Quantifying the distribution and abundance of predators is integral to many ecological studies, but can be difficult in remote settings such as Antarctica. Recent advances development unmanned aerial systems (UAS), particularly vertical takeoff landing (VTOL) aircraft, have provided a new tool for studying predator populations. We detail our experience testing selecting VTOL platform use remote, windy, perennially overcast settings, where acquiring cloud-free high-resolution satellite images...

Vertical aerial photographs were collected of gray whales migrating along the California Coast between 1994 and 1998 to readdress some published findings on biology life history this population based examination specimens. For each whale, an attempt was made measure standard total length, width whale at its widest point, distance from tip rostrum flukes. southbound whales, early migrants longer average more likely be parturient than those later. Near-term pregnant females wider relative...

Conventional aircraft have been used for photogrammetry studies of free-ranging whales, but are often not practical in remote regions or affordable. Here we report on the use a small, unmanned hexacopter (APH-22; Aerial Imaging Solutions) as an alternative method collecting photographs to measure killer whales (Orcinus orca) at sea. We deployed and retrieved by hand during 60 flights (average duration 13.2 min, max 15.7 min) from upper deck 8.2 m boat, utilizing aircraft's vertical takeoff...

Baleen whales are the largest animals ever to live on earth, and many populations were hunted close extinction in 20th century (Clapham et al. 1999). Their recovery is now a key international conservation goal, they important marine ecosystems as massive consumers that can promote primary production through nutrient cycling (Roman 2014). However, although abundance has been assessed monitor of some large whale (e.g., Barlow 2011, Laake 2012) wide-ranging pelagic, this inaccessibility...

Measurements of body size and mass are fundamental to pinniped population management research. Manual measurements tend be accurate but invasive logistically challenging obtain. Ground-based photogrammetric techniques less invasive, inherent limitations make them impractical for many field applications. The recent proliferation unmanned aerial systems (UAS) in wildlife monitoring has provided a promising new platform the photogrammetry free-ranging pinnipeds. Leopard seals (Hydrurga...

Geographic variations in size and proportions of blue whales (Balaenoptera musculus) were investigated using length data acquired from whaling records aerial photogrammetric surveys. Results showed that found the eastern Pacific off Central North America are significantly shorter (by approximately 2m) than at higher latitudes Pacific. support occurrence a morphologically distinct (ENP) whale population which migrates spring/summer warm waters Mexico to temperate feeding grounds along west...

Climate change is affecting a wide range of global systems, with polar ecosystems experiencing the most rapid change. Although climate impacts affect lower-trophic-level and short-lived species directly, it less clear how long-lived mobile will respond to warming because they may have short-term ability accommodate ecological disruptions while adapting new conditions. We found that population dynamics an iconic highly polar-associated are tightly coupled Arctic prey availability access...

A bstract We conducted shore‐based sighting surveys to estimate the number of northbound migrating gray whale calves passing Piedras Blancas, California, for seven consecutive years (1994–2000). In addition, we aerial determine offshore distribution migration in 1994 and 1995, measured day/night rates with thermal sensors 1994–1996, maintained concurrent replicate watches near peak each proportion cow/calf pairs missed by standard watch team. During good weather, counted 325, 194, 407, 501,...

In the early 1980s, 2 groups of Soviet scientists independently described 1, possibly new dwarf species killer whales (Orcinus) from Antarctica. We used aerial photogrammetry to determine total length (TL) 221 individual Type C whales—a fish-eating ecotype that inhabits dense pack ice—in southern Ross Sea in January 2005. confirmed it as one smallest known: TL adult females (with calves) averaged 5.2 m ± 0.23 SD (n = 33); males 5.6 0.32 65), with largest measuring 6.1 m. Female A...

ABSTRACT We summarize fin whale Balaenoptera physalus catch statistics, sighting data, mark recoveries and acoustics data. The annual cycle of most populations whales had been thought to entail regular migrations between high‐latitude summer feeding grounds lower‐latitude winter grounds. Here we present evidence more complex varied movement patterns. During summer, range from the Chukchi Sea south 35 °N on Sanriku coast Honshu, Subarctic Boundary (ca. 42 °N) in western central Pacific, 32...

The North Pacific right whale ( Eubalaena japonica ) was heavily exploited by both nineteenth century whaling and recent (1960s) illegal Soviet catches. Today, the species remains extremely rare especially in eastern Pacific. Here, we use photographic genotype data to calculate first mark–recapture estimates of abundance for whales Bering Sea Aleutian Islands. were very similar: = 31 (95% CL 23–54), genotyping 28 24–42). We also estimated population contains eight females 7–18) 20 males...

Aerial imagery is the most effective method National Marine Fisheries Service (NMFS) uses to assess abundance of Steller sea lions (Eumetopias jubatus). These images are traditionally captured from occupied aircraft, but long distances between airfields along 1900 km Aleutian Island chain, inclement weather during survey season, and dangerous winds at sites adjacent cliffs severely limit flying opportunities. Because pressing need for current trend information a population in persistent...

Unoccupied aerial systems (UAS) have become common tools for ecological monitoring and management. However, UAS use has the potential to negatively affect wildlife. Both policy makers practitioners require data about impacts of on natural biota, but few studies exist some published results conflict. We conducted two experiments assess responses chinstrap penguins ( Pygoscelis antarcticus ), Antarctic fur seals Arctocephalus gazella leopard Hydrurga leptonyx ) overflights. First, provide a...

Body growth of North Atlantic right whales (Eubalaena glacialis) was described from measurements known-age live and dead individuals to gain insights into the nutritional needs life-history strategies this endangered species. lengths 154 revealed that calves more than doubled in size attained three-fourths asymptotic adult by time they had weaned at 12 months. Calves gained on average ∼1.7 cm ∼34 kg per day while nursing during extremely rapid phase. Mean predicted body mass were 4.2 m 1.1...

Research vessel and aerial platforms were used between 1997 2000 to collect genetic photographic data from a small populationof right whales that summers in the southeastern Bering Sea. Totals of 11 six unique individuals identified using photographicand methods, respectively. Single matches years occurred both all samples turned out befrom male whales. Long-term research is needed estimate size this population determine what threats may befacing.

Abstract: At least four morphologically distinct forms of common dolphins are found in the eastern Pacific, We compared length data for photographed from northern, central and southern regions as defined by Perrin et al. (1985) significant differences average adult animals (>150 cm) “adult females” our purposes accompanied calves. Analyses calculated birth dates calves demonstrated timing reproduction between geographically adjacent forms. Length distributions aerial photographs samples...

Abstract This paper describes the relationship between eastern North Pacific gray whale calf production and environmental conditions in Arctic where they feed. The results show how interannual variation sea ice cover Bering Chukchi Seas along with broader indices of climate, such as Decadal Oscillation (PDO) Index (NPI), are linked to reproductive output. Estimates were derived from 23 consecutive years (1994–2016) shore‐based visual surveys conducted off California during northward...

A bstract We recorded the blows of gray whales during their southbound migration past central California in January 1994, 1995, and 1996, using thermal imaging sensors. For our sampling purposes, we defined day (0730–1630) night (1630–0730) to coincide with on/off effort periods visual counts being conducted concurrently. pooled data across three years tested for diel variation surfacing interval, pod size, offshore distance, rate, swimming speed by comparing paired day/night means samples...

Abstract Estimating the number of dolphins in a group is challenging task. To assess accuracy and precision dolphin size estimates, observer estimates were compared to counts from large‐format vertical aerial photographs. During 11 research cruises, total 2,435 434 groups made by 59 observers. Observer modeled as function photo count hierarchical Bayesian framework. Accuracy varied widely among observers, somewhat less species. Most observers tended underestimate, tendency increased with...

A bstract Analyses of skeletal and external morphology spinner dolphins killed in to the yellowfin tuna purse‐seine fishery eastern tropical Pacific led description two subspecies spinners from this region, spinnen dolphin Central American (Perrin 1990). However, when we examined lengths taken vertical aerial photographs same area, found three unique morphotypes. Two these forms correspond, at least average length distribution, existing subspecies. The third form is intermediate between...

Blubber progesterone levels were measured in biopsy samples and used to predict the pregnancy status of 507 female common dolphins (204 long-beaked dolphins, Delphinus capensis, 303 short-beaked D. delphis). Samples collected coastal waters eastern North Pacific between central California, USA southern end Baja Mexico. The percentage females pregnant was similar two species: 22.1% (n = 45) capensis 28.1% 85) delphis. For both species we found strong geographic patterns pregnancy, suggesting...