Growth and Condition of American Alligators (Alligator mississippiensis) in an Inland Wetland of East Texas (Abstract)

Since removal from the endangered species list, Alligator mississippi-ensis (American Alligator) populations have recovered to allow regulated harvest throughout most of their range. However, harvest/population management is com- plicated since alligators are long-lived, reach sexual maturity at a minimum size rather than age, and experience differential growth rates depending on geographic location, growing season length, local environmental conditions, habitat, and population density. To date, few data exist on age, sex, growth, and size structure of inland alligator populations. In this study, alligator growth rate and condition were quantified through an intensive mark-recapture study conducted at Angelina-Neches/Dam B Wildlife Management Area. Between May 2003 and October 2004, 279 alligators ranging in size from 29.7 cm to 348.0 cm (total length [TL]) were captured, and 48 subadult alligators were recaptured (\u3c125 cm TL). As recaptured individuals were biased towards smaller individuals, recaptured subadult alligators were divided into two size classes: size class 1 (\u3c50 cm) and size class 2 (50–125 cm). Mean growth rates for size class 1 were 32.4 cm/year and for size class 2 were 27.6 cm/year. For both size classes, mean body condition was 1.8. Overall, subadult alligators within our inland study area exhibited faster growth rates and lower body condition than most other populations studied throughout their range

ImgLib2-generic image processing in Java

Summary: ImgLib2 is an open-source Java library for n-dimensional data representation and manipulation with focus on image processing. It aims at minimizing code duplication by cleanly separating pixel-algebra, data access and data representation in memory. Algorithms can be implemented for classes of pixel types and generic access patterns by which they become independent of the specific dimensionality, pixel type and data representation. ImgLib2 illustrates that an elegant high-level programming interface can be achieved without sacrificing performance. It provides efficient implementations of common data types, storage layouts and algorithms. It is the data model underlying ImageJ2, the KNIME Image Processing toolbox and an increasing number of Fiji-Plugins

linkcomm: an R package for the generation, visualization, and analysis of link communities in networks of arbitrary size and type

Summary: An essential element when analysing the structure, function, and dynamics of biological networks is the identification of communities of related nodes. An algorithm proposed recently enhances this process by clustering the links between nodes, rather than the nodes themselves, thereby allowing each node to belong to multiple overlapping or nested communities. The R package ‘linkcomm’ implements this algorithm and extends it in several aspects: (i) the clustering algorithm handles networks that are weighted, directed, or both weighted and directed; (ii) several visualization methods are implemented that facilitate the representation of the link communities and their relationships; (iii) a suite of functions are included for the downstream analysis of the link communities including novel community-based measures of node centrality; (iv) the main algorithm is written in C++ and designed to handle networks of any size; and (v) several clustering methods are available for networks that can be handled in memory, and the number of communities can be adjusted by the user

Seasonal variation in offspring sex ratio in the Snowy Plover

The Snowy Plover (Charadrius nivosus) is unique in being a determinate layer of an odd modal clutch size and in having a variable mating system in which female brood desertion occurs regularly. These traits make determining Snowy Plover offspring sex ratios important not only for long-term population stability, as the species is of conservation concern, but also for application to sex allocation theory. In this study, we determined Snowy Plover offspring sex ratios, examined differential costs of producing male and female offspring, and evaluated sex ratio variation in relation to maternal condition, habitat condition, and time during the nesting season on saline lakes of the Southern High Plains of Texas. Examination of 245 chicks from 118 clutches during 1999–2000 and 2008–2009 showed that male offspring were more costly to produce than female offspring; however, offspring sex ratio did not differ from parity, but was slightly male-biased in most years. The probability of producing a male offspring was greater both earlier and later in the breeding season than in the middle. As the availability of saline lake surface water and the subsequent availability of food vary unpredictably throughout the breeding season, depending on precipitation events, we suggest that sex ratio adjustment in unpredictable environments may not be straightforward and may follow nonlinear models and/or vary annually. The effects such changes in sex ratios may have on population growth and stability remain unknown

Seasonal Variation in Sex Ratios Provides Developmental Advantages in White-tailed Deer, Odocoileus virginianus

Since Trivers and Willard first proposed their hypothesis concerning the adaptive advantages of producing a particular offspring sex in relation to maternal condition in 1973, it has been at the forefront of scientific research concerning sex ratios with most subsequent studies focusing on maternal condition as a key contributor to variations in sex ratios. Another factor that could greatly influence sex ratios, although has been only infrequently examined in mammalian species, is birth date. We investigated how birth date influenced offspring sex ratios in White-tailed Deer (Odocoileus virginianus). Since date of birth can greatly influence an individual’s fitness and reproductive success, we suggest that birth date may be an alternative strategy in determining offspring sex ratios. Since it has been shown that the lifetime reproductive fitness of a mother can be increased by producing a particular sex during a particular time, we hypothesized that more male offspring should be born earlier in the season due to their increased reproductive potential from being born at this time. Offspring born earlier will have a head start in development and therefore have greater potential for increased body size and dominance later in life, traits that greatly influence male reproductive success. In this study, we found that maternal condition did not affect offspring sex ratio in a captive population of White-tailed Deer in Michigan; however, birth date did. We found that more males tended to be born during the second and fourth birthing periods, while more females were born during the first, third and fifth periods. In addition, we found that males born earlier in the season had greater mass the following spring than those born later, a trend that was not as dramatic in females. These results lend moderate support to our hypothesis that in White-tailed Deer offspring sex will tend to vary according to timing of birth and relative reproductive advantages gained by a particular sex being born at that time

Recovery of Nesting Bald Eagles in Texas (Abstract)

One of the most successful conservation stories in United States\u27 history resulted in Haliaeetus leucocephalus (Bald Eagle) being removed recently from the federal endangered species list. Few studies, however, have documented regional long-term recovery trends for Bald Eagles. We quantified Bald Eagle nesting density, distribution, and productivity trends by using aerial surveys of nests located 69 counties in eastern Texas from 1971-2005. The total number of occupied nests, productive nests, and offspring produced increased exponentially during that time with the most dramatic increases occurring from 1995-2005. Since 1971, the total number of occupied nests increased 13% per year, from 5 in 1971 to 157 in 2005 and the total number of young produced also increased 13% per year, from 6 in 1971 to 195 in 2005. Apparent nest success estimates (50- 100%) and mean brood size ( 1-2 young/nest), however, remained relatively consistent from 1971 to 2005. By 1989, Bald Eagles in Texas exceeded recovery goals set by the Southeastern States Bald Eagle Recovery Team (i.e., \u3e0.9 young produced/occupied nest, \u3e 1 .5 young produced/successful nest, and \u3e50% of nests successful in raising at least 1 young). Continued regional increases in Bald Eagle nesting activity may warrant specific attention, particularly as related to anthropogenic pressures and interactions in increasingly fragmented and urbanized habitats

On the analytical approximation to the GLAP evolution at small x and moderate Q^2

Comparing the numerically evaluated solution to the leading order GLAP equations with its analytical small-x approximation we have found that in the domain covered by a large fraction of the HERA data the analytic approximation has to be augmented by the formally non-leading term which has been usually neglected. The corrected formula fits the data much better and provides a natural explanation of some of the deviations from the $\sigma$ scaling observed in the HERA kinematical range.Comment: LaTeX, 13 pages including 6 figures, figure 5 replaced, to appear in Phys. Lett.

Voting procedures and parliamentary representation in the European Parliament

Parliamentary representation is a fluid concept. Yet, while the behaviour of elected representatives during roll call votes has been widely analysed, we know little about how parliamentarians act when their individual voting choices are not made public. This paper explores the relationship between voting procedures and the likelihood that Members of the European Parliament prioritise the interests of their EP party group versus the interests of their national party. Using an original survey, I find that MEPs are more likely to prioritise the interests of their national party over those of their EP party group when voting by show of hands or electronically, as opposed to by roll call. Moreover, this voting procedure effect is particularly salient among MEPs elected from 2004/07 accession countries