Testosterone and cortisol concentrations vary with reproductive status in wild female red deer

Although hormones are key regulators of many fitness and life history traits, the causes of individual level variation in hormones, particularly in wild systems, remain understudied. Whilst we know that androgen and glucocorticoid levels vary within and among individuals in mammalian populations, how this relates to key reproductive processes such as gestation and lactation, and their effects on a female's measurable hormone levels are poorly understood in wild systems. Using fecal samples collected from females in a wild red deer population between 2001 and 2013, we explore how fecal androgen (FAM) and cortisol (FCM) metabolite concentrations change with age and season, and how individual differences relate to variation in reproductive state. Both FAM and FCM levels increase toward parturition, although this only affects FCM levels in older females. FCM levels are also higher when females suckle a male rather than a female calf, possibly due to the higher energetic costs of raising a son. This illustrates the importance of accounting for a female's life history and current reproductive status, as well as temporal variation, when examining individual differences in hormone levels. We discuss these findings in relation to other studies of mammalian systems and in particular to the relatively scarce information on variation in natural levels of hormones in wild populations

Identifying species likely threatened by international trade on the IUCN Red List can inform CITES trade measures

Overexploitation is a major threat to biodiversity and international trade in many species is regulated through the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). However, there is no established method to systematically determine which species are most at risk from international trade to inform potential trade measures under CITES. Here, we develop a mechanism using the International Union for Conservation of Nature’s Red List of Threatened Species to identify species that are likely to be threatened by international trade. Of 2,211 such species, CITES includes 59% (1,307 species), leaving two-fifths overlooked and in potential need of international trade regulation. Our results can inform deliberations on potential proposals to revise trade measures for species at CITES Conference of the Parties meetings. We also show that, for taxa with biological resource use documented as a threat, the number of species threatened by local and national use is four times greater than species likely threatened by international trade. To effectively address the overexploitation of species, interventions focused on achieving sustainability in international trade need to be complemented by commensurate measures to ensure that local and national use and trade of wildlife is well-regulated and sustainable

Cortisol but not testosterone is repeatable and varies with reproductive effort in wild red deer stags

AbstractAlthough it is known that hormone concentrations vary considerably between individuals within a population, how they change across time and how they relate to an individual’s reproductive effort remains poorly quantified in wild animals. Using faecal samples collected from wild red deer stags, we examined sources of variation in faecal cortisol and androgen metabolites, and the potential relationship that these might have with an index of reproductive effort. We also biologically validated an assay for measuring androgen metabolites in red deer faeces.We show that variation in hormone concentrations between samples can be accounted for by the age of the individual and the season when the sample was collected. Faecal cortisol (but not androgen) metabolites also showed significant among-individual variation across the 10-year sampling time period, which accounted for 20% of the trait’s phenotypic variance after correcting for the age and season effects. Finally, we show that an index of male reproductive effort (cumulative harem size) during the mating season (rut) was positively correlated with male cortisol concentrations, both among and within individuals. We suggest that the highest ranking males have the largest cumulative harem sizes (i.e. invest the greatest reproductive effort), and that this social dominance may have associated behaviours such as increased frequency of agonistic interactions which are associated with corresponding high levels of faecal cortisol metabolites (FCM)

Variation in early-life testosterone within a wild population of red deer

Individual differences in circulating hormone concentrations can affect life-history traits throughout an animal's life. Despite this, relatively little is known about the potential drivers or consequences of individual variation in hormone levels, particularly in early life. In animals showing maternal care, early development is often dependent on maternal characteristics and condition. It is therefore possible that individual hormone profiles early in life are dependent on condition-linked characteristics of the mother. Using data from a long-term study of a wild red deer (Cervus elaphus) population, we investigated the potential role of maternal effects on offspring early-life testosterone concentrations and the relationship between these testosterone levels and juvenile survival. Most of the variation among neonatal calves was accounted for by their age and sex. Both sexes showed a steep decline in testosterone levels within 24 h of birth, although concentrations were consistently higher in males, and females showed a steeper decline in testosterone after 24 h. Furthermore, male calves born in years after a brother had lower concentrations than those who were preceded by a sister or who were firstborns. We did not find any evidence of repeatable differences among mothers in the testosterone levels of their calves, but there was significant interannual variation across the 17-year study period. We also found early-life testosterone to be associated with calf survival, but only among individuals already at higher mortality risk: male calves born to first-time mothers were increasingly less likely to survive with higher neonatal testosterone concentrations. These results support the suggestion that a neonate's circulating testosterone concentrations can be linked to both individual and maternal characteristics and that interindividual variation in these levels can have implications for juvenile fitness within a wild mammal population

Rum red deer pedigree

.RData file containing the inverse related matrix for the Isle of Rum red deer pedigree

Status and trends in the international wildlife trade in Chameleons with a focus on Tanzania.

Chameleons (family Chamaeleonidae) are a distinctive group of reptiles, mainly found in Africa, which have high local endemism and face significant threats from the international wildlife trade. We review the scale and structure of international chameleon trade, with a focus on collection in and exports from Tanzania; a hotspot of chameleon diversity. Analysis used data from the CITES Trade Database 2000-2019, combined with assessment of online trade, and on-the-ground surveys in Tanzania in 2019. Between 2000 and 2019, 1,128,776 live chameleons from 108 species were reported as exported globally, with 193,093 of these (from 32 species) exported by Tanzania. Both global and Tanzanian chameleon exports declined across the study period, driven by decreased trade in generalist genera. Whilst the proportion of captive-bred individuals increased across time for the generalist taxa, the majority of range-restricted taxa in trade remained largely wild-sourced. For Tanzanian exports, 41% of chameleons were from one of the 23 endemic species, and 10 of the 12 Tanzanian endemic species in trade are categorised as threatened with extinction by IUCN. In terms of online trade, of the 42 Tanzanian species assessed, there was evidence of online sale for 83.3% species, and 69% were actively for sale with prices listed. Prices were on average highest for Trioceros species, followed by Kinyongia, Rieppeleon, Rhampholeon, and Chameleo. Field work in Tanzania provided evidence that the historic harvest of endemic chameleon species has been higher than the quantities of these species reported as exported by Tanzania in their annual trade reports to CITES. However, we found no field evidence for trade in 2020 and 2021, in line with Tanzanian regulations that applied a blanket ban on all exports of live wild animals. Literature evidence, however, suggests that illegal trade continued to Europe from seizures of Tanzanian chameleon species in Austria in 2021

Neonatal testosterone dataframe

File includes all data required to reproduce analyses in the paper. Definitions of data columns can be found in Table 1 of paper with the exception of "ID": unique number identifying the calf. Calf age column names have also been abbreviated (though definitions can be found in Table 1)- CalfAge24: "At/before or after 24 hours" (see Table1); CalfAgeHrs: "Age (hours)" (see Table1

Data from: Variation in early life testosterone in a wild population of red deer

1. Individual differences in circulating hormone concentrations can affect life history traits throughout an animal’s life. Despite this, relatively little is known about the potential drivers or consequences of individual variation in hormone levels, particularly in early life. In animals showing maternal care, early development is often dependent on maternal characteristics and condition. It is therefore possible that individual hormone profiles early in life are dependent on condition-linked characteristics of the mother. 2. Using data from a long-term study of a wild red deer (Cervus elaphus) population, we investigated the potential role of maternal effects on offspring early life testosterone concentrations and the relationship between these testosterone levels and juvenile survival. 3. Most of the variation among neonatal calves was accounted for by their age and sex. Both sexes showed a steep decline in testosterone levels within 24 hours of birth, although concentrations were consistently higher in males, and females showed a steeper decline in testosterone after 24 hours. Furthermore, male calves born in years after a brother had lower concentrations than those who were preceded by a sister or who were firstborns. We did not find any evidence of repeatable differences among mothers in the testosterone levels of their calves, but there was significant inter-annual variation across the 17-year study period. 4. We also found early life testosterone to be associated with calf survival, but only amongst individuals already at higher mortality risk: male calves born to first-time mothers were increasingly less likely to survive with higher neonatal testosterone concentrations. 5. These results support the suggestion that a neonate’s circulating testosterone concentrations can be linked to both individual and maternal characteristics, and that inter-individual variation in these levels can have implications for juvenile fitness within a wild mammal population.Pavitt, A.T. et al. (2015), Data from: Variation in early life testosterone in a wild population of red deer, Dryad, Dataset, 10.5061/dryad.qb19