilitated by their secretive habits, but in Georgia this is also likely reflected in an extremely low population size, a lack of overlap between Black Rails and bird watchers, or both. Scattered historic occurrences along the outer coast suggested a presence of a potential breeding population (Sykes 2010). The Eastern Black Rail ranks as a species of high conservation concern (GA DNR Wildlife Action Plan 2015) and breeding season surveys ranked as one of the highest conservation action priorities within the plan. The 2016 population estimate for the state (based on available habitat) was 10 to 40 pairs though the uncertainty in this estimate was very high (Watts 2016). The only definitive breeding record in the state comes from Greene County (Sykes 2010), and this site has been the most consistently documented breeding area throughout the state in the past 25 years (Watts 2016). During the 2017 field season, 409 coastal points were surveyed, and during the 2018 field season 206 points were surveyed. All points surveyed in 2017 were along the outer coast in tidal or impounded wetlands. During the 2018 survey, 141 inland points and 65 coastal points were surveyed. Three rounds of surveys were conducted between 18 April and 17 July 2017 and between 1 May and 15 July 2018. All points were surveyed three times unless there were access issues during one of the survey rounds. A total of 1,827 individual play-back surveys were conducted, 1,213 in 2017, and 614 in 2018. We detected no Black Rails during either season

Whimbrel Populations Differ in Trans-atlantic Pathways and Cyclone Encounters

Each year hundreds of millions of birds cross the Atlantic Ocean during the peak of tropical cyclone activity. The extent and consequences of migrant-storm interactions remain unknown. We tracked whimbrels from two populations (Mackenzie Delta; Hudson Bay) to examine overlap between migration routes and storm activity and both the frequency and consequence of storm encounters. Here we show that Mackenzie Delta and Hudson Bay whimbrels follow different routes across the ocean and experience dramatically different rates of storm encounters. Mackenzie Delta whimbrels departed North America from Atlantic Canada, made long (x¯ role= presentation style= box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3ex¯x¯ = 5440 ± 120.3 km) nonstop flights far out to sea that took several days (x¯ role= presentation style= box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3ex¯x¯ = 6.1 ± 0.18) to complete and encountered storms during 3 of 22 crossings. Hudson Bay whimbrels departed North America from the south Atlantic Coast, made shorter (x¯ role= presentation style= box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3ex¯x¯ = 3643 ± 196.2 km) nonstop flights across the Caribbean Basin that took less time (x¯ role= presentation style= box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3ex¯x¯ = 4.5 ± 0.29) to complete and encountered storms during 13 of 18 crossings. More than half of Hudson Bay storm encounters resulted in groundings on Caribbean islands. Grounded birds required longer (x¯ role= presentation style= box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3ex¯x¯ = 30.4 ± 5.32 days) to complete trans-Atlantic crossings and three were lost including 2 to hunters and 1 to a predator. One of the Mackenzie Delta whimbrels was lost at sea while crossing the Intertropical Convergence Zone. Whimbrels use two contrasting strategies to cross the Atlantic including (1) a long nonstop flight around the core of storm activity with a low likelihood of encountering storms but no safety net and (2) a shorter flight through the heart of Hurricane Alley with a high likelihood of encountering storms and a safety network of islands to use in the event of an encounter. Demographic consequences of storm encounters will likely play a role in the ongoing evolution of trans-Atlantic migration pathways as global temperatures continue to rise

Investigation of Red-cockaded Woodpeckers in Virginia: Year 2018 report

The Virginia population of red-cockaded woodpeckers is the northernmost throughout the species range and has been in eminent danger of extinction for more than 30 years. The Piney Grove Preserve represents a nucleus for recovery in the state and the focus of a multi-organizational partnership designed to increase the population to a sustainable level. The partnership has executed a program of aggressive habitat management, cavity-tree management and woodpecker population monitoring and management that has resulted in a quadrupling of the breeding population since the early 2000s. During the 2018 breeding season, Piney Grove Preserve supported 15 potential breeding groups (including one in the Big Woods) that produced 25 fledglings. All groups made breeding attempts except for cluster 18 and a new cluster in the Big Woods. Only two of the remaining clusters failed to produce fledglings. The population as a whole had a reproductive rate of 1.7±0.33 (mean±SE) young/breeding group. The 13 groups that made breeding attempts had a success rate of 85% (11 of 13). Fledging rate for the11 productive pairs was 2.3±0.27. Of the 46 eggs followed in 2018, 21 (45.7%) hatched, 21 (45.7%) survived to banding age, and 20 (43.5%) fledged. Birds that fledged included 12 females, 10 males and 1 bird where gender remains unknown. Eleven of these birds were retained and detected during the winter count and two (male and female, hatching-year birds) were translocated to Great Dismal Swamp, NWR on 8 November. During the calendar year of 2018, 91 individual red-cockaded woodpeckers were identified within Piney Grove preserve including 66 birds that were hatched at Piney Grove during previous years and 25 nestlings that fledged during the 2018 breeding season. Thirty-six birds (40%) were in their fourth year or more and six birds (7%) were at least in their tenth year. Two birds were fourteen years old (fifteenth calendar year). Moving into the breeding season there were 65 birds were identified within Piney Grove Preserve distributed among 14 clusters. This is the highest number of adults that Piney Grove has ever carried into the breeding season. The number of birds per cluster varied from two to nine with a mean of 4.5+0.53 (mean+SE). Seventy-three birds were detected during the 2018 winter survey. This represents a 7% increase over the winter of 2017 and a 35% increase over the winter of 2016. Birds present include 12 of the 25 birds fledged in 2017 and 61 adult birds hatched in previous years. Group size in winter ranged from two to eight birds and averaged 4.9+0.52 (mean±SE) birds per group

Erdos-Ko-Rado theorems for simplicial complexes

A recent framework for generalizing the Erdos-Ko-Rado Theorem, due to Holroyd, Spencer, and Talbot, defines the Erdos-Ko-Rado property for a graph in terms of the graph's independent sets. Since the family of all independent sets of a graph forms a simplicial complex, it is natural to further generalize the Erdos-Ko-Rado property to an arbitrary simplicial complex. An advantage of working in simplicial complexes is the availability of algebraic shifting, a powerful shifting (compression) technique, which we use to verify a conjecture of Holroyd and Talbot in the case of sequentially Cohen-Macaulay near-cones.Comment: 14 pages; v2 has minor changes; v3 has further minor changes for publicatio

Assessment of Black Rail Status in North Carolina, Breeding Season 2017 and 2018 Summaries

The Black Rail (Laterallus jamaicensis) is the most secretive and least understood marsh bird in North America with the Eastern Black Rail (L. j. jamaicensis), one of two subspecies that occur here, listed as endangered in six states along the Atlantic Coast and proposed for federal listing under the Endangered Species Act (USFWS–R4–ES–2018–0057, 2018). Black Rails require dense vegetation for cover during all stages of their life cycle. They require wetlands with minimal water coverage during the breeding season. Historic population size for the Eastern subspecies was likely in the tens of thousands (25,000 to 100,000; Delaney and Scott 2002) but is now believed to be in the hundreds to low thousands. Eastern Black Rails breed within three geographic areas within North America including the Atlantic Coast, the Gulf Coast, and the Midwest. The Atlantic Coast has generally been thought to support the largest breeding population throughout the range with pairs mostly confined to the highest elevations within tidal salt marshes. The historic breeding range along the Atlantic Coast has contracted more than 450 kilometers south and the population is estimated to be declining by 9% annually (Watts 2016). The primary driver of declines over the past three decades is believed to be sea-level rise and associated tidal inundation during the nesting season. North Carolina has long been recognized as a stronghold for Black Rails within the mid-Atlantic region. Most of what we know about the distribution and abundance of Black Rails in the state is based on site specific surveys and scattered anecdotal records (Fussell and McCrimmon 1976, Fussell and Wilson 1983, Davis et al. 1988, Collazo et al. 1990, LeGrand 1993, Fussell 1994, Paxton and Watts 2002, Watts 2016). These reports have documented a number of tidal marsh breeding locations, a well-known larger population at the Cedar Island National Wildlife Refuge, and at Piney Island military installation (both in Carteret County). In the late 1800s and early 1900s Black Rails were documented in the western part of the state using agricultural fields but there have not been consistent records since that time (Lee 1999, Watts 2016). Prior to 2014, a comprehensive status assessment for Black Rails in North Carolina had not been conducted, nor were there any existing systematic monitoring programs in place to assess the health of Black Rail populations. The purpose of this project is to gain a systematic view of the distribution of Black Rails in coastal North Carolina to help determine their status and distribution, to expand upon previous survey locations from the 2014 and 2015 field seasons, to determine if Black Rails continue to occupy historic strongholds, and to initiate an inland survey centered on agricultural lands with high density freshwater wetlands, farm ponds, Carolina Bays, and other water features that Black Rails have historically used within the region. We designed a broad survey frame so sampling locations could be used for monitoring purposes into the future. During the 2017 field season, 284 coastal points were surveyed, and during the 2018 field season 192 points were surveyed. All points surveyed in 2017 were along the outer coast in tidal or impounded wetlands. During the 2018 survey, 169 inland points and 23 coastal points were surveyed. The 2018 coastal survey locations were comprised of a network of previously occupied areas from year 2000 on. Three rounds of surveys were conducted between 18 April and 20 July 2017 and between 1 May and 15 July 2018. All points were surveyed three times unless there were access issues during one of the survey rounds. We conducted a total of 1,394 individual play-back surveys, 844 in 2017 and 550 in 2018. We detected a minimum of 9 individual Black Rails at 4 survey points in 2017 and we detected zero Black Rails in 2018 for survey occupancy of .01% (4 of 476 total survey points). During the 2014 and 2015 breedin

Investigation of Red-cockaded Woodpeckers within the Great Dismal Swamp National Wildlife Refuge: 2018 report

The Virginia population of red-cockaded woodpeckers is the northernmost throughout the species range and has been in eminent danger of extinction for more than 30 years. The single remaining population within the Piney Grove Preserve has responded to intensive management and is now approaching capacity but continues to be at risk to stochastic events such as hurricanes, tornadoes and disease. To offset this risk a three-phase conservation plan was developed that includes the establishment of additional breeding locations. The Great Dismal Swamp National Wildlife Refuge was identified as a high priority site for the establishment of a second population due to its capacity for habitat management and the similarity of habitat to non-typical red-cockaded woodpecker sites in nearby coastal North Carolina. In an effort to establish a population within the swamp, habitat management was initiated several years ago and translocation of birds into established recruitment clusters began in 2015. During the 2018 breeding season, three potential breeding groups were supported within the Great Dismal Swamp, NWR (clusters S2-3, S3-3, C3-3) and nest trees appeared to be prepared by early May. Clusters supporting potential breeding groups were monitored weekly from mid-April through June but no breeding attempts were documented. During the calendar year of 2018, 18 individual red-cockaded woodpeckers were identified within the Great Dismal Swamp, NWR including two birds from the 2015 translocation cohort, one bird from the 2016 translocation cohort, seven birds from the 2017 translocation/local productivity cohort and eight birds from the 2018 translocation cohort. Two birds were lost between the 2017 winter survey and the 2018 spring survey leaving three males and seven females during the breeding season. Two translocation events were executed during the fall of 2018 including a move of four birds (2 females and 2 males) from Carolina Sandhills, NWR and two birds (1 female and 1 male) from Palmetto-Peartree Preserve on 26 October and two birds (1 female and 1 male) from Piney Grove Preserve on 8 November. Eleven birds were detected during the 2018 winter survey. This compares to seven in 2015, eight in 2016 and twelve in 2017. A total of 65 woodpecker cavities had been created within the Great Dismal Swamp, NWR by the end of 2018. Three cavity trees were lost in October of 2016 during Hurricane Matthew, six cavity trees were lost in March of 2017 during high-wind events and three cavity trees were lost during a high-wind event in February of 2018. In addition, a natural cavity was lost during the February storm and a tree was lost to lightening during the fall of 2018. The second completed natural cavity (S3-2) was being used in December of 2018

Long distance airborne transmission of SARS-CoV-2:rapid systematic review

OBJECTIVES: To evaluate the potential for long distance airborne transmission of SARS-CoV-2 in indoor community settings and to investigate factors that might influence transmission. DESIGN: Rapid systematic review and narrative synthesis. DATA SOURCES: Medline, Embase, medRxiv, Arxiv, and WHO COVID-19 Research Database for studies published from 27 July 2020 to 19 January 2022; existing relevant rapid systematic review for studies published from 1 January 2020 to 27 July 2020; and citation analysis in Web of Science and Cocites. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Observational studies reporting on transmission events in indoor community (non-healthcare) settings in which long distance airborne transmission of SARS-CoV-2 was the most likely route. Studies such as those of household transmission where the main transmission route was likely to be close contact or fomite transmission were excluded. DATA EXTRACTION AND SYNTHESIS: Data extraction was done by one reviewer and independently checked by a second reviewer. Primary outcomes were SARS-CoV-2 infections through long distance airborne transmission (>2 m) and any modifying factors. Methodological quality of included studies was rated using the quality criteria checklist, and certainty of primary outcomes was determined using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. Narrative synthesis was themed by setting. RESULTS: 22 reports relating to 18 studies were identified (methodological quality was high in three, medium in five, and low in 10); all the studies were outbreak investigations. Long distance airborne transmission was likely to have occurred for some or all transmission events in 16 studies and was unclear in two studies (GRADE: very low certainty). In the 16 studies, one or more factors plausibly increased the likelihood of long distance airborne transmission, particularly insufficient air replacement (very low certainty), directional air flow (very low certainty), and activities associated with increased emission of aerosols, such as singing or speaking loudly (very low certainty). In 13 studies, the primary cases were reported as being asymptomatic, presymptomatic, or around symptom onset at the time of transmission. Although some of the included studies were well conducted outbreak investigations, they remain at risk of bias owing to study design and do not always provide the level of detail needed to fully assess transmission routes. CONCLUSION: This rapid systematic review found evidence suggesting that long distance airborne transmission of SARS-CoV-2 might occur in indoor settings such as restaurants, workplaces, and venues for choirs, and identified factors such as insufficient air replacement that probably contributed to transmission. These results strengthen the need for mitigation measures in indoor settings, particularly the use of adequate ventilation. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021236762

A retinoscopic survey of 333 horses and ponies in the UK

Introduction: Ophthalmic examination in the horse is generally limited to crude assessment of vision and screening for ocular lesions. The refractive state of equine eyes and the potential impact on vision and performance requires further investigation. Objective: To assess the refractive state of a large, mixed breed sample of horses and ponies in the United Kingdom (UK). Procedure: The refractive state of both eyes of 333 horses and ponies was determined by streak retinoscopy and the effect of age, height, gender, breed and management regime on the refractive state assessed. Results: The majority of eyes tested were emmetropic (83.63%), with 68.5% of horses having refractive errors of ≤ -0.50D or ≥ +0.50D. Refractive errors of greater than 1.50D (in either direction) were found in 2.7% of the eyes tested. Ametropic eyes included hyperopia (54%) and myopia (46%). Anisometropia was found in 30.3% of horses and ponies. Breed of horse/pony was the only factor that affected refractive state (in the left eye only, p<0.05) with 2 Thoroughbred crosses having a tendency towards myopia and Warmbloods / Shires towards hyperopia. Discussion / Conclusion: The retinoscopic survey found emmetropia to be the predominant refractive state of the equine eye with no evidence of an overall trend towards myopia or hyperopia. However, individual and breed related differences were found. Such factors should be considered in the selection of horses for sport and leisure, and when evaluating their performance potential. More comprehensive visual testing would be valuable in identifying underlying causes of behavioural problems