Satellite tracking is helping protect the Spectacled Petrel

Satellite tracking is increasingly being used to track and provide valuable insight into the movement of birds. In a recent doctoral study at the University of Glasgow, Leandro Bugoni applied satellite transmitter technology to track several albatross and petrel species off the coast of Brazil. His research focused on different aspects of seabird biology, however his work on the non-breeding habits of Spectacled Petrel Procellaria conspicillata revealed some significant findings.

Spectacled Petrel © Peter RyanSpectacled Petrel, a species recently split from White-chinned Petrel Procellaria aequinoctialis, only breeds on Inaccessible Island in the Tristan da Cunha archipelago. It is listed as vulnerable by the IUCN because of the impact of longline fishing on its population numbers. Each year approximately 9 million hooks are set by longline fisherman off the coast of Brazil, an area where Spectacled Petrels spend their non-breeding season, and several albatross and petrel species fall prey to these hooks. This from the abstract of Leandro’s thesis:

A range of poorly-known hook-and-line commercial fisheries carried out by the Itaipava fleet, southeastern Brazil, composed of 497 vessels, was described with seven fisheries defined. Capture rates were higher for the surface longline for Dolphinfish (0.15 birds/1000 hooks and 1.08 turtles/1000 hooks), slow trolling for Bigeye Tuna (0.41 birds/day) and handlining targeting Yellowfin Tuna (0.61 birds/day). Bycatch of 47 seabirds, mainly the endangered Spectacled Petrel, Atlantic Yellow-nosed, and Black-browed Albatrosses, and 45 turtles of four species were recorded. Longline and other hook-and-line fisheries are the major threat for albatrosses and petrels from different origins when foraging in the SW Atlantic Ocean, and require urgent conservation measures.

Longline fishing is a well-known culprit of seabird mortalities, which has driven much research by Professor Peter Ryan of the Percy Fitzpatrick Institute of African Ornithology on bycatch reduction strategies. An important component of these strategies is understanding the feeding habits of bycatch species. Longline fising bycatch © Peter Ryan

Research by Ryan et al (2006) suggests that Spectacled Petrel population comprises approximately 20, 000 adult birds. This from the report abstract:

The population has increased over the last five years, continuing the apparent recovery from a very small population size in the early 20th century. Despite this increase, demographic models indicate that the population remains at risk from relatively small increases in mortality, if mortality is determined primarily by fishing effort. Mitigation of long-line mortality remains the key conservation goal for this species.

A key finding of Leandro’s thesis relates to the feeding habits of Spectacled Petrel. It was assumed that Spectacled Petrel adopted similiar feeding patterns to its cousin the White-chinned Petrel, however results from the satellite tracking analysis indicate that Spectacled Petrel may feed both during the day and night (White-chinned Petrel only forage during the day), which has important implications. A common bycatch mitigation strategy involves baiting and setting longlines at night when most pelagic species do not feed, however this strategy will need to be reviewed in the case of Spectacled Petrel. Here’s another excerpt from Leandro’s thesis:

Satellite transmitters were used to determine the marine habitat utilization and fishery overlap of wintering Spectacled Petrels Procellaria conspicillata in the southwestern Atlantic Ocean in 2006 and 2007. Kernel density analysis of tracked birds demonstrated intense use of waters in the Brazilian Exclusive Economic Zone, from 26 to 31ºS, mainly over the continental shelf break and offshore waters (mean depth in the < 20% kernel density areas = 1043 ± 794 m), over warm tropical and subtropical (mean SST = 22°C and 21°C in 2006 and 2007, respectively) and mesotrophic/oligotrophic (chlorophyll a density 0.301 mg m-3 and 0.281 mg m-3 in 2006 and 2007, respectively) waters. The marine habitats used by Spectacled petrel and described by bathymetry, SST and productivity are remarkably different from those of the sister species White-chinned Petrel P. aequinoctialis, which occurs in the area during the winter, but remains over the continental shelf, on Sub-Antarctic and oligotrophic waters. A close association between birds and pelagic longline fishery was demonstrated through comparison of the main kernel areas used by Spectacled Petrels and the pelagic longline fleet, with fishing effort at resolution of 1° x 1° quadrants and complete temporal overlap between bird tracking and fishing period. Travelled speeds and distances during night and daytime periods did not differ. This study demonstrates the importance of high resolution fishing effort data to address relationships between bird marine habitat use and specific fishing fleets, and to determine marine habitats and investigate at sea segregation between closely related species.

That’s quite a heavy read. Find a lighter version here.

Step aside Justin Timberlake, birds have rhythm too!

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Recent research published in Current Biology reveals that particular bird species, Snowball the Sulphur Crested Cockatoo in this case, are able to dance to a beat, a characteristic previously only attributed to humans.

This from Schachner et al (2009):

The human capacity for music consists of certain core phenomena, including the tendency to entrain, or align movement, to an external auditory pulse. This ability, fundamental both for music production and for coordinated dance, has been repeatedly highlighted as uniquely human. However, it has recently been hypothesized that entrainment evolved as a by-product of vocal mimicry, generating the strong prediction that only vocal mimicking animals may be able to entrain. Here we provide comparative data demonstrating the existence of two proficient vocal mimicking nonhuman animals (parrots) that entrain to music, spontaneously producing synchronized movements resembling human dance. We also provide an extensive comparative data set from a global video database systematically analyzed for evidence of entrainment in hundreds of species both capable and incapable of vocal mimicry. [more here]

Additional research was conducted by Patel et al (2009).

According to the vocal learning and rhythmic synchronization hypothesis, entrainment to a musical beat relies on the neural circuitry for complex vocal learning, an ability that requires a tight link between auditory and motor circuits in the brain. This hypothesis predicts that only vocal learning species (such as humans and some birds, cetaceans, and pinnipeds, but not nonhuman primates) are capable of synchronizing movements to a musical beat. Here we report experimental evidence for synchronization to a beat in a sulphur-crested cockatoo (Cacatua galerita eleonora). By manipulating the tempo of a musical excerpt across a wide range, we show that the animal spontaneously adjusts the tempo of its rhythmic movements to stay synchronized with the beat. These findings indicate that synchronization to a musical beat is not uniquely human and suggest that animal models can provide insights into the neurobiology and evolution of human music. [more here]

For a watered-down account of this story and some video of Snowball busting some moves, check out BBC Science.