A female treecat

Treecat was the common name of the native sentient species of the planet Sphinx in the Manticore System. They were often referred to by the shortened version, 'cats, and referred to themselves as The People.

A male treecat


Despite the name treecat, some considered the species to more closely resemble members of the Terran weasel group Mustelidae. Since they had prehensile tails and were larger than Terran weasels, they were also roughly comparable to Terran bearcats in that respect and in size, though they were much more intelligent. Most considered treecat heads to be strikingly similar to those of Earth domesticated felines. There was no connection whatever with any of these. The name "treecat" was chosen by the first human to discover their existence (as well as the first person adopted by a 'cat), Stephanie Harrington, and it remained the common name for several hundred T-years.

Treecats' body length was commonly around 60 centimeters, not including tail (usually about the same length). Larger specimens grew to over 70 centimeters, though. The tail usually doubled the overall body length. Typical adult males weighed about 9-10kg (or 20-22 lbs); adult females were somewhat smaller weighing 8-9kg (17-20lbs). Males were usually cream and gray with faint stripes (rings) on the tail whose number correlate with age in Sphinx years, minus five years; females were typically dappled brown and white, without stripes. With age, fur lost pigmentation and became more gray in both sexes. Treecats were hexapedal, having six limbs with hand-like paws, with three fingers and an opposable thumb on each hand-paw. The front two pairs of limbs could both be used as hands. The paws were formidably armed with retractile centimeter-long claws on all paws (used for tree climbing, hunting, and attack and defense). The claws were notable in not being merely curved and pointed 'fingernails', but rather, curved, pointed, and much broader at the base than Terran feline claws. They were extremely sharp along the inside edge, and could thus not only pierce, but slice/shred as well. They were mineral based, more like teeth than like horn or nail in Terran animal claws or nails.

Treecats had long curved teeth, mostly concealed when the mouth was closed.

The tails were similar in function to those of some Terran monkeys, being prehensile, and functioning as an additional grasping limb. The tail was used to grip onto branches, leaving all three sets of hand-paws free. And, like several Terran animals (e.g. felines, some primates, and some monkeys), the tails served as a balance mechanism when moving. Unlike Terran animal tails it was not round, but actually very broad and flat, with no hair on the leathery underside. When not being used to grab something or balance, the tail was rolled up lengthwise such that the hairy side was outward, in a furry "tube" which appeared much as a Terran cat's tail would. When sitting, the tubular tails were often wrapped around the feet and, when sleeping, wrapped around the body, both much in the manner of Terran cats.

Like many Terran furred animals, treecats grew and shed fur in response to climate change. The shedding/growing mechanism was not triggered by seasonal indicators, but changes in ambient temperature. The fur was thick, soft, three layered, and nearly friction-less, required insulation for anything to survive the intense and prolonged Sphinx winters without freezing in the absence of industrial technology. It thinned out as the weather grew warmer losing the middle layer and a thinning of the inner layer, but if there is an extreme change in temperature a Treecat will shed both the middle and inner layers. Treecats shed when it was warm, and were in this sense "high maintenance" in some situations when living with humans. Treecats would also use their shed fur in bases for their weaving and for insulating their nests.

The equivalent of a war cry, or attack / threat warning, resembled a "ripping canvas" noise and could be quite loud. It was used only when about to fight in lethal earnest. Hissing, and a rumbling snarling growl, were used as imminent warnings. They also made a noise similar to a purr when contented, and when treecats are worried about their humans due to injury or sickness their purring has been known to vibrate furniture. They make a shriek when traumatically injured, and several sounds (including bleeks, chirps, chitters, and croons) which variously conveyed (among other things) amusement, contentment, excitement, laughter, and derision—if not sarcasm, to other treecats and to humans as well. They also flicked their ears, tilted their heads, "flirted" their tails, and yawned—all of which are also communication signals and generally understandable by humans.

Their vocal cords were ill-suited to anything resembling human speech, which was not a serious handicap in treecat society given their telepathic abilities.

Treecats will reach maturity at about 8 Sphinx years of age (42 T-year) and reach full maturity at age 10 Sphinx years of age (52.5 T-years).


In their native environment young treecats will often form temporary relationships, but mature treecats are monogamous and mate for life. Unmated treecats are relatively infertile but mated pairs are not. Treecats are sexually active year-round and have no seasonal mating periods or fertility cycles. Treecats have multiple births usally resulting in a litter of three to seven treekittens with four being the most common. Female treecats remain fertile for 150 T-years after reaching maturity and average a pregnancy every eight to ten T-years, with the pregnancy lasting 4.5 T-months.[1][2] Treecats who have been adopted will foster the resulting treekittens with their or their mates clan. Military personnel who have been adopted by female treecats will be granted 'maternity leave' that can last from three years to as long as ten years if they are unable to foster the 'kittens. (HH6 , HH7)


Treecats were primarily carnivores,[3] though they required steady access to certain vegetables to stay healthy. All treecats were enthusiastic about the Terran vegetable celery, as they enjoyed the taste. Sphinxian adapted celery had been genetically modified to fix certain trace elements in the Sphinx ecosystem, and provided an unexpected benefit to treecats, who were able to absorb some trace chemicals from it (much better than the closest Sphinxian vegetable, purple thorn) and boost their mental abilities to new intensities. Unfortunately, they are unable to adequately digest Terran vegetables, including celery, and their teeth are unsuited to its fibrous qualities, so eating "too much" celery caused difficulties.

Treecats became the main predator of the rabbit, an earth species that was introduced to the Sphinx biosphere by the human settlers. (HH2)

Psychic abilities[]

Treecats communicated telepathically and were able to "feel" other treecats' and humans' emotions. Among themselves, they were telepathic, capable of the silent equivalent of speech; this was not possible with humans. Likewise, humans could not sense others' emotions in the treecat manner.

Memory singers with special and uncommon mental qualities (including capacious and accurate memories, very powerful mind voices, ...) served as cultural and historical "archives" for each treecat clan, and for the species.


Treecats were empaths who could form a very intense, though limited, bond to humans. This bond, also known as an adoption (of the human by the treecat), was emotionally perceptible in both directions, but did not permit exchange of thoughts, nor use of language, visual or auditory images with extremely rare exceptions, nor any deliberate or unconscious control by the human partner. Humans were, in treecat terms, mind blind, though they had very powerful, if unaware, "mind glows". Treecats were far more capable in the human–treecat bond and could deliberately intervene in the emotional and mental health of their partners and others. They did not, except in the rarest of circumstances, as both their ethos of bonding amongst themselves, and strong inhibitions against interference with the mental processes of others, precluded this, probably as an evolutionary adaptation to social living as telepaths/empaths.

Bonding to a human occurred, rapidly and with little warning on either side; the result is initially startling, if generally welcome, to the human—especially if the human's friends and family were not from Sphinx. The imprinting phase lasted for several minutes and could last as long as 30 minutes. This was demonstrated by the treecat rubbing its muzzle against the adoptee's cheek with the treecat purring and crooning and the human going into a trance-like state. After the pair came out of the trance-like state, it would take several months to as long as a T-year or more for the bond to completely settle out. During this time, and especially in the case of children, the adoptee would carry the treecat everywhere and refuse to put the treecat down. The bond became so close that strong emotions (rage, fear, anguish, etc.) in the human partner could often be detected in the treecat partner's body language and stance. Very strong emotions in the human could even incapacitate a bonded treecat.

It was not possible even for treecats to predict which human can (or would) bond, nor with which treecat; it was still less so for humans, who had detected no differences between those who bonded to treecats and those who did not despite opportunities to do so. It has been speculated that certain genetic manipulations may explain why a large share of the Harrington family and the Manticoran royal family, both of which have been genetically engineered, have been adopted. After some hundreds of years of experiences, shared via the memory singers, treecats had come to understand that some have an urge to find and bond with humans; many had noticed the traits in themselves, though without understanding prior to extended experience with humans. The initial bonding rate was rather less than one human in 1 million, and has decreased with the increase of Sphinx's human population. Humans might be of nearly any age from child to adult when "adopted", though few human children actually were adopted. Bonding treecats had been generally older, as they had not left their home clan's range, and so potentially encounter humans, until mature. The most common age for humans was between 25 and 35 T-years, for treecats it was 9 to 10 Sphinxian years to as late as 13 Sphinxian years. This first changed when Nimitz and Samantha decided to raise their first kittens with humans, and then led a small group to Grayson.

Treecats were both empaths and telepaths with other treecats, and mated pairs form a permanent bond, though it was more complete than with humans since it was both telepathic and empathic, and "properly" supported from both ends. Mature treecats are monogamous; adolescents are somewhat more flexible. The range of the telepathic/empathic contact in both cases (treecat–treecat and human–treecat) was limited to at most a few kilometers, and decreases to mere "awareness" of the other at the extremes.

Bonded treecats stayed physically close to their human as separation (particularly extended separation) beyond contact range was distressing, if temporarily endurable, for both. Separation between mated pairs was also possible but also distressing, and so was similarly rare.

Since there had been no noticeable tendency for bonded humans to join treecat clans high in the picketwood trees, bonding between a human (aside from Sphinx Forestry Service personnel) and a treecat had always involved separation of the treecat partner from his/her clan, and indeed from essentially all treecat society, given the rarity of human bonded treecats. This abandonment of an existing social life was a measure of the intensity of the attraction and of the bond for treecats. Few bonded treecats have mated and produced kittens, which was likely another such indication.

Bonded treecats preferred to ride on their human's shoulder when possible; it had become traditional. Given the size and sharpness of their claws, and the limitations of a human shoulder as a treecat "saddle", this posed problems which were usually solvable by installing armor cloth layers at appropriate locations in the human's clothing.

A human-treecat bond was almost unfailingly permanent in nature, ending only when one partner or the other died. On Sphinx, in their native forests, treecats ordinarily live 250 T-years (traditionally 48 Sphinxian years)[4], barring accident, disease, or other difficulty. The mismatch between typical (pre-prolong) human lifetimes and typical treecat lifetimes ensured that the human partner usually died first, which often had tragic results. Treecats would sometimes return to their clan after the death of their human, or in rare cases would adopt another human. However, the most common result was that the treecat would commit suicide usually by dehydration or starvation. There are only two known treecats to have re-bonded following the death of their partner

Ecological position[]

They were, when in groups, the dominant predator on Sphinx. There were larger predators, such as the related hexapuma (three meters long and ill-tempered), but these resembled Terran lions or tigers, and were much less intelligent than treecats. They were referred to as Death Fangs by treecats. Hexapumas generally learned to be careful around treecats, unless that treecat was alone and catchable on or near ground level; hexapumas were too large to follow treecats more than arm's reach up a tree, Hexapumas who were too bold were generally, and enthusiastically, killed by groups of treecats.

When acting in groups (as in defense of their home territory) nothing on Sphinx was a match for treecats. Treecats were largely immune from predation themselves as they could travel continental distances without descending to the ground using the picketwood trees unique to Sphinx which grew, in part, horizontally and regularly connected with each other, reaching across vast expanses. They thus provided something akin to elevated throughways for treecat-sized tree dwellers.



Treecats referred to themselves as The People. In their native forests, they were organized into territorial clans of up to several hundred or more. Each was centered on its memory singers, who were rarely permitted to leave their home area because they were so important. Otherwise, treecats would not have had a cultural memory, being without physical records like writing or painting). Memories were retained and replayed in great detail by singers and went back several hundred or more T-years with some memory songs going back over one thousand T-years.[5]

Governance of the clans was by Elders, largely chosen for technical ability (like hunting or scouting); memory singers automatically became Elders in their clan.

Young treecats were very active, inquisitive, and exploratory. Raising, training, and teaching them was typically done with the assistance of other adults in the clan. In the case of kittens whose parent(s) were bonded with humans, the usual procedure had long been to foster them within the clan of one of the parents when old enough. In the case of 'kittens living off Sphinx, provisions were needed for such assistance, as humans unfit to adequately substitute and educate them. (HH7)

At the time of their discovery, treecat civilization had not developed advanced technology, but was at or beyond the equivalent of the Terran Stone Age well before humans arrived, being able to control open fire, work stone, make stone and wood tools, weave fibers, make and use cordage (eg, knots, nets, lines, ...), and so on. Being fundamentally organized as territorial hunter-gatherer bands, they had not developed farming when humans colonized Sphinx, although shortly after they developed a rudimentary understanding of farming by observing humans and their gardens.[6]

Trade between clans was of long standing preceding the contact with humans. After that, treecats acquired new tools like metal knives directly from humans, as well as considerable practical knowledge. They also acquired an unsuspected taste for a kind of musical grace note, becoming fans of wind chimes and at least some clans mounted such chimes near their home trees.

Treecats were socially and culturally cautious and have not shown the innovation, restlessness, or recklessness characteristic of humans either individually or collectively. Those few treecats who have been innovative are especially important, particularly since contact with humans. (HH1)


See Treecat Language.


Treecat names have been long unknown to humans, as have the names treecats use for humans who have bonded. With advent of treecat sign language, treecat names have been revealed to be descriptors of the treecat's personality or traits eg Seeker of Dreams and Stone Biter, which will often change several times over the course of a treecat's life. Human names were given to treecats by their humans when they bonded, with the act acquiring considerable significance to both treecats and their humans. The human names given by Honor Harrington to unbonded treecats illustrated both her keen interest in naval history (including ancient 'wet navy' history) and knowledge of ancient Greek mythology, her attempt to take into account their individual personalities, and an attempt to keep several treecats in the same space straight, humans being without any ability to directly perceive personality. (HH7) , (HH9)


To an adopted human, and generally to anyone more than marginally perceptive who spends time in contact with a treecat, it became rapidly apparent that treecats had definite personalities. Those who meet more than one usually realized that they have distinct personalities as well. They were not pets in any sense of the word, even with respect to an adopted/bonded human. Problems resulted when humans made the unfortunate inference that they are pets or are identical, and there have been a few, very rare, instances of adoptions which have failed due to the human partner coming to treat the treecat as a pet/possession. Until a bonded treecat learned enough about human society to "fit in", there could be difficulties as well for this reason. As they were rapid learners, and since they had a direct connection to the emotions of all humans within range, and a particularly close bond with their adopted human, nearly all treecats adapted to necessary aspects of human society (e.g., machinery dangers, doors and door locks, toilet conventions, etc) rather quickly. Treecats usually retained a bemused, if not incredulously baffled, attitude toward many human activities and practices, and put up with them largely for the sake of their adopted human, or for treecat-human relations generally, if not adopted.

Table manners were an example. Basic treecat table manners are suited to forest life in trees. They could become more than acceptable, by human standards, for human environments, even quite formal ones; more because they realize it matters to humans, especially their own human, than because they saw much point in the whole business. A particular problem was that treecat teeth were not suited to coping at all well with fibrous foods such as celery, nor were their digestive arrangements well suited to such foods. Their devotion to celery was such, however, that their humans, and others, were rarely able to resist supplying them, despite their difficulties.

In general, their manners in human society were excellent, though absurd humans, and human absurdity, could sometimes provoke "violations" which were perhaps best understood as mild revenge or practical joke, though this might not be apparent to the "victim", who was likely to be somewhat thick to have evoked such a response. Almost never had any treecat committed an actual faux pas, much less a crime in human terms. Being able to sense emotions provided considerable immunity to such errors, though not from fixed and inaccurate expectations held by some humans.

History and relation with humans[]

The treecats evolved on Sphinx as an arboreal species long before the colonization of the surrounding sector of space by humans.

They made a planet-wide decision to stay hidden when human settlers arrived on their planet. Memory singers preserved the scouts' observations of the first human pathfinders, including the killing of an attacking hexapuma with "one loud noise" from a stick at a considerable distance.[7]

This revelation of human capacities suggested reticence both then and again several hundred years later, when humans returned, this time to stay. The treecats managed to remain entirely unsuspected by humans for several T-decades during which human settlements were established across their planet, until the bonding possibilities between humans and treecats were accidentally discovered, as an indirect result of the newly noticed, and inexplicable, low level disappearance of celery from gardens and greenhouses throughout Sphinx, that was eventually discovered to be due to treecat raiders.

Stephanie Harrington and Lionheart

In 1519 PD, the first bonding between a treecat and a human took place on Sphinx: Stephanie Harrington 'caught' the treecat Climbs Quickly as it was stealing celery from the Harrington greenhouse and later defended it against a hexapuma. (HHA1.1: ABF)

Lionheart defends Stephanie from a Hexapuma

Treecats were generally friendly towards humans, all of whom had a very strong "mind glow" for almost all treecats. They were universally enthusiastic about human children — their "mind taste" being particularly attractive, clear and direct. Adult treecats were excellent playmates for older children, being tough, fast, playful, and capable of sensing malicious intent. They were especially good attendants for infants.

In the late 17th Century PD, the Royal Manticoran Navy, on the initiative of Queen Adrienne, allowed bonded treecats on board RMN vessels, when their bondmates are assigned to the vessel. (HH1)

Even thereafter, their intelligence level and social arrangements remained deliberately and intentionally obscured, as the result of another explicit planet-wide choice which remained effective for several hundred T-years despite many bondings throughout that period, and despite many humans' attempts to study the treecats. Their cooperation with intelligence measurements and attempts to teach sign language on at least two occasions, was deliberately obstructive. Adopted humans were of equally little help, since they were universally reluctant to convey to others what they had learned, or suspected, about their companions. They were officially rated 0.83 on the sentience scale, even using primitive tools like axes and fishing nets and were thought to be slightly more intelligent and mentally capable than Beowulf's gremlins or perhaps Earth's dolphins (HHA1.1: ABF). They were the twelfth—and physically smallest—intelligent species known to humans.

Nimitz, founder of the first off-world colony

This combination kept treecats and their abilities veiled for a very long time. On the treecats' side, this strategy was proposed by Sings Truly of the Bright Water Clan, sister to Lionheart, the first treecat to bond to a human. A new policy supplanted this only with Samantha and Nimitz' decision to raise their 'kittens on Grayson with Honor Harrington's assistance.

With the coming of war between the People's Republic of Haven and the Star Kingdom of Manticore, treecats became aware that Sphinx might experience a disaster to the detriment of their entire race. Innate conservatism made the implications of this fact less apparent, and it was only when Samantha and Nimitz' kittens were born that a treecat posed it seriously. The issue was raised in the Bright Water Clan, and after some discussion, a decision was made to use Steadholder Harrington's good offices to establish a small and experimental colony off Sphinx.

When a group of adult treecats arrived unheralded at the Harrington homestead on Sphinx and made clear they would be leaving Sphinx with Nimitz and Steadholder Harrington, both the Sphinx Forestry Commission and the Admiralty officially disapproved of the departure of any treecat, except Nimitz, to Grayson, especially not for any long term stay. However, no treecat saw a problem – including those bonded with two of the SFS Rangers sent to protect the non-bonded treecats from some sort of obscure exploitation by Harrington – and they made their lack of concern plain. The Admiralty was less easy to convince than the Forestry Commission, and Harrington had to provide transport for them to Grayson.[8] (HH7)

In 1914-5 PD treecats were taught sign language by Dr Adelina Arif, which was publicly demonstrated for the first time at Bay House to Queen Elizabeth III Winton.

In February 1922 PD, as a result of an attack on the Manticore System by the Mesan Alignment, Sphinx was struck by several pieces of debris from the space station Vulcan. This resulted in the near annihilation of Black Rock Clan, killing approximately 8700 treecats, or roughly 725 per mil of the entire population of roughly twelve million.[9] (HH12)

In June 1922 PD, Sorrow Singer the only survivor of Black Rock Clan turned up at the Bright Water Clan central nest. She would later propose that treecats help protect their human friends from the Mesan Alignment's Nano-Virus assassination method. This was a de facto declaration of war by the treecats. (HH13)

Most famous treecats[]

See here for a list of treecats who have become notable for one reason or another.

Note Fan Art that was once here moved to http://honorverse.wikia.com/wiki/Honorverse:Fan_Art?&cb=8875


  1. Speculation on length of pregnancy due to time line stated in referenced books
  2. A single mated pair will produce between 45 and 95 'kittens
  3. Primary prey was Tree Hoppers, Ground Runners, Lake Builders and Chipmunks.
  4. Sphinxian year is equal to 5.22 T-years
  5. The memory song depicts the first human explorers.
  6. Growing vegetables like White Root Golden Ear and Lace Leaf.
  7. That incident occurred before treecats of the time had come to a conclusion about revealing themselves.
  8. Before this group decided to relocate, the only other adult treecat unbonded to a human ever to leave Sphinx was Richtmann's captured 'cat.
  9. One member of the Black Rock Clan turned up a short while later with the Moonlight Dancing Clan.