How far and how old: Longevity and displacement records from the South African Bird Ringing Scheme for Ardeidae, Threskiornithidae and Ciconiidae

Background: Understanding the movement and displacement of individuals within avian species is important for conservation. Herons, Storks and Egrets are especially important as they are migratory species and are potential indicator species. It is therefore valuable to set life history baselines to understand survival.Objectives: To establish baseline longevity and displacement values for the avian families Ardeidae, Threskiornithidae and Ciconiidae using the South African Bird Ringing Scheme (SAFRING) data for Africa and to highlight gaps in the SAFRING database for these families.Method: We used data archives of ringed and subsequently reported individuals to determine maximum displacement and longevities from the past seven decades for each species within these three families. Displacement was estimated by the straight-line distance between subsequent records for the same individual. Longevity is the measure of time elapsed in records for the same individual.Results: Displacement and longevity data were available for 17 of the 24 species in the focus families. Individuals of most of the species were ringed as nestlings so displacement records may represent dispersal. Displacement ranged from a maximum of 10 114 km for a White Stork (Ciconia ciconia) to 2.5 km for a Little Bittern (Ixobrychus minutus). Several species are poorly sampled, resulting in longevity records of just a few days. Despite that, longevity values were 5 years for 16 species, and the highest value was 25.3 years for a White Stork.Conclusion: It was possible to determine longevity values for most of the species within the three families investigated. Based on the displacement profiles for species with sufficient records, there are large differences in movement between species. Certain common species such as Purple Heron (Ardea purpurea) have very few ringing records, which indicate a need for further species-specific research as the longevity values are not representative. This could greatly benefit studies aiming to use these species as ecosystem health indicators as well as identify which species are at risk.

Download Full-text

Sea-ice crossings by caribou in the south-central Canadian Arctic Archipelago and their ecological importance

Rangifer ◽

10.7557/2.25.4.1773 ◽

2005 ◽

Vol 25 (4) ◽

pp. 77 ◽

Cited By ~ 10

Author(s):

Frank L. Miller ◽

Samuel J. Barry ◽

Wndy A. Calvert

Keyword(s):

Sea Ice ◽

Rangifer Tarandus ◽

Canadian Arctic ◽

The Arctic ◽

Canadian Arctic Archipelago ◽

The South ◽

South Central ◽

Straight Line ◽

Straight Line Distance ◽

Ecological Importance

The islands of the Canadian Arctic Archipelago lie immediately north of mainland North America in the Arctic Ocean. They are surrounded by ice for most of each year. Caribou (Rangifer tarandus) cross the sea ice in seasonal migrations among the islands and between the mainland and Arctic Islands. We compiled observations of 1272 discrete caribou crossings on the sea ice of northeastern Franklin Strait, Bellot Strait, Peel Sound and Baring Channel in the south-central Canadian Arctic Archipelago during four May—June search periods from 1977 to 1980. We clustered the 850 caribou trails found on the sea ice of northeastern Franklin Strait and on outer Peel Sound as 73 sea-ice crossing sites. We investigated whether caribou at the origin of a sea-ice crossing site could see land on the opposite side at the potential terminus. We measured the straight-line distance from where the caribou first came onto the ice (origin) to the first possible landfall (potential terminus). Potential termini were geodetically visible to caribou from elevated terrain near 96% of the origins of the 73 sea-ice crossing sites and still visible at sea-level at the origins on 68%. Caribou are able to take advantage of seasonal use of all of the islands and the peninsula by making sea-ice crossings, thereby helping to increase the magnitudes and durations of population highs and reduce their lows. Knowledge of these alternative pat¬terns of use made possible by sea-ice crossings is necessary to fully understand the population dynamics of these caribou and the importance of possible future changes in ice cover.

Download Full-text

Editorial

Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad ◽

10.17159/1727-3781/2015/v18i7a1135 ◽

2015 ◽

Vol 18 (7) ◽

pp. 0-0

Author(s):

Christa Rautenbach

Keyword(s):

South Africa ◽

South African ◽

Unemployment Insurance ◽

Sex Offender ◽

Legal Protection ◽

The United States ◽

Common Species ◽

Road Accident ◽

Criminal Court ◽

The South

The last general issue of 2016 boasts 11 contributions dealing with a variety of issues. Chrizell Chürr compares some of the challenges experienced in the South African educational system with the situation in the German system to propose alternatives for South Africa. Deon Erasmus and Angus Hornigold discuss the emergence of a different kind of model of litigation in South African law, which they refer to as "court supervised institutional transformation". They also investigate the feasibility of importing something like the American special master into South African law to assist with the implementation of court sentences. Wian Erlank's first contribution re-evaluates traditional conceptualisations of property rights in space, especially against the background of objects that are deemed to be res nullius (things belonging to nobody) as well as the theory of terra nullius (land belonging to nobody). Wian Erlank's second contribution also deals with property but this time he deliberates on the relevance and meaning of virtual property in modern society. Evode Kayitana moves further abroad to the International Criminal Court (ICC) and the question of whether and to what extent foreign State officials can plead immunity when they are accused of international crimes before South African courts. Drawing an analogy with the American Bald and Golden Eagle Protection Act of 1940, Johann Knobel argues in favour of extending the legal protection afforded to rare bird species to more common species to prevent the use of the excuse that a protected species was mistaken as a common species and therefore mistakenly killed. Tumo Maloka two high court cases which dealt with the question whether a person with previous convictions could be considered a "fit and proper person" to be admitted to the roll of attorneys. Lindiwe Maqutu charts the narrative of judicial influence on the diminishing credibility of the National Prosecuting Authority, using selected cases from the past, including those involving the South African president, Jacob Zuma. Nina Mollema gives a comparative narrative of sex offender registration in South Africa, the United States and the United Kingdom and comes to the conclusion that a sex offender register would not necessarily prevent the commission of sexual offences in South Africa. Marius Olivier and Avinash Govindjee reflect on the shortcomings and deficiencies of the proposed amendments to the Unemployment Insurance Act 63 of 2001, introduced via the provisions of the Unemployment Insurance Amendment Bill of 2015. Riette du Plessis reviews the appropriateness of some of the assessment models available in Clinical Legal Education courses within a South African environment and, finally, Sarah Fick and Paul van der Merwe critique the interpretation of the "cap provision" in section 17(4)(c) of the Road Accident Fund Act 56 of 1998 in Road Accident Fund v Sweatman (162/2014) [2015] ZASCA 22 (20 March 2015).

Download Full-text