A pilot study to estimate the population size of endangered Galápagos marine iguanas using drones.

Background: Large-scale species monitoring remains a significant conservation challenge. Given the ongoing biodiversity crisis, the need for reliable and efficient methods has never been greater. Drone-based techniques have much to offer in this regard: they allow access to otherwise unreachable areas and enable the rapid collection of non-invasive field data.

Using bear rub data and spatial capture-recapture models to estimate trend in a brown bear population.

Trends in population abundance can be challenging to quantify during range expansion and contraction, when there is spatial variation in trend, or the conservation area is large. We used genetic detection data from natural bear rubbing sites and spatial capture-recapture (SCR) modeling to estimate local density and population growth rates in a grizzly bear population in northwestern Montana, USA. We visited bear rubs to collect hair in 2004, 2009-2012 (3,579-4,802 rubs) and detected 249-355 individual bears each year.

Environmental temperatures shape thermal physiology as well as diversification and genome-wide substitution rates in lizards.

Climatic conditions changing over time and space shape the evolution of organisms at multiple levels, including temperate lizards in the family Lacertidae. Here we reconstruct a dated phylogenetic tree of 262 lacertid species based on a supermatrix relying on novel phylogenomic datasets and fossil calibrations. Diversification of lacertids was accompanied by an increasing disparity among occupied bioclimatic niches, especially in the last 10 Ma, during a period of progressive global cooling.

Demographic mechanisms underpinning genetic assimilation of remnant groups of a large carnivore.

Current range expansions of large terrestrial carnivores are occurring following human-induced range contraction. Contractions are often incomplete, leaving small remnant groups in refugia throughout the former range. Little is known about the underlying ecological and evolutionary processes that influence how remnant groups are affected during range expansion.

The complete mitochondrial genomes of the Galápagos iguanas, Amblyrhynchus cristatus and Conolophus subcristatus.

The Galápagos iguanas are among the oldest vertebrate lineages on the Galápagos archipelago, and the evolutionary history of this clade is of great interest to biologists. We describe here the complete mitochondrial genomes of the marine iguana, Amblyrhynchus cristatus (Genbank accession number: KT277937) and the land iguana Conolophus subcristatus (Genbank accession number: KT277936). The genomes contain 13 protein-coding genes, 22 transfer RNAs, and two ribosomal RNAs genes, as well as a control region (CR).

Hybridization masks speciation in the evolutionary history of the Galápagos marine iguana.

The effects of the direct interaction between hybridization and speciation-two major contrasting evolutionary processes--are poorly understood. We present here the evolutionary history of the Galápagos marine iguana (Amblyrhynchus cristatus) and reveal a case of incipient within--island speciation, which is paralleled by between-island hybridization. In-depth genome-wide analyses suggest that Amblyrhynchus diverged from its sister group, the Galápagos land iguanas, around 4.

Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?

Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of multiple detection methods may be more appropriate. We evaluated the effects of combining two detection methods on the identification of variables important to local abundance using detections of grizzly bears with hair traps (systematic) and bear rubs (opportunistic).

Hearing threshold shifts and recovery in harbor seals (Phoca vitulina) after octave-band noise exposure at 4 kHz.

Safety criteria for underwater sounds from offshore pile driving are needed to protect marine mammals. As a first step toward understanding effects of impulsive sounds, two harbor seals were exposed to octave-band white noise centered at 4 kHz at three mean received sound pressure levels (SPLs; 124, 136, and 148 dB re 1 μPa) at up to six durations (7.5, 15, 30, 60, 120, and 240 min); mean received sound exposure level (SEL) range was 166-190 dB re 1 μPa(2) s.