Field Notes: Familiar Faces and New Kids on the BlockMar 10, 2016
Goshawk courtship is underway. Some well-known breeding pairs have disappeared or moved elsewhere. The reason may be that one of the mates died (we suggest that illegal persecution is again an issue in Berlin!), because of disturbance or because the nest came down during winter. On the other side, new, formerly vacant places are now occupied by goshawk pairs performing courtship display. In such cases, often one, or both partners are in their second year, thus breeding for the first time. This clearly indicates that the goshawk population is subject of highly dynamic demographic processes. Colonization of new breeding places also shows that the Berlin goshawk population is still growing and does not yet acquire saturation.
Field Notes: Eagle Owl in the Havel River Valley, NE GermanyMar 08, 2016
I confess, I have been remiss updating my blog regularly in the past year. Honestly, I make a vow to nourish and cherish it on a regular schedule from now on! Here is a short note on the successful reproduction of the Eagle Owl (Bubo bubo) in 2015 in the lower Havel River valley after almost one century of absence. The female shown above raised three chicks in a nest of the Red Kite (Milvus milvus) which the latter has built in the previous year. Following an all-time low in the twentieth century (principally due to human persecution) Eagle Owls currently expand their range and rapidly gain lost territory. Eagle Owl is a top predator even of other raptors as is indicated by the remains of Black and Red Kites and Common Buzzards found below the nest tree (both, fledglings and adults). Soon after the young eagle owls have fledged, the nest came down during a summer storm. Actually, the hooting calls of the Eagle Owl can be heard again in calm nights.
Tracks and Signs: Goshawk KillMar 07, 2016
The picture above shows a Eurasian Coot (Fulica atra) killed and partly eaten by a male goshawk. The bird has been killed in a nearby park and subsequently transported to the nest site. Here it has been partly plucked on the ground and partly eaten. It is a rather untypical example of a goshawk kill. In Berlin, coots do not belong to the typical goshawks prey since they show an explicit preference for Feral pigeons. Second, male goshawks normally completely pluck their prey and start with eating the head (i. e., the brain, which contains lots of nutrients). Here the bird started with the meat of the breast, a strategy more typical for Peregrine falcons. I found this coot on a track of a little used cemetery. I suppose the goshawk has been disturbed and would return later to finish its meal.
Shooting Damselflies with the Canon EF 70-200mm f/2.8 LensFeb 23, 2016
Although the Canon 70-200mm F/2.8 is not a macro lens, close-up photography, at least in some sense, is possible. Last summer, I was photographing damselflies at the Müritz Nationalpark in northeast Germany. First, I tried the EF 100mm F.2.8 macro. However, much to often the minor working distance of this lens scared the object of desire away. The solution would be a longer lens. Since I do not possess the Canon EF 180mm f/3.5L macro lens, I thought it would be a good idea to try out my EF 70-200mm f/2.8L IS II lens. Additionally, I used a 25mm extension tube and a polarizer. It was a bright, sunny say, so I relinquished using flash. I stopped down to f7 and activated the image stabilizer. Some of the results (fairly sufficient) can be seen above. The species is the Banded Demoiselle (Calopteryx splendens), a rather common damselfly found at rivers and creeks.
The Bruno Affair and the Slaughter of Large Carnivores by U.S. Government AgenciesFeb 18, 2016
The first brown bear (JJ1, also known as “Bruno”) returning to the German Alps in 2006 was soon after assassinated by hired hunters. American diplomats mailed to their superiors back home about the so-called "Bruno affair" (leaked by WikiLeaks):
“Perhaps the greatest insight from the whole Bruno affair might be that despite the veneer of "greenness" extolled by German society, modern Germany in fact coexists uneasily with untamed nature. (…) True wilderness, even in mountainous Bavaria, hasn't really existed in Germany for generations -- nature is good, as long as it is controlled, channelled, and subdued. If the saga of Bavaria's "Problem Bear" is any indicator, the strategy of reintroducing wild bears to the Alps, at least the German Alps, may be doomed to failure -- that is, unless the bears are willing to cooperate by not being too wild.
This statement is in stark contrast with dealings with large carnivores in the United States:
Allone in 2014, U.S. Fish and Wildlife Services shot, trapped or poisoned 796 bobcats, 322 wolves, 580 black bears, 305 cougars, and 1,186 red foxes
. And that’s nothing compared to coyotes. That year, the agency killed 61,702
, one coyote every eight and a half minutes. The main reason for this killing is toy to defend livestock and revenue-generating game animals like deer, often on public land (source: HCN
A Pallid Harrier (Circus macrourus) in the Havelland MarshesMay 28, 2015
This is just a brief account on the sighting of a Pallid harrier (Circus macourus) which momentarily can be observed in the "Havelländisches Luch" between the villages Buckow and Garlitz next to the country town of Nennhausen. The pallid harrier is the rarest species among the four western Palearctic harriers (i.e., Hen, Montagu’s, Western marsh and Pallid harrier). It is a scarce vagrant in Germany. The pallid harrier’s present breeding range extends from the Ukraine and southern Russia, to north-western China and western Mongolia. Formerly, the breeding range used to be much greater, extending further into Eastern Europe. It winters mainly in sub-Saharan Africa, and from Pakistan, India and Sri Lanka, east to south China.
It is worth mentioning that this bird was first observed on May 14th. It is a second year immature bird with the inner primaries just starting to be replaced. On the base of the yellow iris color and the almost unbanded primaries, this bird can be sexed as a male individual. Comparable to spring 2014, there have been a fair number of records so far of this graceful harrier in Germany.
Migration WeatherMar 23, 2015
After a period of cold northeasterly winds, this weekend the wind calmed down and veered to a southwest direction: Migration weather! Promptly, the ospreys returned from their western african wintering grounds and already occupied their breeding territories. Now they are busy with repairing and overhauling nests from last year’s breeding season or erecting new ones. Red kites are also mating now. The first marsh harriers show up over flood plains and reed beds, whereas wintering hen harriers are still present. Also, the first black kites have been spotted. It’s springtime!
Bird from the North CountryFeb 20, 2015
Field voles are plentiful this winter and so it is surprising that so few hen harriers (Circus cyaneus) are encountered at their traditional wintering sites in northern Germany. Birds from Fennoscandia, the Baltic and Russia are strictly migratory and normally the first birds show up in September at their wintering grounds. There is a peak in October and spring migration lasts from March until May. Hen harriers are solitary hunters but use communal roost, mostly in reed beds. One traditional roost site northeast of Berlin is used for many years together with Merlin falcons.
One explanation for the low number of wintering hen harriers is that there is still enough prey available in the north so that the birds do not feel the need to migrate further south. The other, and more probable explanation is that overall hen harrier numbers are on the decline due to habitat loss and poor reproduction success.
I was lucky to watch and photograph this hunting female last weekend on the Havel river floodplains west of Berlin.
Goshawk Cover StoryJan 05, 2015
The image of a goshawk pair bathed in the warm light of the winter afternoon sun is one of my most frequently published and most widely recognized photographs. It now made it on the cover of the ornithological journal "Der Falke
", Germany's leading birding and field ornithology magazine.
Picture book on the Northern Goshawk now available!Dec 04, 2014
As posted earlier, (see entry from October 20), the Northern goshawk (Accipiter gentilis
) has been chosen as the "Bird of the Year 2015" by Germany’s major nature conservation organization NABU. So I am happy to announce our recently published book on the Northern goshawk, which will be available from now on (and not a moment too soon before christmas!) at bookstores, Amazon.de etc.. Copies can also be ordered directly from the publisher
. Our book is a picture book comprising 144 pages and about 100 full-sized photographs of the private life of goshawks. Topics covered by text and photographs include courtship, breeding biology, hunting behavior, banding, falconry, and mortality (including illegal persecution), among others.Lutz Artmann, Norbert Kenntner, Christian Neumann & Stefan Schlegl: Der Habicht. Vom Waldjäger zum Stadtbewohner
Oertel + Spörer Verlag 2015, 144 pp. ISBN: 978-3-88627-899-2
Price: 24,90 Euro
Flying SquirrelsDec 04, 2014
This fall, I spent some afternoons photographing Red squirrels (Sciurus vulgaris). My intention was to catch them in action. So I lured them with a handful of hazlenuts and prepared for shooting from a low angle with my 70-200 mm/f 2.8 lens. The autofocus did a pretty good job although the failure rate at such a close distance is still immense.
Sunset StarlingsOct 30, 2014
Not much to report currently. I shot this beautiful scene of Eurasian starlings ( Sturnus vulgaris) flying to their roost two weeks ago at Gülper See, (Brandenburg/Germany) with a 600 mm / f 4.0 and a mounted 2x extender at ISO 5000.
Goshawk is Bird of the Year 2015Oct 20, 2014
The goshawk (Accipiter gentilis) has been elected as the "Bird of the Year" 2015 by the NABU (Naturschutzbund Deuitschland), Germany's largest nature conservation organization, and its Bavarian sister organization LBV (Landesverband Vogelschutz). Although there are some prospering urban populations , this species is still on the decline in rural areas, due to illegal persecution.
Dogfight!Oct 09, 2014
In late summer and fall, when the young goshawks are fully fledged, one can frequently observe spectacular dogfights among goshawks and hooded crows. Such fights do also occur among crows and kestrels, but these have a rather sportive and fun character. Goshawks, however, are hooded crow's most deadly enemies and there is a profound hatred of goshawks. Young goshawks have a significant lack of hunting experience and so, one can observe goshawks chasing crows and vice versa, crows (once the whole bunch is alarmed) chasing the goshawk. The goshawk, almost ever, will turn tail and run. You can be sure, that adult goshawks won’t think twice and make short shrift of a hooded crow!
Red-Footed Falcon Irruption UpdateSep 11, 2014
This is a short update of the current red-footed falcon irruption: As the map (taken from ornitho.de) shows, the most records of this fall are from southeast Brandenburg and northern Saxony. There is another isolated cluster in central Lower Saxony. Only few birds have been recorded from the other German countries, most of these are from Bavaria and Thuringia. Although there was a break in the weather with an incoming low pressure area on Monday, a flock of 25 red-footed falcons has been discovered in the Spreewald swamps (Brandenburg) two days ago. In the Berlin city limits, 2 to 4 birds were still present this morning.
Red-Footed Falcon Irruption!Sep 09, 2014
Red-footed Falcons everywhere! The Red-footed falcon (Falco vespertinus) is a small falcon breeding in the steppe area of central Asia and Eastern Europe. In the west, the breeding distribution reaches into the Pannonian Basin (Hungary). Red-footed falcons are strictly migratory, wintering in Africa south of the tropics. During fall migration, vagrant birds, especially juveniles, regularly show up far west of their normal migratory routes. This phenomenon is supported by easterly or southeasterly winds and warm temperatures. This was exactly the case during the last couple of days and so, a flock of 10 Red-Footed falcons was discovered last weekend just at the southern city limits of Berlin. Although knocked out by a serve cold, I could not resist to grab my photo gear and to try my luck. The first picture shows a juvenile bird, the second one shows a flock of four Red-footed falcons (the bird in the top center is an adult female) mobbing a kestrel (the bird on the top right). The third picture shows a juvenile Red-footed falcon snatching an insect. Flying insects (dragonflies, mayflies, caddisflies and such) play an important role in the diet of Red-footed falcons and they are acrobatically hunted in flight and digested on the wing.
Yesterday, a sleeping roost of 22 birds was reported from the banks of the Oder River, just south of Frankfurt and single or small groups of falcons are currently reported from all over the country.
Poor Goshawk Breeding Success in Berlin Jul 10, 2014
2014 was not a good breeding season for Berlin's goshawk population. For unknown reasons, many pairs did not breed and others had little success, raising one or two instead of three or four hatchlings. Moreover, in many well-known breeding pairs, one of the adult and experienced partners was replaced by a young (2nd year) bird which bred for the first time. Why are so many adult goshawks missing? Is this a hint to human persecution? For the moment, we don't know. However, the goshawk pair in my neighborhood was successful, raising two hatchlings as usual.
The pictures above show the two siblings waiting to be fed by their parents, and one of the birds stretching. In the lowermost picture, the color band of the actual banding programme is visible.
The Apical Region of the Mediterranean Heart-Urchin Echinocardium fenauxi Pequignat, 1963Jun 26, 2014
This is a close-up view (1x2 mm) of the apical region of the heart urchin Echinocardium fenauxi, a sea urchin of the order Spatangoida. This species is to be found in parts of the Mediterranean, where it is endemic. Prior to photography, the test has been denuded from spines and cleaned with hydrogen peroxide to reveal the delicate surface details. In the center of the image, the apical disk with the madreporite (sieve plate) and the four genital pores are visible. Above, two straight rows of ambulacral pores belonging to the frontal ambulacrum reach for the margin of the frame. Here, and in contrast to the otherwise similar and much commoner species Echinocardium cordatum, the pores are arranged in regular lines, whereas in the latter species, the pores are alternating in an irregular manner. The ambulacral rows of pores are guarded by enlarged tubercles which supported specialized spines. Since E. fenauxi is a species burrowing deep into fine to medium sandy substrates, the spines had the function of forming a protective arc over the ambulacral furrow to prevent sand grains blocking the respiratory tube feet and the ciliated mucus band transporting nutrients to the mouth. The apical disk and the frontal ambulacrum are bounded by a fasciole. In the case of this species it is an internal fasciole, a diagnostic feature of the Echinocardiid family. Fascioles are bands of milliary ciliated spines creating water currents for the animal’s respiration and waste disposal. In the lower corners of the image, parts of the paired ambulacra with their large respiratory pores can be seen.
This picture is an excellent example that high quality imaging complying with scientific standards can be carried out with low-budget equipment. This photograph has been taken with my Nikon Coolpix 4500 workhorse and a mounted Nikon SL-1 ring light. This old-time 4mp compact digicam went on sale in July 2002 and is still available from Ebay. Its excellent depth of field and close-up proficiencies still make it my first choice for scientific imaging.
A Black-Browed Albatross at HeligolandJun 06, 2014
The Black-browed Albatross (Thalassarche melanophris) is a pelagic bird of the southern oceans which breeds on the subantarctic islands between South America to New Zealand. Its normal northern range is in the Humboldt Current to Peru and in the Atlantic to southern Brazil. Occasionally birds show up in the northern hemisphere. So did an adult Black-browed Albatross which was first noticed at Skagen (Denmark) on the morning of May 27th. Later that day the bird was seen from a vessel off the Swedish coast. On next morning (cloudy and windy) the bird was first seen on the roadstead between Heligoland main island and the Heligoland dune, heading north. It came around briefly later that day and the next morning, only seen by few excited birders. Later on May 29th, the sky had cleared and the wind declined, the bird pleased numerous birders gathering at the “Lange Anna” (a famous sandstone pinnacle), by flying several circuits just over their heads, before it flew off and was not seen any more for the next couple of days. It returned to the island on June 4th and was also seen the following day.
There are about 30 records in Western Europe including birds building nests in Northern Gannet colonies and returning for many years. According to Howell (2012), summer records on the northern Hemisphere mirror the species’ higher-latitude summer distribution and lower-latitude winter distribution in the southern hemisphere. This is the first species record for Heligoland and the second for Germany.
Note: Heligoland is a small German archipelago in the North Sea, located 46 kilometers off the German coastline. It consists of two islands: The main island and the “dune”. What Cape May is for American birders and the Isles of Scilly for the British, is Heligoland for the German Birding community.
Mating GoshawksMar 21, 2014
After some hard- and software problems (solved), I loaded up a number of goshawk images of this years‘ courtship/breeding season. Among these is a sequence of a mating goshawk pair. Three images are shown here. The female is a second year immature, breeding for the first time in her life. The male is adult, but suffers from a lesion of the left eye. The complete sequence and many more new images can be viewed in the Birds of Prey gallery.
Tracks and Signs: Kingfisher PelletsFeb 28, 2014
As many other birds do, kingfishers (Alcedo atthis) regurgitate pellets consisting of indigestible remains of their diet. Since kingfishers are specialized fish predators, these remains consist of fish bones and scales. Surprisingly, no figures are available from literature, at least not from popular field guides such as Mark Elbroch’ s amazing “Bird Tracks and Signs” and Preben Bang’s “Animal Tracks and Signs”.
So now, here it is: Underneath a favored kingfisher perch I found an accumulation of numerous pellets of different ages. They are elongate, cylindrical with rounded, blunt rather than pointed ends. They measure approximately 20 mm in length and are up to 10 mm thick. The colour is whitish. Since the pellets are not covered with mucus, they decay rapidly, as illustrated by the third image of an aged pellet.
This is the first contribution of a series dedicated to animal tracks and signs
Shooting the CurlJan 23, 2014
I love waves. The raw power and pure energy fascinates me. I can spend hours and hours watching a big swell approaching the shore, generated and driven by storms somewhere out in the open ocean. Early morning or evening light and a fresh offshore breeze blowing the spray over the wave crests generate stark images of nature’s powerful beauty. The west coast of Fuerteventura (Canary Islands) is a wonderful and easy-to-reach place for wave-watchers. You have miles of untouched rugged coastlines, crystal-clear water and often a big swell with a wonderful shorebreak (at least during the winter months). Furthermore, the reliable trade winds blowing from the northeast cause a steep and spectacularly breaking surf. For photography, I mostly used my EOS 7D together with the EF 70-200 mm f/2.8 II and EF 400 mm f/5.6 lenses. Selecting Tv mode with a fast shutter speed (1/2500s), AF on “Ai” plus zonal mode and high speed continuous shooting proved to be the best setting.
Capturing Swifts in Flight – More than Spray and Pray!Jan 10, 2014
Photographing birds in flight is not an easy task. Capturing swifts in flight is a challenge! Swifts are considerably small birds, their flight is erratic and flight speed is incredibly fast. When hunting insects or during courtship display, swifts can reach maximum speeds of 200 km/h (125 mph)! However, achieving sharp images of flying swifts is more than spray and pray. You can increase your chances of success when you are prepared and keep some important things in mind. Here is a short tutorial of how to capture tack sharp images of flying swifts. Of course, it can be applied for other fast flying birds as well.
Locality and lighting: First, you need to find a suitable locality where swifts are commonly passing by. This could be in the vicinity of a breeding colony or at preferred hunting sites. These may be found far away from their breeding places. Since you want the swifts to pass by at eye level, it would be favorable to position yourself on a raised structure. The roof of a large building or a cliff edge will work well. Also keep in mind that during cold or windy weather, swifts prefer to hunt over open water such as lakes and ponds. You also don’t want the swift to occur as a black silhouette against the sky, so lighting is very important. Avoid overcast skies when the birds will appear against a white background. The best light is front lighting. Shooting against the western sky in the morning and against the eastern sky in the evening will work fine. At my experience the best light occurs about one hour after sunrise and one hour before sunset, respectively, when it is bright enough to achieve high shutter speeds. Avoid the dull and harsh light of midday.
Lens and camera choice: Swifts are small birds, about the equal size of a sparrow, so a long lens is a must. I tested the Canon EF 70-200mm /f2.8 L USM II (with and without the 1.4 x extender), the EF 300mm /f2.8 L USM and the EF 400mm /f5.6 L. The 70-200mm lens does not match the focal length you will need and the 300mm /f2.8 is a heavy weight. You need to shoot free-handed over a considerable time span and this lens will soon lead to muscle fatigue (unless you are not a trained U.S marine!). So the light-weight and handy EF 400mm /f5.6 lens is my favorite choice. Your camera body should possess a good and fast autofocus, a high burst rate (about 8fps or more) and a sufficient ISO/noise performance. I am mostly shooting with Canon’s EOS 7D which is an sufficient camera for this purpose. Moreover, its sensor–related cropping factor adds a subjective 1.6x of focal length.
Camera settings: High shutter speed is the name of the game. Everything faster than 1/1600s will do, but I prefer higher shutter speeds such as 1/2500s. Set your camera on Tv mode and select shutter speed. If you start shooting after sunrise, subsequently adjust shutter speed when daylight continues to improve. Select ISO “auto”. Shooting against a bright sky requires exposure compensation of + 1 to 1 ½ f-stops. If your lens or camera possesses an image stabilizer (IS), deactivate it. At the applied shutter speeds IS is not only unnecessary but moreover, the engine processing time makes your camera slower. Set your camera’s shooting mode on “High speed continuous shooting”. Make sure that you have installed the camera’s newest firmware. For example, in the Canon EOS 7D, updating the firmware almost duplicated the camera’s image buffer when shooting at the maximum 8fps, letting you to grab up to 25 RAW images (15 with the 1.0 firmware) before things start to slow down. Select Autofocus mode “AI Servo AF”. Generally I prefer single point AF with the central AF point active. This is the most accurate and fastest AF point available. However, you will see that it is nearly impossible to keep a small and fast flying bird in the center of the viewfinder which furthermore makes unpredictable turns and maneuvers. I therefore achieved much better results selecting “Zone AF” with the central zone activated. This allows 11 sensors (in the EOS 7D) to keep the subject in focus. It is also very useful to set custom function “AI Servo tracking sensitivity” to “Slow”. This keeps the camera from jumping quickly to the background if the sensor falls off the subject momentarily. In my EOS 7D, this is custom function C.Fn III/1. Check out your camera instructions for other cameras/brands.
Shooting strategy: When you are on location with your camera prepared, make sure that the battery is charged (with a second one in your bag) and that you've got enough memory space in your camera (the last point mentioned is not negelectable since shooting numerous bursts will fill up your memory card much faster than you may think!). So you are ready to shoot. Swifts have their activity maximum in the morning hours and in the late afternoon until dawn. These are also the times when they tend to fly low. During the rest of the day, they are hunting actively as well but do so at much higher altitudes. Once you have spotted a flock of swifts or a single bird flying into your direction, select one of them in the viewfinder and try to keep it in the center. It is also important to pre-focus on distant birds. Press the AF button when the bird approaches and track the bird until it is in shooting distance. Shoot a burst while panning the camera. You need to react fast and response quickly. This is a little bit like skeet shooting and a large part of the fun! Do not try to switch to another bird when you lost your target in the viewfinder. Wait for another flock. The rest is practice. I still discard 98 percent of the images, but 2 percent are keepers.
In central Europe, swifts are elusive summer birds arriving in May and leaving in August, so be prepared.
Berlin: Goshawk Capital of the WorldDec 04, 2013
The Goshawk (Accipiter gentilis
) is a magnificent and powerful raptor distributed all over the Palaearctic and parts of North America. Hated and illegally pursued by pigeon breeders and gamekeepers, it remains a timid woodland bird over large parts of its range. Not so in Berlin! The buzzy German capital with its vivid night life, club scene and cultural offerings not only attracts flocks of tourists but also hosts a large and healthy population of the Northern goshawk. Since monitoring started in the 1980s, the population number is constantly growing up to recent > 85 breeding pairs with an estimated number of unknown pairs in Berlin’s large forests. In Berlin, goshawks prefer to breed in parks and cemeteries where they build their large nests in the tops of old trees. Courtship begins in January when the mating calls can be noticed by the wary observer. Egg deposition is generally in March. One to four hatchlings are raised which become full-fledged in July. Berlin’s goshawks mainly feed on domestic pigeons and rats, thus rendering a great job to control these pests.
To learn more about origin, dispersal, longevity and population dynamics of Berlin’s goshawks, a color banding program has been started in 2012. Detailed information (in German) can be found here
Urbanisation of goshawks has occurred also in other large European cities such as Amsterdam, Prague or Cologne, but none of these cities can claim to host such a large breeding population. The main reason of this phenomenon might be the constant availability of prey all year round plus the security from human prosecution. Many birds even became accustomed to the presence of humans and became very trustful, thus offering great photo opportunities which are difficult to find elsewhere.
The first picture above shows a pair of goshawks during courtship feeding in March. In close vicinity of the nest, the male (left, notice red eyes and smaller size) deposits prey on a perch and subsequently attracts the female by calling her. Generally the male flies off before she approaches but this time, I was lucky to catch Mr. and Mrs. Goshawk smiling for the camera!
Kestrel on the CoverNov 26, 2013
One of my kestrel portraits made it on the cover of the NABU journal Natur in Berlin
. NABU (Naturschuzbund Deutschland) is Germany’s largest and oldest nature and bird conservation organization. The recent issue of Nature in Berlin
is a special volume featuring the astonishing diverse birds of prey occurring in the German capitol. Apart of the title page, the volume contains seven other of my raptor images. The complete contend can be viewed online here
Grassshopper SnackNov 25, 2013
During late summer and early fall, the Great green Bush-Cricket (Tettigonia viridissima) represents an important food source for the Eurasian kestrel, especially in years when voles are scarce. The grasshoppers are most active in the late afternoon and this is the hunting time for both, kestrels and photographers.
Interestingly, prey handling behavior differs much among individual birds: Whereas some kestrels manipulate and ingest their prey in flight, others prefer the comfort of a perch, usually a fence post. Generally, the first thing kestrels do after a successful catch is to bite off the head of their wriggly prey, thus preventing escape. Sometimes, however, they omit to do so, as in the case pictured above.