An assessment of eggshell pigments as non-invasive biomarkers of organochlorine pollutants in gull-billed tern.

Eggshell pigmentation has been assessed as an indicator of exposure to environmental pollutants in birds, but these studies have only used reflectance spectrophotometry to measure such pigmentation. The present study is the first one that measures eggshell pigments and pollutants in the same eggs to explore their use as biomarkers in birds. We have studied the concentration of organochlorine pesticides and polychlorinated biphenyls (PCBs) in the content of 97 deserted eggs of gull-billed terns (Gelochelidon nilotica) after the abandonment of the colony in Mesas de Asta (Cádiz, S Spain) in 2012. Eggshell thickness and stage of embryo development were studied together along with the concentrations of protoporphyrin IX and biliverdin in eggshells. p,p'-DDE concentrations were high when compared with other studies done with terns in the Mediterranean basin in the past. p,p'-DDE and PCB levels associated with reduced reproductive success were found in 5.1% and 2.1% of the eggs respectively. Eggshell index was largely affected by the embryo development stage, which highlights the need of knowing this information to avoid potential biases in the interpretation of results. The concentrations of protoporphyrin IX and biliverdin in the eggs of gull-billed terns were negatively associated with DDTs levels, which seems to confirm previous observations with phylogenetically related species.

Aggressive behavior and hair cortisol levels in captive Dorcas gazelles (Gazella dorcas) as animal-based welfare indicators.

Ensuring welfare in captive wild animal populations is important not only for ethical and legal reasons, but also to maintain healthy individuals and populations. An increased level of social behaviors such as aggression can reduce welfare by causing physical damage and chronic stress to animals. Recently, cortisol in hair has been advanced as a non-invasive indicator to quantify long-lasting stress in many species. The sensitivity of social behavior and hair cortisol concentration was evaluated in several groups of dorcas gazelles (Gazella dorcas). Four different groups of gazelles from three different zoos were observed and the expression of intra-specific affiliative and negative social behaviors was assessed across the different groups. Hair samples were taken from sub-groups of animals and analyzed for cortisol concentrations. Significant differences between groups of dorcas gazelles were found in frequency of negative social behavior and hair cortisol concentration. Despite the low sample size, these two parameters had a positive Spearman correlation coefficient (rs = +0.80, P = 0.20). These results suggest that hair cortisol levels are sensitive to differences in the social structure of dorcas gazelles. Zoo Biol. 35:467-473, 2016. © 2016 Wiley Periodicals, Inc.

Male vulnerability explains the occurrence of sexual cannibalism in a moderately sexually dimorphic wolf spider.

Sexual cannibalism is a widespread phenomenon among a few animal taxa. Its occurrence is interpreted as female and/or male optimal reproductive decisions or as a non-adaptive side effect of selection for efficiently foraging females. In spite of the amount of research addressed at understanding its evolutionary origins, we lack accurate information about the proximate causes of sexual cannibalism. In a moderately sexually dimorphic wolf spider (Hogna radiata, Araneae, Lycosidae) we assessed the factors mediating the occurrence of sexual cannibalism and its fitness benefits to females. Sexual cannibalism was a rather common outcome of laboratory mating interactions, occurring in more than a quarter percent of courtship interactions involving virgin females. Sexual cannibalism mostly followed mating. Occurrence of sexual cannibalism depended on male vulnerability to female attacks: relatively smaller males were at higher risk of being attacked and older males were less likely to avoid female attacks. Sexual cannibalism had direct and positive effects on female fitness, as sexually cannibalistic females exhibited increased fecundity irrespective of their size, condition and foraging rate. Male consumption was almost complete and represented a relevant food intake to females. We interpret sexual cannibalism as a strategic foraging decision for H. radiata females that adjust their aggressive behaviour towards males so as to limit its potential costs.

Comparison between tail and jugular venipuncture techniques for blood sample collection in common chameleons (Chamaeleo chamaeleon).

The most common technique used for collecting blood samples from chameleons, ventral tail caudal venipuncture (Reptile care. An Atlas of Diseases and Treatments, Vol. II, T.F.H. Publication, New Jersey, 1991) sometimes presents undesired effects. Here we compared tail versus jugular vein venipuncture techniques in the common chameleon. In the first experiment, we collected 0.25% of the chameleon's body mass in blood from either tail or jugular sites in size-matched pairs of animals to check for secondary effects. In a second experiment, we measured white blood cells (WBC), red blood cells (RBC), total plasma protein and uric acid in blood samples collected from both sites in the same individual. We found few secondary effects following the use of either venipuncture site although skin darkening was observed in few specimens when using the ventral tail vein. Blood profiles were similar between samples. The repeatability of measurements was similar in RBC and WBC counts and remarkably low (<0.90). Despite the few differences recorded, we recommend jugular venipunction in chameleons as skin darkening is unlikely, blood volumes are easily obtained and collection time is shorter.