Amazing Arachnids: Pirate Spiders

Adapted from pages 285 to 286 of Amazing Arachnids:

With infinite patience, the pirate spider Mimetus slips into the web of an orb weaver and approaches its prey. Its progress is almost imperceptible as it pauses for long minutes between each stealthy step. But eventually the pirate spider is within striking distance of its quarry. With a sudden lunge, Mimetus attacks the target, using its long chelicerae to administer the lethal bite. Immediately, it releases the victim and waits a bit, making sure that the spider victim is dead. It does not have long to wait; the orb weaver dies almost instantly from the potent venom,  which is highly effective against spiders. The pirate spider then settles down to suck out the contents of the orb weaver, leaving the cuticle of its prey almost completely intact. The web built by the orb weaver to capture food is now the platform for its own consumption.

Slow and stealthy, pirate spiders hardly seem like lethal predators at first glance. But pirate spiders have made a specialty of hunting other spiders, especially the orb weavers and the combfooted spiders (the theridiids), including even black widows. The spiders in the family Mimetidae possess extremely long front legs armed with heavy, slightly curved setae. Another spider hunter, Rhomphaea, also has exceptionally long front legs. Perhaps this is a useful adaptation when attacking a spider in its web, giving the attacker a superior reach.

Pirate spider

A Metapeira met a pirate. Incredibly slow and stealthy, the female pirate spider Mimetus hesperus slipped into the web of a small Metapeira orb weaver, taking more than an hour before getting close enough for the final lethal attack. The pirate spider then fed at her leisure.

The name Mimetidae is based on the Greek word for “imitator, actor, and impersonator.” In fact, the genus Eros is notorious for incorporating deception into its hunting repertoire, utilizing what is called aggressive mimicry. Aggressive mimicry is defined by a predator (the mimic) imitating a harmless organism (the model), thereby attracting the prey. Aggressive mimics that target more than one species of prey may have evolved highly complex repertoires of behaviors, and may demonstrate plasticity in the use of these behaviors. Staying near the periphery of the victim’s web, Eros seductively plucks the silk, imitating a courting male. When the resident spider hurries over to investigate, Eros bites her on the leg and kills her. Eros then eats not only the spider, but any eggs as well. In 1850, Nicholas Marcellus Hentz wrote, “The Mimetus … prefers prowling in the dark, and taking possession of the industrious Epeira’s threads and home, or the patient Theridion’s web, after murdering the unsuspecting proprietor.” Occasionally, though, if Mimetus becomes a little careless, the hunter may become the hunted, and the pirate spider may be killed by the resident spider and then eaten.

Although the female Mimetus seems to prefer spiders as the predominant prey, male Mimetus readily hunt other small arthropods such as gnats. The males may be seen as regular visitors on sliding glass doors at night, feeding on small gnats attracted to the light. It is sometimes difficult to imagine that this innocuous male belongs to the same species as the lethal female.

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

 

Bird Fact Friday—Giant Hummingbirds

Adapted from page 156 of Birds of Chile:

The Andean Giant Hummingbird is from the North Andes, and is fairly common in precordillera, south of Tarapacá. Their wingbeats are slow and strong, which causes undulating flight broken by glides. Their flight is often seen in jerky, hovering bursts of ‘slow-motion’ fly-catching. These birds are slightly larger and longer-billed than the Chilean Giant Hummingbird (more info on that one below) – these two birds do not have any range overlap. Adults have broader, dark tail tips, and buffer under tails than the Chilean hummingbirds. Juvenile birds have whitish feather tips on wings. Both sexes are similar. Their call are high, shrill squeaks in a short series.

An Andean Giant Hummingbird

An Andean Giant Hummingbird

A Chilean Giant Hummingbird

A Chilean Giant Hummingbird.

 

 

 

 

 

 

 

 

Meanwhile, the Chilean Giant Hummingbird is typically seen in Central Chile, where it is a fairly common breeding visitor in material, open woodland, and gardens from south Atacama to south Araucanía. Despite having no range overlap, their habits are similar to the Andean Giant Hummingbird. These birds often feed at Puya and Eycalyptus trees, and perch atop Puya trees, along with phone wires. The nests for these birds are often conspicuous. Their calls are loud, sharp seek! noises, and slightly whining tseeich chee-chee

Birds of Chile
A Photo Guide
By Steve N. G. Howell & Fabrice Schmitt

This is the first modern-style photographic field guide to the birds of Chile, an increasingly popular destination with birders and naturalists. Compact and easy to carry, pack, and use, Birds of Chileis ideal for curious naturalists and experienced birders alike, providing everything anyone needs to identify the birds they see. Clear photographs and brief, facing-page species accounts highlight what to look for and how to quickly identify species. The photos include both close-ups and birds-in-habitat images to further aid real-life identification. An introduction and maps provide an overview of Chile’s geographic regions and their distinctive birdlife. Birds of Chile is also a great resource for birding in nearby countries, especially Argentina, Bolivia, and Peru.

  • The first field-friendly photographic guide to the birds of Chile
  • More than 1,000 real-life photos and brief, facing-page text make bird identification easy
  • Overview and maps describe the distinct bird regions of Chile
  • Perfect for curious naturalists and experienced birders alike
  • Compact and easy to carry and pack
  • Also a great resource for birding in Argentina, Bolivia, and Peru

 

The Dog Days of Summer: How Dogs Play

Adapted from pages 92-95 of The Dog:

Rough and tumble is a form of play-fighting for dogs and only rarely escalates to real conflict. To ensure harmless play, dogs need to get the necessary experience as puppies. Photo credit: Dora Zett, Shutterstock

In social species, play represents one of the most complex interactions between two members of a group. The behavior elements displayed during play are actions borrowed from various other behavioral contexts (including agonistic and predatory), but they are modified versions of the original actions and can be combined in novel ways. At the higher level of complexity, during play the partners need to cooperate and adjust their actions in order to achieve their common goal of playing together.

Social play appears to serve many functions in juveniles, improving physical fitness and motor skills, and helping the puppy to learn social skills such as bite inhibition. Social play allows dogs to practice and combine actions they will use later in their lives, and in general play also prepares them for the unexpected. In dogs (and wolves) social play is not limited to juvenile individuals—adults play too— so one main role of play is to maintain the social cohesion of the group.

One of the biggest questions in the study of dyadic play is whether intentional descriptions are appropriate when we interpret the dog’s behavior. Play can take many forms, from simple learned play, such as ball fetching, to pretend play, where the dog displays signals indicating an inner state (aggression, for example) that is not real, such as when the dog pretends he is defending an object.

Play signals have several functions: They clearly distinguish such interactions from real competitive situations, and they serve to initiate play and also to synchronize the actions of the partners. Play signals can be highly variable and can include open mouth display, high-pitched barking, bounding over to the other dog in an exaggerated manner, a bowed head, pawing, or exaggerated retreat. Barking used as a play signal is specific to dogs; it is absent in the play of other canines.

The best-known, highly stereotyped play signal in dogs is the play-bow. It not only conveys the playful intent but it is also used after ambiguous behaviors (such as a playful bite or snap) to display the dog’s willingness to continue the interaction. When the play partners are familiar with each other, bows most often occur after a brief pause with the aim of reinitiating play.

It was once assumed that competitive games increase agonistic tendencies in behavior, suggesting an effect of play activity on later sociability with partners. It turned out, however, that competitive games do not increase aggressive tendencies in real-life situations. On the contrary, it seems that the type of game dogs prefer to play depends on whether they have a cooperative or competitive personality.

Over time dog and owners develop a routine of games, and dogs do not generalize these behavior routines to other, functionally different situations. Thus, it is very important, starting during puppy age, that the dog gets many opportunities to play with other dogs and also humans. Play is one of the best ways to improve the physical and social skills of dogs, and it also facilitates people’s understanding of their companion. A day without play is a lost day!

The Dog: A Natural History
By Ádám Miklósi

As one of the oldest domesticated species, selectively bred over millennia to possess specific behaviors and physical characteristics, the dog enjoys a unique relationship with humans. More than any other animal, dogs are attuned to human behavior and emotions, and accordingly play a range of roles in society, from police and military work to sensory and emotional support. Selective breeding has led to the development of more than three hundred breeds that, despite vast differences, still belong to a single species, Canis familiaris.

The Dog is an accessible, richly illustrated, and comprehensive introduction to the fascinating natural history and scientific understanding of this beloved species. Ádám Miklósi, a leading authority on dogs, provides an appealing overview of dogs’ evolution and ecology; anatomy and biology; behavior and society; sensing, thinking, and personality; and connections to humans.

Illustrated with some 250 color photographs, The Dog begins with an introductory overview followed by an exploration of the dog’s prehistoric origins, including current research about where and when canine domestication first began. The book proceeds to examine dogs’ biology and behavior, paying particular attention to the physiological and psychological aspects of the ways dogs see, hear, and smell, and how they communicate with other dogs and with humans. The book also describes how dogs learn about their physical and social environments and the ways they form attachments to humans. The book ends with a section showcasing a select number of dog breeds to illustrate their amazing physical variety.

Beautifully designed and filled with surprising facts and insights, this book will delight anyone who loves dogs and wants to understand them better.

Amazing Arachnids: Tarantulas

Adapted from pages 165-172 of Amazing Arachnids:

Tarantulas range in size from the largest spider in the world, Theraphosa blondi of South America, with a leg span of up to about 10 inches (25 cm), to Aphonopelma paloma, with a leg span of only 0.75 inches (2 cm).

Tarantulas also have a variety of lifestyles and behaviors, from the stereotypically solitary burrow dweller to the subsocial behavior of some communal species, such as the dwarf tarantula species Holothele (from South America) and Heterothele (from Africa). These communal spiders may cooperatively kill prey and young spiders share the kill. Circumstantial evidence suggests that even some species that live in underground burrows may have extended maternal care of young. In a number of instances, young tarantulas well beyond the third instar have been found  sharing an adult female’s burrow, leading to speculation regarding whether the mother shares food with her offspring.

Tarantula

Aphonopelma chalcodes adult male. These large males have a leg span of about 4 inches (10 cm) and are a common sight as they wander during the summer monsoon season (July and August) in southern Arizona.

The tarantulas of the southwestern United States belong to the genus Aphonopelma. These range in size from fairly large species such as Aphonopelma chalcodes, with a leg span of about 4 to 5 inches (10– 12.7 cm), to the tiny Aphonopelma paloma. A number of Aphonopelma are intermediate in size and are restricted to the mountains of southern Arizona. These tarantulas have a leg span of only about 2 inches (5 cm). The males mature in late fall or winter and may be seen as they wander in search of females even when there is snow on the ground. Because these mountain ranges are separated by barriers of low desert, many of the “sky island” populations have been geographically separated long enough that they are separate species.

One of the most common and conspicuous species is Aphonopelma chalcodes, also known as the desert blond tarantula. This handsome spider lives in an underground burrow in the low-elevation deserts of Arizona and may take about 10 years to reach maturity. The male looks markedly thinner and leggier than the female and, in addition, acquires a tibial spur on his front legs with his final molt. The males leave their burrows upon reaching maturity and go wandering in search of females. They are a familiar sight in the southern Arizona desert during the summer monsoon season, cruising at night or during the late afternoon, especially after a summer rain storm.

Hollywood has effectively exploited these fears, conjuring up giant tarantulas, deadly venomous tarantulas, and tarantulas that wipe out entire towns. But these animals have so much more to offer than cheap thrills. Their beauty and their diversity in both appearance and lifestyle defy the imagination and far surpass Hollywood’s wildest dreams. Certainly, they compel our respect, as does any predator capable of self-defense, but they also deserve our appreciation and protection.

We included a photo of one of the largest tarantulas – but what about the smallest? Head to our Instagram to see how tiny tarantulas can be. 

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Bird Fact Friday – the Andean and Austral Negrito

Adapted from page 189 of Birds of Chile:

The Austral Negrito is frequently found in central or southern Chile. These birds are common summer residents from eastern Aysén, and south to Tierra del Fuego. They are fairly common from northern Chiloé to southern Atacama, mainly near the coast. Additionally, they are local in Andes. During the winter, these birds withdraw north, when they are common in Central Chile, and rare north of Arica. They prefer open areas, from sandy beaches to grassy plains, lakeshores, and riverbanks. They’re also rather quiet, with soft, high chips at times, and in display flight males give high, accelerating chips and a high slurred tssiu that carries well. Sexes are similar while immature, while the adult male is darker.

andean negrito

An adult male Andean Negrito (Lessonia oreas).

an austral negrito

An adult male Austral Negrito (Lessonia rufa).

 

 

 

 

 

 

 

 

 

 

The Andean Negrito inhabits the North Andes, and is fairly common but somewhat local to Coquimbo. They frequently live in bogs, adjacent to open ground. Their calls are quiet, slightly frog like peeks. Both sexes have whitish wing patches, but female are paler. Their habits are very similar to the Austral Negrito. 

Birds of Chile
A Photo Guide
By Steve N. G. Howell & Fabrice Schmitt

This is the first modern-style photographic field guide to the birds of Chile, an increasingly popular destination with birders and naturalists. Compact and easy to carry, pack, and use, Birds of Chileis ideal for curious naturalists and experienced birders alike, providing everything anyone needs to identify the birds they see. Clear photographs and brief, facing-page species accounts highlight what to look for and how to quickly identify species. The photos include both close-ups and birds-in-habitat images to further aid real-life identification. An introduction and maps provide an overview of Chile’s geographic regions and their distinctive birdlife. Birds of Chile is also a great resource for birding in nearby countries, especially Argentina, Bolivia, and Peru.

  • The first field-friendly photographic guide to the birds of Chile
  • More than 1,000 real-life photos and brief, facing-page text make bird identification easy
  • Overview and maps describe the distinct bird regions of Chile
  • Perfect for curious naturalists and experienced birders alike
  • Compact and easy to carry and pack
  • Also a great resource for birding in Argentina, Bolivia, and Peru

Announcing the trailer for On the Future by Martin Rees

Humanity has reached a critical moment. Our world is unsettled and rapidly changing, and we face existential risks over the next century. Various outcomes—good and bad—are possible. Yet our approach to the future is characterized by short-term thinking, polarizing debates, alarmist rhetoric, and pessimism. In this short, exhilarating book, renowned scientist and bestselling author Martin Rees argues that humanity’s prospects depend on our taking a very different approach to planning for tomorrow.

On the Future Prospects for Humanity, by Martin Rees from Princeton University Press on Vimeo.

Martin Rees is Astronomer Royal, and has been Master of Trinity College and Director of the Institute of Astronomy at Cambridge University. As a member of the UK’s House of Lords and former President of the Royal Society, he is much involved in international science and issues of technological risk. His books include Our Cosmic Habitat (Princeton), Just Six Numbers, and Our Final Hour (published in the UK as Our Final Century). He lives in Cambridge, UK.

The Dog Days of Summer: Social Behavior & Hunting

Adapted from pages 70-71 of The Dog:

Being highly social and living in families is a special feature of canines. The basic theme is the same—differences are only quantitative. Family dogs have inherited most social traits present in their wild relatives, but they also need to learn about the peculiarities of social interaction. This is especially important if many dogs are living together in a human family.

Typically, two or three generations live together in a wolf pack, while groups of jackals and coyotes are usually smaller. The actual organization depends on many factors, and in wolves it is not infrequent for such family packs to join together and form even larger packs of 20–30 individuals. The genetic relationship among the members ensures that pack life is usually peaceful because its success depends both on the parents and the survival of the offspring. Thus, the oldest male that is the father of the younger pack mates is closer to a leader who has the most experience and takes the most decisions. But in the end his interests are likely to concur with those of the family.

When wolves reach two or three years of age, they leave the pack to establish a new family. Given that a specific area is covered by territories of other wolves, this task requires courage and experience. It is not surprising that only a few wolves make it. This is one feature that is not typically present in family dogs because most of them prefer to stay with their human family. Free-ranging dogs disperse at various ages, but they are also more easily accepted by other packs.

wolves

Aggressive interactions may take place within a family pack but they are usually followed by some form of reconciliation. Photo credit: Popova Valeriya, Shutterstock

Hunting is a central activity in all canines, but the most complex hunts involving large numbers of individuals have been observed mainly in wolves living in the far north of Canada and Alaska. It is assumed that the typical family size of wolves is also determined by the size of their prey. Wolves live in larger packs if they have to hunt elk or muskoxen, but will hunt alone if their prey is smaller.

Hunting does not consist merely of locating and chasing prey. Wolves need to know their sometimes vast territories very well—where and when prey is moving— and to be able to organize hunts over a range of 12–40 miles (20–65 km). Wolves have been observed to make short cuts or even ambush for a surprise attack. Free-ranging dogs rarely hunt in groups, for simpler tactics suffice to find food near human settlements.

The Dog: A Natural History
By Ádám Miklósi

As one of the oldest domesticated species, selectively bred over millennia to possess specific behaviors and physical characteristics, the dog enjoys a unique relationship with humans. More than any other animal, dogs are attuned to human behavior and emotions, and accordingly play a range of roles in society, from police and military work to sensory and emotional support. Selective breeding has led to the development of more than three hundred breeds that, despite vast differences, still belong to a single species, Canis familiaris.

The Dog is an accessible, richly illustrated, and comprehensive introduction to the fascinating natural history and scientific understanding of this beloved species. Ádám Miklósi, a leading authority on dogs, provides an appealing overview of dogs’ evolution and ecology; anatomy and biology; behavior and society; sensing, thinking, and personality; and connections to humans.

Illustrated with some 250 color photographs, The Dog begins with an introductory overview followed by an exploration of the dog’s prehistoric origins, including current research about where and when canine domestication first began. The book proceeds to examine dogs’ biology and behavior, paying particular attention to the physiological and psychological aspects of the ways dogs see, hear, and smell, and how they communicate with other dogs and with humans. The book also describes how dogs learn about their physical and social environments and the ways they form attachments to humans. The book ends with a section showcasing a select number of dog breeds to illustrate their amazing physical variety.

Beautifully designed and filled with surprising facts and insights, this book will delight anyone who loves dogs and wants to understand them better.

Bird Fact Friday – the Tyrant Birds of Chile

Adapted from page 187 of Birds of Chile

The Patagonian Tyrant is found in central and southern Chile, and is an uncommon summer resident from Maule to the Tierra del Fuego. In the winter, they are fairly common from Biobío to Coquimbo, and become uncommon south of the Lake District. These birds breed in native forests and edge, as well as the woodland and gardens during the winter. Breeding birds go to the mid-upper levels of tall trees, at times forming small flocks in fruiting trees. Their songs are varied arrangements of high, thin, plaintive or penetrating whistles (s-weeu s-weeu w-syiu or swii-ii w-syiin). Their calls are thin, whining, drawn out whistles (pssiiiiiiiiui). These birds are understated, “soft-faced” flycatcher with a rounded head and dark cheek patch, along with rusty wingbars. There are no similar species in Chile.

A Patagonian Tyrant (Coloramphus parvirostris) perched on a tree.

A Patagonian Tyrant (Coloramphus parvirostris) perched on a tree.

Meanwhile, the Spectacled Tyrant can be found in central and southern Chile, where it is fairly common, particularly from Atacama to Chiloé, or Aysén to Magallanes, in the summer. They inhabit marshes with tall rushes, brushy fields, damp grassy plains with scattered bushes, and other locations typically near water. The males perch atop bushes and have near-vertical display flight, swooping back to perch with a flourish. Females often hide in vegetation, and are overlooked easily. In display flight, male wings make low, booming drrrrup that may suggest a bullfrog. These birds are distinctive and attractive; males have white wing flashes, while these flashes are rusty on females. Additionally, males from Aysén have bigger white wing patches. Juveniles have dark eyes, and are uniformly smaller. There are no similar species in Chile.

To catch a glimpse of the Spectacled Tyrant, along with an additional photo of the Patagonian Tyrant, head over to our Instagram

Birds of Chile
A Photo Guide
By Steve N. G. Howell & Fabrice Schmitt

This is the first modern-style photographic field guide to the birds of Chile, an increasingly popular destination with birders and naturalists. Compact and easy to carry, pack, and use, Birds of Chile is ideal for curious naturalists and experienced birders alike, providing everything anyone needs to identify the birds they see. Clear photographs and brief, facing-page species accounts highlight what to look for and how to quickly identify species. The photos include both close-ups and birds-in-habitat images to further aid real-life identification. An introduction and maps provide an overview of Chile’s geographic regions and their distinctive birdlife. Birds of Chile is also a great resource for birding in nearby countries, especially Argentina, Bolivia, and Peru.

  • The first field-friendly photographic guide to the birds of Chile
  • More than 1,000 real-life photos and brief, facing-page text make bird identification easy
  • Overview and maps describe the distinct bird regions of Chile
  • Perfect for curious naturalists and experienced birders alike
  • Compact and easy to carry and pack
  • Also a great resource for birding in Argentina, Bolivia, and Peru

The Dog Days of Summer: Pariah Dogs

Adapted from page 36-37 of The Dog:

There are only estimates regarding the number of dogs living around the world. The boldest assumes that we share our planet with about 1 billion dogs, and most likely only about 20 percent of these live under close human supervision—which means that there are about 800 million pariah dogs worldwide. The vast majority of them live in warmer climates, especially in India and Southeast Asia, Africa, Mexico, and South America.

Pariah dogs lack the bewildering variability of looks we are familiar with in purebred dogs and their hybrids— indeed, pariah dogs show surprising uniformity across continents. They are small to medium-sized, short-haired dogs with rectangular-proportionate build, and mostly tan or tan-and-white. This suggests that pariah dogs have undergone natural selection that resulted in an economic but tough organism, highly successful in its ecological niche—that is, at the fringe of human society.

Pariah dogs depend on human food resources—however, they are seldom provisioned willingly by humans, but rather fend for themselves. They live and feed mostly on the streets of cities and villages, or almost permanently encamped at environments that provide a constant supply of food—such as trash dumps. Human-provided food is available in a steady flow at these sites, which results in a stable population of feral dogs.

However, the nutritional quality of this food is much lower than the meat-based diet of wolves. Pariah dogs adjusted to this specific niche with their smallish size—leftovers do not sustain large dogs and are a food source that does not need to be subdued by physical strength. Pariah dogs also seem not to hunt in packs. 

Pariah dogs

Free-ranging dogs rely on a constant supply of nutrition from human society. They are highly adaptable and usually coexist with humans without causing major problems; otherwise they would not be tolerated. Photo credit: StudioByTheSea, Shutterstock

Pariah dogs may live in groups of hierarchical organization and show territorial aggression against other groups. They reproduce all year around— mirroring the steady food supply and the supportive climatic conditions. Pariah dog males are constantly pursuing available females, and the females may have two litters yearly. Pariah dog mothers nurture their young only in the first 8–10 weeks,  and there are no helpers (older siblings or caretaking fathers. Therefore, when the pariah dog puppies are weaned, they immediately face strict competition with the adults for food, and most of them die in the first year.

Importantly, pariah dogs are not “wild,” in the sense that they do have some type of relationship with humans. Although they are not socialized like family dogs, the puppies are born in a human-made environment, where traces from the humans (such as olfactory cues, artifacts, visual stimulation) are abundant. Puppies are often adopted by local children, who may offer them to tourists to buy. Adult pariah dogs move confidently around in human settlements and rarely get into conflict with humans. Some citizens routinely feed the local pariah dog groups, with the intention of using them for guarding duties against burglars and other pariah dogs.

The phenomenon of domestic species going wild (feralization) is a worrisome tendency, which often has a heavy impact on ecosystems. Cats, ferrets, camels, and other species are documented as burdens on the local fauna or flora in particular parts on the world. Thus, one might assume that the existence of many hundreds of millions of pariah dogs would negatively affect indigenous species—both as potential predators of prey animals and as competitors of other carnivores. However, because pariah dogs rely mostly on human waste as food, it is less likely that these dogs act as exploitative competitors and hunt for the same prey as lions or cheetahs. Their presence may instead make them interference competitors to some species living in the wild, such as jackals, badgers, and smaller cats, by harassing them or disrupting their hunts.

The Dog: A Natural History
By Ádám Miklósi

As one of the oldest domesticated species, selectively bred over millennia to possess specific behaviors and physical characteristics, the dog enjoys a unique relationship with humans. More than any other animal, dogs are attuned to human behavior and emotions, and accordingly play a range of roles in society, from police and military work to sensory and emotional support. Selective breeding has led to the development of more than three hundred breeds that, despite vast differences, still belong to a single species, Canis familiaris.

The Dog is an accessible, richly illustrated, and comprehensive introduction to the fascinating natural history and scientific understanding of this beloved species. Ádám Miklósi, a leading authority on dogs, provides an appealing overview of dogs’ evolution and ecology; anatomy and biology; behavior and society; sensing, thinking, and personality; and connections to humans.

Illustrated with some 250 color photographs, The Dog begins with an introductory overview followed by an exploration of the dog’s prehistoric origins, including current research about where and when canine domestication first began. The book proceeds to examine dogs’ biology and behavior, paying particular attention to the physiological and psychological aspects of the ways dogs see, hear, and smell, and how they communicate with other dogs and with humans. The book also describes how dogs learn about their physical and social environments and the ways they form attachments to humans. The book ends with a section showcasing a select number of dog breeds to illustrate their amazing physical variety.

Beautifully designed and filled with surprising facts and insights, this book will delight anyone who loves dogs and wants to understand them better.

Amazing Arachnids: Orb Weavers

Adapted from pages 184-186 of Amazing Arachnids:

A delight to the eye and an engineering marvel, the orb web epitomizes the stereotypical spider web. It is built in a vertical plane, with strong, nonsticky silk radiating out from a central hub like the spokes of a wheel, supporting a spiral of evenly spaced sticky silk threads. A gap in the sticky silk near the hub allows the orb weaver to rapidly climb from one side of the web to the other, depending on which side of the web a flying insect has blundered into. Some orb weavers wait in the center of the web, legs stretched out in contact with the radiating silk lines that convey the vibrations of a struggling insect. Others build a little retreat at one side of the web, maintaining contact with the radiating lines via a signal thread leading to the hub. Lying in wait in the retreat, the spider rests with one leg touching the signal line. At the first indication that an insect has been caught, the spider moves into the web and tugs at the radial lines, testing to see the general location of the prey. It then uses the nonsticky radial lines as a quick pathway leading to the insect. Once the prey is reached, the spider uses large amounts of silk to wrap and immobilize it prior to settling in for the meal.

Many orb weavers build a fresh web every night and eat the silk by the next morning. Experiments with radioactive labeling have shown that spiders are the ultimate recyclers; up to 90 percent of the old silk is recycled into the new web, and such ingestion and reuse of the silk protein can occur in as little as 30 minutes. The spiral silk of the orb weavers owes its stickiness to the addition of little beads of viscous glue along its length, like the beads of a necklace. Neither the radial threads nor the hub threads have this glue, allowing the spider easy and rapid access to all parts of its web.

An orb weaver spider

Surreal in color and form, the spiny orb weaver, Gasteracantha cancriformis, builds its web in trees and other tall
vegetation. This genus occurs primarily in the tropics; however, this particular species is also found across the
southernmost states in North America.

Some orb weavers build a web that remains in place for more than one day. Among these diurnal spiders are some that incorporate a special structure into the web, called the stabilamentum. The stabilamentum is composed of a thicker kind of silk, frequently appearing as a conspicuous white area in the web. It may look like a lace doily, or like one or more heavy zigzags in the web. Another type of stabilamentum consists of a line of silk above and below the resting spot in the hub of the web. The empty husks of insect prey are attached to this line, forming irregular clumps of detritus. Sitting motionless in the open spot in the middle of this detritus, the orb weaver Cyclosa appears to be just one more clump of debris in the stabilamentum. Camouflage protects the spider against predation by birds. Yet a different type of protection from birds may be derived from the presence of stabilamenta.

Orb weavers are more flexible in their ability to react to different circumstances than one might imagine. They build larger webs when they are hungry or if they are in areas of low prey availability than when they are well fed or in areas of high prey availability. Both web design and the timing of its construction are synchronized with the type of prey and its availability, requiring the adjustment of the spider’s circadian rhythm. In addition, orb weavers modify their approach to different types of prey in the web depending on whether the prey is potentially dangerous or not. They seem to know what kind of prey has been captured (perhaps based on the vibrations transmitted from its struggles) even before the spider physically makes contact with the prey. Some undesirable prey, such as stinging insects, are deliberately cut loose and released from the web. Other prey, like stink bugs, may be carefully wrapped so as to avoid eliciting a release of defensive chemicals until the killing bite can be administered in safety.

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Bird Fact Friday — Flamingos

Adapted from page 116 of Birds of Chile:

Flamingos are unmistakable, social wading birds. They are often associated with hot climates, but 3 species breed in the North Andes, where lakes often freeze at night. Juveniles are typically dirty whitish and brownish, with dark streaking. 1st-years are whitish overall with little pink, but attain fully pink adult plumage in 2–3 years. Within mixed-species flocks, each species tends to group together. They nest colonially in remote areas, building raised mud cup nests on ground.

An adult Chilean flamingo.

More specifically, the Chilean Flamingo is widespread throughout the country, but fairly common in the North Andes, south of Atacama. They wade in shallow, saline lakes, with non-breeders also at fresh lakes, sheltered inshore waters. Their calls suggest geese, and is made while in flight,  sounding like a honking 3-syllable ah ah-ah. The first note is quieter, last note more emphatic. Feeding birds typically give quieter bleating and honking calls. While immature Chilean flamingos soon develop pale eyes, adults are distinctive: they are pale pink with reddish-pink bustle, have red ‘knees’ on grayish legs, and pale eyes. First years are appreciably smaller than adults. 

To see what an juvenile flamingo looks like, head to our Instagram.

Birds of Chile
A Photo Guide
By Steve N. G. Howell & Fabrice Schmitt

This is the first modern-style photographic field guide to the birds of Chile, an increasingly popular destination with birders and naturalists. Compact and easy to carry, pack, and use, Birds of Chile is ideal for curious naturalists and experienced birders alike, providing everything anyone needs to identify the birds they see. Clear photographs and brief, facing-page species accounts highlight what to look for and how to quickly identify species. The photos include both close-ups and birds-in-habitat images to further aid real-life identification. An introduction and maps provide an overview of Chile’s geographic regions and their distinctive birdlife. Birds of Chile is also a great resource for birding in nearby countries, especially Argentina, Bolivia, and Peru.

  • The first field-friendly photographic guide to the birds of Chile
  • More than 1,000 real-life photos and brief, facing-page text make bird identification easy
  • Overview and maps describe the distinct bird regions of Chile
  • Perfect for curious naturalists and experienced birders alike
  • Compact and easy to carry and pack
  • Also a great resource for birding in Argentina, Bolivia, and Peru

The Dog Days of Summer: How Dogs Develop

All summer long, Princeton Nature wants to celebrate man’s best friend. With our new blog series, we’ll be sharing some of the most interesting facts about dogs, as found in Ádám Miklósi’s The Dog: A Natural History.

Adapted from pages 84-85 of the text:

Dog puppies are born blind and deaf; they are not able to walk, can barely crawl, and do not survive without their mother’s care. In the subsequent weeks and months, they grow rapidly in size and develop the abilities and skills they need as adults. The size of newborn puppies differs depending on the size of the breed, so the duration of the physical development of dog puppies varies greatly, depending on the size the dog reaches as an adult. For very small dogs it may take approximately 6 months to reach their adult size, while for giant breeds it may take 18 months. There are also differences in the timing of development between breeds, with some skills and behaviors emerging much sooner in some breeds than in others.

A corgi and pups cuddling. Photo credit: Grigorita Ko, Shutterstock

From birth to death canines undergo a series of changes in their physical, ecological, and social environment. For example, a few weeks after birth, from the safety of the small and confined space of the litter, puppies are gradually exposed to richer and more stimulating surroundings. Puppies learn to recognize individuals, to form affiliative relationships with some, and to avoid others. Dogs’ social environment is particularly rich and complex because it includes not only conspecifics but also members of another species: humans.

It is well known that early experiences can greatly affect the later behavior of dogs. In some early experiments researchers deprived dog puppies at various ages of human contact. Dogs that had never experienced humans during their early development showed marked avoidance toward them, and this behavior could not be alleviated by subsequent socialization. This explains why many feral dogs that do not spend time with humans as puppies keep avoiding people later in life. However, dogs are special because even a very little social exposure, up to a few hours per day, may develop their preference for humans.

During sensitive periods the puppy is exceptionally quick to learn about particular stimuli in its environment. The experience gained during this period is thought to have a great impact on future behavior. If the dog misses specific inputs, it may develop behavior malformations. Lack of experience with other dogs may lead to inappropriate behavior, including fear or aggression when encountering a conspecific.

The Dog: A Natural History
By Ádám Miklósi

As one of the oldest domesticated species, selectively bred over millennia to possess specific behaviors and physical characteristics, the dog enjoys a unique relationship with humans. More than any other animal, dogs are attuned to human behavior and emotions, and accordingly play a range of roles in society, from police and military work to sensory and emotional support. Selective breeding has led to the development of more than three hundred breeds that, despite vast differences, still belong to a single species, Canis familiaris.

The Dog is an accessible, richly illustrated, and comprehensive introduction to the fascinating natural history and scientific understanding of this beloved species. Ádám Miklósi, a leading authority on dogs, provides an appealing overview of dogs’ evolution and ecology; anatomy and biology; behavior and society; sensing, thinking, and personality; and connections to humans.

Illustrated with some 250 color photographs, The Dog begins with an introductory overview followed by an exploration of the dog’s prehistoric origins, including current research about where and when canine domestication first began. The book proceeds to examine dogs’ biology and behavior, paying particular attention to the physiological and psychological aspects of the ways dogs see, hear, and smell, and how they communicate with other dogs and with humans. The book also describes how dogs learn about their physical and social environments and the ways they form attachments to humans. The book ends with a section showcasing a select number of dog breeds to illustrate their amazing physical variety.

Beautifully designed and filled with surprising facts and insights, this book will delight anyone who loves dogs and wants to understand them better.