Riding the storm out: select demographics of a breeding population of Cooper’s hawks (Accipiter cooperii) following a severe spring snowstorm

The demographic responses to severe weather by top-level predators, including birds of prey, are underreported and/or unknown. Severe storms are predicted by climate change models to increase globally and in frequency into the 22nd century. In April 2018, a population of breeding Cooper’s hawks (Accipiter cooperii) in central Wisconsin, USA, experienced three days of heavy snowfall in the most severe storm, in pre-incubation-stage, for 39 years (1980–2018). Here I report select demographic outcomes of this nesting population following this intense weather. The median hatching date of 10 June in 2018 was the sixth latest such metric in those 39 years (and the latest in 22 years since 1996) for this population, which has advanced its breeding schedule about 1.3 days/decade due to climate change or warming. Survival of a total of 16 color-marked breeding adults, 15 males and 1 female, observed pre-storm in the nesting areas, was 100% up through the late nestling stage in the same nesting areas where these birds were initially detected in 2018. Average clutch size (4.4 eggs/nest) and average brood size (4.0 young/nest) were similar to the overall average annual metrics of these demographics for this population in the earlier 38 study years. Nest success, whereby 95% of 21 nests with eggs produced advanced-aged young, was higher in 2018 than the overall average of 77% nest success rate during the earlier years. The later timing of hatching in 2018, likely due to the severe spring snowstorm, appeared to have no deleterious effects either on survival of the breeding adults or on the reproductive output of this healthy study population. Tree-canopy prey may have served as important alternative food for this typically ground-foraging raptor in 2018.

A model to estimate seabird field metabolic rates

For free-ranging animals, field metabolic rate (FMR) is the sum of their energy expenditure over a specified period. This quantity is a key component of ecological processes at every biological level. We applied a phylogenetically informed meta-analytical approach to identify the large-scale determinants of FMR in seabirds during the breeding season. Using data from 64 studies of energetics in 47 species, we created a model to estimate FMR for any seabird population. We found that FMR was positively influenced by body mass and colony latitude and that it increased throughout the breeding season from incubation to brood to crèche. FMR was not impacted by colony-relative predation pressure or species average brood size. Based on this model, we present an app through which users can generate estimates of FMR for any population of breeding seabird. We encourage the use of this app to complement behavioural studies and increase understanding of how energetic demands influence the role of seabirds as driving components of marine systems.

Breeding biology of the house sparrow (Passer domesticus) in the Faroe Islands / Nøringin hjá føroyska gráspurvinum (Passer domesticus)

<p><strong>A</strong><strong>bstract</strong>: The breeding biology of the Faroese house sparrow (<em>Passer domesticus</em>) is described based on the results from nestlings that were ringed just before they were fledging. By means of dates and numbers, the beginning and duration of the breeding seasons are determined and the reproductive output is estimated. Our study has shown that Faroese house sparrows produce two, occasionally three, broods annually. Overall, eggs of the first, second and third clutch are normally laid in the beginning of May, in the middle of June and in the beginning of July, respectively. In a season, a female produced 6.3 nestlings, on average. For the whole period, the average brood size was 3.5 nestlings. During the first part of the time series (1985­1989), the breeding season became earlier each year, but then to be later again in the years 1990 to 1992. The first clutch was laid more than five weeks earlier in 1989 than in 1985 and the second clutch almost seven weeks earlier.</p><p> </p><p><strong>Úrtak</strong>: Árini frá 1985 til 1992 vóru tilsamans 347 gráspurvaungar (<em>Passer domesticus</em>) merktir í bygdini Nólsoy, beint áðrenn teir vóru floygdir. Við at nýta dagfestingina tá ungarnir vórðu merktir og talið av ungum er ásett, nær og hvussu ofta gráspurvurin verpur og hvussu nógvar ungar hann fær hvørja ferð. Kanningarnar vísa, at føroyski gráspurvurin verpur tvær ferðir um árið, viðhvørt tó tríggjar ferðir: Fyrstu urptin er í byrjanini av mai mánað, tann næsta er um miðjan juni og triðja urptin í byrjanini av juli mánað. Hvør bøga fær í miðal 6,3 ungar um árið. Í miðal vóru 3,5 ungar í hvørjari urpt. Úrslit okkara vísa, at tey fyrstu árini varp gráspurvurin fyrr og fyrr, fyri hvørt árið. Hetta broyttist tó tey seinru árini sum kanningin vardi: Í 1989 vórðu fyrstu eggini vorpin meira enn fimm vikur fyrri enn í 1985, og næstu urptin næstan sjey vikur fyrr.</p>

Fecundity and brood loss in four species of fiddler crabs, genus Uca (Brachyura: Ocypodidae), in the mangroves of Inhaca Island, Mozambique

In this study, four species of fiddler crabs (Uca) at Inhaca Island, Mozambique, were studied: their fecundity determined and egg loss between the first and last embryonic development stage evaluated. Ovigerous female crabs were collected throughout February to March (wet season) of 2006, during day-time at low tide, in Ponta Rasa (U. annulipes and U. inversa) and Saco (U. chlorophthalmus and U. vocans) mangroves. Average brood size increased significantly with female and species size, ranging from 932 (CW = 8.51 mm) in U. annulipes, to 18,057 (CW = 23.5 mm) in U. vocans. The number of embryos decreased significantly over the incubation period for each species. Brood loss from embryonic stage I to stage IV for U. annulipes, U. inversa, U. chlorophthalmus and U. vocans was 12.3%, 14%, 43.2% and 23.6%, respectively (P < 0.05). Positive allometry was recorded for all species in the early development stage, however, due to the higher relative brood loss in larger females (U. vocans), when comparing the number of embryos in late developmental stage, a negative allometry was possible to observe. The average volume of embryos at the same stage differed among species although significant differences were found between embryonic stages for all species. Embryo volume increased 96.1%, 93.3%, 92.9% and 96.3% in, respectively, U. annulipes, U. inversa, U. chlorophthalmus and U. vocans (P < 0.05). Differences in brood loss were attributed to habitat substrate and structure, stress factors and behavioural aspects.

Repellency and Toxicity of Conophthorus ponderosae Hopkins (Coleoptera: Scolytidae) by the Host Monoterpene Myrcene

Seed orchards produce high-quality seed from selected tree genotypes. In the intermountain west, Conophthorus ponderosae Hopkins (Coleoptera: Scolytidae) is a pest in seed orchards of ponderosa pine, Pinus ponderosa (Laws). The effect of myrcene as a deterrent to coneattack by C. ponderosae in a ponderosa pine seed orchard was examined. Two factors were considered, timing of cone cluster attack and average brood production per cone cluster. There was a delayed attack by C. ponderosae on cones treated with vials of myrcene attached at thebase of cone clusters. During both 2003 and 2004, final brood production per cone was not affected significantly by the presence of myrcene. During 2003, brood production was influenced by the timing of attack, with later attacks resulting in fewer brood adults per cone cluster. The toxicity of myrcene to adult C. ponderosae was examined in a laboratory and compared with that of (+)-α-pinene, another host-produced monoterpene that acts as a synergist for the male attractant pheromone pityol.

Impact of Hurricane Isabel on Bald Eagle Nests and Reproductive Performance in the Lower Chesapeake Bay

Abstract We evaluated the impact of Hurricane Isabel on nest loss and reproductive performance of Bald Eagles (Haliaeetus leucocephalus) in the lower Chesapeake Bay. Approximately 40% of Bald Eagle nest trees (n = 527) were damaged and 127 nests were lost during the storm. Nest loss was significantly higher than in years prior to and after the storm. Only 46% of pairs that lost nests attempted to breed the following season, compared to 85% of pairs that did not lose nests. Of the pairs that made breeding attempts, only 69% of pairs that lost nests during the hurricane produced young compared to 83% of pairs that did not lose nests. Average brood size was also reduced for pairs that lost nests. The disparity in reproductive performance between the two groups narrowed in the second breeding season after the storm. Hurricane Isabel had a significant but short-lived impact on the Bald Eagle breeding population in the lower Chesapeake Bay.

Analysis of stimulus apitechnical measures in bee society spring development

Influence of stimulus apitechnical measures on bee community biological development in spring was examined in this paper. Bee societies were placed in Langstrot-rut beehives with 10 frames, settled with bees belonging to Apis meliifera race. During the experiment, appropriate apitechnical measures were done during winter, spring and summer period and following parameters were observed: brood, honey and pollen surface. Application of timely warming, control and bee society expanding enabled regular bee community developing, that was established by following honey and pollen proceeds, and brood development. Average brood surface on the beginning of fruit pasture was 67.68 dm2 while at the end of fruit pasture was 81.81 dm2. Honey surface decreased on the average 8.93 dm2, while pollen surface because of the large proceeds, increased for 0.802 dm2. Statistical analysis of data showed that the pollen surface decreased for 0.429 dm2 if the brood surface increased for 1 dm2. Existing of mean degree of dependence (31.36%) of brood surface and changes of honey and pollen surface was established as well, but no statistical significance between brood surface and examining factors observing together was found.

THERMODYNAMICS IN NESTS OF TWO MELIPONA SPECIES IN BRASIL

SUMMARY Thermodynamics within 10 nests of Melipona rufiventris and M. seminigra were recorded during 48 horurs with thermocouple probes. Strikingly similar patterns were found for both species. Homeostasis did not occur; temperatures within the brood area, honey and pollen stored in pots and nest cavity space all followed ambient temperature fluctuations. Nest temperatures were consistently higher than ambient in all portions of the nest except the upper extremith of vertically elongate hives. Near the brood, temperature fluctuations were damped and displayed a time lag of one to two hours in following ambient temperature. The thoracic temperature of resting worker bees was near 34°C, and the average brood temperature was 31 — 32°. The involucrum surrounding the brood retained a portion of radiated heat from immatures and workers resting between combs, and brood temperature was two to three degrees higher than internal nest temperature immediately outside the involucrum. The brood chamber, the largest nest structure, contained from 2000 to 6000 immatures, and adult bee populations were less than 1000. The brood nest acts as a heat source at the base of the nest and dissipates heat upwards, creating a thermal gradient. Immature bees appear to supply most of the heat for the nest, and excess heat is shunted by fanning workers through the nest entrance, usually connected to the brood area. There is no evidence of evaporative cooling from water brought into the nest in these or other species of Meliponinae.

A difference in production and associated events in two races of spruce grouse

Analyses are given for several parameters in the production of juvenile spruce grouse in a local population in southwest Alberta (Canachites canadensis franklinii), 1970–1975, and in northeast New Brunswick (C. c. canace), 1975–1980. Canachites c. canace exhibited greater clutch size, nest success, proportion of females with broods and production of juveniles. Hatchability of eggs, average brood sizes, and mortality rates of juveniles were similar. Differential nest success appeared to be a primary influence on the difference in production of juveniles. In autumn, canace exhibited a substantial net reduction in juveniles as a consequence of dispersal, but not franklinii. Densities of juveniles in winter were similar. Speculation is provided about the differences in production and their association with other aspects of life history, notably the quality of juvenile stock.

The life history and distribution of Neomysis americana (Smith) (Crustacea, Mysidacea) in Passamaquoddy Bay

Neomysis americana in Passamaquoddy Bay produces two generations per year. Breeding occurs during the spring, summer, and early fall. Each female is capable of producing two or three broods; average brood sizes for spring and summer females were 45 and 32, respectively. Development time of eggs varied directly with temperature. The intermolt period of juveniles remained constant up to the time of the development of secondary sexual characteristics, between the eighth and ninth molts, and then increased. The life history of N. americana in Passamaquoddy Bay is compared with that in other areas.