Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Bird Observer”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
USGS2013

A hierarchical nest survival model integrating incomplete temporally varying covariates

Nest success is a critical determinant of the dynamics of avian populations, and nest survival modeling has played a key role in advancing avian ecology and management. Beginning with the development of daily nest survival models, and proceeding through subsequent extensions, the capacity for modeling the effects of hypothesized factors on nest survival has expanded greatly. We extend nest survival models further by introducing an approach to deal with incompletely observed, temporally varying covariates using a hierarchical model. Hierarchical modeling offers a way to separate process and observational components of demographic models to obtain estimates of the parameters of primary interest, and to evaluate structural effects of ecological and management interest. We built a hierarchical model for daily nest survival to analyze nest data from reintroduced whooping cranes (Grus americana) in the Eastern Migratory Population. This reintroduction effort has been beset by poor reproduction, apparently due primarily to nest abandonment by breeding birds. We used the model to assess support for the hypothesis that nest abandonment is caused by harassment from biting insects. We obtained indices of blood-feeding insect populations based on the spatially interpolated counts of insects captured in carbon dioxide traps. However, insect trapping was not conducted daily, and so we had incomplete information on a temporally variable covariate of interest. We therefore supplemented our nest survival model with a parallel model for estimating the values of the missing insect covariates. We used Bayesian model selection to identify the best predictors of daily nest survival. Our results suggest that the black fly Simulium annulus may be negatively affecting nest survival of reintroduced whooping cranes, with decreasing nest survival as abundance of S. annulus increases. The modeling framework we have developed will be applied in the future to a larger data set to evaluate the biting-insect hypothesis and other hypotheses for nesting failure in this reintroduced population; resulting inferences will support ongoing efforts to manage this population via an adaptive management approach. Wider application of our approach offers promise for modeling the effects of other temporally varying, but imperfectly observed covariates on nest survival, including the possibility of modeling temporally varying covariates collected from incubating adults.

Wisconsin↗
USGS2021

Current distribution and abundance of Kohala forest birds in Hawai‘i

The Kohala volcano is home to the most spatially isolated population of Hawaiian forest birds on Hawai‘i Island and contains one of the few native bird populations in the state that has not been monitored since the original Hawai‘i Forest Bird Survey (HFBS) in 1979. We surveyed 143 stations across 13 transects in Pu‘u ‘O ‘Umi Natural Area Reserve on Kohala from February through April 2017 and compared our results to data from the 1979 HFBS conducted at 80 stations across three transects in the same location as our study site. We detected 2806 individuals of 15 species and measured relative abundance, relative occurrence, and density for seven species. We observed changes in species densities ranging from −8.4% (Hawai‘i ‘Elepaio, Chasiempis sandwichensis ) to +714% (‘I‘iwi, Drepanis coccinea ). Equivalence testing showed meaningful increases in population densities for all but one species, the Hawai‘i ‘Elepaio. The increases in population densities on Kohala are in stark contrast to the widespread declines in population densities of native species elsewhere in Hawai‘i. Relative occurrence was greater in 2017 than in 1979 for all species except Hawai‘i ‘Elepaios and House Finches ( Haemorhous mexicanus ), and relative abundance increased for all species except Hawai‘i ‘Elepaios, House Finches, and Melodious Laughing Thrushes ( Garrulax canorus ). We also documented the range expansion of Japanese Bush Warblers ( Cettia diphone ) in Kohala. Our results indicate that this spatially isolated avian community remains biologically diverse, and most population densities are increasing in the study area. Our results provide a framework for future surveys and a baseline for understanding possible changes in population and community dynamics as birds respond to climate change and avian disease on Kohala volcano.

Hawai'i↗
USGS2013

Demographic variation, reintroduction, and persistence of an island duck ( Anas laysanensis )

Population variation in life history can be important for predicting successful establishment and persistence of reintroduced populations of endangered species. The Laysan duck (Anas laysanensis) is an endangered bird native to the Hawaiian Archipelago that was extirpated from most islands after the introduction of mammalian predators. Laysan ducks were restricted to a single remote island, Laysan Island (4.1 km 2 ), for nearly 150 years. Since the species is not known to disperse between distant Hawaiian Islands today, 42 wild birds from Laysan Island were translocated to another mammalian predator-free low-lying atoll (Midway Atoll; 6.0 km 2 ) to reduce extinction risk. We explored how variation in demography influences establishment and longer-term retention of genetic diversity (rare alleles) for reintroductions of this species. We observed dramatic differences in population growth between the source (λ = 1.18) and reintroduced (λ = 3.28) population. The number of eggs hatched at Midway Atoll was greater than at Laysan Island, however, we found no difference in hatching success (proportion of clutch hatched) between populations. Adult females produced 3 times as many fledglings per breeding year on Midway Atoll compared to Laysan Island. We estimated population abundance of both populations until 2010 and applied a Gompertz model with a Bayesian approach to infer density dependence, process variation, observation error, and carrying capacity for the Laysan Island and Midway Atoll populations. The carrying capacity from the Gompertz model for Midway Atoll (K = 883 ± 210 SD) was estimated to be greater than that of Laysan Island (K = 598 ± 76 SD). Translocations with small numbers of founders and no immigration can create population bottlenecks, leading to loss of genetic variation over time, and potentially reducing the reintroduced population's viability or its potential to serve as a source for future translocations. Therefore, we also assessed the probability of retaining rare alleles in an isolated reintroduced Laysan duck population using life history parameters observed from the Laysan Island and Midway Atoll populations; we concluded that additional founders are needed under scenarios using demographic estimates from both Laysan Island and Midway Atoll to retain either 90% or 95% of source population genetic diversity.

Laysan Island;Midway Atoll↗
USGS2012

Avian mortality associated with a volcanic gas seep at Kiska Island, Aleutian Islands, Alaska

We identified natural pits associated with avian mortality at the base of Kiska Volcano in the western Aleutian Islands, Alaska in 2007. Living, moribund, and dead birds were regularly found at low spots in a canyon between two lava flows during 2001–2006, but the phenomenon was attributed to natural trapping and starvation of fledgling seabirds (mostly Least Auklets, Aethia pusilla ) at a colony site with >1 million birds present. However, 302 birds of eight species, including passerines, were found dead at the site during 2007–2010, suggesting additional factors were involved. Most carcasses showed no signs of injury and concentrations of dead birds had accumulated in a few distinctive low pits in the canyon. Gas samples from these locations showed elevated CO 2 concentrations in late 2010. Analysis of carcasses indicated no evidence of blunt trauma or internal bleeding. Volcanic gases accumulating at these poorly ventilated sites may have caused the observed mortality, but are temporally variable. Most auklets breeding in the Aleutian Islands do so in recent lava flows that provide breeding habitat; our study documents a cost of this unusual habitat selection.

Alaska↗
USGS2023

Differential shortstopping behaviour in Whooping Cranes: Habitat or social learning?

Many migratory bird species have begun shifting their wintering grounds closer to their breeding grounds, shortening their yearly migration distance through a behavior called shortstopping. While multiple studies have investigated possible drivers, it remains unclear why only some populations adopt this behavior. We studied the differential occurrence of shortstopping in two populations of Whooping Cranes (Grus americana): a remnant population where juveniles migrate with their parents, and a reintroduced population consisting largely of captive-reared birds trained to migrate by unrelated conspecifics or by humans. Shortstopping is widespread in the reintroduced population, while the remnant population has not shown any appreciable northward movement of its overwintering sites. We examined potential drivers for this lack of shortstopping, including a lack of suitable habitat north of their current wintering area or social differences between populations. Using characteristics of winter locations used by the reintroduced population, we found that 31.4% of the remnant migration corridor was predicted to be suitable for wintering, suggesting that insufficient habitat suitability is not limiting shortstopping behaviour. However, we found evidence for behavioural differences that might explain the absence of shortstopping in the remnant population: while all juveniles of the remnant population associate with their parents during overwintering, juveniles from the reintroduced population did not associate with older conspecifics in 12 out of 25 observed wintering events, suggesting that the social transmission of winter migration behaviours might be less effective in the reintroduced population. Although social learning is generally believed to increase flexibility in migratory strategies, a strong vertical transmission of behaviour might enforce adherence to established traditions and reduce the uptake of novel behaviours such as shortstopping. We suggest that, besides habitat availability, social factors may also play a role in explaining the absence of shortstopping behaviour in some migratory bird populations.

Global Ecology and Conservation↗
USGS2015

Habitat selection and movements of Piping Plover broods suggest a tradeoff between breeding stages

In precocial birds, adults select breeding areas using cues associated with habitat characteristics that are favorable for nesting success and chick survival, but there may be tradeoffs in habitat selection between these breeding stages. Here we describe habitat selection and intra-territory movements of 53 Piping Plover ( Charadrius melodus ) broods (320 observations) during the 2007–2008 breeding seasons on mainland- and island-shoreline habitats at Lake Sakakawea, North Dakota, USA. We used remotely sensed habitat characteristics to separately examine habitat selection and movements at two spatiotemporal scales to account for potential confounding effects of nest-site selection on brood-rearing habitat used. The scales used were (1) the entire brood-rearing period within available brood-rearing areas and (2) 2-day observation intervals within age-specific discrete habitat selection choice sets. Analyses at both scales indicated that broods selected areas which were non-vegetated, moderately level, and nearer to the shoreline. Rate of brood movement increased with age up to 5 days, then stabilized; broods that hatched >50 m away from the shoreline moved toward the shoreline. Brood movements were greater when they were in vegetated areas, when the brood-rearing area was of greater topographic complexity, and when broods aged 6–25 days were further away from the shoreline. Using inferences from our results and those of previously published work, we postulate how a potential tradeoff in habitat selection between nesting and brood-rearing can contribute to an ecological trap in a novel habitat. This work, in the context of published works, suggests that plover breeding habitat is a complex of both nesting and brood-rearing habitats and provides a basis for making remotely sensed abundance estimates of suitable breeding habitat for Piping Plovers.

North Dakota↗
USGS2016

A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells.

H9N2 influenza A viruses are on the list of potentially pandemic subtypes. Therefore, it is important to understand how genomic reassortment and genetic polymorphisms affect phenotypes of H9N2 viruses circulating in the wild bird reservoir. A comparative genetic analysis of North American H9N2 isolates of wild bird origin identified a naturally occurring reassortant virus containing gene segments derived from both North American and Eurasian lineage ancestors. The PB2 segment of this virus encodes 10 amino acid changes that distinguish it from other H9 strains circulating in North America. G590S, one of the 10 amino acid substitutions observed, was present in ~ 12% of H9 viruses worldwide. This mutation combined with R591 has been reported as a marker of pathogenicity for human pandemic 2009 H1N1 viruses. Screening by polymerase reporter assay of all the natural polymorphisms at these two positions identified G590/K591 and S590/K591 as the most active, with the highest polymerase activity recorded for the SK polymorphism. Rescued viruses containing these two polymorphic combinations replicated more efficiently in MDCK cells and they were the only ones tested that were capable of establishing productive infection in NHBE cells. A global analysis of all PB2 sequences identified the K591 signature in six viral HA/NA subtypes isolated from several hosts in seven geographic locations. Interestingly, introducing the K591 mutation into the PB2 of a human-adapted H3N2 virus did not affect its polymerase activity. Our findings demonstrate that a single point mutation in the PB2 of a low pathogenic H9N2 isolate could have a significant effect on viral phenotype and increase its propensity to infect mammals. However, this effect is not universal, warranting caution in interpreting point mutations without considering protein sequence context.

Infection, Genetics and Evolution↗
USGS2009

Spider-mediated flux of PCBs from contaminated sediments to terrestrial ecosystems and potential risks to arachnivorous birds

We investigated aquatic insect utilization and PCB exposure in riparian spiders at the Lake Hartwell Superfund site (Clemson, SC). We sampled sediments, adult chironomids, terrestrial insects, riparian spiders (Tetragnathidae, Araneidae, and Mecynogea lemniscata), and upland spiders (Araneidae) along a sediment contamination gradient. Stable isotopes (? 13 C, ? 15 N) indicated that riparian spiders primarily consumed aquatic insects whereas upland spiders consumed terrestrial insects. PCBs in chironomids (mean 1240 ng/g among sites) were 2 orders of magnitude higher than terrestrial insects (15.2 ng/g), similar to differences between riparian (820?2012 ng/g) and upland spiders (30 ng/g). Riparian spider PCBs were positively correlated with sediment concentrations for all taxa (r 2 = 0.44?0.87). We calculated spider-based wildlife values (WVs, the minimum spider PCB concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Spider concentrations exceeded WVs for most birds at heavily contaminated sites and were ?14-fold higher for the most sensitive species (chickadee nestlings, Poecile spp.). Spiders are abundant and ubiquitous in riparian habitats, where they depend on aquatic insect prey. These traits, along with the high degree of spatial correlation between spider and sediment concentrations we observed, suggest that they are model indicator species for monitoring contaminated sediment sites and assessing risks associated with contaminant flux into terrestrial ecosystems. ?? This article not subject to U.S. Copyright. Published 2009 by the American Chemical Society.

Environmental Science & Technology↗
USGS2019

Frequent use of upland habitats by the endangered Hawaiian stilt (Himantopus mexicanus knudseni)

The Hawaiian Stilt, or Ae’o (Himantopus mexicanus knudseni), is an endangered waterbird endemic to the Hawaiian Islands. Loss of suitable wetland habitats due to anthropogenic development is a leading cause for decline, as well as the introduction of non-native predators and invasive wetland plants. This study fitted four Hawaiian Stilts with GPS satellite tags to document their use of wetland and surrounding habitats on Oahu Island. While other Hawaiian waterbirds are largely restricted to wetlands, we detected Hawaiian Stilts using heavily modified upland habitats, including developed areas, undeveloped fields, sports fields, as well as wetland habitats over a 6-month period. Overall, a high use of non-wetland habitat was observed (up to 58%), with significant differences in habitat occupancy among individual stilts and across different times of day. Wetlands were the dominant habitat occupied from morning to early afternoon, but non-wetland habitats were occupied at higher frequencies in the evening and early morning hours. Although only four birds were tracked, the extensive use of non-wetland habitat by these individuals indicates management of non-wetland habitats may be important for the conservation of this subspecies. However, more research is needed to understand how applicable these results are to other stilt popualtions across the Hawaiian Islands, and better understand the potential risks and benefits of these non-wetland habitats to stilt populations.

Hawaii↗
USGS1981

Estimating bird damage from damage incidence in wine grape vineyards

Bird damage was measured during 1977 and 1978 at 32 wine grape vineyards in the San Joaquin Valley and North Coastal Region of California. Both the percentage bird loss (PBL) and the percentage of bunches damaged (BDI = bird damage incidence) were determined during 55 total-damage assessments, and the resulting data pairs were used to develop a regression of PBL on BDI. The final prediction equation was loge (PBL + 1) = 0.0385 BDI, for which the SE = 9.6297 10-4, and it accounted for 97% of the observed variation. We conclude that by using that equation, reasonably accurate predictions of PBL can be obtained from relatively quick and inexpensive estimates of BDI. Guidelines for the use of the prediction method and the accuracy of some PBL predictions are discussed.

American Journal of Enology and Viticulture↗
USGS1998

Saker falcon research and conservation efforts in Mongolia, 1997

This past summer. our small field team followed a 4000 km route through central and eastern Mongolia. Even though there was a population crash underway for picas (Ochotona sp.) and voles (Microtus sp.). we found 38 new saker nests and visited 60 eyries found in previous years. Many of the former eyries were unoccupied. Others were occupied but without young. Productivity was good at eyries with large young. and southeastern Mongolia seemed unaffected by food shortages. The main goal for 1997 was to create new eyries and enlarge. stabilise. or otherwise alter marginal eyries. \Ve created 65 eyries as follows: 8 on wooden powerlines or telephone supports, 8 on metal power line towers, 3 in trees, 3 on boulders, 11 on cliffs, 17 on abandoned buildings, 9 on metal geological survey towers, and 6 on miscellaneous structures. \Ve also enlarged or repaired three establishedeyries and did minor repairs on several others. Lesser accomplishments include what may be the first observation of siblicide for the saker falcon (please contact us immediately if you have other records of sakerchicks attacking or killing their nest mates) and the description of a new saker flight display. We also documented an unusual golden eagle eyrie containing the remains of nearly 30 foxes, several predatory birds, and a number of gazelle. In 1998. we plan to return to Mongolia to see how many of our 'fake eyries' attracted falcons. Our work in 1997 was supported by Mr. Howell. another philanthropist (anonymous) and the Institute of Raptor Studies.

Falco↗
USGS2017

A genetic signature of the evolution of loss of flight in the Galapagos cormorant

INTRODUCTION Changes in the size and proportion of limbs and other structures have played a key role in the evolution of species. One common class of limb modification is recurrent wing reduction and loss of flight in birds. Indeed, Darwin used the occurrence of flightless birds as an argument in favor of his theory of natural selection. Loss of flight has evolved repeatedly and is found among 26 families of birds in 17 different orders. Despite the frequency of these modifications, we have a limited understanding of their underpinnings at the genetic and molecular levels. RATIONALE To better understand the evolution of changes in limb size, we studied a classic case of recent loss of flight in the Galapagos cormorant ( Phalacrocorax harrisi ). Cormorants are large water birds that live in coastal areas or near lakes, and P. harrisi is the only flightless cormorant among approximately 40 extant species. The entire population is distributed along the coastlines of Isabela and Fernandina islands in the Galapagos archipelago. P. harrisi has a pair of short wings, which are smaller than those of any other cormorant. The extreme reduction of the wings and pectoral skeleton observed in P. harrisi is an attractive model for studying the evolution of loss of flight because it occurred very recently; phylogenetic evidence suggests that P. harrisi diverged from its flighted relatives within the past 2 million years. We developed a comparative and predictive genomics approach that uses the genome sequences of P. harrisi and its flighted relatives to find candidate genetic variants that likely contributed to the evolution of loss of flight. RESULTS We sequenced and de novo assembled the whole genomes of P. harrisi and three closely related flighted cormorant species. We identified thousands of coding variants exclusive to P. harrisi and classified them according to their probability of altering protein function based on conservation. Variants most likely to alter protein function were significantly enriched in genes mutated in human skeletal ciliopathies, including Ofd1 , Evc , Wdr34 , and Ift122 . We carried out experiments in Caenorhabditis elegans to confirm that a missense variant present in the Galapagos cormorant IFT122 protein is sufficient to affect ciliary function. The primary cilium is essential for Hedgehog (Hh) signaling in vertebrates, and individuals affected by ciliopathies have small limbs and ribcages, mirroring the phenotype of P. harrisi . We also identified a 4–amino acid deletion in the regulatory domain of Cux1 , a highly conserved transcription factor that has been experimentally shown to regulate limb growth in chicken. The four missing amino acids are perfectly conserved in all birds and mammals sequenced to date. We tested the consequences of this deletion in a chondrogenic cell line and showed that it impairs the ability of CUX1 to transcriptionally up-regulate cilia-related genes (some of which contain function-altering variants in P. harrisi ) and to promote chondrogenic differentiation. Finally, we show that positive selection may have played a role in the fixation of the variants associated with loss of flight in P. harrisi . CONCLUSION Our results indicate that the combined effect of variants in genes necessary for the correct transcriptional regulation and function of the primary cilium likely contributed to the evolution of highly reduced wings and other skeletal adaptations associated with loss of flight in P. harrisi . Our approach may be generally useful for identification of variants underlying evolutionary novelty from genomes of closely related species.

Science↗
USGS2010

Wayward youth: Trans-Beringian movement and differential southward migration by juvenile sharp-tailed sandpipers

The sharp-tailed sandpiper ( Calidris acuminata ) is a long-distance migrant that travels each year from breeding grounds in the Russian Arctic to nonbreeding areas in Australasia. Most adults migrate rapidly from breeding grounds along a largely inland route through Asia. Here we report on the highly unusual migratory strategy of this species in which some juveniles, but virtually no adults, take a pronounced detour to western Alaska before proceeding on southward migration. We analyzed data from our own studies in this region and published and unpublished observations and specimen records of sharptailed sandpipers from the entire Pacific Basin. Each autumn, sharp-tailed sandpipers began arriving on coastal graminoid meadows and intertidal habitats throughout western Alaska during the last half of August and the last sandpipers departed from southwestern Alaska during October and November. Body mass of birds banded or collected across multiple years and sites in western Alaska ( n = 330) increased by an average of 0.57 ± 0.06 g per day between mid-August and late October. Records suggest a small, regular movement of juveniles (and a very few adults) along the Asiatic coast, but we estimate from surveys that a few tens of thousands of juveniles stage in western Alaska each autumn. The distribution of sight and specimen records from the Pacific Basin during autumn suggests strongly age-segregated migration routes, with the principal migration of juveniles crossing central and western Oceania in a possible nonstop trans-Pacific flight from Alaska. This is only the second well-documented case of differential migration among birds that involves different routes for adults and juveniles, and it raises intriguing questions about how and why this system has evolved.

Arctic↗
USGS1995

Estimating populations of nesting brant using aerial videography

We mounted a video camcorder in a single-engine aircraft to estimate nesting density along 10-m wide strip transects in black brant colonies on the Yukon Delta National Wildlife Refuge, Alaska during 1990-1992. A global positioning system (GPS) receiver was connected to the video recorder and a laptop computer to locate transects and annotate video tape with time and latitude-longitude at 1-second intervals. About 4-5 hours of flight time were required to record 30-40 minutes of video tape needed to survey large (>5,000 nests in > 10 km2)colonies. We conducted ground searches along transects to locate and identify nests for determining detection rates of nests in video images. Counts of nests from video transects were correlated with actual numbers of nests. Resolution of images was sufficient to detect 81% of known nests (with and without incubating females). Of these, 68% were correctly identified as brant nests. The most common misidentification of known nests was failure of viewers to see the nest that the detected bird was incubating. Unattended nests with exposed eggs, down-covered nests, and nesting brant, cackling Canada geese, and emperor geese were identified in video images. Flushing of incubating geese by survey aircraft was not significant. About 10% of known nests were unoccupied in video images compared to 16% unoccupied nests observed from tower blinds during periods without aircraft disturbance.

Wildlife Society Bulletin↗
USGS2015

Contaminants in sea ducks: metals, trace elements, petroleum, organic pollutants, and radiation: Chapter 6

Exposure to lead and petroleum has caused deaths of sea ducks, but relatively few contaminants have been shown to cause mortality or be associated with population level effects. This chapter focuses primarily on field reports of contaminant concentrations in tissues of sea ducks in North America and Europe and results of some pertinent experimental studies. Much of the available interpretive data for contaminants in waterfowl come from studies of freshwater species. Limits of available data present a challenge for managers interested in sea ducks because field reports have shown that marine birds may carry greater burdens of some pollutants than freshwater species, particularly metals. It is important, then, to distinguish poisoning due to a particular contaminant as a cause of death in sea ducks versus simple exposure based solely on tissue residues. A comprehensive approach that incorporates information on field circumstances, any observed clinical signs and lesions, and tissues residues is recommended when evaluating contaminant concentrations in sea ducks.

Book chapter↗
USGS1987

Improving atlas methodology

We are studying a sample of Maryland (2 %) and New Hampshire (4 %) Atlas blocks and a small sample in Maine. These three States used different sampling methods and block sizes. We compare sampling techniques, roadside with off-road coverage, our coverage with that of the volunteers, and different methods of quantifying Atlas results. The 7 1/2' (12-km) blocks used in the Maine Atlas are satisfactory for coarse mapping, but are too large to enable changes to be detected in the future. Most states are subdividing the standard 7 1/2' maps into six 5-km blocks. The random 1/6 sample of 5-km blocks used in New Hampshire, Vermont (published 1985), and many other states has the advantage of permitting detection of some changes in the future, but the disadvantage of leaving important habitats unsampled. The Maryland system of atlasing all 1,200 5-km blocks and covering one out of each six by quarterblocks (2 1/2-km) is far superior if enough observers can be found. A good compromise, not yet attempted, would be to Atlas a 1/6 random sample of 5-km blocks and also one other carefully selected (non-random) block on the same 7 1/2' map--the block that would include the best sample of habitats or elevations not in the random block. In our sample the second block raised the percentage of birds found from 86% of the birds recorded in the 7 1/2' quadrangle to 93%. It was helpful to list the expected species in each block and to revise this list annually. We estimate that 90-100 species could be found with intensive effort in most Maryland blocks; perhaps 95-105 in New Hampshire. It was also helpful to know which species were under-sampled so we could make a special effort to search for these. A total of 75 species per block (or 75% of the expected species in blocks with very restricted habitat diversity) is considered a practical and adequate goal in these States. When fewer than 60 species are found per block, a high proportion of the rarer species are missed, as well as some of the common ones. Similarity indices based on fewer than 60 species per block reflect coverage rather than habitat affinities. Atlas blocks that are ecologically similar should have similarity indices (S) of at least 0.80 to be considered adequately covered. S = 2C/(A + B), where C is the number of species in common and A and B are species totals for each of the two blocks being compared. A series of 15 13-minutes roadside stops yielded more species than 15 off-road stops, but off-road stops always had some species not detected at the roadside stops. A series of timed stops is an excellent way to map relative abundance if the stops are standardized with respect to time of day and weather, and the counts are made by observers of comparable ability. Efforts to estimate Atlas block populations in powers of 10 (as in the French Atlas) have not gained acceptance in U.S.A. Most observers feel unqualified to make estimates. An efficient way to Atlas a block is to make at least 3 early morning visits to 15 or more specific stops. Arrive in the block early enough to check for nocturnal species on at least two days; and after completing the specific stops, search the block for other species and for confirmations.

Acta Oecologica Oecologia Generalis↗
USGS2020

Factors influencing Cinnamon Teal nest attendance patterns

Patterns of nest attendance in birds result from complex behaviours and influence the success of reproductive events. Incubation behaviours vary based on individual body condition, energy requirements and environmental factors. We assessed nest attendance patterns in Cinnamon Teal Spatula cyanoptera breeding in the San Luis Valley of Colorado in 2016–2017 using trail and video cameras to observe behaviours throughout incubation. We evaluated the effect of temporal, life-history and environmental covariates on the frequency and duration of incubation recesses as well as the incubation constancy. There was considerable model uncertainty among the models used to evaluate recess frequency. Recess duration varied according to the interaction between nest age and a quadratic effect of time of day, with hens on older nests taking longer recesses in the afternoon and hens on nests earlier in incubation taking longer recesses in the morning and evening. Incubation constancy decreased with higher ambient temperatures in the study area. This study provides evidence that Cinnamon Teal modify their behaviour during incubation according to the age of the nest and the time of day. These results improve our knowledge of Cinnamon Teal breeding ecology and shed light on the behaviours that fast-lived species may use to cope with environmental factors during nesting.

Colorado↗
USGS2012

Influence of space use on fitness and the reintroduction success of the Laysan teal

Translocation is an important tool for wildlife conservation and biodiversity restoration, but an inefficient one because of the unpredictability of success. Predictors of success such as habitat quality of the release site and number of individuals released have been identified, but the dynamics of successful translocations remain poorly understood. In particular, little is known about the relationship of individual post-release movements to population establishment. In 2004, Laysan teal Anas laysanensis were reintroduced by translocating 20 wild birds from Laysan Island to Midway Atoll. Twenty-two additional wild founders were brought the next year. We monitored the survival, reproductive success and movements of the 42 translocated individuals and their offspring for 4 years. Additionally, we monitored population size from 2004 to 2010. Unlike most translocations, we did not observe elevated post-release mortality despite flight-feather trimming to prevent immediate dispersal off-island: first year survival was > 90% and survival rates until 2009 were 0.65±0.08 for founding adults. Laysan teal flew between the two main islands of Midway Atoll, and offspring had significantly larger maximum movement distances than founders. We monitored 84 nests and observed a significant, negative relationship of home range size to productivity for founding females. Flightless founders did not show fidelity to their release sites, but had strong fidelity to annual home ranges after attaining flight. Although we observed a component Allee effect on mate-finding, this did not translate into a demographic Allee effect, and generally, the high fitness of founders contributed substantially to successful population establishment. Laysan teal abundance increased linearly until 2009, but showed evidence of population regulation afterwards. The population estimate was 473 (95% confidence interval 439–508) in 2010. On the much larger main Hawaiian Islands, we expect greater post-release movement, a stronger component Allee effect, lower survival and lower reproductive rates because of predation to preclude successful reintroductions of this species to sites without predator management.

Laysan Island;Midway Atoll↗